(doc. 6920) manual of aircraft accident investigation

DOC 6920-AN/855/4

MANUAL OF AIRCRAFT ACCIDENT INVESTIGATION

Fourth Edition - 1970

Approved by the Secretary General and published under his authority

INTERNATIONAL CIVIL AVIATION ORGANIZATION

Copyright International Civil Aviation Organization Provided by IHS under license with ICAO

Not for ResaleNo reproduction or networking permitted without license from IHS

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1 I M

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Monthly supplements announce new publications and audio-visual training aids, amendments, supplements, reprints, etc.

Available free from the Document Sales Unit, ICAO



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DOC 6920-AN/855/4


Fourth Edition - 1970

Approved by the Secretary General and published under his authority

INTERNATIONAL CIVIL AVIATION ORGANIZATION



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AMENDMENTS

No.

The issue of amendments is announced regularly in the ICA0 Journal and in the monthly Supplements. to the Catalogue of ICA0 Publications and Audio Visual Training Aids, which holders of this publication should consult. These amendments are available free upon request.

Date Entered by Entered by

15/12/71

24/2/72 ICAO

3

4

16/4/73 ICAO

30/8/74 ICAO

5

6

15/7/76 ICAO

10/9/76 ICAO

I 9 I 18/6/78 , I ICAO I

7

8

30/5/77 ICAO

30/3/7a ICAO

10

11

' 1711 0186 ICAO

7/7/93 ICAO

(ii)



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MANUAL. OF AIRCRAFT ACCIDENT INVESTIGATION

TABLE O F CONTENTS

Page

m m v o m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . í i x )

PART I. - GENERAL CONSLC ?ATIONS AND NOTIFICATION OF ACCIDENTS

CHAP!ER 1. - PURPOSE OF THE INQUIRY . . . . . 1-1-1 . . CHAPTER 2. - NOTIFICATION O F ACCIDENTS

2.1 Genera l . . . . . . . . . . . . . . . . . . . . . . . . . * . 1-2-1

2.2 N o t i f i c a t i o n o f N a t i o n a l A u t h o r i t i e s . . . . . . . . . . . 1-2-1

2.3 R e s p o n s i b i l i t y o f t h e S t a t e of Occurrence . . . . . . . . . 1-24?

2.4 Format and Content of t h e N o t i f i c a t i o n . . . . . . . . . . . . 1-2-2

2.5 Forwarding of t h e N o t i f i c a t i o n . . . . . . . . . . . . . 1-2-4

2.6 Arrangement f o r Prompt De l ive ry o f the N o t i f i c a t i o n . . . . . 1-2-4

2.7 R e s p o n s i b i l i t y of t h e S t a t e s Receiving t h e N o t i f i c a t i o n . . . 1-2-4

PART II. - ORGANIZATION O F TKF: INVESTIGATION

CHARER 1. - T I E INVESTIGATOR 0 . . . . . 0 . 11-1-1

1.1 k i u a l i t i e s of t h e I n v e s t i g a t o r . . . . . . . . . . . . . . . 11-1-1

1.2 I n v e s t i g a t o r ' s Equipment . . . . . . . . . . . . . . . . . . . 11-1-2

1.3 Lia i son with Other N a t i o n a l A u t h o r i t i e s . . . . . . . . . . . 11-1-4 1.4 Removal of Disabled A i r c r a f t : Pre-planning . . . . . . . . . 11-1-5

CHAPTER 2. - SIZE AND SCOPE O F THE INVESTIGATION . 11-2-1

2.1 Genera l . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2-1

2.2 The Inves t iga tor - in-Charge . . . . . . . . . . . . . . . . . . 11-2-2

2.3 The Group Organ iza t ion . . . . . . . . . . . . . . . . . . . . 11-2-3

2.4 m e Accredi ted R e p r e s e n t a t i v e . . . . . . . . . . . . . . . . 11-2-6

2.5 S p e c i a l i s t Examinat ions . . . . . . . . . . . . . . . . . . . 11-2-7

í i i i )



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í i v ) Manual of A i r c r a f t Accident I n v e s t i g a t i o n

Page

PART III . . THE INVESTIGATION

CHAPTER 1 . . INITIAL ACTION AT SCENE OF THE ACCIDENT . . b . . 1.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Rescue Opera t ions . . . . . . . . . . . . . . . . . . . . . . 1.3 Guarding . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4 General Survey of t h e iireckage . . . . . . . . . . . . . . . 1.5 P r e s e r v a t i o n of t h e Evidence . . . . . . . . . . . . . . . . 1.6 Precau t iona ry Measures . . . . . . . . . . . . . . . . . . .

CHAPTER 2 . . I N I T I A T I O N OF THE WRECKAGE INVESTIGATION . . . . . . . . . . . . . .!. '1 Accident Location . . . . . . . . . . . . . . . . . . . . . . 2.2 Photography . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 Wreckage D i s t r i b u t i o n Chart . . . . . . . . . . . . . . . . . 2.4 Examination of Impact Marks and Debris . . . . . . . . . . . 2.5 Wrehkage i n t h e Water . . . . . . . . . . . . . . . . . . . .

CHAPTER 3 . . OPERATIONS'ENVESTIGATION . . . . . . . . . . . . . . . . . . . . . 3 .1 Genera l . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Creu H i s t o r i e s . . . . . . . . . . . . . . . . . . . . . . . 3.3 F l i g h t Planning . . . . . . . . . . . . . . . . . . . . . . . 3.4 Weight and Balance . . . . . . . . . . . . . . . . . . . . . 3.5 Weather . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.6 A i r T r a f f i c Se rv ices . . . . . . . . . . . . . . . . . . . . . 3.7 Communications . . . . . . . . . . . . . . . . . . . . . . . 3.8 Navigation . . . . . . . . . . . . . . . . . . . . . . . . . 3.9 Aerodrome F a c i l i t i e s . . . . . . . . . . . . . . . . . . . . 3.10 A i r c r a f t Performance . . . . . . . . . . . . . . . . . . . . 3.11 Compliance wi th I n s t r u c t i o n s . . . . . . . . . . . . . . . . 3.12 Witness S ta tements . . . . . . . . . . . . . . . . . . . . . 3.13 F i n a l F l i g h t Path Determination . . . . . . . . . . . . . . . 3.14 Sequence of F l i g h t . . . . . . . . . . . . . . . . . . . . .

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Table of Contents ( V I

CHAPTER 4 . . FLIGHT RECORDERS . . . . . . . . . . . . . . . . . . . . . . . . . 4 . 1 Genera l . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 .2 F l i g h t Data Recorders . . . . . . . . . . . . . . . . . . . . 4.3 Cockpit Voice Recorders . . . . . . . . . . . . . . . . . . .

CHAPTER 5 . . STRUCTURES INVESTIGATION . . . . . . . . . . . . . . . . . . . . . 5.1 Recons t ruc t ion of Wreckage . . . . . . . . . . . . . . . . . 5.2 Types of Material F a i l u r e . . . . . . . . . . . . . . . . . . 5.3 Examination of t h e Airframe i n c l u d i n g Undercar r iage

and F l i g h t C o n t r o l s . . . . . . . . . . . . . . . . . . . . 5.4 Recognit ion of F a t i g u e F a i l u r e s . . . . . . . . . . . . . . . 5.5 Recogni t ion of S t a t i c F a i l u r e s . . . . . . . . . . . . . . . 5.6 Sequence of F a i l u r e . . . . . . . . . . . . . . . . . . . . . 5 . 7 Modes of Load A p p l i c a t i o n . . . . . . . . . . . . . . . . . . 5 . 8 S p e c i a l i s t Examinations . . . . . . . . . . . . . . . . . . . 5.9 Fractography . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 6 . . PUWERPLANT 1NVESTIGATION . . . . . . . . . . . . . . . . . . . . . 6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 . 2 Evidence A v a i l a b l e from P r o p e l l e r Examination . . . . . . . . 6 . 3 O p e r a t i o n a l C a p a b i l i t i e s of Engine a t Impact . . . . . . . . 6 . 4 E f f e c t i v e n e s s of F i r e E x t i n g u i s h e r Systems . . . . . . . . . 6 .5 Taking of Samples . . . . . . . . . . . . . . . . . . . . . . 6 . 6 S p e c i a l i s t Examinations . . . . . . . . . . . . . . . . . . .

CHAPTER 7 . . SYSTEMS I N V E S T I G A T I O N . . . . . . . . . . . . . . . . . . . . . . 7 . 1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 . 2 Hydraul ic Systems . . . . . . . . . . . . . . . . . . . . . . 7 . 3 E l e c t r i c a l Systems . . . . . . . . . . . . . . . . . . . . . 7 . 4 P r e s s u r i z a t i o n and A i r Condi t ion ing Systems . . . . . . . . . 7 - 5 Ice and Rain P r o t e c t i o n Systems . . . . . . . . . . . . . . . 7.6 Ins t ruments . . . . . . . . . . . . . . . . . . . . . . . . . 7.7 Radio Communication and Radio Navigat ion Equipment . . . . .

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(vi) Manual of A i r c r a f t Accident I n v e s t i g a t i o n

7.8 F l i g h t Con t ro l System . . . . . . . . . . . . . . . . . . . . 7.9 F i r e De tec t ion and P r o t e c t i o n Systems . . . . . . . . . . . . . 7.10 Oxygen Systems . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 8 .. MAINTENANCE INVESTIGATION . . . . . . . . . . . . . . . . . . . . 8.1 Genera l . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2 Large Transpor t Aircraf t . . . . . . . . . . . . . . . . . . 8.3 Small A i r c r a f t . . . . . . . . . . . . . . . . . . . . . . . 8.4 I n v e s t i g a t i o n Co-ordination . . . . . . . . . . . . . . . . .

CHAPTER 9 .. HUMAN FACTORS INVESTIGATION . . . . . . . . . . . . . . . . . . . 9 . 1 Genera l . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2 Con t r ibu t ion of t h e Human Fac to r s I n v e s t i g a t i o n . . . . . . . 9.3 B r i e f i n g t h e P a t h o l o g i s t . . . . . . . . . . . . . . . . . . 9.4 Tasks a t t h e Accident S i t e . . . . . . . . . . . . . . . . . 9.5 Tasks a t t h e Mortuary . . . . . . . . . . . . . . . . . . . . 9.6 Evidence t o b e Derived from t!ie Pa tho log ica l Examination . . 9.7 Release of Human Remains and Pe r sona l P r o p e r t y . . . . . . . 9.8 The Survived Accide1.t: . . . . . . . . . . . . . . . . . . . . 9.9 Other Aspects of t he Human Fac to r s I n v e c f i z a t i o n . . . . . . 9.10 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER 10.- EVACUATION. SEARCH. RESCUE AND FIRE FIC;'tITlN(I lNVESTIGA.'I'IO?J . . . . 10.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2 Evacuation Opera t ions . . . . . . . . . . . . . . . . . . . . 10.3 Search Opera t ions . . . . . . . . . . . . . . . . . . . . . . 10.4 Rescue Opera t ions . . . . . . . . . . . . . . . . . . . . . . 10.5 F i r e F igh t ing Opera t ions . . . . . . . . . . . . . . . . . .

CHAPTER 11.- INVESTIGATION OF EXPLOSIVES SABOTAGE . . . . . . . . . . . . . . . 11.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 I n v e s t i g a t o r ' s Evidence . . . . . . . . . . . . . . . . . . . 11 .3 M e t a l l u r g i c a l Evidence . . . . . . . . . . . . . . . . . . . . 11.4 S t r u c t u r e and Composition of Fragments . . . . . . . . . . . . 11.5 Chemistry and Mate r i a l s Assessment . . . . . . . . . . . . . .

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1816 / 78 No . 9 Copyright International Civil Aviation Organization

Provided by IHS under license with ICAONot for ResaleNo reproduction or networking permitted without license from IHS

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Table of Contents ( v i i )

Page

PART I V . . REPORTiIIG OF OCCURRENCES - CHAF’I’ER 1 .. GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV-1-1

1.1 Repor ts . . . . . . . . . . . . . . . . . . . . . . . . . . . I V - 1 - 1

1.2 The ADREP Repor ts . . . . . . . . . . . . . . . . . . . . . . I V - 1 - 1

1.3 The N a r r a t i v e Repor t s . . . . . . . . . . . . . . . . . . . . IV-1-2

1.4 Repor t ing Accuracy . . . . . . . . . . . . . . . . . . . . . IV-1-2

CHAPTER 2 . . THF: PRELIMTNAHY REI’ORT . . . . . . . . . . . . . . . . . . . . . . IV-2-1

CHAFTER 3 .. ACCIDENT/INCIDENT DATA REPORT . . . . . . . . . . . . . . . . . . m-3-1 3.1 Accident Data Report . . . . . . . . . . . . . . . . . . . . I V - 3 - 1

3.2 I n c i d e n t Data Repor t . . . . . . . . . . . . . . . . . . . . I V - 3 - 1

3.3 C o n s t r a i n t s on I n c i d e n t Data Report . . . . . . . . . . . . . IV-3-2

IV-4-1 4.1 Genera l . . . . . . . . . . . . . . . . . . . . . . . . . . . Iv-4-1 4.2 Group Repor ts . . . . . . . . . . . . . . . . . . . . . . . . IV-4-1

4.3 Report of t h e Inves t iga tor - in-Charge . . . . . . . . . . . . IV-4-2

4.1, F i n a l Report . . . . . . . . . . . . . . . . . . . . . . . . . IV-4-3

5.1 Purpose of t h e Summary . . . . . . . . . . . . . . . . . . . I V - 5 - 1

CHAFTER 4 .. THE FINAL REPORT . . . . . . . . . . . . . . . . . . . . . . . . .

YHAPTTR 5 . . SUMMARY OF THE FINAL REPORT . . . . o IV-5-1

5.2 Type of Accidents for which a Summary is Required . . . . . . IV-5-1 5.3 Format . . . . . . . . . . . . . . . . . . . . . . . . . . . IV-5-1 5.4 Precau t ions t o be Taken when P repa r ing t h e Summary . . . . . IV-5-2

5.5 Addressee of t h e Summary . . . . . . . . . . . . . . . . . . . IV-5-2

PA2T V . . ACCIDENT PREVENTION

C H A P T E R 1 . -GENEML . . . . e . rn v-1-1

CHAPTER 2 . . STUDY OF INCILIENTS . . . . . . . . . . . . . . . . . . . . . . . . v-2-1

CHAPTER 3 . . SAFETY PUBLICATIONS . . . . . . . . . . . . . . . . . . . . . . . v-3-1

ICHAPTER 4 ENGINEERING ASPECTS V-4-1 . . . . . . . . . . . . . . . . . . . . . . . . . .

1 8 / 6 / 7 8 No . 9



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( v i i i ) Manual of A i r c r a f t A c c i d e n t Invest igat ion

APPENDICES

APPENDIX 1 . . D E F I N I T I O N S AND SYMBOLS ........................................ APPENDIX 2 . . PHOTOGRAPHY .................................................... APPENDIX 3 . . F L I G H T RECORDERS: TYPE I N USE .................................

(See a l s o A p p e n d i x 13)

APPENDIX 4 . . F L I G H T RECORDERS: EXAMPLES O F READ-OUT ........................ (See a l s o A p p e n d i x 13)

APPENDIX 5 . . EXAMPLES O F FRACTURE ANALYSIS .................................. APPENDIX 6 . . EXAMPLES O F SEQUENCE OF FAILURE INVESTIGATION .................. APPENDIX 7; . EXAMPLES OF ELECTRICAId SYSTEMS INVESTIGATION ................... APPENDIX 8 . . AIRCRAFT WEIGHT AND BALANCE .................................... APPENDIX 9 . . I D E N T I F I C A T I O N OF VI.CTIMS ...................................... APPENDIX 10 . . IN-FLIGHT BREAKUP .............................................. APPENDIX 11 . . MID-AIR C O L L I S I O N ANALYSIS ..................................... APPENDIX 12 . . FIRE INVESTIGATION ............................................. APPENDIX 13 . . STATES' FLIGHT RECORDER PLAYBACK FACILITIES AND TECHNIQUES .. APPENDIX 1 4 . . ACCIDENT REPORT FORMS .......................................... APPENDIX 1 5 . . CONVERSION TABLES AND DIAGRAMS ................................. APPENDIX 1 6 . . ADDRESSES OF ACCIDENT INVESTIGATION AUTHOKITIES ................ APPENDIX 1 7 . . L I S T OF NATIONAL LAWS AND REGULATIONS R E I A T I N G TO AIRCRAFT

ACCIDENT INVESTIGATION ......................................... APPENDIX 18 . . SELECTION AND TRAINING OF ACCIDENT INVESTIGATORS AND

ACCIDENT INVESTIGATOR COURSES AVAILABLE I N STATES .............. APPENDIX 19 . . EXPERT ASSISTANCE AND F A C I L I T I T E S AVAILABLE ON REQUEST FOR

THE INVESTIGATION OF MAJOR ACCIDENTS ...........................

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3013178 No . 8 Copyright International Civil Aviation Organization


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The Manual of A i r c r a f t Accident I n v e s t i g a t i o n w a s f i r s t produced i n 1949 and was widely accepted throughout t h e a v i a t i o n i n d u s t r y . i n 1951 t o meet a con t inu ing demand and a p a r t from minor r e v i s i o n s and a d d i t i o n s , repea ted t h e t e x t of t h e f i r s t e d i t i o n . completely reviewed t o update t h e in fo rma t ion t o keep a b r e a s t of t h e c u r r e n t t e c h n o l o g i c a l knowledge.

A second e d i t i o n w a s publ i shed

When t h e t h i r d e d i t i o n w a s produced i n 1959, t h e text w a s

A r i s i n g from t h e Th i rd Sess ion of the Accident I n v e s t i g a t i o n Div i s ion , Montreal , January 1965, i t w a s recommended t h a t t h e Manual of A i r c r a f t Accident Inves t iga - t i o n be r ev i sed t o i n c l u d e guidance t o assist t h e i n v e s t i g a t i o n of a c c i d e n t s i nvo lv ing l a r g e modern a i r c r a f t and t o ensu re a l o g i c a l and balanced p r e s e n t a t i o n . commended t h a t c o n t r a c t i n g States and s e l e c t e d I n t e r n a t i o n a l o r g a n i z a t i o n s be i n v i t e d t o supply t o I C A 0 up-to-date in fo rma t ion and m a t e r i a l t o f a c i l i t a t e such a r e v i s i o n .

It w a s a l s o re-

A Study Group was formed drawing members from s i x Con t rac t ing S t a t e s and t h i s f o u r t h e d i t i o n of t h e Manual is e s s e n t i a l l y t h e r e s u l t of t h e i r work.

The l ayou t of t h i s Manual d i f f e r s from t h a t of t h e earlier e d i t i o n s and follows as c l o s e l y a s p o s s i b l e t h e p r e s e n t a t i o n of Annex 1 3 . It has been drawn up t o f a c i l i t a t e t h e work of i n v e s t i g a t o r s and t o provide a guide f o r members of i n v e s t i g a t i n g teams who may be p a r t i c i p a t i n g i n an i n v e s t i g a t i o n w i t h i n t h e i r own t e r r i t o r i e s o r t hose of any o t h e r Con t rac t ing S t a t e . The Manual should enab le them t o adhe re t o a uniform system and o r g a n i z a t i o n of i n v e s t i g a t i o n which i s known and unders tood i n t e r n a t i o n a l l y . It is n o t in tended t h a t t h i s should be looked upon a s a manual of t r a i n i n g i n a i r c r a f t acc iden t i n v e s t i g a t i o n bu t i t can be used t o supplement p rope r ly supe rv i sed t h e o r e t i c a l and p r a c t i c a l t r a i n i n g . The s k i l l e d i n v e s t i g a t o r who has t h e b e n e f i t of long exper ience and i s consc ious of t h e need t o q u e s t i o n every i t e m of in format ion , no m a t t e r how obvious, may a l s o f i n d t h e r e f e r e n c e material con ta ined i n t h i s document t o be of cons ide rab le a s s i s t a n c e .

It i s n o t p r a c t i c a l t o produce a Manual which i s an encyclopedia f o r a l l t h e t e c h n i c a l m a t t e r s t o be examined du r ing an i n v e s t i g a t i o n ; t h e r e f o r e , t h e t e x t of t h e Manual has been produced t o i n d i c a t e t o t h e i n v e s t i g a t o r t h e e x t e n t and t y p e of i n v e s t i - g a t i o n t o be cons idered i n t h e a r e a s more f r e q u e n t l y encountered. The Appendices con ta in t e c h n i c a l i n fo rma t ion and examples of c u r r e n t i n v e s t i g a t i v e t echn iques : expanded and updated as technology and t h e state of t h e ar t advance t o submit m a t e r i a l f o r p o s s i b l e p u b l i c a t i o n .

t hey w i l l be and you are i n v i t e d

The oppor tun i ty has been taken t o r e f e r t o i n c i d e n t i n v e s t i g a t i o n a s an ad junc t t o t h e promotion of a i r s a f e t y and t h e p reven t ion of a c c i d e n t s . i n u s e by some S t a t e s , such a s t h e d e f i n i t i o n of s u b s t a n t i a l damage, s e r i o u s i n j u r y , c l a s s i f i c a t i o n of a i r c r a f t a c c i d e n t s , have been inc luded a s a gu ide , f o r world-wide s i m i - l a r i t y of c l a s s i f i c a t i o n i s a major f a c t o r i n i n t e r n a t i o n a l exchange of in format ion in tended t o l ead t o a c c i d e n t p reven t ion .

Also , d e f i n i t i o n s

The maintenance of a h igh s t a n d a r d of a i r s a f e t y i s dependent amongst o t h e r t h i n g s upon t h e a p p r o p r i a t e c o r r e c t i v e a c t i o n be ing t aken when f a u l t s o r shortcomings i n t h e des ign o r maintenance of a i r c r a f t are brought t o l i g h t o r when u n s a t i s f a c t o r y procedures f o r t h e i r o p e r a t i o n a r e r evea led . S ince an a i r c r a f t acc iden t r e p r e s e n t s t h e ve ry a n t i t h e s i s

í i x )

3015177 No. 7



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(XI Manual of A i r c r a f t Accident I n v e s t i g a t i o n

of a i r s a f e t y , it i s most important t h a t adequate and r e l e v a n t measures a r e taken expedi- t i o u s l y t o prevent a r e c u r r e n c e a r i s i n g from a s imilar cause. I n o r d e r t o do t h i s i t i s e s s e n t i a l t h a t t h e c a u s a l f a c t o r s are i d e n t i f i e d and p u b l i c i z e d . Th i s c a l l s f o r an a c c u r a t e assessment of all matters r e l a t e d t o t h e a c c i d e n t by p r o p e r l y q u a l i f i e d and experienced i n v e s t i g a t o r s of high i n t e g r i t y .



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P A R T

I

W J U 4 L OF AIRCRAFT ACCIDENT INVESTIGATION

PART I. - GENERAL COEISIDEPATIOE\JS MID NOTIFICATION OF ACCIDENTS



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P a r t I.- General Cons ide ra t ions and N o t i f i c a t i o n of Accidents 1-1-1

CHAPTER 1

PURPOSE OF THE IbQUIRY

The fundamental purpose of i n q u i r y i n t o an a i r c r a f t a c c i d e n t is t o de te rmine t h e f a c t s , c o n d i t i o n s and c i r cums tances p e r t a i n i n g t o t h e a c c i d e n t w i t h a view t o e s t ab - l i s h i n g t h e probable cause t h e r e o f , s o t h a t a p p r o p r i a t e s t e p s may be t aken t o p reven t a r ecu r rence of t h e a c c i d e n t and t h e f a c t o r s which l ed t o i t . An e q u a l l y impor tan t purpose i s t o determine t h e f a c t s , c o n d i t i o n s and c i r cums tances p e r t a i n i n g t o t h e s u r v i v a l o r non- s u r v i v a l , of t h e occupants , and t h e c ra shwor th iness of t h e a i r c r a f t . The n a t u r e of t h e i n q u i r y i n t o an a i r c r a f t a c c i d e n t shou ld n o t be a c c u s a t o r y as t h e o b j e c t is t o t a k e remedia l r a t h e r than p u n i t i v e a c t i c n ; s i m i l a r l y t h e assessment of blame o r r e s p o n s i b i l i t y should no t be inc luded i n t h e d u t i e s of an a i r c r a f t a c c i d e n t i n v e s t i g a t i o n a u t h o r i t y s i n c e th i s f u n c t i o n i s normally t h e p r e r o g a t i v e of t h e j u d i c i a l a u t h o r i t i e s of t h e S t a t e concerned. Pievertheless , i t is unavoidable t h a t ac t s o r ommissions, by i n d i v i d u a l pe r sons o r organi - z a t i o n s , a r e sometimes c l e a r l y r evea led and i n such i n s t a n c e s i t is t h e du ty of t h e i n q u i r y t o say so. i n v e s t i g a t i o n which i s p r i m a r i l y t o i n d i c a t e what caused t h e a c c i d e n t r a t h e r t han who caused i t : t h i s should r i g h t l y be f o r o t h e r s t o dec ide .

Any such s t a t emen t should n o t confuse t h e purpose of t h e a i r c r a f t a c c i d e n t

Aspects of s a f e t y t o t a l l y unconnected wi th t h e c i r cums tances o r c h a i n of e v e n t s l ead ing t o t h e a c c i d e n t a r e o f t e n r evea led du r ing t h e i n v e s t i g a t i o n wi th a r e s u l t a n t b e n e f i t i n terms of e f f e c t i v e a c c i d e n t p reven t ion . from i n v e s t i g a t i n g t h e s e matters D r from drawing a t t e n t i o n t o them merely because they are n o t r e l a t e d t o t h e cause of t h e a c c i d e n t .

I n v e s t i g a t o r s should n o t be i n h i b i t e d

Reduced t o s imple t e rms , ' t h e i n v e s t i g a t o r has t o de te rmine what happened, how i t happened, and why i t happened, app ly ing t h e s e q u e s t i o n s n o t o n l y t o b a s i c cause bu t t o a l l a s p e c t s r e l a t i n g t o s a f e t y i n c l u d i n g s u r v i v a l of occupants . I n doing t h i s he must seek o u t , r eco rd and a n a l y s e t h e f a c t s , draw conc lus ions and , where a p p r o p r i a t e , make recommendations.

The b a s i c cause of an a c c i d e n t and t h e remedia l a c t i o n necessa ry t o ensu re t h a t i t w i l l n o t r e c u r does n o t always emerge from t h e p h y s i c a l f a c t s of t h e case. For example, a f a i l u r e of some mechanica l p a r t may be due t o a f a i l u r e t o i n s p e c t o r f a u l t y i n s p e c t i o n technique i n a f a c t o r y o r a maintenance shop where t h e d e f e c t i v e p a r t should have been d e t e c t e d thereby p reven t ing i t s f a i l u r e i n s e r v i c e . S i m i l a r l y , i f human e r r o r appeazs a s n p o s s i b l e cause of t h e a c c i d e n t a l l f a c t o r s which may have in f luenced t h e a c t i o n s s h o u l d be examined. The i n q u i r y should n o t cease i f o r when i t is e s t a b l i s h e d an e r r o r h a s been made: t h e i n q u i r y should endeavour t o e s t a b l i s h why t h e e r r o r occur red . Poor des ign , i n d i f f e r e n t human eng inee r ing , i nadequa te o r improper o p e r a t i o n a l procedures could w e l l have confused o r m i s l e d t h e pe r son . Experience h a s shown t h a t t h e m a j o r i t y of a i r c r a f t a c c i d e n t s have been caused o r compounded by human e r r o r , o f t e n by c i rcumstances which were conducive t o human e r r o r ; t h i s a p p l i e s t o des ign , manufac ture , t e s t i n g , main- t enance , i n s p e c t i o n and o p e r a t i o n a l p rocedures both ground and a i r . I d e n t i f i c a t i o n o€ t h i s element i s f r e q u e n t l y d i f f i c u l t bu t i t may be r evea led by c a r e f u l , s k i l f u l and p e r s i s t e n t i n v e s t i g a t i v e methods.

Some a i r c r a f t a c c i d e n t s have r e s u l t e d from o r g a n i z a t i o n a l d e f e c t s o r weak- n e s s e s i n management; f o r example, an o p e r a t o r may have p r e s c r i b e d o r condoned procedures n o t commensurate w i t h s a f e o p e r a t i n g c o n d i t i o n s i n p r a c t i c e . S i m i l a r l y , ambiguous



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1-1-2 Manual of A i r c r a f t Accident I n v e s t i g a t i o n

i n s t r u c t i o n s , and those capable of d u a l i n t e r p r e t a t i o n may a l s o have e x i s t e d ; t hese f a c t o r s may w e l l have stemmed i n t h e f i r s t in s t ance from u n c r i t i c a . 1 s c r u t i n y by r e g u l a t i n g au thor - i t ies. It may t h e r e f o r e be necessary t o i n q u i r e c l o s e l y i n t o o t h e r o rgan iza t ions o r agenc ie s not immediately o r d i r e c t l y concerned wi th t h e c i rcumstances of t he acc iden t but where a c t i o n , o r l ack of i t , may have permi t ted o r even caused t h e acc iden t t o happen.

Where t h e cause of an acc iden t is obscure i t may be necessa ry t o pursue as many hypotheses a s could s e r i o u s l y be regarded as p o s s i b i l i t i e s and each pursued t o t h e l i m i t s of its u s e f u l n e s s , o r t o t h e l i m i t where i t can be excluded as a p o s s i b i l i t y . This approach w i l l o f t e n r e s u l t i n some degree of s p e c u l a t i o n and prolonged e x p l o r a t i o n b u t i t may be t h e only cour se open t o t h e i n v e s t i g a t o r . i n t h e l i g h t of t h e evidence adduced, and t h e e x i s t i n g state of a e r o n a u t i c a l knowledge, a number of t h e hypotheses w i l l be e l imina ted : t h e c r e d i b i l i t y of those which su rv ive t h e process i s the reby inc reased and exper ience h a s shown t h a t t h e s e w i l l g e n e r a l l y re la te t o one p a r t i c u l a r area o r group of p o s s i b i l i t i e s .

By c a r e f u l l y cons ide r ing each p o s s i b i l i t y

F indings which have been a r r i v e d a t by more than one l i n e of i n q u i r y , by more than one person each reasoning independent ly , are more l i k e l y t o be c o r r e c t than those conc lus ions a r r i v e d a t by pursu ing one narrow f i e l d of a c t i v i t y .



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P w t I.- Genera l Cons ide ra t ions and N o t i f i c a t i o n o f Accidents 1-2-1

cH?.mx 2

N O T I F I C A T I O N OF ACCIDENTS

2.1 Genera l

The proper conduct o f a n i n v e s t i g a t i o n r e q u i r e s prompt a r r i v a l o f i n v e s t i g a t o r s Any d e l a y i n t h e i r a r r i v a l nay w e l l r e s u l t i n t h e d e t e r i o r a t i o n , o r a t the a c c i d e n t s i t e .

d isappenrancz , o f e s s e n t i a l ev idence due t o : t h e f t , d i sp lacement o r improper hand l ing o f the wreckage, adve r se weather c o n d i t i o n s , pos t -acc ident c o r r o s i o n o f the wreckage, impairment of eyewi tnesses ' accounts through d i s c u s s i o n amongst themselves , e t c . The re fo re immediate n o t i f i , z a t i o n of a c c i d e n t s t o t h e i n v e s t i g a t i n g a u t h o r i t i e s concerned i s e s s e n t i a l .

2.2 N o t i f i c a t i o n o f N a t i o n a l A u t h o r i t i e s

The r e g u l a t i o n s o f each S t a t e should e m u r e t h a t t h e n a t i o n a l a c c i d e n t i n v e s t i - gc i t im a u t h o r i t i e s a r e immediately adv i sed 3f a c c i d e n t s o c c u r r i n g i n t h e i r t e r r i t o r y . S ince acc iden t i n v e s t i g a t i o n o r g a n i z a t i o n d i f f e r s from one S t a t e t o a n o t h e r , i t is imposs ib le t o d e f i n ? ln le ta ; l 3 s -anàari? u r x e d u r - ? for the n o t i f i c a t i o n of a c c i d e n t s t o n a t i o n a l a u t h o r i t i e s . Iiowever, t h e f o l l o i l ng p o i n t s nay s e r v e as a b a s i s f o r t h e p r e p a r a t i o n , or improvement, o f a c c i - dznt n o t i f i c a t i o n procedures .

The f i r s t peysons to know abcnit 21 a c c i d e n t a r e o f t e n s u r v i v o r s o r eyewi tnesses . 3 u r . i i v i n g crew mezlbers should have been provided wi th n a t i o n a l i n s t r u c t i o n i n d i c a t i n g what t o do i n t h e c a s e o f a n a c c i d e n t . Su rv iv ing passengers o r eyewi tnesses should inform l o c a l c i v i l o r m i l i t a r y pe r sonne l who s n o u l ? ther , inform t h e l o c a l a u t h o r i t y i n accordance wi th pre-arranged ?rocedures . c a t i o n of acc i r fcn ts t o the a p 7 r o p r i a t e n a t i o n a l i n v e s t i g a t i o n a u t h o r i t i e s .

The l o c a l a u t h o r i t y must have a v a i l a b l e n a t i o n a l , r e g u l a t i o n s r ega rd ing t h e n o t i f i -

The n o t i f i c a t i o n procedures should be simple and e f f e c t i v e . The most r a p i d ne?ns of cmniu i i ca t ion ( t e l e p h o n e , t r l e t p e o r te le ,yraFh) shovld be used. A list of n a t i o n a l 5 iu thor i t ies t J he n o t i f i e d sho, ! ld be x h l i s i e d and inc lude names, phone number(s ) , t e l e t y p e or t e l e g r i p h i c addres ses . The N o t i f i c a t i o n messaze shou ld be drawn up i n a s t a n d a r d form s i m i l m t o t h a t g iven i n s e c t i o n 2.4. I n a d d i t i o n i t shou ld c o n t a i n :

- t h e s d d r e s s e e o r addres sees ( te le type, t e l e g r a p h i c o r p o s t a l address, o r te lephone number) ;

- means of r e a c h i n g t h e sende r , s o that f u r t h e r d e t a i l s c m be r eques t ed o r u r g e n t i n s t r u c t i o n s g iven , i f necessary .

More than one l o c a l a u t h o r i t y may be r e s p o n s i b l e f o r sendine; t h e acc iden t n o t i f i c a t i o n . For i n s t a n c e , p c l i c e o f f i c i a l s may have t o .lotif;. t h e j u d i c i a l au tho r i t i e s . . and l o c a l a 2 r o n a c t i c a l o f f i c i d s may have t o notif:. a e r o n a n t i c a l a u t h o r i t i e s r e s p o n s i b l e Por acc iden t i n v e s t i g a t i o n s . 1:i s u c h c a s e s , a checX system should be e s t a b l i s h e d t o ensure

10/3/76 No. 6



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1-2-2 Manual o f Aircraft Accident I n v e s t i g a t i on

t h a t eaoh o f t h e addres sees has been du ly n o t i f i e d . __._ ,

.- Accident i n v e s t i g a t i o n services should be organized i n such a way t h a t

q u a l i f i e d i n v e s t i g a t o r s are immediately a v a i l a b l e on a 24-hour b a s i s .

2.3 R e s p o n s i b i l i t y o f t he S t a t e o f Occurrence

Annex 13, Chapter 4, c o n t a i n s s p e c i f i c a t i o n s f o r t he N o t i f i c a t i o n o f a l l " I n t e r n a t i o n a l acc idents" and cer ta in "Domestic acc idents" .

When an acc iden t occur s i n the t e r r i t o r y of a Con t rac t ing S t a t e to an a i r c r a f t r e g i s t e r e d i n ano the r Con t rac t ing S t a t e ( I n t e r n a t i o n a l a c c i d e n t ) , t h e S t a t e i n which the acc iden t occur red ( S t a t e o f Occurrence) message t o t h e S t a t e of Reg i s t ry and t o t h e S t a t e o f Manufacture of t h e a i r c r a f t .

s h a l l immediately forward a N o t i f i c a t i o n

When an acc iden t involv ing matters of a i r w o r t h i n e s s occurs i n t h e t e r r i t o r y of the Cont rac t ing S t a t e i n which the a i r c r a f t is r e g i s t e r e d (Domestic a c c i d e n t ) and when t h e a i r c r a f t involved has a maximum c e r t i f i c a t e d take-of f weight of over 2 250 kg (5 O00 lbs: , t h e S t a t e of Occurrence should immediately forward a N o t i f i c a t i o n message t o the S t a t e of Manufacture of t h e a i r c r a f t , s p e c i f y i n g t h e areas of a i r w o r t h i n e s s concerned and, i f necessary , r eques t t h e p a r t i c i p a t i o n o f t h e S t a t e of Manufacture i n t he i n v e s t i g a t i o n .

For c e r t a i n acc iden t s t he S t a t e of Occurrence may a l s o wish t o forward a N o t i f i c a t i o n message t o o t h e r S t a t e s which may be reques ted t o provide important i n fo rma t ion immediately ( f o r example, t h e S t a t e whose A i r T r a f f i c Se rv ices had the a i r c r a f t under c o n t r o l p r i o r t o the a c c i d e n t ) .

Each S t a t e should have appropr i a t e r e g u l a t i o n s t o ensure t h a t t h e n a t i o n a l ' a u t h o r i t i e s r e spons ib l e f o r acc iden t i n v e s t i g a t i o n s send the N o t i f i c a t i o n , with u minimum

of de l ay , t o the a p p r o p r i a t e a u t h o r i t i e s of t h e S t a t e s concerned. C lea r i n s t r u c t i o n s regard ing the p repa ra t ion and d i s p a t c h of V o t i f i c a t i o i i riessages s h o u l d be r e a d i l y a v a i l a b l e t o i n v e s t i g a t o r s . since this w i l l not. c n l y ? reven t delays i n the sendirìg o f the ; io t i . f ic - l t ion , but a l s o a l l o w the i n v e s t i ; a t i on t o . ... begin prompt1.y.

It is impor tan t t h a t i n v e z t i g a t o r s :xe avai-ble on a 24-hour b a s i s

rlhen p o s s i b l e , t he N o t i f i c a t i o n should be addressed d i r e c t l y t o the i n v e s t i g a t i o n a u t h o r i t i e s i n t h e S t a t e of Xegis t ry and the S t a t e o f Hanufacture . is a l s o adv i sab le t o n o t i f y by te lephone t h e diplornat ic missions ( f o r example the C i v i l A i r At taché of those S t a t e s i n the S t a t e of Occurrence) .

I t

2.4 Format and Content of t he N o t i f i c a t i o n

The N o t i f i c a t i o n shall be i n ? l a i n language and con ta in a s much of t h e information i n d i c a t e d i n the example below as is r e a d i l y a v a i l a b l e . no t be delayed due t o t h e l a c k of complete informat ion . t o provide complete informat ion i n t h e N o t i f i c a t i o n , the S t a t e o f Occurrence s h a l l d i s p a t c h the d e t a i l s omi t ted ,as well as o t h e r r e l e v a n t i n fo rma t ion , as soon as they become a v a i l a b l e .

'dhenever i t is p o s s i b l e t o do s o without caus ing undue de lay t h e N o t i f i c a t i o n

Its d i s p a t c h s h a l l When i t has not been p o s s i b l e

should be prepared i n one of t h e working languages o f ICAO.

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P a r t I-. Genera l Cons ide ra t ions and N o t i f i c a t i o n of Accidents - -

a ) The i d e n t i f y i n g a b b r e v i a t i o n ACCID: a ) ACCID

b) t y p e , model, n a t i o n a l i t y and r e g i s - b ) McDonnell Douglas, C-47B, United Kingdom, G-AMSW t r a t i o n marksof t h e a i r c r a f t ;

c ) name of owner, o p e r a t o r and h i r e r , c ) Derby Av ia t ion i f any, of t h e a i r c r a f t ;

d) name o f t h e pilot-in-command; d > Capta in X

e )

f ) last p o i n t of d e p a r t u r e and p o i n t f ) London - Perpignan

d a t e and time (GMT) o f t h e a c c i d e n t ; e ) 7 October i961 a t O100 hours GMT

of in t ended l and ing of t h e a i r c r a f t ;

g) p o s i t i o n of t h e a i r c r a f t w i t h r e f e r e n c e t o some e a s i l y de f ined geograph ica l pognt and l a t i t u d e and 1ongi tude ; l )

h) number of crew and passenge r s : aboa rd , k i l l e d and s e r i o u s l y i n j u r e d ; o t h e r s : k i l l e d and s e r i o u s l y i n ju red t2 )

i> n a t u r e o f t h e a c c i d e n t and t h e e x t e n t o f damage t o t h e aircraft so far as i t is kn0wn;j)

an i n d i c a t i o n t o w h a t e x t e n t t h e i n v e s t i g a t i o n w i l l be conducted or is proposed t o be d e l e g a t e d by the S t a t e o f Occurrence ; 4J

j )

k) p h y s i c a l c h a r a c t e r i s t i c s o f t h e a c c i d e n t a r e a ;

g) 1 2 km s o u t h of P rades ,

e l e v a t i o n 2 200 m 42'-33 N, 02'-26 W ,

h) 3 crew and 31 passengers aboard, a l l k i l l e d

i) a i r c r a f t c o l l i d e d w i t h mountain s i d e i n t h e Canigou Massif. A i r c r a f t des t royed by fire.

j> i n q u i r y conducted by French a u t h o r i t i e s

k) mountainous a r e a , d i f f i c u l t a c c e s s , p e r p e t u a l snow

i) i d e n t i f i c a t i o n of t h e o r i g i n a t i n g 1) Accident I n v e s t i g a t i o n Bureau. a u t h o r i t i y. P a r i s - France.

1) 2 )

3 )

It ?lay be of i n t e r e s t t o state t h e e l e v a t i o n o f t h e p o i n t o f impact i f i t is known. It is u s e f u l t o i n d i c a t e f i r s t t h e number of pe r sons aboard (crew, pas senge r s ) and t h e n t h e i n j u r i e s s u s t a i n e d as i d e n t i f i e d . A s f a r as p o s s i b l e te rminology ils shown i n the I C A 0 ADREP Manual (Doc 9156-AN/900) shotild be used. exp lana to ry n o t e s - t o convey t o t h e r e a d e r "what happened". I f necessa ry t o t h e S t a t e o f R e g i s t r y .

Th i s te rminology shou ld be expanded as i n d i c a t e d i n t h e a d j a c e n t

4)

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1-2-4

2.5 Forwarding o f t h e N o t i f i c a t i o n

M a n m l o f A i r c r a f t Accident Inves t iga-

To ensu re its prompt d e l i v e r y t h e N o t i f i c a t i o n s h a l l be s e n t w i t h a minimum o f d e l a y and by t h e qu ickes t means a v a i l a b l e .

G e n e r a l l y t h e Aeronaut ica l Fixed Telecommunication Network (X-Prrr) w i l l be used f o r t h i s purpose: f i c a t i o n of t h e cor respondent ) may a l s o be used b u t aormal ly o f f e r less guarantee f o r safeguarding the c o n f i d e n t i a l nature o f communications.

pub l i c t e l e g r a p h o r te lephone networks (wi th p r e c i s e i d e n t i -

The 2 - l e t t e r des igna to r "YL." i n a s s o c i a t i o n wi th an ICAC 4 - l e t t e r Loca t ion I n d i c a t o r forms t h e 6 - l e t t e r Addressee I n d i c a t o r f o r messages s e n t only over t h e A F T N t o a u t h o r i t i e s r e s p o n s i b l e f o r a i r c r a f t acc iden t i n v e s t i g a t i o n s . I n f o r n a t i o n on how t o prepare a message t o be s e n t over t h e ArW is given i n t h e ICAO Aeronaut ica l Informat ion Se rv ices Manual (Doc 8126-dN/872) - Appendix D.

For messages s e n t over t h e pub l i c te lecommunicat ion s e r v i c e , the A Y T N Addressee I n d i c a t o r cannot be used and a f u l l p o s t a l o r t e l e g r a p h i c address ( i f such e x i s t ) must be s u b s t i t u t e d .

Addressee I n d i c a t o r s .and t h e cor responding 20s t a l and t e l e g r a p h i c addres ses a r e publ ished i n t h e ICAO document "Desi,gators f o r A i r c r a f t Opera t ing Agencies, Aero- n a u t i c a l A u t h o r i t i e s and Se rv ices" (Doc 8585). The p o s t a l and t e l e g r a p h i c addres ses o f some acc iden t i n v e s t i g a t i o n a u t h o r i t i e s are given a t Appendix 16 t o this Manual.

2.6 Arrangements f o r Promut De l ive ry of t h e N o t i f i c a t i o n

Arrangements should be made i n each S t a t e i n o r d e r t o ensure prompt d e l i v e r y of a c c i d e n t N o t i f i c a t i o n messages t o t h e addres see , whether r ece ived through the A F T N o r t he p u b l i c telecommunication s e r v i c e . Jhen a coded addres s is used, t h e corresponding addres s o f t h e a u t h o r i t y ( s t r e e t name and number, f l o o r x i d number o f t h e o f f i c e concerned, te lephone number) should be a v a i l a b l e i n the niessage r e c e i v i n g c e n t r e , as wel l a s c l e a r i n s t r u c t i o n s r ega rd ing the xays t o i d e n t i f y a N o t i f i c a t i o n message and t o ensure its -rornpt d e l i v e r y , on a 24-ho.2.r~ b a s i s , t o t h e a u t h o r i t y concerned.

If N o t i f i c a t i o n messages cannot be d e l i v e r e d d i r e c t l y t o t h e i n v e s t i g a t i o c a u t h o r i t i e s , t he nimber 3f i n t e r m e d i a r i e s snouid Se kept t o a minimum. should be taken t o ensu re t h a t t h e H o t i f i c a t l o n rressagos a r e r e - t r s n s n i t t e d r>romptly and a c c x s t e l y t o t h e i n v e s t i g a t i o n a u t h o r i t i e s .

S t r i c t meas;ires

2.7 2 e s u o n s i b i l i t y o f the S t a t e s Rece iv ina the ì l o t i f i c a t i o n

2.7.1 S t a t e of l i e g i s t r y

The competent a u t h o r i t i e s s h a l l , ES soon as 2oso ib le ( i n p r i n c i p l e by the same means of communications) :

- acknowledge r e c e i p t of t h e N o t i f i c a t i o n ;

provide (o r prepare t o provide) t h e S t a t e of Occurrence wi th any r e l e v a n t in format lon r ega rd ing the a i r c r a f t and f l i 2 h t cr.?3;~ involved i n t h e a c c i d e n t ;

-



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P a r t I.- Genera l C o n s i d e r a t i o n s and N o t i f i c a t i o n of Accidents 1-2-5

- inform t h e S t l t e of Occurrence whether t h e y i n t e n d t o be r e p r e s e n t e d a t t h e i n v e s t i g a t i o n and, i f SO,

i n d i c a t e t h e names and q u a l i f i c a t i o n s o f t h e a c c r e d i t e d r e p r e s e n t a t i v e s and t e c h n i c a l a d v i s e r s and a l s o t h e probable d a t e of t h e i r arrival a t t h e a c c i d e n t s i t e , or a t t h e headquar t e r s of t h e a u t h o r i t i e s r e s p o n s i b l e f o r t h e i n v e s t i g a t i o n .

-

Note 1: i n v e s t i g a t i o n , i t should so a d v i s e t h e S t a t e of Occurrence w i t h a ninimum of delay.

Note 2 : Since t h e S t a t e o f R e g i s t r y always h a s the r i g h t t o be r e p r e s e n t e d a t the i n v e s t i - g a t i o n , i t may s u p p l y t h e i n f o r m a t i o n r e f e r r e d t o above on its own i n i t i a t i v e i n t h e case of any de lay i n t h e t r a n s m i s s i o n of t h e N o t i f i c a t i o n .

Should t h e S t a t e o f R e g i s t r y c o n s i d e r i t unnecessary t o be r e p r e s e n t e d at t h e

2.7.2 S t a t e of Manufacture

I f t h e N o t i f i c a t i o n c o n t a i n s a r e q u e s t f o r p a r t i c i p a t i o n of t h e S t a t e o f Manufacture t h e a u t h o r i t i e s of t h a t S t a t e shall:

- - i n t h e case of a n a c c i d e n t t o an a i r c r a f t o f a m a x i m u m c e r t i f i c a t e d

acknowledge r e c e i p t o f t h e N o t i f i c a t i o n ;

t ake -o f f weight of over 100 O00 kq inform the S t a t e o f Occurrence o f t h e name and q u a l i f i c a t i o n s OT its a c c r e d i t e d r e p r e s e n t a t i v e and i n d i c a t e whether he w i l l be p r e s e n t a t t h e a c c i d e n t s i t e . I n t h e a f f i r m a t i v e , a l s o i n d i c a t e t h e expected a c c i d e n t s i t e , or at t h e h e a d q u a r t e r s o f t h e a u t h o r i t i e s r e s p o n s i b l e f o r t h e i n v e s t i g a t i o n , as well as t h e names, q u a l i f i c a t i o n s and d a t e o f a r r i v a l of his a d v i s e r s ;

d a t e of h i s a r r i v a l a t t h e

- i n t h e case o f a n a c c i d e n t t c a n a i r c r a f t o f a maximum c e r t i f i c a t e d t ake -o f f weight o f 100 O00 or l e s s inform t h e S t a t e of Occurrence whether an a c c r e d i t e d r e p r e s e n t a t i v e w i l l be appointed. I n t h e a f f i r m a t i v e , inform t h e S t a t e of Occurrence o f the name a n d . q u a l i f i c a t i o n s o f t h e a c c r e d i t e d r e p r e s e n t a t i v e and his t e c h n i c a l a d v i s e r s , i f any; i n d i c a t e whether t h e y w i l l be p r e s e n t a t t h e a c c i d e n t s i t e and, i n t h e a f f i r m a t i v e , the expected d a t e o f a r r i v a l a t the a c c i d e n t s i t e , or at t h e h e a d q u a r t e r s o f t h e a u t h o r i t i e s r e s p o n s i b l e f o r the i n v e s t i g a t i o n .

__

Note: i n q u i r y , i t should s o a d v i s e t h e S t a t e of Occurrence w i t h t h e minimum of delay. The a t t e n t i o n o f S t a t e s of Manufacture i s drawn t o t h e u s e f u l n e s s o f such p a r t i c i p a t i o n . is h igh ly J e s i r a b l e t h a t t h e y a t t e n d , when r e q u e s t e d t o do s o , u n l e s s i t is r e a l l y imp-ac t i - cable . Occurrence ~ i t h any in fo rma t ion i t may r eques t .

Should t h e S t a t e o f Manufacture c o n s i d e r i t unnecessary t o be r e p r e s e n t e d a t t h e - It

I n any c a s e , i t is t h e du ty of t h e S t . i t e o f Manufacture t o s u p p l y t h e S t a t e o f



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1 - 2 4

2.7.3 Other S t a t e s

Manual of A i r c r a f t Accident Xnves t ißa t ion

When t h e S t a t e of Occurrence has s e n t t h e N o t i f i c a t i o n t o S t a t e ( s ) otkLer than t h e S t a t e of R e g i s t r y and t h e S t a t e of Manufacture, t h e competent a e r o n a u t i c a l a u t h o r i t i e s of those o t h e r S t a t e 8 shall, as soon as p o s s i b l e ( i n p r i n c i p l e by t h e same means of communications) t

- acknowledge r e c e i p t of the N o t i f i c a t i o n ;

- supply (or prepare t o supply) t h e S t a t e conduct ing t h e i n v e s t i g a t i o n wi th ail a v a i l a b l e r e l e v a n t in format ion r eques t ed ;

- inform t h e State conduct ing t h e i n v e s t i g a t i o n whether t hey i n t e n d t o be r ep resen ted a t t h e i n v e s t i g a t i o n and; i f so,

- i n d i c a t e t h e names and q u a l i f i c a t i o n s of the a c c r e d i t e d r e p r e s e n t a t i v e s and his t e c h n i c a l a d v i s e r s and a l s o t h e probable d a t e of their a r r i v a l at t h e a c c i d e n t s i t e or at t h e headquar t e r s of t h e a u t h o r i t i e s r e s p o n s i b l e for t h e i n v e s t i g a t i o n .

1019176 No. 6



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P A R T

I I


PART II. - ORGANIZATION OF THE INVESTIGATION



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Part 11.- Organ iza t ion of t h e I n v e s t i g a t i o n 11-1-1

CHAPTER 1

THE INVESTIGATOR

1.1 Q u a l i t i e s of t h e I n v e s t i g a t o r

A i r c r a f t a c c i d e n t i n v e s t i g a t i o n is a h i g h l y s p e c i a l i z e d t a s k which should only be under taken by t r a i n e d pe r sonne l posses s ing many q u a l i t i e s , n o t t h e least impor tan t of which are a n i n q u i s i t i v e n a t u r e , d e d i c a t i o n t o t h i s kind of work, d i l i g e n c e and p a t i e n c e . The i n v e s t i g a t o r must have a good sound working knowledge of a v i a t i o n and f a c t o r s which a f f e c t o p e r a t i o n s as a whole. Techn ica l s k i l l , perseverance and l o g i c are t h e t o o l s of h i s p r o f e s s i o n ; h u m i l i t y , i n t e g r i t y , and r e s p e c t f o r human d i g n i t y h i s gu id ing r u l e s .

I t i s n o t s u f f i c i e n t t o nominate, as t h e occas ion a r i s e s , a person wi th s p e c i a l i s t a v i a t i o n knowledge a s t h e i n v e s t i g a t o r , f o r a i r c r a f t . a c c i d e n t i n v e s t i g a t i o n i s a s p e c i a l i s t t a s k i t s e l f . The s t a n d a r d of t h e i n v e s t i g a t o r a s s igned t o a n a c c i d e n t inqui ry de t e rmines t h e thoroughness and c l a s s of r e s u l t s ob ta ined more t h a n i n any o t h e r f i e l d of a e r o n a u t i c s and t h e longer a we l l -qua l i f i ed member serves, t h e more e x p e r t he becomes. Wherever p o s s i b l e , t h e r e f o r e , a t least one exper ienced i n v e s t i g a t o r should be ass igned t o each i n q u i r y so t h a t a con t inu ing t h r e a d of expe r i ence may ma in ta in the s t a n d a r d s of a c c i d e n t i n v e s t i g a t i o n and r e p o r t i n g .

It i s d e s i r a b l e t h a t a n a c c i d e n t i n v e s t i g a t o r have , a s a founda t ion on which t o develop h i s s k i l l s , a p r o f e s s i o n a l p i l o t ' s background, an a e r o n a u t i c a l e n g i n e e r i n g . q u a l i f i c a t i o n o r , a s a p p r o p r i a t e , expe r i ence i n s p e c i a l i z e d areas of a v i a t i o n such as o p e r a t i o n s , a i r t r a f f i c c o n t r o l , meteorology, aezodynamics, d e s i g n , e t c .

o r d e r t o d i scha rge e f f e c t i v e l y t h e i r d u t i e s i: i s e s s e n t i a l t h a t a i r c r a f t a c z i d e n t i n v e s t i g a t ó r s a r e provided w i t h s u i t a b l e s t a t u t o r y powers which should, none the le s s ,

t!ie a a j o r i t y of whom recognize t h e i n v e s t i g a t o r ' s s t a t u s and w i l l n o r e o f t e n t h a n n o t f e e l obl iged t o o f f e r a l l a s s i s t a n c e t h e y can wi thout t h e i n v e s t i g a t o r reminding them of the o f f i c i a l powers which are v e s t s d i n him. He w i l l a l s o encounter members of t h e g e n e r a l p u u l i c who are less w e l l acquain ted with h i s a c t i v i t y and who may show r e t i c e n c e t o be for thcoming wi th e v i d e n c e , s t e m i n g Erom a n a t u r a l d e s i r e n o t t o become involved. It may, ix :!lese l a t t e r c i r cums tances , b e necessary f o r t h e i n v e s t i g a t o r t o e x p l a i n h i s f u n c t i o n anC t o e l i c i t t h e i r w i l l i n g co-operat ion.

used w i t n d i s c r e t i o n . The i n v e s t i g a t o r w i l l come i n c o n t a c t w i th many k i n d s of people

When c a l l e d t o t h e scene of t h e accidenrr t h e i n v e s t i g a t o r should endeavour t o a r r i v e a s soon a s p o s s i b l e ; s i m i l a r l y , i n his d e a l i n g s w i t h w i t n e s s e s and o t h e r peop le concerned i n t h e a c c i d e n t , he should be prompt i n a t t e n d i n g a p p o i n t n e n t s and c o r r e c t i n h i s a a n n e r , r e g a r c l e s s of how he may f e e l p e r s o n a l l y . Above a l l , t h e i n v e s t i g a t o r must be a c c x r a t e and f a c t u a l ; he a u s t o b s e r v e , i n t e r p r e t and record c l e a r l y anci a c c u r a t e l y a t a l l tines, because h i s record of what is seen , heard and done , nay well prove t o be Ehe only r-ccrd a v a i l a b l e , t h e a n a l y s i s of whicli may have fa r - reaching e f f e c t s on i n d i v i d u a l people , a i r c r a f t and equipment and a v i a t i o n s a f e t y as a whole.



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1 . 2 I n v e s t i g a t o r ' s Equipment

A person a s s igned t o acc iden t i n v e s t i g a t i o n d u t i e s should hold himself i n r e a d i n e s s and have a working k i t and e s s e n t i a l pe r sona l i t e m s packed and a v a i l a b l e i n o r d e r t h a t he may proceed wi thout de l ay by the qu ickes t a v a i l a b l e means t o t h e scene of t h e acc iden t . Advance c o n s i d e r a t i o n should a l s o be g iven t o such i t e m s as i n o c u l a t i o n s , pas spor t requi rements , t r a v e l f a c i l i t i e s , e tc . I n v e s t i g a t o r s who work amongst wreckage are advised t o b e r e g u l a r l y inocu la t ed wi th a n t i - t e t a n u s serum. apprec i a t ed t h a t t h e prompt a r r i v a l of an i n v e s t i g a t o r a t t h e scene of an acc iden t has cons ide rab le bear ing, on t h e e f f i c i e n c y of t h e i n v e s t i g a t i o n and any i n t e l l i g e n t prepar - edness w i l l be w e l l worthwhile. Every e f f o r t should be made t o provide i n v e s t i g a t o r s w i th p r i o r i t y of movement t o t h e scene of t h e a c c i d e n t .

It should be f u l l y

Accidents are a p t t o occur anywhere; a t a i r p o r t s , on mountains, i n swamps, i n deeply wooded a r e a s , i n d e s e r t s , e t c . , and ha rdsh ips are o f t e n encountered i n r each ing t h e scene of a c c i d e n t s which have occurred i n normally i n a c c e s s i b l e areas. It i s impor tan t t h e r e f o r e t h a t t h e i n v e s t i g a t o r should be p h y s i c a l l y f i t and a c t i v e and t h a t t h e s e l e c t i o n of h i s working gea r i s c a r r i e d o u t w i t h cons ide rab le c a r e , bea r ing i n mind t h e t e r r a i n i n which he might have t o work. C lo thes should be comfortable and a f f o r d p r o t e c t i o n a g a i n s t any cond i t ions o r e lements t h a t may be encountered . Before proceeding t o t h e scene of an a c c i d e n t t h e i n v e s t i g a t o r must a n t i c i p a t e t h e use of s p e c i a l equipment i n unusual s i t u a - t i o n s ; f o r example, c e r t a i n a r e a s may r e q u i r e food and water t o be c a r r i e d , some s i t u a t i o n s may c a l l f o r t h e u s e of camping equipment, mosquito n e t s , s k i s , e t c . It i s a d v i s a b l e t o have t h i s type of equipment r e a d i l y a v a i l a b l e a t a l l t i m e s so t h a t i f an acc iden t occur s i n an a r e a where s p e c i a l equipment i s r e q u i r e d , t h e r e w i l l be no de lay i n procur ing i t . Add i t iona l dry c l o t h i n g may be r equ i r ed e s p e c i a l l y i f t h e scene of t h e acc iden t i s some d i s t a n c e removed f r o m , t h e o p e r a t i o n s headquar t e r s . Probably t h e most e s s e n t i a l i t e m s of pe r sona l c l o t h i n g f o r d i f f i c u l t count ry a r e good footwear , a windproof and waterproof j a c k e t and t r o u s e r s and s u i t a b l e headgear. It i s no t ea sy t o p r e s c r i b e t h e kind of footwear but t he i n v e s t i g a t o r should be i n possess ion of s u i t a b l e b o o t s which are waterproof , a t least t o above t h e a n k l e s . Climbing boo t s a r e e s s e n t i a l in' a p a r t i c u l a r l y mountainous t e r r i t o r y but i t is worthwhile remembering t h a t a l though n a i l studded s o l e s a r e considered t o be good when climbing on grass and snow they can be dangerous on hard rocks . On t h e o t h e r hand, rubber or composition s o l e s can be a d isadvantage i f cl imbing on f r e s h snow, i c e o r w e t ground, whereas they g i v e good r e s u l t s on c l e a n d ry rock. It has been found from expe r i ence t h a t a "paratroop" type of boot w i t h a heavy moulded s o l e g i v e s good s e r v i c e as general-purpose footwear i n d i f f i c u l t t e r r a i n ; "dese r t " boo t s have been found s u i t a b l e i n d r y broken ground. Climbing boo t s and such l i k e footwear should have been "broken-in" be fo re use o therwise cons ide rab le d i scomfor t and h indrance of movement may r e s u l t . Sunburn cream, a n t i - g l a r e s p e c t a c l e s and i n s e c t r e p e l l e n t should a l s o be provided. a p p r o p r i a t e t o t h e t e r r i t o r y normally covered. I f i t i s necessa ry t o e n t e r wild o r rugged t e r r a i n i t i s a d v i s a b l e t h a t a p a r t y should be organized wi th adequate s u p p l i e s , equipment and a competent gu ide - e s p e c i a l l y i f t h e journey is t o be a long one and t h e t e r r a i n d i f f i c u l t . Communication f a c i l i t i e s are e s p e c i a l l y impor tan t i n such c i rcumstances .

I n v e s t i g a t o r s should a l s o be exper ienced i n t h e use of equipment most

The i n v e s t i g a t o r ' s equipment should be s u f f i c i e n t t o enab le wreckage exami- n a t i o n , t h e p l o t t i n g of impact p o i n t s and wreckage p a t t e r n , p a r t s i d e n t i f i c a t i o n and t h e r eco rd ing of obse rva t ions . The fo l lowing l i s t of i t e m s i s provided as guidance as t o t h e type of equipment which might be s e l e c t e d f o r t h e i n v e s t i g a t o r ' s normal f i e l d working k i t (without implying any o r d e r of p r i o r i t y ) :



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P a r t II.- Organ iza t ion of t h e I n v e s t i g a t i o n 11-1-3

I d e n t i f icat ion pape r s , i n v e s t i g a t o r ' s o f f i c i a l t a g o r b r a s s a r d

Large-scale maps. of t h e area of t h e a c c i d e n t

A good magnetic compass

Pocket l e n s and small m i r r o r

Heavy twine o r cord

F lag markers

Heavy g loves and p r o t e c t i v e ove ra 1 1 s

A s t ee l measuring t a p e a t least 20 metres long sweep second hand

An a c c u r a t e w r i s t watch w i t h

N a v i g a t i o n a l computer, c i r c u l a r s l i d e - r u l e , p r o t r a c t o r and d i v i d e r s

Grease p e n c i l s o r i n d e l i b l e marking crayons

Wr i t ing material, n o t e books and l a b e l s

S u i t a b l e t o o l k i t

Model a i r c r a f t

C 1 inome t e r

A s t r o n g multi-purpose k n i f e

A waterproof e lec t r ic t o r c h w i t h s p a r e batteries and f i l a m e n t

Photographic equipment

B inocu la r s

Smal l f i r s t a i d k i t

Crimping t o o l and l e a d seals f o r marking, s e a l i n g and l o c k i n g componente and p i e c e s of wreckage

Copies of r e l e v a n t a c c i d e n t i n v e s t i g a t i o n docuinentation ( S t a t e r e g u l a t i o n s and a c c i d e n t r e p o r t forms, Manual of A i r c r a f t Accident i n v e s t i g a t i o n , etc. )

A c o i l of ny lon rope a b o u t 20 t o 30 metres long (use- f u l i n d i f f i c u l t t e r r i t o r y )

I n a d d i t i o n t h e f o l l o w i n g i t e m s w i l l be found u s e f u l i f a v a i l a b l e :

Walk ie - t a lk i e r a d i o equïpment wi th s p a r e b a t t e r i e s

A p o r t a b l e t y p e w r i t e r

A d u p l i c a t i n g machine. c o n s i d e r a b l e use a t o p e r a t i o n a l h e a d q u a r t e r s when a l a r g e group i n v e s t i g a t i o n is a t work.

This may p o s s i b l y be h i r e d and can be of

P o r t a b l e t a p e r eco rde r . of t h e a c c i d e n t o r when i n t e r v i e w i n g a large number of w i t n e s s e s w i t h l imited t i m e a v a i l a b l e . However, care must be t aken n o t t o r e l y comple te ly on r e c o r d e r s e s p e c i a l l y p o r t a b l e models which use a n enc losed cassette, o the rwise a mishap, similar t o a non- ro ta t ing f i l m i n a camera c a s s e t t e , may r e s u l t i n wasted eff O r t and l o s s of va l u a b l e ev idence .

This i t e m is ext remely u s e f u l a t t h e scene



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11-1-4 Manual of A i r c r a f t Accident l r ivest i r , ' i t ioa

The fo l lowing items can u s u a l l y be suppl ied by t h e o p e r a t o r a t h i s base n e a r e s t t h e scene of t h e a c c i d e n t :

Canvas s h e e t s and bags, polythene bags. F i r s t a i d k i t s

Containers f o r f u e l and o i l samples Q u a n t i t i e s o f rope.

1 .3 Liaison with Other Nat iona l A u t h o r i t i e s

A f u l l - s c a l e e x p e d i t i o n i n a n undeveloped reg ion may have t o be mounted i n which case a d d i t i o n a l problems of t r a n s p o r t a t i o n , camping equipment and f e e d i n g f a c i l i t i e s would arise. Although i t should no t be taken f o r g r a n t e d , c i v i l and m i l i t a r y o r g a n i z a t i o n s may be a b l e t o provide a d d i t i o n a l manpower and f a c i l i t i e s . When a v a i l a b l e , h e l i c o p t e r s , t r a n s p o r t , heavy l i f t i n g and moving g e a r , mine d e t e c t o r s , g e i g e r coun te r s , and r a d i o equipment may be provided by these sources . It is important t h a t p l a n s e x i s t whereby heavy moving gear and recovery equipment such a s c r a n e s , b u l l d o z e r s o r l i f t i n g h e l i c o p t e r s may be made r e a d i l y a v a i l a b l e . It may a l s o be necessary t o o b t a i n t h e s e r v i c e s of profes- s i o n a l surveyors p a r t i c u l a r l y when an e x t e n s i v e wreckage p l o t is required.

The i n v e s t i g a t o r , through the a u t h o r i t y r e s p o n s i b l e f o r a c c i d e n t i n v e s t i g a t i o n should b e a v a i l a b l e t o a d v i s e l o c a l a u t h o r i t i e s r e g a r d i n g p r e p a r a t i o n s f o r a c c i d e n t s involv ing l a r g e a i r c r a f t which may occur i n urban areas o r a t aerodromes. i t is impor tan t t h a t an o r g a n i z a t i o n be i n existence t o meet t h i s e v e n t u a l i t y and t h a t t h e i n v e s t i g a t o r b e aware o f t h e e x t e n t and c a p a b i l i t i e s of the o r g a n i z a t i o n (Chapter 1, Sect ion 1 . 2 - Standard Operat ing Procedures , of t h e I C A 0 Aerodrome Manual, (Doc 7920-ANI865 - P a r t 5 - Volume I) i s p e r t i n e n t t o t h i s subject) .Co-operation of t h e p o l i c e f o r c e s can u s u a l l y b e achieved by l i a i s o n a t headquar te rs level, s u i t a b l e items can t h e n be inc luded in t h e p o l i c e s y l l a b u s o f t r a i n i n g and t h e o f f i c i a l p o l i c e handbook t o ensure t h a t a l l members of t h e f o r c e w i l l be informed i n advance of what is expected of them i n t h e even t of an a i r c r a f t a c c i d e n t .

The a u t h o r i t i e s respons ib le f o r provid ing t h e medica l a n d / o r human f a c t o r s a s s i s t a n c e t o t h e i n v e s t i g a t o r - p a t h o l o g i s t s , f o r e n s i c d e n t i s t s , e x p e r t s i n human engineer ing , e t c . - should always be i n a s t a t e of r e a d i n e s s and t h e i n v e s t i g a t o r should ensure they are always aware of what i s expected of them i n the even t of an a i r c r a f t a c c i d e n t .

Standing i n s t r u c t i o n s should be i n e x i s t e n c e t o e n s u r e t h a t i n t h e event of an a i r c r a f t a c c i d e n t , a l l t ape recordings and a i r t r a f f i c c o n t r o l documents deemed t o be a s s o c i a t e d with t h e f l i g h t are secured and placed i n safe-keeping u n t i l f u r t h e r i n s t r u c t i o n s a r e received from the i n v e s t i g a t o r . o b t a i n and p l ace under s e c u r i t y an o p e r a t o r ' s documents, i n c l u d i n g maintenance documents a s s o c i a t e d with t h e a i r c r a f t and t h e f l i g h t . Arrangements may be en tered i n t o with f u e l companies t o o b t a i n au tomat ica l ly f u e l samples from s t o c k s , o r t h e r e f u e l l i n g p o i n t .

Arrangements should be pre-planned t o immediately

Considerat ion might be given t o seeking t h e co-operat ion of l o c a l news media t o withold precise d e t a i l s of t h e l o c a t i o n of an a i r c r a f t a c c i d e n t f o r a l i m i t e d per iod i n o r d e r t o ensure adequate crowd c o n t r o l measures a r e implemented. might a l s o be p o s s i b l e t o e n l i s t t h e a i d of t h e news media when seeking f u r t h e r in format ion and f o r p u b l i c i z i n g missing items of s t r u c t u r e o r components.

On t h e o t h e r hand, it

Although i t i s u n i v e r s a l l y recognized t h a t t h e circumstances surrounding each acc ident are d i f f e r e n t , t h e importance of good l i a i s o n b e f o r e t h e e v e n t , wi th c i v i l a u t h o r i t i e s , p a r t i c u l a r l y t h e p o l i c e , ambulance and f i r e s e rv i . ce s cannot be over- empha s i zed .

161417 3 No. 3



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Part 11.- Organization of the Invescigation 11-1-5

1.4 Removal of Disabled Aircraft: Pre-planning

Detailed information concerning pre-planning, equipment and procedures is I contained in Part 5 of the ICA0 Airport Services Manual (Doc 9137-AN1898).

- Note: mentioned document could be of value to the investigator.

The general aircraft information contained in the Appendix to the above-

3ûl517 7 No. 7



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P a r t II. - Organ iza t ion of t h e I n v e s t i g a t i o n 11-2-1

CHAPTER 2

SIZE AND SCOPE OF THE INVESTIGATION

2 . 1 General

To a c h i e v e i t s purpose an i n v e s t i g a t i o n should be p r o p e r l y organized , c a r r i e d o u t , Co-ordinated and supe rv i sed by q u a l i f i e d t e c h n i c a l pe r sonne l . It is e s s e n t i a l t h a t t h e magnitude of t h e t a s k and t h e scope of t h e i n v e s t i g a t i o n should be a s ses sed a t an e a r l y s t a g e so t h a t t h e s i z e of t h e i n v e s t i g a t i n g team may be planned, and t h e a p p r o p r i a t e s k i l l s marsha l led and a l l o t t e d t h e i r v a r i o u s t a s k s .

S i m i l a r i t i e s between a c c i d e n t s may tempt t h e unwary t o a r r i v e a t premature

Dependent upon t h e c i r cums tances of t h e conclus ions . It i s impera t ive t h a t each i n v e s t i g a t i o n be approached wi th a view t o app ly ing s u c c e s s f u l l y an e l i m i n a t i o n technique . a c c i d e n t , i t should be p o s s i b l e t o e l i m i n a t e c e r t a i n areas from p o s s i b l e c a u s a l cons ider - a t i o n a t a f a i r l y e a r l y s t a g e d u r i n g t h e i n v e s t i g a t i o n . A s t h e i n v e s t i g a t i o n p r o g r e s s e s , however, t h e need f o r e x t e n s i v e s t u d i e s i n depth i n one o r more p a r t i c u l a r f i e l d s gener- a l l y becomes a p p a r e n t : i t should be c l e a r l y unders tood t h a t n e i t h e r t h i s s t a t emen t no r t h e v a r i o u s s e c t i o n s which f o l l o w are in tended t o convey t h e impress ion t h a t e x t e n s i v e t e c h n i c a l s t u d i e s should be performed i n eve ry i n v e s t i g a t i o n t o cove r eve ry a s p e c t of t h e , i i r c r a f t and i t s ope ra t ion.

It is t h e r e s p o n s i b i l i t y of t h e i n v e s t i g a t o r t o review t h e ev idence as i t is developed and, from t h i s i n i t i a l ev idence , make d e c i s i o n s which w i l l d i r e c t t h e e x t e n t aiid depth of t h e i n v e s t i g a t i o n . It should be recognized t h a r t h e p r e c i s e e x t e n t gnd depth of a p a r t i c u l a r i n v e s t i g a t i o n w i l l be contingent. upon t h e n a t u r e of t h e a c c i d e n t , and p o s s i S l y upon t h e a v a i l a b i l i t y of i n v e s t i g a t i v e sou rces .

Where a l a r g e t r a n s p o r t a i r c r a f t i s involved a s u b s t a n t i a l team of inves- t i g a t o r s , set up in s p e c i a l i z e d groups , i s u s u a l l y necessary t o cove r a l l a s p e c t s . I n sume i n v e s t i g a t i o n s t h e appa ren t cause i s i n d i c a t e d e a r l y i n t h e i n v e s t i g a t i o n ; t h e subsequent prime i n v e s t i g a t i v e e f f o r t may then be channel led t o gocd e f f e c t i n t o a r e l a - t i v e l y narrow but s p e c i a l i z e d a r e a . Neve r the l e s s , it w i l l s t i l l he necessa ry t o exp lo re a l l those avenues which might l ead t o a p o s s i b l e cause cf t h e a c c i d e n t t o e n s u r e t h a t any o t h e r p o s s i b i l i t y i s e l i m i n a t e d . On t h e o t h e r hand, when t h e cause is no t r e a d i l y apparent t h e i n v e s t i g a t o r must p r o g r e s s s t e a d i l y through a l l a s p e c t s and t h i s w i l l e n t a i l t h e whole e f f o r t of t h e many groups of i n v e s t i g a t o r s working i n a ba lanced and co-ordinated manner.

I n t h e case of a small a i r c r a f t t h e i n v e s t i g a t i v e e f f o r t i n terms of manpower r equ i r ed is p r o p o r t i o n a t e l y smaller; t h e f u n c t i o n s of one or more groups o r working p a r t i e s be ing undertaken by one o r two t r a i n e d i n v e s t i g a t o r s , or a l t e r n a t i v e l y , a t r a i n e d inves- t i g a t o r and a s p e c i a l i s t q u a l i f i e d i n a p a r t i c u l a r a s p e c t which r e q u i r e s e x p e r t examination. Again, it is s t r e s s e d t h a t , even when small a i r c r a f t a r e involved , t h e degree of i n d i v i d u a l e f f o r t and d i l i g e n c e i n de t e rmin ing and r eco rd ing t h e f a c t s h a s t o . b e of t h e same h igh s t anda rd as f o r a l a r g e a i r c r a f t .



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2 . 2 The Investipator-in-Ch-

The Invest igator- in-Charge, o r i n c e r t a i n c o u n t r i e s a Board of I n q u i r y , i s appointed t o be respons ib le f o r t h e o r g a n i z a t i o n , conduct and c o n t r o l of t h e i n v e s t i g a t i o n . I t i s important t h a t h e a d q u a r t e r s be e s t a b l i s h e d i n t h e area of t h e a c c i d e n t a s soon a s p o s s i b l e f o r t h e purpose of conduct ing o r g a n i z a t i o n a l meetings and d a i l y bus iness . The Invest igator- in-Charge is r e s p o n s i b l e f o r Co-ordinat i ng t h e a c t i v i t i e s of a l l personnel a s s o c i a t e d with t h e i n v e s t i g a t i o n .

The Invest igator- in-Charge should e s t a b l i s h Working Groups, a s r e q u i r e d , Normally, s p e c i a l i z e d t e c h n i c a l inves- t o cover v a r i o u s a s p e c t s of t h e i n v e s t i g a t i o n .

t i g a t o r s from the S t a t e conduct ing t h e i n v e s t i g a t i o n w i l l head t h e v a r i o u s Working Groups (Croup Chairman) and t h e membership of such Groups may i n c l u d e , as a p p r o p r i a t e , e x p e r t s from t h e opera tor involved, t h e manufacturers of t h e a i r c r a f t , powerplant and a c c e s s o r i e s , and from t h e v a r i o u s f l i g h t crew r e p r e s e n t a t i v e s and o t h e r i n t e r e s t e d p a r t i e s who can c o n t r i b u t e through t h e i r t e c h n i c a l knowledge and exper ience . The number of groups, and t h e number o f personnel ass igned t o each group, w i l l be dependent upon t h e c o n s i d e r a t i o n s se t f o r t h above.

The Inves t igator-in-Charge i n e x e r c i s i n g h i s r e s p o n s i b i l i t y f o r t h e organi- z a t i o n , conduct and c o n t r o l of t h e i n v e s t i g a t i o n does more t h a n pure i n v e s t i g a t i o n of the acc iden t . H e i s t h e manager of t h e i n v e s t i g a t i v e e f f o r t and one of h i s important d u t i e s i s a s s o c i a t e d wi th t h e p a r t i c i p a t i o n of a c c r e d i t e d r e p r e s e n t a t i v e s from o t h e r S t a t e s ( see Sec t ion 2.4 of t h i s Chapter) . Upon t h e a r r i v a l of a n a c c r e d i t e d r e p r e s e n t a t i v e , he should provide a l l t h e necessary f a c i l i t i e s , inc luding a v a i l a b l e informat ion and copies of necessary documents. H e should a l s o ensure t h a t a l l t h e i n v e s t i g a t i n g personnel , p a r t i c u l a r l y the group l e a d e r s o r group chairmen, a r e introduced t o t h e a c c r e d i t e d repre- s e n t a t i v e s and t h e i r a d v i s e r s and are made aware of t h e i r r i g h t s and r e s p o n s i b i l i t i e s . It i s undes i rab le t h a t t h e Invest igator- in-Charge should a t t a c h a n a c c r e d i t e d represent - a t i v e t o the a c t i v i t i e s of one p a r t i c u l a r group but it may w e l l be a p p r o p r i a t e f o r one o r more of t h e a c c r e d i t e d r e p r e s e n t a t i v e ' s a d v i s e r s t o be a s s o c i a t e d wi th a group i n whose. a c t i v i t i e s they a r e p a r t i c u l a r l y q u a l i f i e d t o p a r t i c i p a t e . The I n v e s t i g a t o r - i n - Charge must obviously inform t h e a u t h o r i t y conduct ing t h e i n q u i r y of t h e p a r t i c i p a t i o n of a n a c c r e d i t e d r e p r e s e n t a t i v e and h i s a d v i s e r s .

In view of t h e dramat ic n a t u r e of a i r c r a f t a c c i d e n t s and t h e p u b l i c i n t e r e s t i n t hese matters, as w e l l a s t h e proper i n c e r e s t by world-wide a v i a t i o n , i t may be d e s i r - a b l e i n t h e i n t e r e s t of t h e promulgation of a c c u r a t e informat ion t h a t t h e p r e s s be informed by an a u t h o r i t a t i v e source of such f a c t s which can be r e l e a s e d wi thout p r e j u d i c e t o t h e inqu i ry . t a t i o n and agreement i f p o s s i b l e wi th t h e a c c r e d i t e d r e p r e s e n t a t i v e ( s ) , should draw up s t a t emen t s , as a p p r o p r i a t e , of such facts and circumstances as may be r e l e a s e d t o t h e p r e s s .

I n t h i s connexion i t i s p r e f e r a b l e t h a t t h e Inves t iga tor - in-Charge , i n consul-

I n g e n e r a l , t h e i s s u e of s ta tements t o t h e p r e s s o r p u b l i c by one of t h e p a r t i c i p a t i n g States without p r i o r c o n s u l t a t i o n wi th a l l t h e o t h e r S t a t e s p a r t i c i p a t i n g in t h e i n v e s t i g a t i o n , is undes i rab le . It is l i k e l y t o undermine t h e mutual confidence and co-operation between p a r t i c i p a t i n g S ta t e s and should t h e r e f o r e be avoided.

Emphasis h a s been placed upon t h e a c t i v i t i e s of t h e Invest igator- in-Charge i n r e l a t i o n t o t h e management of t h e i n v e s t i g a t i o n but h i s primary f u n c t i o n and responsi- b i l i t y is i n r e spec t of t h e o r g a n i z a t i o n , conduct and c o n t r o l of t h e i n v e s t i g a t i o n phase



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P a r t II.- Organ iza t ion of t h e I n v e s t i g a t i o n 11-2-3

wi th t h e i n t e n t i o n of g a t h e r i n g f a c t u a l informatior i r e l a t i n g t o t h e a c c i d e n t . l a t e r phase of t h e i n q u i r y when t h e s i g n i f i c a n c e of t h e e s t a b l i s h e d f a c t s are under c o n s i d e r a t i o n t h e Inves t iga tor - in-Charge is t h e f ountain-head from which t h e r e p o r t of t h e inqu i ry is developed: t h e a c t i v i t i e s of t h e v a r i o u s groups cease when t h e i r group r e p o r t s are completed and submi t ted t o t h e Inves t iga tor - in-Charge .

I n some States t h e c o n s o l i d a t e d r e p o r t of t h e I n v e s t igator-in-Charge is

During t h e

cons idered t o be t h e e s t a b l i s h e d r eco rd of f a c t s concern ing t h e a c c i d e n t and may be p laced upon t h e p u b l i c r eco rd as such.

2 . 3 The Group Organ iza t ion

2.3.1 Genera l

The Group system as d e s c r i b e d i n Annex 13 h a s been shown t o be a n e x c e l l e n t method of conduct ing an e x t e n s i v e i n v e s t i g a t i o n i n t o major a c c i d e n t s ; t h e d e c i s i o n t o employ such a n o r g a n i z a t i o n does , however, depend on t h e s i z e and complexity of t h e t a s k , t h e n a t u r e of t h e a c c i d e n t and t h e i n v e s t i g a t i v e s k i l l s a v a i l a b l e ; t h e l o c a t i o n of t h e acc iden t may a l s o be a d e c i d i n g f a c t o r . The Group system h a s t h e advantage of numbers and of a v a l u a b l e combination of views which can be expressed by t h o s e p a r t i c i p a t i n g ; t h e r e may a l s o be a leavening e f f e c t on t h e i n v e s t i g a t i o n as a whole by v i r t u e of t h e i r v a r i o u s s p e c i a l i s t s k i l l s which should be p r e r e q u i s i t e t o t h e i r p a r t i c i p a t i o n . Such a s y s t e m , however, may only be as e f f e c t i v e a s t h e degree of c o n t r o l , d i r e c t i o n and co- o r d i n a t i o n which i s e x e r c i s e d by t h e Inves t iga tor - in-Charge through h i s Group Chairmen. The success of such a n o r g a n i z a t i o n a l s o relies h e a v i l y on t h e l o y a l t y of t h e p a r t i c i p a n t s t o t he Inves t iga tor - in-Charge and t h e i r w i l l i n g n e s s , i n thought and deed , to s u b o r d i n a t e t h e i r own r e p r e s e n t a t i v e i n t e r e s t s t o t h e o v e r a l l t a s k of e s t a b l i s h i n g a l l t h e c a u s a l f a c t o r s , even i f t h e product o r o r g a n i z a t i o n they r e p r e s e n t may u l t i m a t e l y be found t o be a t f a u l t .

The primary purpose of t h e Group system i s t o e s t a b l i s h t h e f a c t s p e r t i n e n t t o an a c c i d e n t by making use of t h e s p e c i a l i z e d knowledge and p r a c t i c a l expe r i ence of t h e pa rc i c ipa t i r ig i n d i v i d u a l s with r e s p e c t t o c o n s t r u c t i o n and o p e r a t i o n of t h e a i r c r a f t involved i n t h e a c c i d e n t and of t h e f a c i l i t i e s and s e r v i c e s t h a t p rovided service t o t h e a i r c r a f t p r i o r t o t h e a c c i d e n t . It a l s o e n s u r e s t h a t undue emphasis i s n o t p laced on any s i n g l e a s p e c t of t h e a c c i d e n t t o t h e n e g l e c t of o t h e r a s p e c t s which might be s i g n i f i c a n t t o t h e i n v e s t i g a t i o n , and t h a t , whenever i t i s p o s s i b l e t o e s t a b l i s h a p a r t i c u l a r p o i n t by means of s e v e r a l methods, a l l t h o s e methods have been r e s o r t e d t o and Co-ordination of r e s u l t s h a s been ensured.

A t f r e q u e n t i n t e r v a l s du r ing t h e i n v e s t i g a t i o n , t h e Inves t iga tor - in-Charge should hold meet ings t o review t h e p r o g r e s s of work and t o permi t E free Pxchange of i d e a s and informat ion among t h e groups. Very o f t e n one group w i l l have uncovered some f a c t o r f a c t s which w i l l s e r v e a s a v a l u a b l e l e a d t o a n o t h e r group i n t h e i r work. I n t h i s manner, a l l t h e r e l e v a n t f a c t s , c o n d i t i o n s and c i rcumstances r e l a t i n g t o t h e a c c i d e n t are progres- s i v e l y developed.

Much of t h e work of t h e groups can be completed a t t h e a c c i d e n t s i t e , but f r e q u e n t l y t e s t s o r t h e cont inued s tudy of p a r t s o r components are c a r r i e d out a t t e s t i n g f a c i l i t i e s which may i n c l u d e t h e manufac tu re r ’ s base . t h e powerplan ts , i n s t rumen t s and /o r system components immediately and c a r e f u l l y t o more f avourab le l o c a t i ons f o r d i sassembly and s tudy. Th i s requires e x p e r t packing, l a b e l l i n g , and t r a n s p o r t a t ion .

Often i t may be necessa ry t o move



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11-2-4 Manual of A i r c r a f t Accident Inves t i g a t ioii

S p e c i a l i s t s ass igned t o the i n v e s t i g a t i o n may communicate w i t h any u n i t f o r necessary t e c h n i c a l a s s i s t a n c e . t he invest igator- in-Charge and t h e head of t h e i r group on t h e n a t u r e of t h e problem and keep them f u l l y informed regard ing t h e i r a c t i v i t i e s .

I n such cases i t i s e s s e n t i a l t h a t they Co-ordinate wi th

A s each group completes i t s p o r t i o n of t h e i n v e s t i g a t i o n , a l l of t h e f a c t u a l d a t a accumulated i s s t u d i e d and a group f a c t u a l r e p o r t i s prepared. The Inves t iga to r - in - Charge Superv ises t h e c o l l e c t i o n of a l l group r e p o r t s and is r e spons ib l e f o r t h e composi te r e p o r t . This r e p o r t s h a l l be a comprehensive f a c t u a l r epor t of t h e whole i n v e s t i g a t i o n and s h a l l form the b a s i s f o r development of a n a n a l y s i s r epor t which must be f u l l y suppor ted Dy t h e f a c t u a l in format ion c o l l e c t e d , and recorded du r ing t h e i n v e s t i g a t i o n , and which i eads u l t i m a t e l y t o the es tab l i shment of t h e probable c a u s e ( s ) , t o g e t h e r wi th t h e d e f i n i t i o n of any o the r ma t t e r s which may have a bea r ing on a i r s a f e t y .

2 . 3 . 2 %rat ions Groue

The Operat ions Group is re spons ib l e f o r developing a l l f a c t s concerning t h e h i s t o r y of t h e f l i g h t and f l i g h t crew a c t i v i t y i n t h e f i n a l phases of t h e f l i g h t , d u r i n g and a f t e r t h e acc iden t . This i nc ludes f l i g h t p lanning , d i s p a t c h i n g , weight and ba lance , weather and weather b r i e f i n g , r a d i o communications, a i r t r a f f i c c o n t r o l , nav iga t ion f a c i l - i t i e s , en-route s t o p s , r e f u e l l i n g , a e r o n a u t i c a l exper ience , f l i g h t checks and g e n e r a l information concerning t h e f l i g h t crew. The medical h i s t o r y of t h e crew, inc lud ing any recent i l l n e s s e s , psychologica l f a c t o r s , crew rest pe r iods , and a c t i v i t i e s ( p a r t i c u l a r l y dur ing the twenty-four hours p r i o r t o the a c c i d e n t ) should be determined. T h i s l a t t e r a spec t of t h e i n v e s t i g a t i o n should be Co-ordinated wi th t h e Human Fac to r s Group t o ensu re t h a t a l l i n f o r m t i o n assembled is u t i l i z e d t o f u l l advantage. The Opera t ions Group should ï I s o develop information on t h e f l i g h t pa th j u s t p r i o r t o t h e a c c i d e n t . I n t h i s e f f o r t , Co-ordination wi th t h e Witness Statement Group i s e s s e n t i a l . There are occas ions when i t i s d e s i r a b l e t o form one o r two a d d i t i o n a l groups t o t ake over some of t h e f u n c t i o n s of t h e Operat ions Group. The fo l lowing two Groups a r e examples of t h i s .

7 .3 .3 Weather Group

An acc iden t i n which weather is a n important f a c t o r can bes t be served by a sepa ra t e group of weather s p e c i a l i s t s . This grôup would be r e spons ib l e f o r t h e c o i l e c t i o n and compilat ion of a l l f a c t u a l meteoro logica l d a t a p e r t i n e n t t o t h e a c c i d e n t , i nc lud ing both su r face and upper a i r r e p o r t s of a c t u a l cond i t ions , p i l o t r e p o r t s , recorded meteoro- ; a g i c a l d a t a , a s well. a s f o r e c a s t s of a n t i c i p a t e d cond i t ions prepared and i ssued by t h e appropr i a t e agencies . Of n e c e s s i t y , c l o s e Co-ordinat ion must be maintained wi th o t h e r groups, p a r t i c u l a r l y t h e Opera t ions , A i r T r a f f i c Cont ro l and Witness Statement Groups.

7.3.4 A i r T r a f f i c Se rv ices Group

When a i r t r a f f i c services o r nav iga t ion a i d s a re involved , t h e A i r T r a f f i c Services Group, which inc ludes a i r t r a f f i c s e r v i c e s s p e c i a l i s t s , should be e s t a b l i s h e d . This group would be r e spons i3 l e f o r t h e review of t he o r i g i n a l r eco rds of t h e a i r t r a f f i c s e r v i c e u n i t s concerned inc luding when a v a i l a b l e , r ada r s c reen r eco rd ings , t h e moni tor ing of any o r i g i n a l vo ice record ings , and v e r i f i c a t i o n t h a t w r i t t e n t r a n s c r i p t s of vo ice communications a r e c o n s i s t e n t wi th t h e record ings . Th i s group would provide , when appro- p r i a t e , a r econs t ruc t ion of t h e h i s t o r y of t h e f l i g h t based on ATC informat ion . t h e group would determine t h e ope ra t ing s t a t u s of p e r t i n e n t nav iga t ion a i d s , communications equipment, r ada r , t ransponder equipment, computers, e t c . , and provide t e c h n i c a l d a t a on a l l such equipment and i t s ope ra t ion , whenever it i s deemed necessary .

I n a d d i t i o n



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Par t II.- Organ iza t ion of t h e , I n v e s t i g a t i o n 11-2-5

2.3.5 Witness S ta tement Group

The Witness Statement Group is r e s p o n s i b l e f o r c o n t a c t i n g and i n t e r v i e w i n g a l l persons who may have seen o r hea rd some p o r t i o n of t h e f l i g h t o r who may have knowledge concerning t h e f l i g h t o r of t h e weather c o n d i t i o n s a t t h e t i m e of t h e a c c i d e n t . They w i l l o b t a i n s igned s t a t e m e n t s from w i t n e s s e s , i n c l u d i n g s u r v i v o r s of t h e f l i g h t . The e x t e n t of t he group ' s a c t i v i t y can range from q u e s t i o n i n g a r e l a t i v e l y few w i t n e s s e s t o a door-to- door a c t i v i t y cove r ing g r e a t d i s t a n c e s a l o n g t h e f l i g h t pa th i n which hundreds of p o s s i b l e wi tnesses are in te rv iewed. In fo rma t ion concern ing observed p o s i t i o n s , h e i g h t s , a l t i t u d e s , sounds, a i r c ra f t behaviour and a i r b o r n e d i s i n t e g r a t i o n can be developed i n t h i s manner. The l o c a t i o n of w i t n e s s e s a t t h e t i m e of t h e a c c i d e n t should be p l o t t e d on a s u i t a b l e map of t h e area. Whi ls t i n t e r v i e w i n g w i t n e s s e s , c l o s e Co-ordination must be main ta ined wi th the Opera t ions Group i n deve loping t h e probable f l i g h t pa th from t h e w i t n e s s e s ' s t a t e m e n t s and wi th t h e Human F a c t o r s Group. In many i n s t a n c e s i n t e r p r e t a t i o n and t r a n s l a t i o n f a c i l - i t i e s have t o be provided f o r t h e i n t e r r o g a t i o n of w i tnes ses .

2 . 3 . 6 F l i g h t Recorder Group

Th i s group w i l l l o c a t e and s e c u r e t h e f l i g h t d a t a r e c o r d e r and v o i c e r eco rde r c a r r i e d on t h e a i r c r a f t , and a r r a n g e through t h e Inves t iga tor - in-Charge f o r t h e i r readout . The c a l i b r a t i o n of t h e r e c o r d e r must be t aken i n t o c o n s i d e r a t i o n i n t h e procurement of such a readout . The completed readout when compiled must be eo-ord ina ted w i t h t h e Opera t ions Group and stich o t h e r groups as t h e readout i n d i c a t e s .

Due t o t h e importance of f l i g h t r eco rd ings extreme care must be t a k e n i n handl ing t h e r e c o r d e r s t o p reven t damage. to recover and handle t h e r e c o r d e r s .

Only f u l l y q u a l i f i e d p e r s o n n e l should be a s s igned

2 . 3 . 7 S t r u c t u r e s Group

The S t r u c t u r e s Group is r e s p o n s i b l e f o r i n v e s t i g a t i n g t h e a i r f r a m e and f l i g h t c o n t r o l s . I f t h e wreckage is s c a t t e r e d , t h e g roup ' s f i r s t concern is t o l o c a t e and i d e n t i f y as many s e c t i o n s , components and p a r t s a s p o s s i b l e and t o p l o t t h e i r e x a c t p o s i t i o n on a wreckage d i s t r i b u t i o n c h a r t .

A r e c o n s t r u c t i o n of t h e s t r u c t u r e may be d e s i r a b l e and t h i s could v a r y from l ay ing out v a r i o u s p i e c e s of wreckage on a f l a t area t o t h e more compl ica ted reassembly of a l l a v a i l a b l e p i e c e s i n p o s i t i o n on a framework. T h i s procedure is most o f t e n used i n c o l l i s i o n , s t r u c t u r a l f a i l u r e , i n - f l i g h t f i r e o r exp los ion type a c c i d e n t s . Its purpose i s t o i d e n t i f y t h e p o i n t of o r i g i n a l f a i l u r e and t o e s t a b l i s h p rogres s ion of t h e break-up p a t t e r n .

2 . 3 . 8 Powe rp l a n t s Group

The Powerplan ts Group i s r e s p o n s i b l e f o r i n v e s t i g a t i o n of t h e eng ine o r eng ines , i nc lud ing f u e l and o i l sys tems, p r o p e l l e r ( s ) and engine and powerplant c o n t r o l s . The i n i t i a l work of t h i s group may be c a r r i e d out i n con junc t ion wi th t h a t of t h e S t r u c t u r e s Group i n t h e l o c a t i n g and p l o t t i n g of wreckage. Powerplant f i r e i s t o be i n v e s t i g a t e d as . t o t h e e x t e n t and t i m e of occu r rence . t h e type of f u e l , t h e p o s s i b i l i t y of i t be ing contaminated, and t h e e f f e c t i v e n e s s of t h e powerplant f i r e e x t i n g u i s h e r system. These funct ion 's m u s t be Co-ordinated w i t h t h e S t r u c t u r e s Group.

T h i s group i s a l s o r e s p o n s i b l e f o r i n v e s t i g a t i n g



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Svstems Croup 3 . 3 . 0 A-

The Systems Group is r e spons ib l e f o r d e t a i l e d examinat ion of a l l systems and components, such as h y d r a u l i c s , pneumatics, e lec t r ica l and e l e c t r o n i c s , r a d i o communication 3nd nav iga t ion equipment, a i r cond i t ion ing and p r e s s u r i z a t i o n , i c e and r a i n p r o t e c t i o n , :abin f i r e e x t i n g u i s h e r , oxygen, e tc . The examinat ions w i l l i nc lude de te rmina t ion of t h e ,:ondition a n d / o r o p e r a t i o n a l c a p a b i l i t i e s of components. It is important t h a t a l l system ~omponents be accounted f o r w i th in reason. The examinat ion inc ludes de t e rmina t ion of t h e ; tosi t ions of a s s o c i a t e d c o n t r o l s and swi tches .

S.3.10 Maintenance Records Group

T h i s group is re spons ib l e f o r reviewing a l l maintenance r eco rds t o a s c e r t a i n the maintenance h i s t o r y of t h e aircraft in r e spec t t o adequacy of inspe.ct ion, ma l func t ions t h a t might be r e l a t e d t o the occurrence, t i m e on t h e a i r c r a f t , eng ines and components, and the t i m e s i n c e overhaul . The func t ion of t h i s group invo lves Co-ordination wi th t h e S t a t e v f Regis t ry and t h e ope ra to r involved, and is normally performed a t t h e maintenance base hnsdquar te rs of t h e o p e r a t o r . This group i s a l s o r e spons ib l e f o r reviewing a p p r o p r i a t e recovered f l i g h t document s.

2.3.11 Human Fac to r s Group

T h i s group i s r e spons ib l e f o r t h e aero-medical and crash- in jury a s p e c t s of the t n v e s t i g a t i o n . I t i s concerned wi th t h e p o s s i b i l i t y of crew i n c a p a c i t a t i o n , t h e gene ra l p h y s i c a l and psychologica l cond i t ions of t h e crew members and t h e environmental factors which might have a f f e c t e d t h e crew. It i s concerned wi th t h e i d e n t i f i c a t i o n of t he crew, t h e i r l o c a t i o n a t t h e t i m e of t he a c c i d e n t , and, by review of t h e i r i n j u r i e s and :3athological cxarninat i o n of t h e cockpit , what they were doing a t t h e t i m e of t h e impact. Tt i s a l s o concerned wi th the p o s s i b i l i t y of psychologica i f a c t o r s among passengers t h a t rr,igk.t have con t r ibu ted t o the acc iden t . It w i l l cover matters invo lv ing a u t o p s i e s of crew -id passengers , as a p p r o p r i a t e , no t on ly t o i d e n t i f y t h e v i c t i m s and t o ass i s t in l e g a l l y determining t h e cause of d e a t h , but t o ob ta in a l l p o s s i b l e medica l evidence which may be sf a s s i s t a n c e i n t h e t e c h n i c a l i nves t iga t ion . It w i l l a l s o i n v e s t i g a t e t h e evacuat ion and % u n i v a l a s p e c t s , t h e des ign f a c t o r s ( a s r e l a t e d t o human eng inee r ing ) which may have con- : r ibuted t o the cause of t h e a c c i d e n t , t h e i n j u r y o r dea th o€ a i r c r a f t occupants , and t h e r ïashwor th iness of t h e a i r c r a f t . The func t ions of t h i s group must be c l o s e l y Co-ordinated with t h e Opera t ions , Witness Statement and S t r u c t u r e s Groups.

2 . 3 . 1 2 Evacuat ion, Search , Rescue and F i r e F i g h t i n g Group

‘ïhhis group i s r e spons ib l e f o r i n v e s t i g a t i n g t h e c i rcumstances of evacua t ion , c,earch and r e scue , and t h e p e r f o r m n c e of ground f i r e f i g h t i n g s e r v i c e s . nt t h i s group i-:clride an examinaticn of the r e s p e c t i v e equipment and of t h e manner i n which it w a s used. The func t ion of t h i s group must be Co-ordinated, i n p a r t i c u l a r , wi th t h e Witness Statement , S t r u c t u r e s and Human Fac tors Groups.

2 . G The Accredi ted Representa t ive

The a c t i v i t i e s

The a c c r e d i t e d r e p r e s e n t a t i v e i s t h e e s s e n t i a l l i n k between t h e S t a t e conduc t ing t h e i n v e s t i g a t i o n and t h e S ta t e s which have a d i r e c t i n t e r e s t i n t h e acc iden t : S t a t e of Reg i s t ry , S t a t e of Manufacture and any o t h e r S t a t e s w h i c h are provid ing informat ion r e l evan t t o the a c c i d e n t . Annex 13 s p e c i f i e s t he c o n d i t i o n s under which t h e s e S t a t e s are



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P a r t II.- Organizat ion of t h e I n v e s t i g a t i o n 11-2-7

e n t i t l e d t o appo in t a n a c c r e d i t e d r e p r e s e n t a t i v e and t h e i r r i g h t s of access t o in fo rme t ion and documents r e l e v a n t t o t h e i n q u i r y . The e s s e n t i a l guide i n t h e conduct of i n v e s t i g a t i o n s i n which a c c r e d i t e d r e p r e s e n t a t i v e s p a r t i c i p a t e is one of a f u l l s p i r i t of co-operat ion, p a r t i c i p a t i o n , a v a i l a b i l i t y of f u l l i n fo rma t ion , mutual t r u s t and c o n s u l t a t i o n .

The primary f u n c t i o n of t h e a c c r e d i t e d r e p r e s e n t a t i v e is t o be a b l e t o commu- n i c a t e t o t h e a p p r o p r i a t e a u t h o r i t i e s i n h i s State a l l necessa ry in fo rma t ion concerning t h e a c c i d e n t and t o p r o v i d e t h e l i a i s o n and l e g a l a u t h o r i t y f o r t h e a c q u i s i t i o n of i n fo rma t ion which is only o b t a i n a b l e w i t h i n t h e j u r i s d i c t i o n of h i s government. p o s i t i o n i n which t h e r e are r e s p o n s i b i l i t i e s towards t h e i n q u i r y as w e l l as r i g h t s of information from t h e i n q u i r y .

It is obviously d e s i r a b l e t h a t t h e a c c r e d i t e d r e p r e s e n t a t i v e should be a b l e

It is t h e r e f o r e a

to . a r r i v e a t t h e a c c i d e n t s cene w i t h t h e least p o s s i b l e d e l a y and in t h i s connexion Annex 9 r e l a t i n g t o f a c i l i t a t i o n p r o v i d e s f o r t h e temporary e n t r y i n t o a C o n t r a c t i n g S t a t e for t h e purpose of p a r t i c i p a t i o n i n an i n v e s t i g a t i o n . advised t o proceed d i r e c t t o t h e a c c i d e n t site and make c o n t a c t w i t h t h e I n v e s t i g a t o r - i n - Charge. i n accordance with Annex 13 , a couamnication i n d i c a t i n g t h e i n t e n t i o n t o nominate a n a c c r e d i t e d r e p r e s e n t a t i v e and s t a t i n g t h e p robab le d a t e of h i s a r r i v a l . During t h e inves- t i g a t i o n phase of a n i n q u i r y i t is p r e f e r a b l e t h a t t h e a c c r e d i t e d r e p r e s e n t a t i v e should be i n c l o s e c o n t a c t w i t h t h e Invest igator- in-Charge r a t h e r t han i n a p a r t i c u l a r group i n o r d e r t ha t he might have a n o v e r a l l a p p r e c i a t i o n of a l l t h e f a c t s r e l a t i n g t o t h e a c c i d e n t . shoi l ld be cons ide red f ree t o communicate any in fo rma t ion t h u s ob ta ined t o h i s own government a u t h o r i t i e s though he should e x e r c i s e c o n s i d e r a b l e c a r e t o ensu re t h a t t h e c o n f i d e n t i a l n a c u r e of any in fo rma t ion which t h e S ta te conduct ing t h e i n q u i r y might wish t o p r e s e r v e , i s maintained. To t h i s end t h e a c c r e d i t e d r e p r e s e n t a t i v e would be w e l l a d v i s e d t o use t h e communications f a c i l i t i e s which might be a v a i l a b l e a t t h e n e a r e s t d i p l o m a t i c o r c o n s u l a r e s t ab l i shmen t of h i s government, s i n c e t h e s e c u r i t y of communications by t e l e x o r Aeronau- t i c a l Fixed Telecommunications Network (AFTN) and o t h e r p u b l i c s e r v i c e s cannct be guaranteea.

I n normal c i r cums tances h e would be well

Upon h i s a r r i v a l t h e State conduct ing t h e i n q u i r y should have a l r e a d y r ece ived ,

H e

On those occas ions when t h e Invest igator- in-Charge r e q u i r e s documents, inf or- mation o r a i r c r a f t component examinat ions t o be c a r r i e d out i n t h e S t a t e of R e g i s t r y o r Manufacture, i t i s t h e r e s p o n s i b i l i t y of t h e a c c r e d i t e d r e p r e s e n t a t i v e t o endeavour t o comply with t h e requirement and t o u s e h i s a u t h o r i t y i n h i s own S t a t e t o ensu re t h a t t h e requirements a r e met i n s o f a r as t h e y are compatible with t h e p o l f s y of h i s government. The more f r e q u e n t use of f l i g h t r e c o r d e r s of complex des ign n e c e s s i t a t i n g use of p a r t i c - u l a r i z e d r eadou t equipment i s an example of one a r e a i n which t h e a c t i v e co-operation and p a r t i c i p a t i o n of t h e S t a t e of R e g i s t r y o r Manufacture is necessa ry through t h e act ivi t ies of t h e a c c r e d i t e d r e p r e s e n t a t i v e .

During t h e later s t a g e s of t h e i n q u i r y i n which t h e s i g n i f i c a r i c e of t h e e s t a b l i s h e d f a c t s a r e under examinat i o n , i t is d e s i r a b l e t h a t t h e a c c r e d i t e d r e p r e s e n t a t i v e i s kept f u l l y informed and i n v i t e d t o e x p r e s s h i s views p a r t i c u l a r l y when conc lus ions a r e being developed which bea r upon pe r sons , o r g a n i z a t i o n s , o r a c t i v i t i e s w i t h i n h i s S t a t e ,

2.5 S p e c i a l i s t Examinations

2.5.1 Genera 1

I f t h e i n v e s t i g a t o r should d e c i d e t h a t spec ia l i s t examinat ion o r t e s t i n g of s p e c i f i c components o r i t e m s may be d e s i r a b l e o r necessa ry h e h a s t o bea r i n mind t h a t i n many S t a t e s t h e n a t i o n a l l e g i s l a t i o n may f o r b i d t h e removal of any p a r t from t h e wreckage without t h e e x p r e s s agreement of t h e j u d i c i a l a u t h o r i t i e s .



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LI-2-8 Manual of A i r c r a f t Accident I n v e s t i g a t i o n

I n accordance wi th Annex 9 - F a c i l i t a t i o n , when i t becomes necessary t o send a p a r t o r parts of a damaged a i r c r a f t t o ano the r Con t rac t ing S ta te f o r t e c h n i c a l examinat ion o r t e s t i n g , each Cont rac t ing S t a t e concerned s h a l l ensu re t h a t t h e movement of such p a r t o r p a r t s i s e f f e c t e d without de l ay . The Cont rac t ing S t a t e s concerned s h a l l l i kewise f a c i l i t a t e :he r e t u r n of such p a r t o r p a r t s , t o t h e S t a t e conducting t h e acc iden t i nqu i ry should t h e Latter S t a t e r e q u i r e them i n o rde r t o complete t h e inqu i ry .

Whether t h e acc iden t i n v e s t i g a t i o n invo lves a small a i r c r a f t o r a t r a n s p o r t type a i r c r a f t , cons ide ra t ion should always be g iven t o t h e need o r d e s i r a b i l i t y of ob ta in ing e x p e r t l abo ra to ry adv ice o r of conducting d e f i n i t i v e t e s t i n g under c o n t r o l i e d c o n d i t i o n s , S p e c i a l i s t examinations may range from microscopic examination of one f a i l u r e t o e x t e n s i v e chemical a n a l y s i s , systems t e s t i n g , and /o r f l i g h t t e s t i n g .

I t should not be overlooked t h a t t h e medical and /o r human f a c t o r s a s p e c t s of t h e i n v e s t i g a t i o n are i n f a c t no d i f f e r e n t from t h e mechanical i n v e s t i g a t i o n s and t h e r e f o r e they should be superv ised and c o n t r o l l e d by t h e i n v e s t i g a t o r i n t h e same manner. H e should cons ide r what s p e c i a l examinations may be r equ i r ed , f o r example , f i r e i n f l i g h t , dece la ra - i - f o r c e s , c r a sh i n j u r y o r s u r v i v a l , f o r e n s i c d e n t i s t r y f o r i d e n t i f i c a t i o n .

S p e c i a l i s t o r l a b o r a t o r y examination and t e s t i n g g e n e r a l l y e n t a i l s t h e u s e of s p e c i a l i z e d equipment n o t r e a d i l y a v a i l a b l e i n t h e f i e l d , and o f t e n beyond t h e c a p a b i l i t i e s of t h e average r e p a i r s t a t i o n o r g e n e r a l shop. I n r ega rd t o t e s t i n g of components o r systems p n y o p e r a t o r s do no t possess f u l l c a p a b i l i t i e s f o r ove rhau l and t e s t i n g of t h e more intr icate systems components, t h e r e f o r e , c o n s i d e r a t i o n w i l l need t o be g iven t o u t i l i z i n g t h e f a c i l i t i e s of t h e component manufacturer where t h e s p e c i a l i z e d equipment and t r a i n e d personnel are r e a d i l y avai lable .

Laboratory t e s t i n g should not be l i m i t e d t o s t anda rd tests. The i n v e s t i - g a t i n g group should a t tempt t o dev i se tes ts which w i l l f u l l y e x p l o i t t h e component capa- b i l i t i e s under unusual c i rcumstances . The wide range of a v a i l a b l e s p e c i a l i z e d t e s t i n g equipment w i l l permit s imula t ion of a n i n f i n i t e v a r i e t y of ma l func t ions , t h e only l i m i t a t i o n be ing t h e ingenui ty of t h e i n v e s t i g a t o r .

The i n v e s t i g a t o r should forward a s much informat ion as p o s s i b l e r e l a t i v e t o t h e c i rcumstances surrounding t h e suspec ted f a i l u r e o r component. i n d i c a t i o n of what he suspec t s and what he hopes t o e s t a b l i s h , bu t he should ensu re t h a t he does no t i n f luence t h e s p e c i a l i s t examination t o t h e e x t e n t t h a t t h e s p e c i a l i s t i s only looking f o r t h e answer t h e i n v e s t i g a t o r hopes t o ob ta in . The i n v e s t i g a t o r ' s b r i e f i n g is intended as a gu ide l ine and t h e s p e c i a l i s t examination should cover a l l a s p e c t s which might poss ib ly be r e l e v a n t . In a d d i t i o n t h e i n v e s t i g a t o r should forward a d e t a i l e d h i s t o r y of t he p a r t , cover ing such i t e m s as : (1) i n s t a l l a t i o n d a t e on t h e a i r c r a f t , 1 2 ) t o t a l hours Gn p a r t , ( 3 ) t o t a l hour s s i n c e overhaul o r i n s p e c t i o n , ( 4 ) prev ious d i f f i c u l t i e s r epor t ed , (5) any o t h e r p e r t i n e n t d a t a which might throw l i g h t on how and why t h e p a r t f a i l e d . examination with t h e innocuous i n s t r u c t i o n s " fo r t e s t i n g " .

H e should inc lude a n

I t i s seldom, i f e v e r , adequate t o forward p a r t s f o r s p e c i a l i s t

System components, f r a c t u r e d par t s , o r items f o r s p e c i a l i s t examination a r e o f t e n s p o i l e d by though t l e s s methods of e x t r a c t i o n from t h e wreckage. Systems, whether they be mechanical, e l e c t r i c a l , h y d r a u l i c o r pneumatic sho'cild be maintained i n s e c t i o n s as l a r g e as p r a c t i c a b l e , o r i n r e l evan t s e c t i o n s d i sman t l ing l i n e s e t c . r a t h e r than c u t t i n g . i f m e t a l l u r g i c l abora to ry work is requi red on a p i ece of me ta l s t r u c t u r e never use a c u t t i n g corch but always u s e a saw, however l a b o r i o u s it may be. Pa in t smears which a r e o f t e n extremely important both i n c o l l i s i o n a c c i d e n t s and i n - f l i g h t f a i l u r e r e q u i r e s p e c i a l p r o t e c t i o n : t h i s a l s o a p p l i e s t o smoke or s o o t smears, It i s o f t e n b e s t t o cu t out an a r e a of metal with t h e smear a t t a c h e d t o i t .



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P a r t II.- Organ iza t ion of t h e I n v e s t i g a t i o n 11-2-9 -

2 . 5 . 2 F a c i l i t y a r rangements

The i n v e s t i g a t o r should de te rmine what components w i l l r e q u i r e s p e c i a l i s t

t h e i n v e s t i g a t o r must a l s o e n s u r e h e chooses a examination o r t e s t i n g a s e a r l y as p o s s i b l e . mine t h e type of f a c i l i t y t o be chosen: f a c i l i t y which h a s f u l l c a p a b i l i t i e s f o r p rov id ing t h e d e s i r e d t e s t i n g . d e c i s i o n s have been made, a r rangements should be made wi th t h e f a c i l i t y as f a r i n advance a s p r a c t i c a b l e f o r s e v e r a l reasons . i n v e s t i g a t i o n s o t h a t a l l p e r t i n e n t f ac t s can be developed p r i o r t o beginning t h e tests. T i m e must a l s o be allowed f o r packaging and sh ipp ing t h e components and t r a v e l t i m e for t h e i n v e s t i g a t i n g group who w i l l w i t n e s s t h e t e s t i n g . a l low p lanning t i m e f o r t h e f a c i l i t y management t o a s s i g n pe r sonne l and equipment t o do t h e work wi thout undue d i s r u p t i o n of t h e i r normal r o u t i n e .

The e x t e n t of t h i s s p e c i a l work w i l l d e t e r -

Once t h e s e

T i m e must be allowed f o r comple t ing t h e on-scene

Advance a r rangements w i l l a l s o

2 . 5 . 3 Choosing and l a b e l l i n e ,

When choos ing t h e components f o r f u r t h e r s t u d i e s it is d e s i r a b l e t o inc lude r e l a t e d components which may have had a bea r ing on t h e o p e r a t i o n of t h e component i n ques t ion . T e s t s conducted on s i n g l e components can only provide informat ion on t h e . o p e r a t i o n of t h a t u n i t whereas t h e problem may a c t u a l l y have been i n one of t h e r e l a t e d components. most v a l i d test r e s u l t s w i l l be ob ta ined by u s i n g as many of t h e o r i g i n a l sys tem components a s p o s s i b l e .

Th i s would i n c l u d e w i r i n g h a r n e s s e s and r e l a y s o r c o n t r o l v a l v e s and r e g u l a t o r s .

The

Each component should be p r o p e r l y tagged wi th nomencla ture , p a r t number, s e r i a l number and t h e a c c i d e n t i d e n t i f i c a t i o n . The i n v e s t i g a t o r should ma in ta in a complete l i s t i n g , (keyed t o t h e wreckage d i s t r i b u t i o n c h a r t ) w i t h t h e s a m e i n fo rma t ion , p l u s a complete set of d e s c r i p t i v e n o t e s and photographs of a l l components t o be sh ipped . These components should be removed t o a p r o p e r s e c u r i t y area f o r p r o t e c t i v e s t o r a g e u n t i l ready f o r sh ipp ing .

2 .5 .4 P r e c a u t i o n s t o be t a k e n f o r shipment

Packing of t h e components f o r shipment should be accomplished i n such a manner t h a t damage due t o t r a n s p o r t a t i o n w i l l be h e l d t o a minimum. P a r t i c u l a r c a r e should b e taken t o e n s u r e t h a t f r a c t u r e f a c e s are n o t damaged by b r i n g i n g mat ing f a c e s i n t o con tac t with each o t h e r o r w i th o t h e r p a r t s . F r a c t u r e f a c e s should be p r o t e c t e d by packing care- f u l l y wi th a p p r o p r i a t e d ry packing. of material recovered from water.

Grease o r o i l should no t be used excep t i n t h e case

Powerplants shou ld , whenever p o s s i b l e , be shipped i n t h e i r s p e c i a l s t a n d s and c o n t a i n e r s . Other heavy components such a s f l i g h t c o n t r o l power u n i t s , s t a b i l i z e r screw j a c k a s sembl i e s and a c t u a t o r s should be packed i n a p r o t e c t i v e wrapping and p laced i n s e p a r a t e wooden c o n t a i n e r s . Blocks o r b r a c i n g should be i n s t a l l e d i n s i d e t h e c o n t a i n e r s t o prevent any movement of t h e component d u r i n g t r a n s p o r t t o t h e t e s t f a c i l i t y . Smal le r and l i g h t e r components may be sh ipped i n t h e same manner wi th more than one t o a box but i n a manner which w i l l p r e v e n t t h e i r c o n t a c t i n g one ano the r i n t r a n s i t . Very l i g h t u n i t s may be packaged i n heavy co r ruga ted pas t eboa rd c a r t o n s wi th cuff i c i e n t packing m a t e r i a l t o prevent damage from mishandl ing i n t r a n s i t . A l l boxes and c a r t o n s should be w e l l marked f o r i d e n t i f i c a t i o n by t h e i n v e s t i g a t o r and an inventory list made f o r each c o n t a i n e r .



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Manual of A i r c r a f t Acctdent 1nvcstigaiiot . i _-. --______ 11-2-10

2.5.5 Notes and t e s t r e s u l t s

The o f f i c i a l n o t e s of s p e c i a l examinat ions and t e s t i n g should be kept by t h e i n v e s t i g a t o r who s u p e r v i s e s t h e work. used by t h e f a c i l i t y f o r such work. cop ie s being f u r n i s h e d t o t h e wi tness ing group members and t o the f a c i l i t y f o r t h e i r r eco rds .

Test r e s u l t s should be e n t e r e d on t h e s tandard forms The i n v e s t i g a t o r should r e t a i n a l l o r i g i n a l s wi th

P r io r t o beginning t h e tests o r examinat ions, assemble t h e w i t n e s s i n g group and a p p r o p r i a t e f a c i l i t y management personnel f o r a b r i e f i n g . of d e s i r e d tests and procure a copy of t h e test procedures t o be used. Review t h e s e proce- d u r e s t o ensure t h e i r adequacy. Some i t e m s on s tandard tes ts w i l l be unnecessary and may be e l imina ted by group consent .

Explain t h e type and e x t e n t

Any d i s c r e p a n c i e s noted during t h e t e s t s should be w r i t t e n i n t o t h e o f f i c i a l n o t e s wi th a n e x p l a n a t i o n a s t o t h e i r bear ing on proper o p e r a t i o n of t h e components under test . Bear i n mind t h a t t h e t o l e r a n c e s c a l l e d f o r i n t h e test procedures apply t o new or overhauled components. Components in s e r v i c e f o r some l eng th of t i m e may have a c c e p t a b l e l i m i t s which a r e o u t s i d e t h e s e t o l e r a n c e s and t h i s should be taken i n t o account when w r i t i n g t h e n o t e s .

I f t h e n a t u r e of a r.oted discrepancy w a r r a n t s , t h e component should be d i s - assembled fo l lowing complet icn of t h e t e s t s t o a s c e r t a i n t h e cause . T h e f i n d i n g s a r e t o be w r i t t e n i n t o t h e o f f i c i a l no te s . T h e tùitriessing group and f a c i l i t y personiiel should reassemble f o l l o w i n g completion of t h e t e s t s t o review t h e o f f i c i a l n o t e s and t e s t r e s u l t s . When a l l are i n agreement t h a t t h e d a t a developed p r e s e n t s a t r u e and f a c t u a l p i c t u r e of t h e component c o n d i t i o n and c a p a b i l i t i e s , a l l d a t a should be reproduced and a copy presented t o each member of t h e group assembled f o r t h e i r r eco rds .



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W A L OF AIRCRAFT ACCIDENT INVESTIGATION

PART III. - THE INVESTIGATION

P A R T

I I I



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PART III

CHAPTER 1. - I N I T I A L ACTION AT SCENE OF- THE ACCIDENT



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III- 1- 1 ________- - Par t 111.- 'The I n v e s t i g a t i o n _ _ _ _ .-

CHAPTER 1

INITIAL ACTION AT SCENE OF THE ACCIDENT

1.1 General

Aerodrome o f f i c i a l s , l o c a l i n h a b i t a n t s and/or l o c a l p o l i c e w i l l probably be t h e f i r s t p e r s o n s t o a r r i v e a t t h e scene of an a i r c r a f t a c c i d e n t . It is t h e r e f o r e extremely impor tan t t o e n l i s t t h e co-operat ion of aerodrome o f f i c i a l s and t h e p o l i c e f o r c e s i n order t o e n s u r e t h a t v i t a l ev idence is not l o s t by unnecessary i n t e r f e r e n c e wi th t h e wreckage b e f o r e t h e a r r i v a l of t h e i n v e s t i g a t i n g t e a m . I n v e s t i g a t o r s should be w e l l aware t h a t a c c i d e n t s may be s u b j e c t n o t on ly t o t e c h n i c a l i n v e s t i g a t i o n b u t a l s o t o some form of j u d i c i a l i n q u i r y and t h a t n a t i o n a l l a w s may g i v e precedence t o t h i s l a t t e r a s p e c t . N a t i o n a l l e g i s l a t i o n may s p e c i f y t h e procedure t o be fol lowed r e g a r d i n g t h i s j u d i c i a l a s p e c t w h i l s t a d m i n i s t r a t i v e r e g u l a t i o n s determine t h e r e l a t i o n s h i p of t h e t e c h n i c a l i n v e s t i g a t i o n t o i t . Co-operation w i t h aerodrome o f f i c i a l s i s normally ensured by a n a p p r o p r i a t e s t a n d i n g o rde r : t h i s should a l s o e n s u r e t h e safe-keeping of ground t a p e r e c o r d i n g s , documents, etc. Co- o p e r a t i o n of t h e p o l i c e f o r c e s can u s u a l l y b e s t be achieved by l i a i s o n a t h e a d q u a r t e r s l e v e l , t h e i n i t i a 1 l i a i s o n having been undertaken d u r i n g t h e p lanning a s s o c i a t e d wi th t h e p o s s i b i l i t y of an a c c i d e n t o c c u r r i n g . Members of t h e p o l i c e f o r c e s should be aware i n advance of what is expec ted of them i n t h e e v e n t of a n a i r c r a f t a c c i d e n t . They should ensure t h a t arrangements f o r t h e f o l l o w i n g e s s e n t i a l i t e m s are made wi thout delay:

o b t a i n necessary medica l a t t e n t i o n ;

s e c u r e t h e wreckage from t h e h a z a r d s of f i r e o r f u r t h e r damage;

n o t i f y t h e a p p r o p r i a t e n a t i o n a l a u t h o r i t y , o r d e l e g a t e d agency;

check f o r t h e p o s s i b i l i t y of r a d i o - a c t i v e i s o t o p e s or o t h e r radio- a c t i v e material b e i n g c a r r i e d as f r e i g h t , and t a k e a p p r o p r i a t e a c t i o n ;

p l a c e guards t o e n s u r e t h a t t h e a i r c r a f t is n o t moved, except as s p e c i f i e d i n Annex 13, o r tampered wi th u n n e c e s s a r i l y ;

t a k e s t e p s t o p r e s e r v e any evidence of a f l e e t i n g o r ephemeral n a t u r e such a s i ce , s o o t d e p o s i t s , e t c . by photography o r o t h e r a p p r o p r i a t e means;

o b t a i n t h e names and a d d r e s s e s of a l l a v a i l a b l e w i t n e s s e s whose tes t imony may a i d i n t h e i n v e s t i g a t i o n of t h e a c c i d e n t .

Apart from t h e s e n e c e s s i t i e s , t h e wreckage should be l e f t undis turbed u n t i l t h e a r r i v a l of t h e Invest igator- in-Charge. rescue a u t h o r i t i e s t h a t t h e bodies of t hose persons who have been k i l l e d i n t h e a c c i d e n t , and human remains, should where p r a c t i c a b l e , be l e f t i n s i t u f o r examinat ion and record ing by t h e i n v e s t i g a t i n g personnel . S i m i l a r l y , p e r s o n a l belongings should remain untouched as t h e i r l o c a t i o n may assist i n i d e n t i f i c a t i o n of t h e v i c t i m s .

I t should be emphasized t o t h e p o l i c e and

16/4/73 No. 3



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I II- 1-2 . Manual of A i r c r a f t Accident i n v e s t i g a t i o n

1.2 Rescue Opera t ions

The primary concern of tlie f i r s t persons t o a r r i v e a t t h e scene of an a i r - c r a f t acc iden t w i l l be t h e rescue and succour of s u r v i v o r s and pro tec t i ,on of proper ty wi th in t h e means a v a i l a b l e .

Persons who may be concerned wi th the e x t r i c a t i o n of v i c t ims from a i r c r a f t wreckage should be a l e r t e d t o t h e need f o r t h e record ing a t t h e ear l ies t oppor tuni ty of t h e i r observa t ions regard ing t h e p o s i t i o n s and seat numbers i n which t h e su rv ivo r s were loca ted i n t h e a i r c r a f t and what p o r t i o n s of t h e wreckage had t o be moved dur ing t h e removal. I f c i rcumstances permi t , t h e bod ies of persons k i l l e d i n the acc iden t should be l e f t as found u n t i l t h e p o s i t i o n and cond i t ion of t h e bodies is noted by a t r a i n e d inves- t i g a t o r , photographs taken , a ske tch p l an made t o i n d i c a t e t h e i r p o s i t i o n s r e l a t i v e t o t h e wreckage, and seat numbers recorded where p o s s i b l e . Where v i c t i m s are loca ted a t p o s i t i o n s away from t h e wreckage t h e p o s i t i o n s should be marked by a s t a k e wi th a l a b e l i d e n t i f y i n g t h e v i c t i m and t h e seat, I n a l l ca ses i t is d e s i r a b l e t h a t the v i c t i m s should have an i d e n t i f y i n g l a b e l a t t a c h e d t o them s t a t i n g where they were found and i n which seat . Apart from ga in ing informat ion which may assist i n t h e acc iden t i n v e s t i g a t i o n , t h e c a r e f u l r eco rd ing of t h i s d a t a may assist i n t h e i d e n t i f i c a t i o n of v i c t ims .

I n t h e event t h a t t he v i c t i m s , both i n j u r e d and dead, are removed from t h e wreckage of an a i r c r a f t before t h e a r r i v a l of t h e i n v e s t i g a t o r s , i t i s important t h a t i t be e s t a b l i s h e d quick ly whether an accu ra t e r eco rd as se t out above h a s been maintained and i f n o t , t o set about r e c t i f y i n g t h e s i t u a t i o n .

The i n v e s t i g a t o r must determine i f t h e r e h a s been any d i s tu rbance of t h e wreckage during t h e rescue ope ra t ions and ensu re t h a t any such d i s tu rbance is recorded.

I t i s important t h a t on completion o f t h e i n i t i a l r e scue ope ra t ion , t h e succour of su rv ivo r s and p ro tec t ion of p r o p e r t y , t h a t the r e scue personnel e x e r c i s e as much ca re as poss ib l e t o ensure their: movements t o s ecu re the s i t u a t i o r i do not need le s s ly des t roy evidence which may be of va lue i n t h e i n v e s t i g a t i o n . For example, once i t i s e s t a b l i s h e d beyond reasonable doubt t h a t a l l s u r v i v o r s have been rescued , and f'ire r i s k h a s Seen e l imina ted a s f a r as p r a c t i c a b l e , movement of ambulance and f i r e veliic.Les should not be modi: a long t h e wreckage t r a i l i f a l t e r n a t i v e a c c e s s i s poss ib l e .

Fu r the r i n v e s t i g a t i o n work which i s a s s o c i a t e d w i t h t h i s phase i s d e t a i l e d i n P a r t III., Chapter 9 , Human Fac to r s I n v e s t i g a t i o n , and i n Appendix 9 - I d e n t i f i c a t i o n of V i c t i m s ,

1 . 3 {Guardinq

A t t h e t i m e of i n i t i a l n o t i f i ca t ior i of tìie acc iden t t he Inves t iga tor - in-Charge should make p o s i t i v e arrangements t o ensure t h e s e c u r i t y of t h e wreckage u n t i l h i s a r r i v a l . This i s normally arranged through t h e p o l i c e f o r c r s bu t , i n some cases, m i l i t a r y personnel o r s p e c i a l l y r e c r u i t e d c i v i l i a n s may be employed.

Ti i i n s t ances where i t i s suspec ted t h a t t h e a i r c r a f t may have c a r r i e d any dangercas cargo such a s rad io-ac t ive consignments, exp los ives , ammunition, co r ros ive l i q u i d s gaseous, l i q u i d o r s o l i d poisons o r even b a c t e r i d l c u l t u r e s , s p e c i a l p recau t ions should be taken i n p lac ing the guards a t a s a f e d i s t a n c e from t h e wreckage. important when a f i r e h a s occurred. be f i x e d whenever p o s s i b l e u n t i l an expe r t h a s thoroughly eva lua ted t h e danger involved.

Th i s i s p a r t i c i i l a r l y Also, p o s t s i n d i c a t i n g t h e p o s s i b l e danger a r e a should



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P a r t III.- The I n v e s t i g a t i o n 111-1-3

Upon a r r i v a l a t t h e a c c i d e n t scene t h e f i r s t t a s k s of t h e i n v e s t i g a t o r should be t o review guard ing arrangements. d u t i e s , which are:

The guards should be thoroughly conversant w i th t h e i r

a ) t o p r o t e c t p r o p e r t y ;

b ) t o prevent d i s t u r b a n c e of t h e wreckage ( i n c l u d i n g bod ies and c o n t e n t s of t h e a i r c r a f t ) ;

t o admit t o t h e a c c i d e n t a r e a on ly those pe r sons who are duly a u t h o r i z e d by t h e I n v e s t igator-in-Charge;

t o p r o t e c t and p r e s e r v e , where p o s s i b l e , any ground marks made by t h e a i r c r a f t .

c )

d )

I n a r r a n g i n g t h e guard ing of t h e wreckage clear and s p e c i f i c i n s t r u c t i o n s should be g iven t o t h o s e guard ing t h e area i n r e g a r d t o t h e i d e n t i f i c a t i o n of au tho r i zed persons. I n t h e case of major i n v e s t i g a t i o n s t h i s can be accomplished by t h e i s s u i n g of badges or l a b e l s or some form of p a s s t o a l l a u t h o r i z e d persons .

I n a c c i d e n t s i n which t h e wreckage h a s no t been s c a t t e r e d e f f e c t i v e c o n t r o l can be achieved by rop ing o f f t h e area r e q u i r e d t o beguarded . wreckage t r a i l t h e t a s k of guard ing may be fo rmidab le and many guards w i l l be r equ i r ed . The p o l i c e can be of c o n s i d e r a b l e a s s i s t a n c e by t h e i r l i a i s o n w i t h t h e l o c a l popu la t ion , p a r t i c u l a r l y wi th r e g a r d t o l o c a t i o n of o u t l y i n g p i e c e s of wreckage. The people l i v i n g i n t h e neighbourhood should be encouraged by a l l a v a i l a b l e means t o r e p o r t t h e d iscovery of p i e c e s of a i r c r a f t wreckage and a t t h e same t i m e t hey should be impressed wi th t h e importance of l e a v i n g t h e p i e c e s und i s tu rbed . The c o l l e c t i o n of o u t l y i n g p i e c e s of wreckage i n t o a n e a t p i l e a l o n g s i d e t h e main wreckage is sometimes done wi th good but misguided i n t e n t i o n s . I t may make easier t h e immediate t a s k of t h e guards and t h e subsequent s a l v a g e o p e r a t i o n s bu t such a c t i o n could r e s u l t i n t h e l o s s of ev idence v i t a l t o t h e i n v e s t i g a t i o n . S i m i l a r l y , t h e removal of p i e c e s of wreckage by souveni r h u n t e r s must be prevented . The guard ing of t h e wreckage should be main ta ined u n t i l such t i m e as t h e Inves t iga tor - in-Charge h a s s a t i s f i e d h imsel f t h a t t h e i n v e s t i g a t i o n h a s reached a p o i n t where a l l ev idence a t t h e s i te h a s been ga the red . mile t h e guard ing i s i n f o r c e , t h e i n v e s t i g a t o r should rev iew t h e s i t u a t i o n so t h a t p r ,og res s ive release of guards may be achieved.

When t h e r e is a l a r g e

1.4 Genera l Survey of t h e Wreckage

A p r e l i m i n a r y survey should be c a r r i e d o u t by t h e i n v e s t i g a t i n g team as soon as p o s s i b l e a f t e r t h e i r a r r i v a l a t t h e scene and p r e l i m i n a r y d i s c u s s i o n w i t h t h e p o l i c e (or o t h e r l o c a l a u t h o r i t i e s ) h a s been completed. A t t h i s s t a g e no d e t a i l e d examination should be a t t empted , t h e a i m be ing t o o b t a i n a complete and as clear a p i c t u r e as p o s s i b l e of t h e c i r cums tances under which t h e a c c i d e n t occur red . The p o i n t of i n i t i a l impact w i t h t h e ground o r o b j e c t s should be e s t a b l i s h e d and t h e subsequent p a t h of t h e a i r c r a f t should then be fo l lowed by s e a r c h i n g f o r ground markings o r s c a r s upon b u i l d i n g s , trees, shrubs , rocks , etc.

The g e n e r a l s t a t e of t h e wreckage should be t a k e n i n t o account a t t h i s t i m e i nc lud ing l o c a t i o n of i t e m s of wreckage, c o n t e n t s of a i r c r a f t and l o c a t i o n of s u r v i v o r s and bod ies , bu t t h e wreckage should n o t be moved o r d i s t u r b e d . The primary c o n s i d e r a t i o n s a t t h i s t i m e are t h o s e aimed a t e s t a b l i s h i n g a p robab le f l i g h t p a t h , impact a n g l e , impact



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111-1-4 Manual of A i r c r a f t Accident i n v e s t i g a t i o n

speeds, whether o r not t h e a i r c r a f t may have been under c o n t r o l and i f s t r u c t u r a l f a i l u r e occurred p r i o r t o impact. t h e acc iden t s i t e w i l l provide a good i n d i c a t i o n (though not a completely r e l i a b l e one) whether o r no t s t r u c t u r a l f a i l u r e i s a f e a t u r e . Whether o r n o t t h e acc iden t appears t o have been s u r v i v a b l e , a l s o t h e opera t ion of t h e f i r e and rescue service: should be kept i n mind. gained of t h e t e r r a i n w i l l assist t h e Invest igator- in-Charge i n ' planning t h e i n v e s t i g a t i o n and a s s e s s i n g p r i o r i t i e s i n t h e work t o be undertaken.

A check t h a t a l l t h e e x t r e m i t i e s of t h e a i r c r a f t are p r e s e n t a t

The impressions gained during t h e g e n e r a l survey of t h e wreckage and t h e knowledge

1.5 P r e s e r v a t i o n of t he Evidence

When making the pre l iminary survey of t h e e n t i r e acc ident scene, t h e inves- t i g a t o r h a s t h e oppor tuni ty t o review t h e guard ing arrangements and t o emphasize t o a l l engaged i n t h e guarding and i n t h e i n v e s t i g a t i o n t h a t t h e p i e c e s of wreckage must n o t be moved o r d i s tu rbed . The p r e s e r v a t i o n of ground marks is e q u a l l y important and i n t h e i n i t i a l survey, c a r e f u l no te should be made of a l l ground marks so t h a t guard arrangements may be amended where necessary t o provide a d d i t i o n a l s e c u r i t y . a s p e c t s of t h e wreckage t r a i l be preserved u n t i l t hey have been photographed and t h e i r d e s c r i p t i o n and l o c a t i o n have been recorded. upon trees, sh rubs , rocks, l o c a t i o n of p i e c e s of wreckage, l o c a t i o n of bodies o r human remains, e tc .

It is e s s e n t i a l t h a t a l l

Th i s i n c l u d e s such items as marks o r scars

1.6 Precaut ionary Measures

1 .6 .1 Precaut ions t o be taken a g a i n s t f i r e

There is obviously a h igh f i r e r i sk a s s o c i a t e d w i t h most a i r c r a f t wreckage and s t r ic t precaut ions should be adopted t o ensure s a f e t y f o r a l l personnel and a l s o t o p r o t e c t t h e wreckage. Arrangements should be made f o r f i r e Light ing appl iances t o s t a n d by whi le a high f i r e r i s k remains. I f t h e f u e l t a n k s of t h e a i r c r a f t are s t i l l i n t a c t , c o n s i d e r a t i o n should be given t o d e f u e l l i n g as soon as p o s s i b l e . t h e q u a n t i t y removed from each tank should be measured and recorded , and the t ank i d e n t i f i e d . s t r i c t l y c o n t r o l any a c t i v i t y such as t h e moving of p a r t s of t h e a i r c r a f t wreckage which could i n c r e a s e t h e p o s s i b i l i t y of i g n i t i o n . equipment o r t h e use of salvage equipment may p r e s e n t a f i r e r i s k and should not be car- r i e d o u t u n t i l t h e f i r e r i s k has been assessed and judged t o be s a f e f o r t he ope ra t ion .

1.6.2

When f u e l i s removed

I f t h e r e h a s been a l a r g e s p i l l a g e of f u e l t h e Invest igator- in-Charge must

The o p e r a t i o n of a i r c r a f t r a d i o o r e l e c t r i c a l

Precaut ions t o be taken wi th dangerous cargoes

A s soon as p o s s i b l e a check ' should be made t o a s c e r t a i n whether any dangerous cargo was being c a r r i e d on t h e a i r c r a f t . an enquiry t o the o p e r a t o r ' s agent should r e s o l v e t h i s ques t ion . i nc lude such i t e m s as rad io-ac t ive consignments, e x p l o s i v e s , ammunition, c o r r o s i v e l i q u i d s , gaseous, l i q u i d o r s o l i d poisons o r even b a c t e r i a l c u l t u r e s .

A p r e l i m i n a r y check of t h e f r e i g h t mani fes t o r Dangerous cargoes may

Radio-active material is b e i n g c a r r i e d a s f r e i g h t wi th i n c r e a s i n g frequency i n a i r c r a f t and i f i t i s e s t a b l i s h e d t h a t such material w a s be ing c a r r i e d , s t e p s must b e taken immediately t o make s u r e t h a t i t i s removed by proper ly q u a l i f i e d and equipped persons t o a p l a c e of s a f e t y b e f o r e any harm is caused t o personnel working i n c l o s e proximity t o t h e wreckage. The small s i z e of a r a d i o - a c t i v e i s o t o p e l i k e l y t o be c a r r i e d i n an a i r c r a f t , t h e s t r e n g t h of i ts package and t h e s h i e l d i n g incorpora ted i n i t minimize

16/4/73 No. 3



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II I- 1-5 __ ._ . - _____-- - P a r t III .- The I n v e s t i g a t i o n

t h e p o s s i b i l i t y of damage even when s u b j e c t e d t o t h e i m p a c t of an a i r c r a f t acc iden t . AS long a s t h e package and s h i e l d i n g remain i n t a c t t h e r e i s l i k e l y t o be l i t t l e danger from r a d i a t i o n , bu t where f i r e fo l lows t h e impact t h e package and s h i e l d i n g may be damaged. Radio-ac t ive i s o t o p e s may then be changed i n t o gaseous form by h e a t i n which case rad ia - t i o n may sp read i n a downwind d i r e c t i o n .

In i n s t a n c e s where an a c c i d e n t r e s u l t i n g i n a f i r e occur s t o a n a i r c r a f t c a r r y i n g r a d i o - a c t i v e i s o t o p e s , a l l pe r sonne l who p a r t i c i p a t e d i n t h e r e s c u e and f i r e f i g h t i n g o p e r a t i o n s should be checked, decontaminated and put under medica l o b s e r v a t i o n a s necessary . N o examinat ion of t h e wreckage should be commenced u n t i l t h e degree of r a d i a t i o n h a s been checked by a n e x p e r t and dec la red s a f e .



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PART I I I

CHAPTER 2. - INITIATION OF THE WRECKAGE INVESTIGATION



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111-2-1 P a r t 111.- The I n v e s t i g a t i o n

CHAPTER 2

INITIATION OF THE WRECKAGE INVESTIGATION

2 . 1 Accident Locat i o n

The p r e c i s e l o c a t i o n of t h e a c c i d e n t s i t e must be determined and recorded. This can be achieved by p l o t t i n g t h e b e a r i n g s and d i s t a n c e s from known p o s i t i ó n s on a l a rge - sca l e map o r by u s i n g aer ia l photography of t h e a c c i d e n t s i t e i n con junc t ion wi th a s u i t a b l e map. t h e need f o r de t e rmina t ion of any s i g n i f i c a n t g r a d i e n t i n t h e a c c i d e n t area. c i rcumstances and when t e r r a i n is deemed t o be s i g n i f i c a n t i n t h e i n v e s t i g a t i o n , it may be d e s i r a b l e t o have a p r o f i l e of t h e t e r r a i n prepared by a surveyor . Maps of the l o c a l area and a p p r o p r i a t e a e r o n a u t i c a l c h a r t s should be used t o e s t a b l i s h t h e l o c a t i o n of t h e acc i - dent i n r e l a t i o n t o a i rways f a c i l i t i e s and t o a i r p o r t s . approach c h a r t s should be used i n connexion wi th a c c i d e n t s o c c u r r i n g du r ing t h e approach o r take-off phase of f l i g h t .

The e l e v a t i o n of t h e s i t e should be determined and c o n s i d e r a t i o n g iven t o I n some

Airpor t lay-out c h a r t s and

2.2 Photography

Photographs should be t aken as soon as p o s s i b l e a f t e r t h e a c c i d e n t occur s

photographs should a l s o be t aken of t h e l o c a t i o n of a n d ' b e f o r e t h e wreckage is moved o r d i s t u r b e d . should be t a k e n befor-e removal: s u r v i v o r s . Good photographs f u r n i s h t h e b e s t p o s s i b l e r e c o r d of a n a c c i d e n t and whenever a p p r o p r i a t e t o t h e type of a c c i d e n t a e r i a l photography should be a r ranged . t h a t each member of t h e team, o r i n group i n v e s t i g a t i o n s , each group,be f u l l y equipped t o t a k e photographs independent ly of t h e o t h e r s , bu t be fo re d e t a i l e d i n v e s t i g a t i o n work i s under taken t h e Inves t iga tor - in-Charge should a r r a n g e f o r photography i n g e n e r a l t o be commenced wi thou t d e l a y i n o r d e r t o o b t a i n a good coverage of t h e wreckage and t h e condi- t i o n i n which it is found. Genera l views of t h e scene from f o u r d i r e c t i o n s and back a long t h e wreckage t r a i l t o t h e f i r s t p o i n t of c o n t a c t should be inc luded .

Where p o s s i b l e , photographs of bod ie s

I t is d e s i r a b l e

The l o c a t i o n and d i r e c t i o n of each photograph should be recorded and p a r t i c - u l a r a t t e n t i o n should be p a i d t o t h e fo l lowing s u b j e c t s :

i n s t rumen t s ;

p o s i t i o n of c o n t r o l s i n t h e c o c k p i t ;

r a d i o s e t t i n g s ;

au tomat i c p i l o t s e t t i n g ;

f u e l cock p o s i t i o n s ;

swi t ch p o s i t i o n s ;

p o s i t i o n of f l a p j a c k s , u n d e r c a r r i a g e j a c k s , l a t c h e s , e tc . ;

c o n t r o l s u r f a c e p o s i t i o n s ;

t r i m t a b s e t t i n g s ;

s u s p i c i o u s breakages o r bends;



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111-2-2 Manual of A i r c r a f t A c c d e n t i n u e s t i g a t -- ion -___--

k) p r o p e l l e r b lades showing p i t c h p o s i t i o n s ;

1) engines and engine c o n t r o l l e v e r p o s i t i o n s i n t h e cockpi t and a t t h e engines;

m) f i r e damage;

n) ground impact marks;

o) seats and seat b e l t s .

This w i l l ensure t h a t as complete a r e c o r d as p o s s i b l e is made be fo re t h e Cons idera t ion should be g iven t o t h e use of s t e reograph ic p a i r s wreckage is d i s tu rbed .

which are sometimes of p a r t i c u l a r va lue f o r both ae r i a l and c l o s e ' photography.

Typ ica l photographs of an acc iden t s i t e are inc luded a t t h e end of t h i s chapter and f u r t h e r in format ion on acc ident i n v e s t i g a t i o n photography i s g iven i n Appendix 2 .

2 . 3 Wreckage D i s t r i b u t i o n Chart

A f t e r t h e i n i t i a l s tudy of t h e g e n e r a l scene of t h e acc iden t has been made and photographs taken t h e f i r s t s t e p i n t h e a c t u a l i n v e s t i g a t i o n is usua l ly t h a t of p l o t t i n g t h e d i s t r i b u t i o n of t h e wreckage. I n simple terms t h i s is done by measuring from a s u i t a b l e datum t h e d i s t a n c e s and bear ings of t h e main wreckage and a l s o of t h e s c a t t e r e d p a r t s of t h e wreckage, i nc lud ing t h e con ten t s of t h e a i r c r a f t , s u r v i v o r s and v i c t ims , a l l impact and ground markings, and then record ing t h i s in format ion on a c h a r t t o a convenien? scale.

While ,in many acc iden t s t h e p r e p a r a t i o n of a wreckage d i s t r i b u t i o n c h a r t is a t a s k cons idered t o be w e l l w i th in t h e c a p a b i l i t i e s of an i n v e s t i g a t o r , cons ide ra t ion shou ld be g iven t o employing t h e s e r v i c e s of a q u a l i f i e d surveyor when t h e circumstances of t h e acc iden t a r e such t h a t t h e r e has been e x t e n s i v e s c a t t e r i n g of t h e wreckage.

The p repa ra t ion of a wreckage d i s t r i b u t i o n c h a r t i s worthy of pa ins t ak ing e f f o r t t o ensu re i t s completeness and accuracy , f o r t h e s tudy of t h e completed c h a r t may sugges t p o s s i b l e f a i l u r e p a t t e r n s o r sequences, and t h e s i g n i f i c a n c e of l a te r f i n d i n g s may o f t e n depend upon r e fe rence t o t h e o r i g i n a l c h a r t . It w i l l n o t on ly be used as a r e f e r e n c e document throughout t h e i n v e s t i g a t i o n but a l s o i t w i l l remain a most important document € o r i n c l u s i o n i n t h e i n v e s t i g a t o r ' s doss i e r and w i l l supplement t h e w r i t t e n r e p o r t .

In determining t h e type and amount of i n fo rma t ion t o be included on t h e c h a r t i n any sprci € i c acc ident t he i n v e s t i g a t o r must be guided by t h e circumstances sur rounding the p a r t i c u l a r acc iden t , but i n most a c c i d e n t s t h e c h a r t should r eco rd t h e l o c a t i o n s of a l l major components, p a r t s and accesso r i e s , f r e i g h t , and t h e l o c a t i o n s a t which the a c c i d e n t v i c t ins were found, o r su rv ivo r s loca ted , and t h e i r i d e n t i t i e s . The i n i t i a l con tac t markings and o t h e r grouid nark ings should a l s o b e i nd ica t ed on t h e c h a r t w i th s u i t a b l e r e f e r e n c e t c ] i d e n t i f y the pa r t of the a i r c r a f t o r component r e s p o n s i b l e f o r t h e marking. When t e r r a i n fea t -ures appear t o have n hearing on t h e accitlerit o r on t h e type o r ex ten t o € s t r u c t u r a l damage they t o e s h o u l d be noted on t h e wreckage d i s t r i b u t i o n c h a r t . P e r t i n e n t dimensions, descr i -pt ive not.ei; and a l s o t h e loca t ions froin which pliotographs were taken add t o t h e com- p l e t e n e s s of the cha r t .

The P repa ra t ion of a wreckage d i s t r i b u t i o n s k e t c h may be accomplished i n v a r i o u s ways but t he fol lowing a r e some examples of s imple methods:

a ) When t h e wreckage is concen t r a t ed i n a s m a l l area, d i s t a n c e s and b e a r i n g s (magnetic) can be measured from a c e n t r a l p o i n t of t h e wreckage. The p l o t t i n g of t h e i tems can be made on a p o l a r diagram (see page 111-2-13).



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I II- 2-3 P a r t III.- The I n v e s t i g a t i o n

b) When t h e wreckage i s s c a t t e r e d , a base l i n e can be l a i d o u t usu'ally a long t h e main wreckage t r a i l , dependent upon t h e t e r r a in , and d i s - t a n c e s measured a l o n g t h e base l i n e from a r e f e r e n c e p o i n t and then p e r p e n d i c u l a r l y from t h e base l i n e t o t h e s c a t t e r e d p i e c e s of wreckage. A c h a r t i s then prepared from t h i s i n fo rma t ion u s i n g a s u i t a b l e scale. The use of squared paper may be u s e f u l i n p r e p a r i n g simple p l o t s ( s e e page 111-2-14).

Where t h e r e are a g r e a t many p i e c e s of wreckage t h e p r e s e n t a t i o n of t h e c h a r t can be s i m p l i f i e d by us ing a le t te r o r a numeral f o r each i t e m and p repa r ing a s u i t - a b l e index f o r i n c l u s i o n on t h e c h a r t ( s ee page 111-2-15).

2 .4 Examination of Impact Marks and Debr is

The marks of f i r s t impact of t h e a i r c r a f t w i th t h e ground should be found and from t h e s e and t h e d i s t r i b u t i o n of t h e wreckage i t can u s u a l l y be determined which p a r t of t h e a i r c r a f t s t r u c k t h e ground f i r s t . c a r e f u l examinat ion of ground marks o r s c a r s upon trees, sh rubs , rocks , p o l e s , power l i n e s , b u i l d i n g s , e t c . Wing t i p s , p r o p e l l e r s o r l and ing g e a r l eave te l l - ta le marks o r to rn-of f p a r t s a t p o i n t s of c o n t a c t w i th f i x e d o b j e c t s . Ground scars used i n c o n j u n c t i o n wi th he igh t of broken trees o r brush w i l l assist i n e s t a b l i s h i n g t h e a n g l e and a t t i t u d e i n which t h e ae rop lane s t r u c k t h e ground. Examination of t h e v i c t i m s of t h e a c c i d e n t , c l o t h i n g , c o n t e n t s of t h e a i r c r a f t , w i l l a l s o assist i n e s t a b l i s h i n g a n g l e , a t t i t u d e , and speed a t impact. The g e n e r a l s tate of d i s t o r t i o n and " t e l e scop ing" of t h e s t r u c t u r e w i l l permit an exper ienced i n v e s t i g a t o r t o deduce whether t h e a i r c r a f t c r a shed a t h igh o r low speed. Only l o c a l damage occur s a t low speed impact, bu t a t h i g h speed wings and t a i l become buckled and fo resho ï t ened . Cases have occurred i n which t h e a i r c r a f t h a s been completely b u r i e d i n a deep c r a t e r , w i t h only a few t w i s t e d f ragments d i s p e r s e d a d j a c e n t t o t h e impact s i t e . Shor t s t r a i g h t furrows running o u t from each s i d e of t h e crater t o l d where t h e l e a d i n g edges of t h e o u t e r wings had h i t t h e ground w h i l e t r a v e l l i n g almost v e r t i c a l l y downwards a t very h igh speed . When eng ines have n o t p e n e t r a t e d i n t o t h e ground t h e i r v e r t i c a l descen t speed has probably been s m a l l , but t h e a i r c r a f t might have been t r a v e l l i n g ve ry fas t a t a sha l low a n g l e and i n such c i r cums tances , t h e wreckage w i l l be spread f a r a long a l i n e from t h e mark of f i r s t impact. I f t h e wreckage is wide ly s c a t t e r e d a long t h e f l i g h t p a t h , t h i s may i n d i c a t e t h a t some s t r u c t u r a l d i s i n t e g r a t i o n had occurred be fo re impact w i th t h e ground. It is u s u a l l y p o s s i b l e t o form a p r e l i m i n a r y menta l p i c t u r e o f :

The p a t h of t h e a e r o p l a n e may be deduced by

a ) t h e d i r e c t i o n , a n g l e and speed of descen t ;

b) whether i t w a s a c o n t r o l l e d o r u n c o n t r o l l e d descen t ;

c )

d )

whether t h e e n g i n e s were under power a t t h e time of impact;

whether t h e a i r c r a f t w a s s t r u c t u r a l l y i n t a c t a t t h e p o i n t of f i r s t impact.

The e x t e n t of t h e damage t o t h e wreckage w i l l g i v e some p re l imina ry ind ica- t i o n of t h e ev idence t h a t can be ob ta ined from i t by subsequent d e t a i l e d examination. I f s t r u c t u r a l d i s i n t e g r a t i o n i n t h e a i r i s suspec ted , i t i s e s s e n t i a l t o p l a n t h e i n v e s t i g a t i o n t o ensu re t h a t a l l in fo rma t ion which w i l l h e l p t o t r a c e t h e pr imary f a i l u r e i s e x t r a c t e d from t h e wreckage b e f o r e i t i s moved. s c a t t e r e d over s e v e r a l m i l e s of woodland, f i e l d , marsh, o r b u i l t - u p area and may be d i f - f i c u l t t o l o c a t e . Search p a r t i e s should comb t h e d i s t r i c t and t h e s e a r c h should be

I n such c i rcumstances a i r c r a f t wreckage may be



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Xanual. of t \ i r c r a € t iiccidtvit Irivc.stig3t i o n - I I I - 2 - .4 -

cont inued u n t i l a l l s i g n i f i c a n t components have been found. of m i l i t a r y personnel, p o l i c e , s choo l s and l o c a l r e s i d e n t s should be reques ted b u t a t t h e same t i m e s e a r c h e r s should be informed of t h e need t o r e p o r t t h e l o c a t i o n of p icces of wreckage without d i s t u r b i n g them. mine t h e exac t l o c a t i o n of such p i eces a s they f e l l t o t h e ground. Light detached p o r t i o n s of low d e n s i t y tend t o d r i f t i n t h e d i r e c t i o n of t he p r e v a i l i n g wind a t t h e time of ttie acc ident w h i l s t dense o b j e c t s w i l l be less a f f e c t e d by wind e f f e c t s , and knowledge of t h i s d i r e c t i o n may save t i m e i n l o c a t i n g a i r c r a f t p i eces . t u rbed or removed u n t i l :

The co-operation iri t h e s t a r c h

This w i l l enable t h e i n v e s t i g a t o r t o examine and de te r -

No p iece of wreckage should be d i s -

a ) i t s p o s i t i o n i s recorded;

b) an iden t i f icat ion t h e case of small

c) no te s are made of t h e na tu re of t h e p r i o r t o t h i s .

number i s pa in t ed on i t on an undamaged area, o r i n p o r t i o n s , a l a b e l a t t ached ; and

t h e manner i n which t h e p i e c e s t r u c k t h e ground, what ground w a s , and whether it h i t trees o r bu i ld ings , e t c . ,

Such no te s and photographs w i l l be ve ry v a l u a b l e when a later d e t a i l e d examina- t i o n i s made and may h e l p t o s e p a r a t e ground impact damage from t h e o t h e r damage. A s p e c i a l s ea rch should be made f o r any p a r t no t accounted f o r and i f i t cannot be found t h e f a c t must be recorded.

I n t h e case of acc iden t s a s s o c i a t e d wi th wheels-down landings , t y r e marks should be c a r e f u l l y recorded and examined. The width of t h e t y r e impr in t of each wheel and t h e dens i ty of t h e co lour of t h e marks should b e noted. The t y r e marks may w e l l p rovide evidence of brak ing o r sk idding o r s l i d i n g and, i n p a r t i c u l a r , may provide a c l u e t o an aquaplaning s i t u a t i o n . An aquaplaning t y r e l eaves a very d i s t i n c t i v e wh i t i sh mark on t h e runway. These t racks are t h e r e s u l t of a scrubbing a c t i o n which i s provided by t h e f o r c e s under t h e t y r e dur ing aquaplaning.

I t should never be overlooked t h a t t h e v i c t i m s of a n a i r c r a f t a c c i d e n t , i f o b j e c t i v e l y examined i n t h e same manner as t h e a i r c r a f t wreckage, w i l l r e v e a l important information r e l a t i n g t o a i r c r a f t speed, a i r c r a f t a t t i t u d e a t impact , sequence of break-up, etc. This is r e f e r r e d t o i n more d e t a i l i n P a r t III , Chapter 9 , Human Fac to r s I n v e s t i g a t i o n .

Photographs showing t y p i c a l impact marks, e t c . , a r e included a t t he end of t h i s chapter .

2.5 Wreckage i n t h e Water

2.5.1 I. I

Decision t o recover t h e wreckage

If an acc ident occurs over a l ake o r t h e sea and t h e a i r c r a f t f a l l s i n t o t h e water the wreckage and, t h e r e f o r e , t h e evidence wliich may be forthcoming from i t , w i l l b e much less a c c e s s i b l e than when i t f a l l s on l a r i d . however, t h a t it has been poss ib l e t o recover 70 per c e n t of t h e t o t a l wreckage of an a i r - c r a f t which had d i s i n t e g r a t e d a t 30,000 f ee t (9,3.40 m) and was s p r e a d over 1.2 square i n i l e s (31 sq.km) of sea bed i n water 600 f ee t (183 m ) d t . 2 ~ . opera t ion covering s e v e r a l months but the r e s u l t s accomplished exceeded the i n i t i a 1 expec ta t ions and t h e evidence obtained from t h e wreckage f i rmly e s t a b l i s h e d ttie cause of t h e acc ident .

Experience i n r ecen t yea r s h a s demonstr:ited,

This n e c e s s i t a t e d an expensive

There have been o ther i n s t ances of recovery of a i r c r a f t wreckage from deep



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111-2-5 - P a r t III.- ‘The I n v e s t i g a t i o n .

water over a r e l a t i v e l y s h o r t p e r i o d of t i m e w i th t h e equipment which i s now a v a i l a b l e . The c i rcumstances and l o c a t i o n of a n a c c i d e n t w i l l de te rmine whether sa lvage of t h e wreckage i s p r a c t i c a b l e . I n most c a s e s wreckage can be recovered i f i t i s cons ïdered t h a t t h e ev idence i t could p rov ide would j u s t i f y t h e expense and e f f o r t involved. I f t h e i n v e s t i g a t o r is convinced t h a t t h e key t o t h e cause of t h e a c c i d e n t l i e s i n submerged wreckage, o r t h e wreckage is l i k e l y t o c o n t a i n ev idence s i g n i f i c a n t t o a i r s a f e t y , he must provide t h e impetus needed t o e n s u r e t h a t e f f e c t i v e a c t i o n is promptly under taken t o b r i n g t h e ev idence t o t h e l i g h t of dav.

2.5.2 Determina t ion of t h e l o c a t i o n of t h e wreckage

To t h i s end, as soon as i t h a s been determined t h a t t h e wreckage is i n t h e water, s t r e n u o u s e f f o r t s must be made t o have t h e b e s t t e c h n i c a l knowledge brought t o bea r upon t h e problem. marine s a l v a g e s e r v i c e s , and a l s o wi th a c c i d e n t i n v e s t i g a t i o n a u t h o r i t i e s of o t h e r States known t o have expe r i ence i n t h i s f i e l d . I n many cases v a l u a b l e a s s i s t a n c e and adv ice can be ob ta ined from f i shermen and oceanographers whose knowledge of l o c a l c o n d i t i o n s , such as c o n f i g u r a t i o n of t h e l a k e o r sea-bed, l o c a l c u r r e n t s , is o f t e n e x t e n s i v e and e x p e r t . The f i r s t s t e p f o r t h e i n v e s t i g a t o r i n de t e rmin ing t h e l o c a t i o n of t h e wreckage is t o a s c e r t a i n as a c c u r a t e l y as p o s s i b l e t h e most p robab le p o i n t of impact and t h i s w i l l be based on wi tness r e p o r t s , s e a r c h and r e scue r e p o r t s and r a d a r c o n t a c t s . A boa t should be p o s i t i o n e d a t t h e e s t i m a t e d p o s i t i o n as a c c u r a t e l y as p o s s i b l e u s i n g any buoys p o s i t i o n e d by s e a r c h and r e scue and t h e most e f f e c t i v e n a v i g a t i o n a l f i x e s p o s s i b l e . r a r i l y t o i n s t a l l n a v i g a t i o n a l equipment of h igh accuracy . Should t h e water be sha l low simple s e a r c h methods u s i n g d i v e r s may be ve ry e f f e c t i v e . excess of 196 f e e t (60 m) t h e f o l l o w i n g s e a r c h methods should be cons idered:

Th i s would normal ly be accomplished by d i s c u s s i o n w i t h Naval A u t h o r i t i e s ,

It may be necessa ry tempo-

When t h e depth of water is in

b) underwater t e l e v i s i o n o r photography;

c ) s p e c i a l e l ec t ro -magne t i c dev ices ;

d ) manned submers ib les .

According t o t h e c i r cums tances t h e r e are advantages and d i sadvan tages of t h e s e methods and a c a r e f u l s tudy and d i s c u s s i o n wi th a p p r o p r i a t e s p e c i a l i s t s should be under taken .

2.5.3 P r e s e r v a t i o n of ev idence

When t h e wreckage h a s been l o c a t e d a c h a r t of t h e wreckage d i s t r i b u t i o n on t h e bottom of t h e l ake o r sea ( see S e c t i o n 2.3 above) should be p repa red whenever f e a s i b l e . Th i s could be achieved by d i v e r s u s i n g compasses and s l i g h t l y modi f ied surveying equipment. Every r e l e v a n t d e t a i l , such as t h e s t a t e of t h e v a r i o u s p i e c e s of wreckage, t h e i r connexion by cables o r p i p e s , t h e c u t t i n g of t h e s e connexions f o r t h e s a l v a g e o p e r a t i o n s , e t c . , should be c a r e f u l l y noted by d i v e r s , b e f o r e proceeding t o t h e l i f t i n g of t h e v a r i o u s p i e c e s of wreckage from t h e bottom. Normally t h e d i v e r s w i l l no t be exper ienced i n a i r c r a f t acc iden t i n v e s t i g a t i o n , t h e r e f o r e e x t e n s i v e d e t a i l e d b r i e f i n g w i l l be necessary .

When t h e v a r i o u s p i e c e s a r e brought up t o t h e s u r f a c e , t h e i n v e s t i g a t o r should proceed t o a b r i e f examinat ion of each of them, j u s t below t h e water s u r f a c e , and n o t e any r e l e v a n t i n fo rma t ion and subsequent d e t e r i o r a t i o n which would normally occur when heavy p i e c e s are l i f t e d ou t of t h e water, lowered on t h e s h i p deck and t r anssh ipped .



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>lanuci L of A i r c r a f t Acridcnt I n v e s t i g a t i o n --- III- 2- G -- 2 .5 .4 Prese rva t ion of t he wreckage

The p rese rva t ion of t h e wreckage taken from sea water r e q u i r e s prompt and

Magnesium components r e a c t q u i t e v i o l e n t l y and u n l e s s recovered b i t h i n t h e f i r s t e f f i c i e n t a c t i o n . ab ly . f e w days they may be completely d i s so lved . s a l t water, but as wi th most o the r me ta l s , co r ros ion w i l l cont inue when t h e component is taken from t h e water un le s s p recau t ions a r e taken t o prevent i t .

The ra tes a t which v a r i o u s metals react wi th s a l t water vary cons ider -

Aluminium is less a f f e c t e d by immersion i n

The f i r s t p reserv ing a c t i o n taken should be t o wash thoroughly t h e component of wreckage wi th f r e s h water. wreckage immediately a s i t i s r a i s e d out of t h e sea and p r i o r t o i t be ing l o w e r e d o n t o t h e sa lvage vesse l . Fresh water washing does n o t s top a l l c o r r o s i v e a c t i o n but due t o t h e l a r g e su r face areas involved, i t may not b e p o s s i b l e t o t a k e any f u r t h e r an t i - co r ros ion ac t ion . On a l l components wi th f r a c t u r e s which may r e q u i r e m e t a l l u r g i c a l examinat ion, how e v e r , f u r t h e r e a r l y p re se rva t ion w i l l be r e q u i r e d t o p r o t e c t t h e evidence.

I n some i n s t a n c e s , i t w i l l be found convenient t o hose t h e

The a p p l i c a t i o n of a "Wates Di sp lac ing Flu id" t o those components which have been washed w i l l p rovide f u r t h e r co r ros ion p r o t e c t i o n . F r a c t u r e s u r f a c e s could then be given a coa t of any of t h e approved temporary co r ros ion p reven t ives r e g u l a r l y used i n t h e a i r c r a f t indus t ry . O i l o r i n h i b i t e d l a n o l i n e i s sugges ted a s being s u i t a b l e .

In i n s t ances where o rgan ic d e p o s i t s may r e q u i r e ana lys ing , f o r i n s t a n c e , soo deposi t ' s o r s t a i n s , o rganic p r o t e c t i v e subs t ances should no t be used. Fresh water washing should b e employed followed by thorough a i r dryi-:. When the component i s completely d ry it should be sea l ed i n a p l a s t i c bag con ta in ing an i n e r t d e s i c c a n t such as s i l i c a - g e l . Thc s i l i c a - g e l should p re fe rab ly be conta ined i r i c l o t h b a g s . S tocks of dehydrated s i l i c a - g e l must, however, be s t o r e d i n an a i r - t i g h t con ta ine r .

Ce r t a in components, such as cockp i t vo ice r e c o r d e r s , shou ld not be d r i e d b u t should be kept i n f r e s h water u n t i l t he a s s igned s p e c i a l i s t can assume r e p o n s i b i l i t y .

2.5.5 Precaut ionary measures

I n a r ranging t h e sa lvage of wreckage from t h e sea due cons ide ra t ion must be given t o s a f e t y precaut ions . t y r e s and p res su re v e s s e l s as e a r l y as p o s s i b l e i n t h e sa lvage programme. wheel assembl ies , p a r t i c u l a r l y where magnesium i s involved , can ve ry r a p i d l y p rogres s u n t i they a r e p o t e n t i a l "bombs" wi th l e t h a l c a p a b i l i t i e s . discharged as soon as t h e i r con ten t s have been eva lua ted .

I n p a r t i c u l a r , cons ide ra t ion should be g iven t o d e f l a t i n g Corrosion of

Other p r e s s u r e v e s s e l s choc Id be



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111-2 -7 - -.- - . _- P a r t III.- The Investigation

GENERAL AERIAL VIEW ALONG THE APPROACH FLIGHT PATH

Note the approach l ight ing system crossing the valley and the impact swath of the a i rc ra f t t o the r igh t of the inner'end of the approach l igh ts .



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111-2-8 Manual of A i r c r a f t Accident Inves t iga t ion

AERIAL PHOTOGRAPH: GENERAL VIEW OF THE ACCIDENT S I T E



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Par t III.- The Inves t iga t ion I I I- 2-9

INITIAL TREE CONTACT AREA

Note cuts i n the treetops indicat ing angle of f l i g h t path.



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111-2- 10 M a n u a l of A i r c r a f t A c c i d e n t I nvec t jgac ion

LEFT PROPELLER I ,

I N I T I A L GROUND IMPACT ON THE SLOPE BELOW THE AERODROME BOUNDARY



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I I I- 2- 11 Part 111.- The Inves t iga t ion -.

RIGHT PROPELLER CYLINDER GROUP 1 RIGHT ENGINE



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111-2-12 Manual of A i rc ra f t Accident -- Inves t iga t ion



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I I I- 2-13 2_ - Part III.- The Investigation

N

WRECKAGE DISTRIBUTION POLAR DIAGRAM



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I II- 2- 14 Hanual of A i r c r a f t A c c i d e n t Inves t iga t ion

WRECKAGE D I S T R I B U T I O N DIAGRAM



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I II- 2- 1 5 -- -- -- - P a r t III.- The I n v e s t i g a t i o n

1 O 1

L

2 I

SCALE

1

3 U

5 6 7 8 9

10 11 12 13 lu 15 16 17 18

19

40. DESCRIPTION

20 PORT YIMG. L.E. 2 1 PORT RUDDER. CENTRE PIECE 22 STbRBOARD UGINE NACELLE

Mo. DESCRIPTION EMCINE, STARBOARD OUTER ENGINE. PORT WTER 6

FUSELAGE, PORT TIP b PROPELLER

ELEVATOR F A I R I N G S T ~ ~ ~ O A R O ELEVATOR SERVO 23 PORT FIN-BASE

STARBOARD YIMG TIP PORT RUDDER. UPPER PIECE STARBOARD WING TIP PIECE

LUGGAGE O I MGHY

WRECKAGE TRAIL



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THE FLIGHT PATH OF THE AIRCRAFT HAS BEEN DEDUCED FROM SCARS ON TREES (1 and 2), MARKS ON THE GROUND ( 4 ) AND THE FINAL SWATH I N THE TREES I N THE FOREGROUND



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I I I- 2-17 -. Part III.- The Investigation



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EVIDENCE OF VERY STEEP APPROACH ANGLE

Note h m the a i rc ra f t is ent i re ly surrounded by t a l l trees .



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P a r t 111.- The Investigation I I I- 2-19-

EVIDENCE OF SLOW FORWARD SPEED (STALLIîJG)

FIRST MARKS OF I m m WITH THE GROUND



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III- 2-20 Manual of A i r c r a f t Accident Inves t iga t ion

-

SIGNIFICANT MARKS

Following the discovery of brickwork marks on a propel ler blade, a scale model of the house struck was constructed and the a t t i t u d e and a l t i t u d e

of the a i r c r a f t a t the time of impact was established.



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111-2-21 --_ P a r t 11T.- The Investigation I_____ ____--

1YPTCAL SEMI-AQUAPLANING MARK ON T I R E



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PART I I I

CHAPTER 3. - OPERATIONS INVESTIGATION



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I I I- 3- 1 - -- .- Part III.- The I n v e s t i g a t i o n

CHAPTER 3

OPERATIONS INVESTIGATION

3 . 1 Genera l

The Opera t ions I n v e s t i g a t i o n is concerned wi th the i n v e s t i g a t i o n and r e p o r t - i ng of a l l t h e f a c t s r e l a t i n g t o t h e h i s t o r y of t h e f l i g h t and t o t h e a c t i v i t y of t h e f l i g h t crew b e f o r e , d u r i n g , and a f t e r t h e f l i g h t i n which t h e a c c i d e n t occur red .

The major areas involved i n t h e Opera t ions I n v e s t i g a t i o n are a s fo l lows:

C r e w H i s t o r i e s

F l i g h t P lanning

Weight and Balance

Weather

A i r T r a f f i c S e r v i c e s

Communications

Naviga t ion

Aerodrome F a c i l i t i e s

A i r c r a f t Performance

Compliance wi th I n s t r u c t i o n s (Opera t ions Manual, NOTAMs, etc.)

Witnesses ' S t a t emen t s

F i n a l F l i g h t Pa th Determina t ion

Sequence of F l i g h t

There is a c l o s e l i n k between t h e work i n t h e Opera t ions I n v e s t i g a t i o n and t h a t i n o t h e r i n v e s t i g a t i o n areas - f o r i n s t a n c e t h e f l i g h t pa th of an a i r c r a f t as recons t ruc t ed from a i r t r a f f i c c o n t r o l i n fo rma t ion and wi tnesses ' s t a t e m e n t s should be compared wi th t h e f l i g h t p a t h d e r i v e d from t h e f l i g h t record ing . Such c o r r o b o r a t i o n , when- eve r p o s s i b l e , c o n s t i t u t e s one of t h e p r i n c i p l e s of a p rope r ly executed i n v e s t i g a t i o n , namely, c ross -checking t h e v a l i d i t y of i n fo rma t ion from one source a g a i n s t i n fo rma t ion on t h e same s u b j e c t de r ived from a d i f f e r e n t source . F l i g h t tests i n connexion wi th some of t h e major areas l i s t e d above, e.g. f l i g h t p a t h , performance, hand l ing c h a r a c t e r i s t i c s , are o f t e n of c o n s i d e r a b l e v a l u e t o c l a r i f y o r conf i rm some p o i n t s of d e t a i l n o t on ly i n rela- t i o n t o matters of d i r e c t concern t o t h e Opera t ions Group bu t matters i n t e r r e l a t e d wi th s t r u c t u r a l l oad ing , o p e r a t i o n of sys tems, eng ines , etc.

3 .2 C r e w H i s t o r i e s

A s tudy of a l l t h e f a c t s p e r t a i n i n g t o t h e crew forms an impor tan t p a r t of both t h e Opera t ions and Human F a c t o r s i n v e s t i g a t i o n s . Because t h e s e two a s p e c t s are c l o s e l y r e l a t e d a h igh degree of Co-ordination i n t h e c o l l e c t i o n and e v a l u a t i o n of t h e r e l e v a n t f a c t s is r e q u i r e d t o a c h i e v e t h e b e s t p o s s i b l e use of t h e in fo rma t ion c o l l e c t e d .



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on duty: fo l lowing informat ion should be ob ta ined i n r e s p e c t of each crew member

duty performed on board (pilot-in-command, Co-pilot , nav iga to r , f l i g h t eng inee r , pu r se r , steward, e t c . ) ;

name, surname, age;

g e n e r a l record of a v i a t i o n c a r e e r ( i n i t i a l and subsequent t r a i n i n g , s p e c i a l i z e d t r a i n i n g , cour ses fo l lowed, employers and sequence of d u t i e s c a r r i e d ou t , cond i t ions under which v a r i o u s l i c e n c e s and r a t i n g s were ob ta ined , v a l i d i t y of l i c e n c e s h e l d , ea r l ie r a c c i d e n t s o r i n c i d e n t s and causes t h e r e o f ) ;

medical h i s t o r y ( r ecen t i l l n e s s o r i n t e r r u p t i o n of f l i g h t a c t i v i t y , last medical examination, i n v e s t i g a t i o n of f a t i g u e f a c t o r i nc lud ing an assessment of duty time and rest t i m e w i t h i n t h e month preceding t h e a c c i d e n t and p a r t i c u l a r l y w i t h i n t h e l as t week and l a s t 48 hours ) ;

o v e r a l l exper ience and exper ience on a i r c r a f t t ype involved i n a c c i d e n t (examination of f l i g h t log-books, t o t a l f l y i n g times (day and n i g h t , ins t ruments i f r e l e v a n t - t o t a l , w i t h i n l as t month, last week and l a s t 48 hours ) , type of ground t r a i n i n g ( f l i g h t s i m u l a t o r e t c . ) and f l i g h t t r a i n i n g , las t p ro f i c i ency checks and ground and f l i g h t checks i n c l u d i n g knowledge of emergency procedures , emergency evacuat ion d r i l l , e v a l u a t i o n by ,monitors , f l i g h t c o n t r o l l e r s o r o p e r a t o r s ) ;

exper ience on t h e r o u t e o r on t h e aerodrome where t h e a c c i d e n t occur red ( i n p a r t i c u l a r t h e s tudy of t h e r a t i n g f o r t h e r o u t e , f a m i l i a r i t y w i t h t h e r o u t e , IMC o r VMC cond i t ions encountered p rev ious ly , number of landings o r take-Offs, p r a c t i c a l knowledge of procedures) .

I n order t o ga the r t h i s in format ion t h e i n v e s t i g a t o r may have t o o b t a i n many s t a t emen t s (poss ib ly from o t h e r f l i g h t crew members who have flown wi th t h e person conce rned) , and make use i n p a r t i c u l a r of t h e r eco rd ings of communications exchanged du r ing earlier f l i g h t s , as w e l l as readout of f l i g h t d a t a recorded on board dur ing preceding f l i g h t s t ages . The e x t e n t t o which any of t h e above in fo rma t ion is r e q u i r e d w i l l depend on t h e p a r t i c u l a r n a t u r e of t h e acc iden t under i n v e s t i g a t i o n .

3.2.2 Act iv i ty before , du r inn and a f t e r t h e a c c i d e n t

The e v a l u a t i o n of t h e crew members a c t i v i t i e s is n o t s o l e l y of i n t e r e s t t o t hose concerned wi th t h e Opera t ions I n v e s t i g a t i o n ; i n many i n s t a n c e s such an e v a l u a t i o n is ve ry r e l e v a n t t o t h e Human Fac to r s and Evacuation, Search, Rescue and F i r e prevent ion i n v e s t i g a t i o n s a l so .



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111-3-3 Par t III.; T h e I n v e s t i g a t i o n --

a ) Before t h e Accident

The i n v e s t i g a t o r should examine s p e c i f i c a l l y :

i )

i i )

i i i )

a c t i v i t i e s w i t h i n t h e 24 o r 48 hours p r i o r t o t h e acc iden t with p a r t i c u l a r r e f e r e n c e t o psycho log ica l f a c t o r s t h a t might have a bear ing on t h e performance of t h e crew members, t h e i r p h y s i c a l c o n d i t i o n i n r e l a t i o n t o t h e work/ res t c y c l e and meal i r r e g u l a r i t y , p a r t i c u l a r l y i f t h e r e had been a s u b s t a n t i a l change of l ong i tude on a r e c e n t f l i g h t and an assessment of t h e i r s l e e p c r e d i t be fo re depa r tu re .

c i rcumstances and d i s t a n c e involved i n t h e journey t o t h e a i r p o r t be fo re commencing crew d u t i e s and each crew member's a c t i v i t y i n p r e p a r a t i o n f o r t h e f l i g h t , (computat ion of a i r c r a f t weight and ba lance , f u e l l oad , nav iga t ion f l i g h t p l a n , weather b r i e f i n g s , pre-f l i g h t checks, etc. )

t h e a c t i v i t i e s and watch keeping schedu le , i f any, i n f l i g h t . Th i s i n fo rma t ion is u s u a l l y obtafned from statements of s u r v i v i n g crew members and/or r eco rd ings o r statements r ega rd ing a i r l g r o u n d communications.

During t h e Accident

I n t h e l i g h t of t h e informat ion ob ta ined above, t h e i n v e s t i g a t o r should endeavour t o r e c o n s t r u c t t h e r o l e and behaviour of each of t h e c r e w mep i - b e r s du r ing t h e s e q u e n t i a l phases of t h e a c c i d e n t i t s e l f .

It is a l s o impor tan t t o examine, i n con junc t ion wi th t h e Human Fac to r s Group, t h e c o n t r i b u t i o n made by such f a c t o r s as t h e cockp i t l ayou t , t y p e s of c o n t r o l l e v e r s swi tches , etc. S i m i l a r c o n s i d e r a t i o n s need t o be kept i n mind f o r review of t h e c r a s h i n j u r y and /o r s u r v i v a b i l i t y a s p e c t s.

A f t e r t h e Accident

Obviously t h e r o l e of t h e i n v e s t i g a t o r and t h e informat ion u s e f u l f o r t h e conduct of t h e i n v e s t i g a t i o n a r e not l i m i t e d t o t h e h i s t o r y of t h e f l i g h t and of t h e acc iden t . The fo l lowing p o i n t s should a l s o be con- s i d e r e d :

i ) a c t i v i t i e s of t h e c r e w immediately fo l lowing t h e acc iden t (phys i ca l c o n d i t i o n immediately a f t e r impact , c o n d i t i o n s under which t h e crew evacuated from t h e a i r c r a f t , p a r t i c i p a t i o n of crew members i n t h e evacua t ion of passengers and o r g a n i z a t i o n of rescue , e t c . )

ii) subsequent a c t i v i t i e s (medical examinat ions and checks a l r eady c a r r i e d out o r planned, ground and f l i g h t competency tests, v a r i o u s t e s t i m o n i e s ) .



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3 . 3 F l i g h t P lanning

For many ope ra t ions , a f l i g h t p l an i s prepared and f i l e d wi th a i r t r a f f i c c o n t r o l agencies . w i l l r e q u i r e d e t a i l e d examination. Addit i o n a l l y , i n t h e case of comrnercj-al o p e r a t i o n s , t h e f l i g h t crew u s u a l l y e s t a b l i s h wi th t h e a s s i s t a n c e of f l i g h t ope ra t ions o f f i c e r s a d e t a i l e d t e c h n i c a l f l i g h t p l an o r nav iga t ion log t h a t can be used t o advantage by t h e i n v e s t i g a t o r . of acc iden t s involv ing nav iga t iona l f a c t o r s o r f u e l consumption ques t ions i t w i l l be necessary t o check t e c h n i c a l f l i g h t p l ans and nav iga t ion logs and ensure t h a t t h e g r a p h i c a l o r t abu la t ed d a t a (or computer programme) from which they were der ived were r e l e v a n t t o t h e p a r t i c u l a r c i rcumstances of t h e intended f l i g h t , such as weather , a i r c r a f t type and model, c r u i s i n g he igh t , etc.

This w i l l provide the i n v e s t i g a t o r w i th c e r t a i n s p e c i f i c d a t a which

A copy of t h i s document is usua l ly r e t a i n e d by t h e opera tor . I n t h e case

Although t h e ques t ion r a r e l y arises i n connexion wi th commercial f l i g h t s ope ra t ing a planned s e r v i c e , it w i l l o f t e n be u s e f u l , e s p e c i a l l y i n t h e case of l i g h t a i r - c r a f t f l i g h t s opera ted on demand and t r a i n i n g f l i g h t s , t o endeavour t o a s c e r t a i n what were t h e crew's i n t e n t i o n s r ega rd ing t h e f l i g h t and t h e v a r i o u s manoeuvres planned.

3 . 4 Weight and Balance

A weight and balance shee t based on t h e planned f l i g h t and weather c o n d i t i o n s may have been prepared. General ly , commercial f l i g h t s use a s t anda rd form f o r t h e s e cal- c u l a t i o n s but t h i s is r a r e l y t h e case i n r e s p e c t of l i g h t a i rc raf t (see Appendix 8) . The

r econs t ruc t it - when a form i s not a v a i l a b l e t h e i n v e s t i g a t o r w i l l have t o use documenta- t i o n provided by t h e manufacturer:

. i n v e s t i g a t o r must take t h e fo l lowing i n t o account and produce and check t h i s form o r

a) most r ecen t weighing of t h e a i r c r a f t ;

b) f u e l and o i l c a r r i e d (check r e f u e l l i n g , t es t imony of f u e l pump o p e r a t o r s , f u e l o rde r s , ear l ier f l i g h t s - t a k e samples f o r a n a l y s i s i n con junc t ion wi th power p l a n t i n v e s t i g a t i o n ) ;

c ) crew and passengers c a r r i e d (check mani fes t , t i c k e t s i s sued , customs o r immigration documentation, s t a t emen t s of w i t n e s s e s t o embarkation, persons embarked o r disembarked a t ear l ie r s t o p s , assessment of s t a n d a r d weights o r a s c e r t a i n a c t u a l weights ) ;

d) cargo and loading (check man i fe s t s , customs, m a i l and forwarding a g e n t ' s documentation, baggage taken over from o t h e r f l i g h t s , weight of packages salvaged, s ta tements from persons wi tnes s ing o r performing loading a t t h e las t a i r p o r t of landing and a t preceding a i r p o r t s , d i s t r i b u t i o n among t h e va r ious baggage compartments, etc.)

Weight and balance a t t h e t i m e of t h e a c c i d e n t w i l l be deduced from t h e above bas i c information according t o t h e circumstances of t h e f l i g h t and from t h e d i s t r i b u t i o n and weight of cargo as determined from the wreckage examinat ion , t oge the r w i t h t h e l o c a t i o n and weight of passengers and crew as determined from t h e wreckage examinat ion ( inc lud ing pa tho log ica l examinat ion where necessary) .

The s e t t i n g i n t h e cockpi t and t h e p o s i t i o n of t h e v a r i a b l e t a i l p l a n e i n c i - dence, o r t h e t r i m t a b s , i f app ropr i a t e , should be checked a g a i n s t t h e s e t t i n g and p o s i t i o n appropr i a t e t o t h e ca l cu la t ed weight and ba lance of t h e a i r c r a f t a t t h e moment of t h e a c c i d e n t ,



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3.5 Weather

A n a c c i d e n t i n v e s t i g a t i o n i n which weather i s an important f a c t o r w i l l b e n e f i t from t h e format ion of a s e p a r a t e Group which inc ludes a q u a l i f i e d (and non- involved) me teo ro log i s t . Whether o r n o t t h i s cour se is taken t h e fo l lowing matters w i l l normally need t o be i n v e s t i g a t e d .

3.5.1 Observa t ions

The a c t u a l weather c o n d i t i o n s p r e v a i l i n g a t t h e t i m e and p l a c e of t h e accident and, i f p e r t i n e n t , a long t h e r o u t e may be de r ived from a v a r i e t y of d a t a such as:

hour ly and s p e c i a l a v i a t i o n weather r e p o r t s

weather r a d a r r e p o r t s

a i r c r a f t weather r e p o r t s (AIREPs)

s u r f a c e weather obse rva t ions , l ogs and r e c o r d s

p r e c i p i t a t i o n r e c o r d s

barograph r e c o r d s

wind r e c o r d s ( g r a p h i c a l )

s y n o p t i c c h a r t s

upper a i r c h a r t s of p r e s s u r e , wind and tempera ture

Rawinsonde o b s e r v a t i o n s

upper wind r e p o r t s

ce i lome te r r e c o r d s

RVR r e c o r d s

t e l eau tog raph r e c o r d s ( e l e c t r o w r i t e r ,

s a t e l l i t e c loud p i c t u r e s

e l e s c r i b e r , e

c o n d i t i o n s of n a t u r a l l i g h t (day, t w i l i g h t , n i g h t , moonlight , e t c . )

s u n r i s e , s u n s e t

r eco rd ings , e.g. VOLMET b roadcas t s where a v a i l a b l e .

I n a d d i t i o n v a l u a b l e informat ion may o f t e n be de r ived from l o c a l me teo ro log ica l s t a t i o n obse rva t ions , eyewi tness o r from o t h e r a i r c r a f t i n f l i g h t , w i tnes ses ' s t a t emen t s and examinat ion of t h e wreckage ( h a i l damage, i c e accumulat ion, e t c . )

The s e l e c t i o n of o b s e r v a t i o n a l d a t a t o be c o l l e c t e d and reviewed w i l l be dependent upon t h e c i rcumstances of t h e a c c i d e n t be ing i n v e s t i g a t e d . I t is most d e s i r a b l e t h a t t h e i n v e s t i g a t o r examine t h e o r i g i n a l r a t h e r t han cop ie s of t h e recorded obse rva t iona l da t a .

In some S t a t e s Aeronau t i ca l Meteoro logica l Personnel are r equ i r ed t o make s p e c i a l weather o b s e r v a t i o n s whenever they are aware t h a t a n a c c i d e n t i s l i k e l y t o occur o r has occurred u n t h e aerodrome o r i n i t s immediate v i c i n i t y . " Tl ie i n v e s t i g a t o r should pay p a r t i c u l a r a t t e n t i o n t o such s p e c i a l o b s e r v a t i o n s when a v a i l a b ì e .

*Note: I t is d e s i r a b l e t h a t such s t a n d i n g arrangements b e made i n a n t i c i p a t i o n of an a c c i d e n t o c c u r r i n g .



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3.5.2 Forecas t s

The f o r e c a s t s of weather cond i t ions p e r t i n e n t t o the acc ident should be documented. Dependent upon the na tu re of t h e occurrence , some o r a l l of t he fo l lowing types of f o r e c a s t s may r e q u i r e review:

a ) area o r r o u t e

b) t e rmina l (TAFS and amended TAFS)

c ) upper wind and tempera ture

d ) s i g n i f i c a n t weather (SIGMET in format ion)

e ) landing f o r e c a s t s

I n connexion with s i g n i f i c a n t weather f o r e c a s t s , s p e c i a l a t t e n t i o n should be pa id t o any SIGMET information messages ( informat ion on t h e occurrence o r expected occurrence of s p e c i f i e d hazardous weather phenomena) which may have been i ssued and which would have been a p p l i c a b l e t o any p a r t of t h e f l i g h t .

3.5.3 Br i e f ing and f l i g h t documentation

A copy of any weather documentation cover ing t h e f l i g h t should be ob ta ined f o r s tudy. P a r t i c u l a r a t t e n t i o n should be pa id t o a l l me teo ro log ica l in format ion t h a t w a s reques ted by and/or provided t o t h e f l i g h t crew i n t h e p r e f l i g h t p r e p a r a t i o n and d u r i n g t h e f l i g h t .

Statements should be obta ined from personnel who supp l i ed weather in format ion t o t h e crew both p r i o r t o depar ture and wh i l e en-route. Emphasis should be placed upon determining whether t h e crew w a s adequately informed regard ing hazardous weather cond i t ions .

3.5.4 Post f l i g h t a n a l y s i s

An assessment should be made by a q u a l i f i e d (and non-involved) me teo ro log i s t of t h e weather cond i t ions throughout t h e f l i g h t r e s u l t i n g from an a n a l y s i s of a l l t h e meteoro logica l in format ion brought t o l i g h t i n the i n v e s t i g a t i o n . Ca re fu l c o n s i d e r a t i o n should be given t o t h e p o s s i b i l i t y t h a t hazardous phenomena may have been p resen t which were no t r e a d i l y apparent from t h e f o r e c a s t s and obse rva t ions a v a i l a b l e a t t h e r e l e v a n t t i m e , p a r t i c u l a r l y i n t h e case of en-route a c c i d e n t s involv ing s t r u c t u r a l f a i l u r e . phenomena might inc lude mountain wave e f f e c t s , r evo lv ing s torms , s eve re turbulence , f r e e z i n g r a i n , etc.

Such

3.5.5 Adequacy of s e r v i c e

The observing, f o r e c a s t i n g and b r i e f i n g f a c i l i t i e s involved and t h e s e r v i c e s provided should be examined with a view t o de te rmining whether:

a ) p e r t i n e n t r e g u l a t i o n s and procedures were s a t i s f a c t o r y and were adhered t o ;

b)

c )

d i s p a r i t i e s e x i s ted be tween workload and manpower;

f o r e c a s t s and b r i e f i n g s made e f f e c t i v e use of a l l known and r e l e v a n t in format ion; and



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d ) communication of in format ion t o t h e r e l e v a n t a e r o n a u t i c a l pe r sonne l was accomplished wi thou t de lay and i n accordance w i t h p r e s c r i b e d procedures.

3 . 6 A i r T r a f f i c S e r v i c e s

It may be d e s i r a b l e because of t h e c i rcumstances of t h e a c c i d e n t t o form a sepa ra t e Group which i n c l u d e s an exper ienced (and non-involved) A i r T r a f f i c Se rv ices O f f i c e r amongst i t s members t o i n v e s t i g a t e a l l a s p e c t s of A i r T r a f f i c S e r v i c e s i n r e l a t i o n t o t h e a c c i d e n t . o t h e r r e l a t e d areas such as Communications, Aerodrome F a c i l i t i e s and Naviga t ion ( i n so f a r as t h e l a t t e r is concerned wi th ground equipment) w i t h i n t h e sphe re of i n v e s t i g a t i o n conducted by t h i s Group.

I f t h i s a c t i o n is fo l lowed it may be convenient and p r a c t i c a b l e t o inc lude

A i r T r a f f i c S e r v i c e is by d e f i n i t i o n a service provided f o r t h e purpose of preven t ing c o l l i s i o n s between a i r c r a f t , p reven t ing c o l l i s i o n s between a i r c r a f t and obs t ruc- t i o n s on t h e manoeuvring area, f o r e x p e d i t i n g and ma in ta in ing a n o r d e r l y f low of a i r t r a f f i c , f o r p r o v i d i n g in fo rma t ion u s e f u l f o r t h e safe and e f f i c i e n t conduct of f l i g h t s and f o r n o t i f y i n g a p p r o p r i a t e o r g a n i z a t i o n s of a i r c r a f t i n need of s e a r c h and r e s c u e a i d .

The A i r T r a f f i c S e r v i c e s i n v e s t i g a t i o n should e s t a b l i s h , r e c o r d and v e r i f y t h e accuracy of a l l in fo rma t ion r e l e v a n t t o i t s a c t i v i t y i n r e l a t i o n t o t h e f l i g h t . can inc lude t h e fo l lowing :

This

Re levan t A I P ’ s

NOTAMS A.I.S. 1 A e r o n a u t i c a l In fo rma t ion C i r c u l a r s

F l i g h t P l an

F l i g h t P l a n Message

Depar ture Message

Aerodrome C o n t r o l P rogres s S t r i p s

Area C o n t r o l P r o g r e s s S t r i p s

F l i g h t In fo rma t ion S e r v i c e S t r i p s

Approach Con t ro l P rogres s S t r i p s

R I T T r a n s c r i p t s ( s e e Communication i n S e c t i o n 3 . 7 below)

R a d a r Recordings ( s e e Navigation i n Sec t ion 3.8 below)

The p r o g r e s s of t h e f l i g h t should be t r a c e d f r m t h e p l ann ing s t a g e , through t h e v a r i o u s f u n c t i o n s e x e r c i s e d by the Air Triffic Cerv ices , e . g . ground movement c o n t r o l , depa r tu re c o n t r c l , a r e a (o r a i r r o i i t r ) c o n t r o l , approach c o n t r 5 l a-rd aerodrone c o n t r o l , up t o the s t a g e a t which the acc iden t occuï red .

i t may be necessary t o i n v e s t i g a t e t h e e f f i c i e n c y arid e f f e c t i v e n e s s of t h e A i r T r a f f i c S e r v i c e , p a r t i c u t a r ! y i n an acc iden t i nvo lv ing mid-air c J l l i s i o n o r c o l l i - s i o n on t h e manoeuvring a r e a . examined :

I n t h i s even t t h e Ccllnt;iiig a s p e c t s should be c l o s e l y

a ) s i t i n g of and v i s i b i l i t y from t h e Con t ro l Tower;

b ) adequacy of accommodation of a s s o c i a t e d ATS U n i t s ;



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c ) ATS personnel , i nc lud ing appropr i a t e number, q u a l i f i c a t i o n s ( l i c e n c e s ) and supe rv i s ion of personnel ;

d ) work and rest schedules of ATS personnel ;

e) adequacy of s p e c i f i e d procedures;

f ) adequacy of equipment inc lud ing r a d a r s .

Determination of t h e p r e c i s e t i m e of t h e acc iden t i s important. It is l i k e l y t h a t t h e f i r s t i n d i c a t i o n of t h e approximate t i m e of t h e a c c i d e n t w i l l be obta ined from t h e A i r T r a f f i c Se rv ice Un i t s i n communication wi th t h e f l i g h t . When t h e t r a n s c r i p t s of t h e rad io te lephony communication r eco rd ings become a v a i l a b l e i t i s u s u a l l y p o s s i b l e t o e s t a b l i s h wi th in about one minute t h e time of t h e acc iden t . Sometimes g r e a t e r accuracy i s poss ib l e . munications i t w i l l probably be p o s s i b l e t o narrow down t h e a c c i d e n t t i m e t o w i t h i n one o r two seconds. I f , f o r t u i t o u s l y , t h e r eco rd ings of a seismograph, l oca t ed s u f f i c i e n t l y c l o s e t o t h e acc iden t s i te t o d e t e c t t h e impact, a r e a v a i l a b l e t h e t i m e of t h e a c c i d e n t can be e s t a b l i s h e d wi th g r e a t accuracy. Every e f f o r t should be made t o determine as p r e c i s e l y as p o s s i b l e t h e t i m e of an acc iden t i n order t o be a b l e t o make use of in format ion d e r i v e d from t h e synchroniza t ion of t h e f l i g h t r eco rde r s w i th t h e t i m e b a s e of t h e r ad io t e l ephony record ing .

I f t h e a i r c r a f t was f i t t e d with a vo ice r eco rde r which a l s o r eco rds r a d i o com-

3.7 Communications

Communications with A i r T r a f f i c Se rv ices (and t h e s e may va ry wi th t h e c h a r a c t e r i s t i c s of t h e s e c t o r e n t e r e d by a i r c r a f t ) are e i t h e r recorded o r r e p o r t e d i n l i s t e n i n g logs by t h e s e r v i c e s concerned. However, t h e i n v e s t i g a t o r must not over look t h e p o s s i b i l i t y of ob ta in ing furthercomrminicationsevidence from o t h e r sou rces such as t h e air- c r a f t cockpi t v o i c e r e c o r d e r , o the r a i r c r a f t whether on t h e ground or i n f l i g h t and/or o t h e r ground s t a t i o n s l i s t e n i n g on t h e same f r e q u e n c y ( i e s ) . Furthermore, when a p p r o p r i a t e , communications on the o p e r a t o r ' s communication network should a l s o be i n v e s t i g a t e d .

Magnetic tape r eco rde r s a r e a v a i l a b l e a t most of t h e wor ld ' s a i r p o r t s and ATS cen t r e s . Recordings may cover not only air-ground r a d i o communications, but a l s o r a d i o and land l i n e communications between t h e v a r i o u s ground s e r v i c e s o r s t a t i o n s ( t r a n s f e r of c o n t r o l , exchanges between tower and MET O f f i c e , f i r e - f i g h t i n g v e h i c l e s , e t c . ) . The t a p e r eco rde r s may be e i t h e r "voice-controlled" (economical on t a p e which r u n s only du r ing message t ransmiss ion , but chronology may i n some cases be somewhat d i f f i c u l t and opening s y l l a b l e s may be obscured) o r "continuous" (heavy on t ape which runs even between messages, bu t chronology can be e a s i l y e s t a b l i s h e d wi th a simple t imep iece ) . mu l t i - t r ack models a l low f o r t h e inpu t of time s i g n a l s i n any of a number of forms (hook-up wi th a t a l k i n g c lock provided as an accessory t o t h e r eco rd ing machine o r f o r o t h e r purposes: code or p l a i n language s i g n a l s ) . datum a s the record ings on t h e d i f f e r e n t t r a c k s a r e n a t u r a l l y synchronized. r e g u l a t i o n s governing t h e p r e s e r v a t i o n of such r eco rd ings vary somewhat, t h e minimum pe r iod being i n t h e order of 30 days. as e a r l y a s p o s s i b l e i n t h e i n v e s t i g a t i o n - p r e f e r a b l y by pre-planning procedures t o cove r t h e p o s s i b i l i t y of an acc iden t - t h a t a l l r eco rd ings l i k e l y t o be a s s o c i a t e d wi th t h e f l i g h t are removed from t h e normal day-to-day system and p l aced i n safe-keeping pending h i s i n s t r u c t i o n s . be performed under t h e supe rv i s ion of a member of t h e i n v e s t i g a t i n g team. s e c u r i t y , t hese comments a l s o apply t o a l l documents a s s o c i a t e d wi th t h e f l i g h t . )

With e i t h e r k ind , s imul taneous

This provides an exac t ch rono log ica l r e f e r e n c e Na t iona l

It i s d e s i r a b l e , however, f o r t h e i n v e s t i g a t o r t o ensu re

I t i s a l s o d e s i r a b l e t h a t t h e t r a n s c r i p t of t h e r e l e v a n t r eco rd ings should ( I n r e s p e c t of



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111-3-9 P a r t 111.- The I n v e s t i g a t i o n - Where such r eco rd ings e x i s t , they r e p r e s e n t a ve ry impor tan t sou rce of

in format ion f o r t h e i n v e s t i g a t o r . The read-outs are as a r u l e f a i r l y easy bu t c a l l f o r c e r t a i n e s s e n t i a1 p r e c a u t i o n s :

a ) extreme c a r e must be e x e r c i s e d i n handl ing and s t o r i n g ' m a s t e r t a p e s ( t h e r i s k o f . d e t e r i o r a t i o n o r o b l i t e r a t i o n must always be borne i n mind) ;

b) a w i s e p r e c a u t i o n i s t o make, wherever p o s s i b l e , one o r more cop ie s of t h e master t a p e and and t o use t h e s e cop ie s f o r most of t h e p laybacks when i t i s no t e s s e n t i a l t o u s e t h e o r i g i n a l r e c o r d i n g ;

c ) i n r e c o n s t r u c t i n g t h e t iming f o r a l l documentation, t h e same r e f e r e n c e datum must n a t u r a l l y be used throughout , and t h e i n v e s t i g a t o r w i l l t he re - f o r e be r e s p o n s i b l e f o r f i x i n g t h e datum p o i n t and e s t a b l i s h i n g any d i f f e r e n c e s between times quoted o r used i n t h e r e c o r d i n g s from v a r i o u s sour ces ;

d) it w i l l be necessa ry t o synchronize t h e r a d i o telecommunication r eco rd ing t i m e datum wi th t h a t on t h e f l i g h t d a t a and v o i c e r e c o r d e r s from t h e a i r c r a f t .

The t r a n s c r i p t s of t h e r e a d o u t s are l i k e l y t o be used by many pe r sons who have no t l i s t e n e d t o t h e t a p e s which,moreover,may come from v a r i o u s a i r t r a f f i c s e r v i c e u n i t s ; c e r t a i n s p e c i f i c d a t a should t h e r e f o r e be provided wi th each t r a n s c r i p t and a uniform p r e s e n t a t i o n should be adopted:

a ) an i n t r o d u c t o r y page should i n d i c a t e t h e u n i t t h a t made t h e r eco rd ing , t h e f requency o r f r e q u e n c i e s r eco rded , t h e p e r i o d covered by t h e t r a n s c r i p t , reason f o r making t h a t t r a n s c r i p t , pe r sons r e s p o n s i b l e f o r i t and where and when i t was made (poss ib ly t h e l o c a t i o n of t h e master t a p e s ) ;

b) each suc.ceeding page may c o n t a i n a t least t h e fo l lowing columns;

t i m e i n d i c a t i o n s

send ing s t a t i o n s

r e c e i v i n g s t a t i o n s

material which w a s read-out wi thout d i f f i c u l t y

d o u b t f u l o r u n i n t e l l i g i b l e material

remarks of t h e p e r s o n ( s ) r e s p o n s i b l e f o r t h e t r a n s c r i p t .

For ease of r e f e r e n c e , t h e i n v e s t i g a t o r may f i n d i t u s e f u l t o u n d e r l i n e i n t h e t e x t of t h e message t h e word o r words spoken a t t h e moment of each t ime s i g n a l .

An example of t h e form used i n some S t a t e s f o r t h e t r a n s c r i p t of land l i n e telephony and r ad io t e l ephony communication r e c o r d i n g s is given at Appendix 14.



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I II- 3- Ir? Manual of Ai rc ra f t Accident Inves t iga t ion --

NORMAL PHOTOGRAPH OF SOILED DOCUMENT

INFRA-RED PHOTOGRAPH OF SOILED DOCUMENT

Infra-red photography o f soi led document found i n the wreckage revealed wri t ing,



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3.8 Navigat ion

Where r e l e v a n t t h e n a v i g a t i o n a l a s p e c t s of an i n v e s t i g a t i o n are t h e concern of t h e Opera t ions i n v e s t i g a t i o n (or t h e A i r T r a f f i c S e r v i c e s i n v e s t i g a t i o n i f a p p r o p r i a t e ) . The n a v i g a t i o n a l equipment c a r r i e d i n t h e a i r c r a f t should be checked a g a i n s t t h e a i r c r a f t r eco rds and t h e remains of t h e n a v i g a t i o n a l equipment recovered from t h e wreckage. r a d i o n a v i g a t i o n ground fac i l i t i es may r ange from medium frequency NDB's t o DECCA, VOR DME, ILS o r r a d a r equipment.

The

The fo l lowing f e a t u r e s should be cons idered i n r e s p e c t of each ground r a d i o f a c ' i l i t y examined:

Locat i o n (geographic co-ordinates)

i d e n t i f i c a t i o n s i g n a i

Power ou tpu t and supply

Emergency equipment - warning sys tem(s) - r eco rd ing of mal func t ion

Rad ia t ion p a t t e r n

Opera t ing and maintenance schedules , and t h e i r n o t i f i c a t i o n (AIP, NOTAMs)

Normal l e v e l of performance

ï n t e r f e r e n c e ( s )

P a s t compla in ts (crew, o p e r a t i o n , e t c . )

S ta tements from crew(s) who used t h e s e a i d s around t h e t i m e of t h e a c c i d e n t

Phraseology and language used i n communications ( d i f f i c u l t i e s i n unders tanding r e s u l t i n g from i t )

Procedures .



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I 11-3- 1 2 Manual of A i r c r a f t Accident Inves t iga t ion

PAPER RECOVERED FROM WRECKAGE

This paper, recovered from the ureckage of an a ircra f t which "undershot" the runway indicated tha t the approach procedure used was incorrect.

3.8.1 Ground and F l i g h t Check

When t h e r e i s any reason t o suspect t h a t a navigat ion a i d may be involved i n t h e causa l area, t h e inves t iga to r ' should reques t , without delay, s p e c i a l ground and f l i g h t checks. being used, o r i f t h e r e is any p o s s i b i l i t y they were being used, by the a i r c r a f t involved i n t h e accident a t t h e t i m e of t h e accident.

Standard checks should be performed on navigat ional a i d s a t a l l t i m e s i f they w e r e

I n addi t ion t o reviewing the r e s u l t of s p e c i a l ground and i n - f l i g h t checks, t h e i n v e s t i g a t o r should study t h e r e s u l t s of normal rout ine checks ( s i t e evaluat ion, com- missioning and recent per iodic checks).

At ten t ion should be drawn t o t he value of these checks i n regard t o poss ib le d i f fe rences betweenthe s ta te of t h e equipment used a t t he t i m e of t he accident and t h e s ta te of t h e equipment a t t h e t i m e of ground o r in - f l igh t check.

3.8.2 Radar image recording

P P I images c o n s t i t u t e v i t a l information f o r recons t ruc t ing t h e progress of a f l i g h t . For example, one system c o n s i s t s i n time-elapsed f i lming spots represent ing moving a i r c r a f t on PPI screens a t ATC a r e a c o n t r o l c e n t r e s and a t major a i r p o r t s .

Various systems have been developed by c e r t a i n States f o r recording this. ,data. (one frame per sweep) of f h e

Each frame bears t h e da te and t i m e (possibly a se r ia l number) and t h e main



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111-343 _-- I-

P n ï t III.- The Inves t iga t ion --_--_I_-

repor t ing p o i n t s o r p o i n t s of Signif icance i n t h e sec tor covered, together with d is tance markings and s p o t s represent ing the a i r c r a f t .

A system has been developed f o r pro jec t ing the r e s u l t i n g f i lms a t any desired speed, frame stopping, and making st i l l photographs. l e a s t a nionth and developed only i n t h e event of an accident o r incident .

These f i lms are re ta ined f o r a t

EXAMPLE OF A SEQUENCE OF RADAR IEAGE RECORDING



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-- i II-3-i4 I-- Manual of A i r c r a f t Accident Inves t iga t ion

EXAMPLE OF A SEQUENCE OF RADAR IMAGE RECORDING (contd)



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Part III.- The Investigation 111-3-15 -

RECONSTRUCTION OF THE FLIGHT PATH FROM THE RADAR IMAGE RECORDING APPEARING ON PREVIOUS TWO PAGES



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111-3-16 ?lanual of A i r c r a f t Accident Inves t iga t io i i

3.8.3 Maps and c h a r t s

It may be necessary t o e s t a b l i s h what maps and c h a r t s were provided f o r

T h i s might a l s o inc lude an a n a l y s i s of where

The l i m i t a t i o n s a s s o c i a t e d wi th maps of

n a v i g a t i o n a l purposes and t o examine t h e i r adequacy and accuracy i n r e l a t i o n t o t h e navi- g a t i o n a l e f f o r t involved i n t h e f l i g h t . t h e c h a r t s d i f f e r i n any important r e s p e c t from t h e "Standards" i n Annex 4 , s i n c e "uniformity" i s b a s i c t o i n t e l l i g e n t c h a r t use. a p a r t i c u l a r i z e d n a t u r e , e.g. those s p e c i a l l y produced f o r use wi th automatic r a d i o navi- g a t i o n a l dev ices , should be c r i t i c a l l y examined. It may a l s o be p e r t i n e n t t o examine t h e f u n c t i o n a l i n t e r r e l a t i o n s h i p of t h e va r ious c h a r t s designed f o r d i f f e r e n t phases of t h e ope ra t ion , where i t is evident t h a t some d i s o r i e n t a t i o n may have taken place. It may a l s o be r e l e v a n t t o cons ider t h e a b i l i t y of f l i g h t crews t o handle t h e maps and c h a r t s provided i n t h e confined environment of t h e i r ope ra t ing p o s i t i o n s and whether adequate l i g h t i n g w a s a v a i l a b l e f o r t h e i r i l l umina t ion .

As a p p r o p r i a t e t o t h e phase of o p e r a t i o n i n which t h e acc iden t occur red the i n v e s t i g a t o r should check such as:

P l o t t i n g c h a r t s

Radio nav iga t ion c h a r t s

Terminal area c h a r t s

Instrument approach c h a r t s

Aeronaut ica l c h a r t s ( t opograph ica l )

V i sua l approaeh c h a r t s

Landing c h a r t s

Aerodrome c h a r t s

Aeronau t i ca l nav iga t ion charts

3.9 Aerodrome F a c i l i t i e s

A s c i rcumstances d i c t a t e , t h e i n v e s t i g a t o r may have t o examine and v e r i f y t h e s t a t u s of many aerodrome f a c i l i t i e s used by o r a v a i l a b l e t o t h e a i r c r a f t involved i n t h e acc iden t . Amongst t h e i t e m s t h a t may need t o be checked are t h e fo l lowing:

a ) Runway i n use - dimensions ( l e n g t h and wid th) of runways, stopways, clearways (see Annex 14)

l o c a t i o n of t h re sho ld a t t h e t i m e of t h e a c c i d e n t

runway marking

shou lde r s (width and c o n s t r u c t i o n )

e l e v a t i o n (s)

slopes

type of su r f ace

cond i t ion of s u r f a c e (dry, w e t , ice, snow, s l u s h , e t c . )

runway b e a r i n g s t r e n g t h

a i r c r a f t a r r e s t i n g system

o b s t r u c t i o n s

work i n p rogres s (NOTAM a p p l i c a b l e )



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P a r t III.- The I n v e s t i g a t i o n I II- 3-17

b) Apron and Taxiways - bea r ing s t r e n g t h

- dimensional adequacy

- marking

- o b s t r u c t i o n s

- snow o r s l u s h c l e a r a n c e - - work i n p rogres s (NOTAM a p p l i c a b l e )

type of s u r f a c e and s u r f a c e q u a l i t i e s

c ) L i g h t i n g - - VASIS (check al ignment) -

approach ( t y p e r dimensions, c o l o u r * i n t e n s i t y )

runway edge, t h r e s h o l d , and end (co lour , i n t e n s i t y )

- runway c e n t r e l i n e ( c o l o u r , i n t e n s i t y )

- runway touchdown zone - - aerodrome beacon

- o b s t r u c t i o n

taxiway ( c e n t r e l i n e , edge, s t o p b a r , e t c . )

d ) Emergency and Rescue S e r v i c e s - Fire-f i g h t i n g s e r v i c e - equipment

- p e r s o n n e l

- t r a i n i n g

e ) Documentation

- Rescue s e r v i c e

- A I P

- equipment

- p e r s o n n e l

- t r a i n i n g

- NOTAM

- Aerodrome Obs t ruc t ioneChar t (ICA0 Type A)

- adequacy of d i s semina t ion of p e r t i n e n t i n fo rma t ion

f ) Aerodrome Genera l - Compliance wi th s p e c i f i c a t i o n s of Annex 14

An example of a form used i n some S t a t e s f o r r e p o r t i n g t h e aerodrome s t a t u s a t t h e t i m e of t h e a c c i d e n t i s given a t Appendix 1 4 .



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- 111-3-18 Manual of A i r c r a f t Accident I n v e s t i g a t i o n

3.10 A i r c r a f t Perf ormance

3.10.1 F l i g h t Manual

The b a s i c source of in format ion concerning a i r c r a f t performance i s t h e F l i g h t Manual, t h e p r o v i s i o n of which i s a requirement as a Standard i n Annex 8. Whi ls t i n most cases t h i s in format ion w i l l prove t o be adequate f o r normal i n v e s t i g a t i o n purposes i t may be necessa ry , i n c e r t a i n cases , t o examine t h e d a t a from which F l i g h t Manual performance i s determined i n order t o e s t a b l i s h i ts v a l i d i t y t o t h e p a r t i c u l a r c i rcumstances of t h e acc iden t f l i g h t . I n t h a t event a d e t a i l e d r e s e a r c h i n t o t h e r eco rds of t h e appro- p r i a t e a i rwor th iness a u t h o r i t y and t h e a i r c r a f t manufacturer may be necessary . Manual is d iv ided i n t o de f ined s e c t i o n s as follows:

The F l i g h t

Sec t ion 1 - General

Sec t ion 2 - L i m i t a t

-

ons -

Sec t ion 3 - Emergency Procedures -

Sec t ion 4 - Normal Procedures -

amendment r eco rds , g e n e r a l arrangement drawing, o t h e r dimensional d a t a , r e g ist r a t ion , p a r t i c u l a r s , convers i o n t a b l e s l g r a p h s , d e f i n i t i o n s .

con ta ins l i m i t a t i o n s of we igh t s , f u e l loading , f l o o r loading , c e n t r e of g r a v i t y , atmospheric c o n d i t i o n s (ambient a i r p r e s s u r e and t empera tu re ) , powerplant ope ra t ion , a i r speed and Mach number, crosswind (maximum v a l u e and d i r e c t i o n ) manoeuvres, minimum crew, maximum number of occupants , e l e c t r i c a l system and a u t o p i l o t l i m i t a t i ons , e t c .

con ta ins e s s e n t i a l o p e r a t i n g procedures f o r emergency cond i t ions which are f o r e s e e a b l e but unusual and demand immediate and p r e c i s e a c t i o n .

i nc ludes procedures a p p r o p r i a t e i n t h e event of m a l - f unc t ion ing t h a t are not con ta ined i n Sec t ion 3 and should normally inc lude t h e fo l lowing items:

powerplants (engines and p r o p e l l e r s )

f u e l s system

engine l u b r i c a t i o n system

f i r e e x t i n g u i s h e r sys tem

elec tr ica 1 systems

h y d r a u l i c systems

pneumatic systems

i c e p r o t e c t i o n systems

f l i g h t d i r e c t i o n systems

f l y i n g c o n t r o l system

automat ic p i l o t

procedure f o r s e v e r e tu rbu lence

p r e s s u r i z a t i o n system and a i r cond i t ion ing

oxygen system

Procedures which are accep ted as be ing p a r t of b a s i c airmanship w i l l riot normally be included.



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I II- 3- 19 -- P a r t III.- The I n v e s t i g a t i o n

S e c t i o n 5 - Performance - c o n t a i n s q u a n t i t a t i v e d a t a r e l a t i n g t o a i r c r a f t performance and which is normally p r e s e n t e d i n sub-sec t ions i n t h e fo l lowing order :

Genera l

Take-off procedures and speeds

Take-off WAT cu rves

Take-off climb g rad . i en t s

Take-off f i e l d l e n g t h s

N e t take-off f l i g h t pa th d a t a

En-route d a t a

Lad ing procedures and speeds

Landing WAT curves

Landing climb g r a d i e n t s

Landing f i e l d l e n g t h s

A d d i t i o n a l s p e c i a l performance d a t a

3.10.2 Mathematical a n a l y s i s

When a l l t h e in fo rma t ion p e r t i n e n t t o t h e performance of t h e a i r c r a f t h a s been e s t a b l i s h e d a mathemat ica l a n a l y s i s of t h e t h e o r e t i c a l performance of t h e a i r c r a f t should be made. Such an a n a l y s i s e a r l y i n t h e i n v e s t i g a t i o n may assist t h e i n v e s t i g a t o r t o de te rmine areas f o r s p e c i f i c examinat ion , f o r example, when f l i g h t r e c o r d e r in format ion o r w i tnes s in fo rma t ion i n d i c a t e s a wide d ivergence from t h e t h e o r e t i c a l performance. A s t h e i n v e s t i g a t i o n proceeds i t may be d e s i r a b l e t o produce f u r t h e r mathemat ica l ana lyses i n c o r p o r a t i n g a l l t h e ev idence from t h e v a r i o u s sources . Th i s s t u d y may range from d i r e c t i n t e r p r e t a t i o n of t h e d a t a pub l i shed i n t h e F l i g h t Manual t o s o p h i s t i c a t e d a n a l y s i s by aerodynamis ts u s i n g computerized in fo rma t ion de r ived from t h e i n v e s t i g a t i o n and t h e manufac turers of t h e a i r c r a f t and t h e powerplant.

When c a l c u l a t i n g p re l imina ry f l i g h t p a t h s t h e " t o t a l energy p lo t " , i.e. t h e v a r i a t i o n wi th t i m e ( o r d i s t a n c e , as a p p r o p r i a t e ) of t h e sum of k i n e t i c energy and p o t e n t i a l energy of t h e a i r c r a f t , may be used wi th advantage. This is based on a s i m p l i f i e d " t o t a l energy theory". However, i t s d i r e c t a p p l i c a t i o n should be examined w i t h care, depending on t h e p a r t i c u l a r s of t h e case under i n v e s t i g a t i o n . and powerplant c h a r a c t e r i s t i c s of t h e a i r c r a f t is e s s e n t i a l when t h e " t o t a l energy theory" is app l i ed t o o t h e r t han e lementary problems.

Knowledge of t h e b a s i c aerodynamic

3.10.3 Performance and hand l ing c h a r a c t e r i s t i c s

F l i g h t tests a r e u s e f u l when cons ide r ing t h e performance and hand l ing charac- t e r i s t i c s of t h e type of a i r c r a f t involved i n t h e a c c i d e n t . For example, f l i g h t r e c o r d e r d a t a , when a v a i l a b l e , and /o r w i t n e s s evidence can be used t o deve lop an envelope of p o s s i b l e



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111-3-20 Elanual of A i rc ra f t Accident I n v e s t i g a t i o n -

a i r c r a f t con f igu ra t ions ; i .e. t h e va r ious combinat ions of t h r u s t , f l a p , l anding gea r , s p o i l e r s e t t i n g s and p i l o t i n g techniques t h a t are c o n s i s t e n t w i t h t h e f l i g h t r eco rde r t race a t chosen t i m e po in t s . A c o l l a t i o n of t h e i n d i v i d u a l combinat ions w i l l o f t e n i n d i c a t e a p a r t i c u l a r set of combinations which bes t f i t t he f l i g h t r eco rde r d a t a and o t h e r known o p e r a t i o n a l information. developed on t h e b a s i s of recorder and/or o the r o p e r a t i o n a l in format ion , f l i g h t tests can be employed t o check on t h e performance and handl ing c h a r a c t e r i s t i c s a s soc ia t ed w i t h f l i g h t p r o f i l e s contained wi th in t h a t envelope.

Once the envelope of p o s s i b l e a i r c r a f t conf igu ' ra t ion has been

I n a d d i t i o n t o gene ra l f l i g h t c h a r a c t e r i s t i c s , s p e c i f i c a s p e c t s such as s u s c e p t i b i l i t y t o f l u t t e r , approach s t a b i l i t y , l o n g i t u d i n a l c o n t r o l , s t a l l and engine response c h a r a c t e r i s t i c s may be documented as t h e needs of t h e v a r i o u s Groups i n t h e i n v e s t i g a - t i o n may d i c t a t e .

3.10.4 Wind tunne l tests

The use of wind tunne l s and dynamic scale models h a s played an important r o l e i n many acc iden t i n v e s t i g a t i o n s . In p a r t i c u l a r , wind t u n n e l s have been used e f f e c t i v e l y f o r t h e d e t a i l e d examination of performance and s t r u c t u r a l q u e s t i o n s i n connexion w i t h acc iden t i n v e s t i g a t i o n s . This technique h a s made i t p o s s i b l e t o s o l v e va r ious problems which o therwise might have been v i r t u a l l y inso luble .

I n t h e cons t ruc t ion of dynamic models, one must determine which are t h e most important i n t e r a c t i o n s i n regard t o t h e phenomenon of concern and ensu re t h a t t h e r e l e v a n t parameters are r ep resen ta t ive . The s i z e o r scale of t h e model i s cont ingent i n l a r g e p a r t upon t h e s i z e of t h e t e s t f a c i l i t y , ease and c o s t of c o n s t r u c t i o n and model d e t a i l r e q u i r e d . When a d e c i s i o n i s made t o b u i l d a model, t h e main purpose of t h e model should be c l e a r l y de f ined a s w e l l as a n understanding of what s c a l i n g must be accomplished t o achieve t h i s purpose. However, t h e r e i s t h e ever-present danger t h a t i f t o o much unders tanding is presumed t h e model may be ove r s impl i f i ed and d i s t o r t e d so t h a t f a l s e answers are b u i l t i n t o i t .

When one b u i l d s a model i n t h e i n t e r e s t of o b t a i n i n g informat ion f o r a s p e c i f i c problem, i t f r equen t ly occurs t h a t o t h e r unexpected and b e n e f i c i a l r e s u l t s are obtained: a s p e c t s which can be pursued by o t h e r a u t h o r i t i e s wi th a view t o improving t h e e f f i c i e n c y and/or s a f e t y of a i r c r a f t opera t ions .

3.11 Compliance wi th I n s t r u c t i o n s

these r e s u l t s may have some d i r e c t bea r ing on t h e a c c i d e n t , o r they may be

Whilst i t is not t he func t ion of an a i r c r a f t a c c i d e n t i n v e s t i g a t o r t o become involved i n t h e d i s c i p l i n a r y a s p e c t s of t h e enforcement of r e g u l a t i o n s and i n s t r u c t i o n s i t i s a necessary p a r t of t h e o p e r a t i o n a l i n v e s t i g a t i o n t o e s t a b l i s h whether t h e a p p l i c a b l e d i r e c t i v e s were complied with. i n t h e l i g h t of t h e acc iden t , they were proper and adequate f o r ensu r ing s a f e t y of opera- t i o n s , and whether they were presented i n a format e a s i l y understood. I n examining t h e s e matters i t i s important t o d i s t i n g u i s h between what ma te r i a l h a s mandatory e f f e c t and what i s advisory.

The d i r e c t i v e s should a l s o be examined t o e s t a b l i s h whether ,

The d i r e c t i v e s may have many d i f f e r e n t forms inc lud ing t h e fol lowing:

Nat i o n a l l e g i s l a t i o n

ICAO Annexes

ICAO Procedures f o r A i r Naviga t iona l Se rv ices



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P a r t 111.- The I n v e s t i g a t i o n 111-3-21

Opera t ions Manual

F l i g h t Manual

NOTAMs

A e r o n a u t i c a l In fo rma t ion P u b l i c a t i o n s (AIP)

Opera to r s i n s t r u c t i o n s t o f l i g h t crew

In f onnat i o n C i r c u l a r s

A i r c r a f t Manufac turers ' n o t i c e s

Ai rwor th iness d i r e c t i v e s

3.12 Witness S ta tements

The i n v e s t i g a t o r should b e a r i n mind t h a t he is o b l i g e d t o comply w i t h t h e l a w s of t h e S t a t e i n which t h e a c c i d e n t occur red and t h a t i n some S t a t e s it may be t h e r e s p o n s i b i l i t y of t h e p o l i c e t o t a k e w i t n e s s e s ' s t a t emen t s .

It may be d e s i r a b l e because of t h e c i rcumstances of t h e a c c i d e n t t o form a Witness Statement Group f o r l o c a t i n g w i t n e s s e s and c o l l e c t i n g t h e i r s t a t emen t s . I f such a group is formed i t normally conce rns i t s e l f w i th t h e t a k i n g of s t a t e m e n t s from "eye wi tnesses" l o c a t e d i n t h e v i c i n i t y of t h e a c c i d e n t : t h e t a k i n g of s t a t e m e n t s a p p r o p r i a t e t o o t h e r groups, e.g. S t r u c t u r e s , Opera t ions , e t c . , i s g e n e r a l l y performed by an i n v e s t i - g a t o r w i t h i n t h a t group.

C o l l e c t i n g ev idence from w i t n e s s e s i s one of t h e i n v e s t i g a t o r ' s main t a s k s ; in format ion t h u s ob ta ined can , i f f a c t , f u r n i s h a l ead as i t goes hand i n hand wi th t h e m a t e r i a l ev idence unear thed i n examinat ion of t h e s i t e and t h e wreckage, and can complement i t or c l a r i f y i t . The i n v e s t i g a t o r must not,however, over look human f a l l i b i l i t y , and he must e x e r c i s e g r e a t c a u t i o n when a n a l y s i n g s t a t emen t s t h a t obv ious ly c o n f l i c t w i t h estab- l i s h e d material ev idence .

A phi losophy of i n t e r v i e w r a t h e r t h a n i n t e r r o g a t i o n is d e s i r a b l e i n t h e ques t ion ing of w i t n e s s e s by t h e i n v e s t i g a t o r : f r o n t e d wi th t h e need f o r a i r s a f e t y and acc iden t p reven t ion , is encouraged t o t e l l h i s s t o r y f r e e l y wi thou t i n t e r r u p t i o n o r i n t i m i d a t i o n , he w i l l normally w i l l i n g l y n a r r a t e h i s obse rva t ions .

when a w i t n e s s is p laced a t ease, is con-

. ,The need f o r e x p e r t i n t e r p r e t a t i o n should no t be underes t imated whenever t h e i n v e s t i g a t o r i n t e r v i e w s a w i t n e s s and t h e mother tongue i s n o t common t o both persons: t h e s t anda rd of communication may be s a t i s f a c t o r y f o r s o c i a l c o n v e r s a t i o n bu t s l i g h t i n t o n a t i o n s i n t h e w i t n e s s ' s ev idence o r d e t a i l which may have t e c h n i c a l s i g n i f i c a n c e can e a s i l y be l o s t because of i nadequa te t r a n s l a t i o n by t h e w i t n e s s , t h e i n v e s t i g a t o r , o r o the r t han an e x p e r t i n t e r p r e t e r .

W r i t t e n statements shou ld be ob ta ined from a l l p e r s o n n e l who were involved i n t h e p r o v i s i o n of a i r t r a f f i c s e r v i c e s o r f l i g h t s e r v i c e f o r t h e a i r c r a f t involved i n t h e a c c i d e n t as w e l l as from t h o s e peop le r e s p o n s i b l e f o r t h e o p e r a t i o n and maintenance of n a v i g a t i o n a l a i d s used by t h e a i r c r a f t . E f f o r t s t o l o c a t e w i t n e s s e s should never be con- f i n e d s o l e l y t o t h e phase immediately p reced ing t h e , a c c i d e n t but should cover a l l matters inc lud ing n o t on ly t h e c o n d i t i o n of t h e a i r c r a f t , but a l s o human f a c t o r s . t h a t might throw l i g h t upon one s i n g l e p o i n t i n t h e i n v e s t i g a t i o n can be impor tan t ; t h e

Any s t a t emen t



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i n v e s t i g a t o r should no t conf ine himself t o l o c a t i n g wi tnes ses i n t h e immediate v i c i n i t y of t h e acc iden t s i t e but should seek s t a t emen t s r e l e v a n t t o t h e whole pa th of t h e f l i g h t , as w e l l a s from f l i g h t crew and passengers (and where a p p r o p r i a t e t h e i r f a m i l i e s ) , t h e o p e r a t o r , t h e manufacturer, r e s p o n s i b l e s e r v i c e s and o the r sources. I n some c a s e s t h e use of power- f u l mass media such as t h e p r e s s , r a d i o and t e l e v i s i o n w i l l assist i n o b t a i n i n g statements supplementing those a l r e a d y vo lun tee red by persons coming forward o r con tac t ed by l o c a l a u t h o r i t i e s .

Depending on t h e type of s ta tement t o be c o l l e c t e d ( in fo rma t ion on r e f u e l l i n g o r d e s c r i p t i o n of t h e apparent sequence of i n - f l i g h t d i s i n t e g r a t i o n ) o r t h e q u a l i t y of w i tnes s being in te rv iewed (gar ru lous , imagina t ive , shocked, r e l u c t a n t ) t h e statement may have t o be taken under very v a r i e d cond i t ions , which t h e i n v e s t i g a t o r must eva l - uate. While t h e purpose of t h e i n v e s t i g a t i o n should be exp la ined , i t is not normally d e s i r a b l e for s t a t e m e n t s t o be t aken i n an i n t e r r o g a t o r y form.

The f a c i l i t i e s a t t h e i n v e s t i g a t o r ' s d i s p o s a l may be anyth ing from a s imple notebook, typing, s t enograph ic o r s tenotype a s s i s t a n c e , t o p o r t a b l e o r s t anda rd r eco rd ing equipment. w e l l as a p p r o p r i a t e i n s t rumen t s and equipment f o r s tudying maps, c h a r t s and photographs. The use of an a i r c r a f t model may o f t e n be adv i sab le .

S u i t a b l e o f f i c e accommodation o r proper t r a n s p o r t a t i o n may be necessa ry , as

I n connexion wi th t h e de te rmina t ion of a p robab le f l i g h t p a t h , f l i g h t t e s t s commonly r e f e r r e d t o as "fly-bys" a r e o f t e n employed f o r t h e purpose of r e f i n i n g and cor- r e l a t i n g wi tnes s observa t ions . t h e acc iden t can be flown on a s e l e c t i o n of f l i g h t p a t h s wh i l e ground w i t n e s s e s , accompanied by i n v e s t i g a t o r y personnel , observe. The wi tnes ses are t h e n asked t o compare t h e s e f l i g h t pa ths wi th t h e i r memory of t h e one flown by t h e a i r c r a f t involved i n t h e acc iden t . Valuable informat ion concerniog probable a l t i t u d e , (or h e i g h t , a s a p p l i c a b l e ) , course and a t t i t u d e can o f t e n be der ived by t h i s means. h e l i c o p t e r t o determine t h e f l i g h t path: t h i s method is u s e f u l where a wi tnes s can relate t h e p o s i t i o n of t h e h e l i c o p t e r t o a f i x e d o b j e c t on t h e ground. A series of such observa- t i o n s w i l l enable a p l o t t o be made which w i l l a c c u r a t e l y r e f l e c t t h e f l i g h t path. Whenever p o s s i b l e two-way r a d i o communications between t h e i n v e s t i g a t o r and t h e a i r c r a f t making t h e "fly-bys" i s d e s i r a b l e .

For example, an a i r c r a f t similar t o t h e one involved i n

I n some a c c i d e n t s i t may be an advantage t o use a

The fo l lowing g e n e r a l p r i n c i p l e s should be borne i n mind:

a ) S ta tements should be taken as soon as p o s s i b l e a f t e r t h e a c c i d e n t ; they can always be ampl i f ied l a t e r i f necessa ry , but f i r s t s t a t e m e n t s are u s u a l l y t h e most accu ra t e ( even t s a r e s t i l l f r e s h i n t h e memory and i n t e r p r e t i v e p rocesses have less time t o work).

It is always ve ry u s e f u l t o hear w i t n e s s e s a t t h e p l a c e where they happened t o be a t t h e t i m e of t h e acc iden t . Th i s can be v e r y h e l p f u l , n o t on ly f o r a c l e a r e r unders tanding of t h e s ta tement bu t a l s o f o r o b t a i n i n g a d d i t i o n a l d e t a i l s ( e s p e c i a l l y i n t h e case of s t a t e m e n t s concerning t h e a i r c r a f t ' s f l i g h t pa th and t h e acc iden t ) . It i s most h e l p f u l f o r t h e , i n v e s t i g a t o r t o use a compass and clinometer t o assist i n documenting a c c u r a t e l y t h e eye-witness observa t ions .

b)

c ) I t is s t r o n g l y recommended t h a t d i s c u s s i o n s wi th w i t n e s s e s be i n i s o l a t i o n i n o rde r t o avoid in f luenc ing o t h e r w i t n e s s e s , a l s o wherever p o s s i b l e w i t n e s s e s should be encouraged t o r e f r a i n from d i s c u s s i n g t h e i r ev idence among themse lves ,be fo re i t has been taken down. J o i n t d i s c u s s i o n s can u s u a l l y be a r ranged subsequently i f r equ i r ed .



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111-3-23 - _- - Part 111.- The I n v e s t i g a t i o n

d ) No s t a t emen t should be d i sca rded ou t of hand. A s t a t emen t from a wi tness exper ienced i n a v i a t i o n is no t n e c e s s a r i l y t h e most v a l u a b l e , and t h e i n v e s t i g a t o r should n o t over look s t a t emen t s from o t h e r w i t n e s s e s who were s i m i l a r l y s i t u a t e d . A s t a t emen t from a c h i l d can be extremely u s e f u l bu t g r e a t care should be e x e r c i s e d i n c o l l e c t i n g and examining i t . N a t i o n a l laws conce rn ing t h e t a k i n g of s t a t e m e n t s from persons under a g e should be kept i n mind.

e ) D i scuss ions wi th w i t n e s s e s may t o a c e r t a i n e x t e n t be conducted i n two s t a g e s : i n t h e f i r s t s t a g e t h e i n v e s t i g a t o r should as f a r as p o s s i b l e let t h e w i t n e s s r ecoun t i n h i s own words e v e n t s as h e s a w them (without i n t e r r u p t i o n except t o keep him t o r e l e v a n t matters); i n t h e second s t a g e t h e i n v e s t i g a t o r may need t o a s k q u e s t i o n s t o clear up any d o u b t f u l p o i n t s o r raise o t h e r s (bu t t hey should never be phrased i n such a manner as t o sugges t t h e answers) .

f ) I t i s a sound p r a c t i c e f o r t h e i n v e s t i g a t o r t o be accompanied by a person who can t a k e down t h e s t a t e m e n t , t h i s l e a v e s t h e i n v e s t i g a t o r f r e e t o concen t r a t e s o l e l y on what is be ing s a i d and t h e r e f o r e t o c o n c e n t r a t e on q u e s t i o n s t o be a sked , i f any.

The fo l lowing in fo rma t ion should be recorded where r e l e v a n t :

- p e r s o n a l d a t a r e g a r d i n g w i t n e s s (surname, g iven names, addres s , t e lephone number i f any, age, occupa t ion , expe r i ence r e l e v a n t t o t h e s t a t e m e n t ) ,

- t i m e of o b s e r v a t i o n ( i f no ted , o therwise as determined i n r e l a t i o n t o o t h e r e v e n t s ) ,

- l o c a t i o n of w i t n e s s r t t i m e of o b s e r v a t i o n (p inpo in ted on a map i f n e c e s s a r y ) ,

- any th ing hea rd o r observed concern ing t h e a i r c r a f t i t s e l f and, i f r e l e v a n t ,

of f l a p s , t r i m , t a x i i n g , run-up, b rakes on s t a r t , i n i t i a t i o n of r o t a t i o n , climb a n g l e , e s t i m a t e d speed, e s t ima ted a l t i t u d e , p o i n t s overflown by t h e a i r c r a f t , headings , manoeuvres, p o s i t i o n of f l i g h t c o n t r o l s , l anding g e a r , f a l l i n g o b j e c t s , f l ames from exhaus t , f i r e o r smoke, l i g h t s i g n a l s , a n t i - c o l l i s i o n and cab in l i g h t s , l and ing l i g h t s , touchdown p o i n t , u se of b rakes , r e v e r s e t h r u s t , j e t d i v e r s i o n , t a i l parachute , any seemingly abnormal n o i s e , phenomena o r movement, e tc .

. o t h e r nearby a i r c r a f t acco rd ing t o t h e s t a g e of f l i g h t , such as: p o s i t i o n

- p o s i t i o n of t h e main and any s c a t t e r e d wreckage,

- p o s i t i o n of bod ie s ( c o n d i t i o n of seat b e l t s , e t c . ) ,

- any s k e t c h e s t h a t t h e w i t n e s s may be a b l e t o p rov ide t o i l l u s t r a t e h i s s t a t e m e n t ,

- any photographs o r f i l m s t aken ,

- r e s c u e o p e r a t i o n s ,



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- i f w i tnes s knows of o t h e r w i tnes ses , t h e i r names and addres ses ,

- s i g n a t u r e on one copy of t h e s ta tement and of any ske tches made.

The i n v e s t i g a t o r should record on t h e s ta tement t h e d a t e and p l ace where i t was taken and poss ib ly h i s own name and capac i ty .

F i n a l l y , i t should be added t h a t f o r e a s e of r e f e r e n c e , t h e assembled ev i - dence should be accompanied by a map i n d i c a t i n g t h e l o c a t i o n of each wi tnes s a t t h e t ime of t h e acc iden t and a key f o r r e f e r r i n g back t o t h e i r i n d i v i d u a l s ta tements .

3 . 1 3 F i n a l F l i g h t Path Determination

The r e c o n s t r u c t i o n of t h e las t s t a g e of t h e f l i g h t , i.e. t h e acc iden t phase , n e c e s s i t a t e s c l o s e Co-ordination between many areas of t h e i n v e s t i g a t i o n but i t is t h e primary concern of t h e Operations i n v e s t i g a t i o n . complete p i c t u r e of t h e f i n a l e v e n t s as they occurred i n proper sequence and e v a l u a t e t h e i r i n t e r r e l a t i o n s h i p . The per iod of t i m e t o be covered w i l l depend upon t h e c i rcumstances ; i n g e n e r a l terms i t should commence a t a s t a g e where t h e f l i g h t d e p a r t s from normal s a f e ope ra t ion and i t can te rmina te when t h e i n e v i t a b i l i t y of t h e a c c i d e n t i s ind i spu tab ly apparent. of a s t r u c t u r a l f a i l u r e i n c r u i s i n g is i n e v i t a b l e , s i m i l a r l y i n an unrecoverable "jet-upset" s i t u a t i o n once t h e a i r c r a f t is t o o low t o r e g a i n a normal a t t i t u d e wi thout g r o s s l y exceeding many l i m i t a t i o n s t h e a c c i d e n t is bound t o follow. I n take-off and landing a c c i d e n t s , however, t h e c ra sh impact w i l l be t h e t e rmina t ing even t and i t may be necessary t o use t h i s a s t h e s t a r t i n g p o i n t of t h e r e c o n s t r u c t i o n and work backwards f o r t h e purpose of synchroniz ing t h e v a r i o u s sou rces of in format ion which may have been e s t a b l i s h e d on a s e q u e n t i a l b a s i s by o t h e r i n v e s t i g a t i o n groups. The F l i g h t Recorder i n v e s t i g a t i o n w i l l p rovide t h e basis of t h e r e c o n s t r u c t i o n and t h e rad io te lephony record ing w i l l p rovide t h e necessary l i n k wi th r e l a t e d a c t i v i t i e s on t h e ground. f i g u r a t i o n and t h e Human Fac to r s i n v e s t i g a t i o n may add t o t h a t ev idence , i t may a l s o e s t ab - l i s h c e r t a i n important cons ide ra t ions r ega rd ing t h e cond i t ion or ope ra t ing e f f i c i e n c y of t h e f l i g h t crew. The Powerplants i n v e s t i g a t i o n should be a b l e t o i n d i c a t e t h e degree of engine power being developed a t t h e time of impact and t h e Systems i n v e s t i g a t i o n should be a b l e t o c o n t r i b u t e t o t h e a i r c r a f t c o n f i g u r a t i o n de te rmina t ion i n some d e t a i l . F i n a l l y t h e r econs t ruc t ion should be considered i n t h e environment i n d i c a t e d from an e v a l u a t i o n of a l l t h e witnesses ' s t a t emen t s and i n t h e meteoro logica l c o n d i t i o n s determined by t h e Weather inves t i g a t i on .

The i n t e n t i o n should be t o b u i l d up a

This need n o t n e c e s s a r i l y be t h e t i m e of c r a sh impact, f o r example i n t h e c a s e f l i g h t , once t h e wings have broken o f f t h e a c c i d e n t

The S t r u c t u r e s i n v e s t i g a t i o n should be a b l e t o determine t h e a i r c r a f t con-

3 . 1 4 Sequence of F l i g h t

The enumeration of t h e above informat ion (Sec t ions 3.2 t o 3.13 above) should b r ing t o l i g h t t h e i tems of importance i n t h e Opera t ions i n v e s t i g a t i o n i n r e l a t i o n t o t h e o the r areas of acc iden t i n v e s t i g a t i o n . Indeed, t h e s y n t h e s i s of a l l t h e d a t a ob ta ined by ope ra t ions i n v e s t i g a t i o n i s t h e main c o n t r i b u t i o n t o any f l . igh t r e c o n s t r u c t i o n . It may a l s o happen t h a t t h e p a r t i c u l a r c h a r a c t e r i s t i c s of t h e a c c i d e n t n e c e s s i t a t e no t on ly t l ie r econs t ruc t ion of t h e acc ident f l i g h t but o t h e r p rev ious f l i g h t s .

Although t h e i n v e s t i g a t i o n w i l l have t o devote p a r t i c u l a r a t t e n t i o n t o t h e phase i n which t h e acc iden t occurred ( see Sec t ion 3.13 above) i t w i l l u sua l ly be d e s i r a b l e t o d i s c u s s t h e development of t h e e n t i r e sequence of t h e f l i g h t . Moreover, i n many c a s e s , t h e i n v e s t i g a t o r w i l l f i n d i t advantageous t o conduct an o v e r a l l review of every major a r e a of t h e Operations i n v e s t i g a t i o n covering each p a r t of t h e f l i g h t . For example, dur ing the en-route phase, such a r e a s as t h e f l i g h t crew, a i r t r a f f i c s e r v i c e s , weather, f l i g h t pl.anning, a i r c r a f t performance and wi tnesses ' s t a t emen t s w i l l a l l f u r n i s h s p e c i f i c in format ion r e l a t e d t o t h e en-route phase which may need t o be developed depending upon t h e n a t u r e of t h e acc iden t .



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I 11-3- 2 5 --- - Par t III.- The Invest igation

CO-ORDINATED FLIGHT DATA TIME IEfORE IMPACT-Sie.

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TIME B € m E IMPACT-Sr.



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PART III

CHAPTER 4. - FLIGHT RECORDERS



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I 11-4- 1 P a r t III.- The I n v e s t i g a t i o n -- -

CHAPTER 4

FLIGHT RECORDERS

4.1 Genera l

The t e r m " F l i g h t Recorders ' ' encompasses two s e p a r a t e and d i s t i n c t t y p e s of t h e a i r b o r n e r e c o r d e r s , namely t h e F l i g h t Data Recorder and t h e Cockpit Voice Recorder:

read-outs of t h e s e two r e c o r d e r s must be synchronized t o o b t a i n t h e maximum b e n e f i t f o r a c c i d e n t i n v e s t i g a t i o n .

The F l i g h t Data Recorder , o f t e n r e f e r r e d t o as " f l i g h t r eco rde r " is a system f o r r e c o r d i n g t h e v a l u e of d e f i n e d b a s i c f l i g h t parameters i n r e l a t i o n t o a t i m e base.

The Voice Recorder i s a system f o r r e c o r d i n g c o c k p i t c r e w c o n v e r s a t i o n , intercommunications, . P u b l i c Address system (P.A.) and radio-telephony communications.

It is d e s i r a b l e t h a t t h e a c c i d e n t i n v e s t i g a t i o n a u t h o r i t i e s of each S t a t e should ma in ta in a list of t h e t y p e and l o c a t i o n of f l i g h t d a t a and v o i c e r e c o r d e r s in r e s p e c t of each o p e r a t o r and a i r c r a f t t y p e r e g i s t e r e d i n t h a t S t a t e .

4.2 F l i g h t Data Recorders

4.2 .1 General

F l i g h t d a t a r e c o r d e r s do n o t remove t h e need f o r a c c i d e n t - - ivest igat ion: t hey a r e a n o t h e r sou rce of i n fo rma t ion a v a i l a b l e t o t h e i n v e s t i g a t o r and t h e i r v a l u e i n t h e i n v e s t i g a t i o n of a i r c r a f t a c c i d e n t s is widely recognized. S p e c i f i c a t i o n s r e l a t i n g t o t h e i r c a r r i a g e on c e r t a i n types of a e r o p l a n e s are contained i n Annex 6 and s e v e r a l States r e q u i r e f l i g h t r e c o r d e r s t o be f i t t e d t o p u b l i c t r a n s p o r t ca t egory a i r c r a f t as a matter of l a w w h i l s t o t h e r S t a t e s make a d m i n i s t r a t i v e arrangements f o r t h e i r use. D e s c r i p t i o n of some approved t y p e s of f l i g h t d a t a r e c o r d e r s a t p r e s e n t i n u s e is g iven a t Appendix 3.

It should be no ted t h a t p a r a g r a p h s 4.2 .2 , 4.2.3 and 4.2.4 of t h i s chap te r r e l a t e t o t h e primary purpose of t h e f l i g h t data r e c o r d e r - namely a c c i d e n t i n v e s t i g a t i o n - and t h e p l ann ing t h a t needs t o be unde r t aken by t h e a u t h o r i t i e s r e s p o n s i b l e f o r a c c i d e n t i n v e s t i g a t i o n i n t h e s e l e c t i o n of pa rame te r s , t h e i n s t a l l a t i o n , and t h e p r o t e c t i o n of t h e r e c o r d e r , t o e n s u r e t h a t adequate and p r o p e r d a t a is a v a i l a b l e should a n a c c i d e n t occur.

4.2.2 Purpose of t h e F l i g h t Data Recorder

The primary purpose of t h e f l i g h t d a t a r e c o r d e r is t o p rov ide s u f f i c i e n t , information t o permit t h e a c c i d e n t i n v e s t i g a t o r t o r e c o n s t r u c t t h e f l i g h t p a t h of t h e a i r c r a f t i n t h r e e dimensions, t o de t e rmine t h e a t t i t u d e of t h e a i r c r a f t i n t h e recon- s t r u c t e d f l i g h t and t o a s s e s s t h e f o r c e s a c t i n g on t h e a i r c r a f t which r e s u l t e d i n t h e a i r - c r a f t ' s f l i g h t p a t h and a t t i t u d e . I f t h e r e c o r d e r h a s s u f f i c i e n t c a p a c i t y i t is d e s i r a b l e a l s o t o r e c o r d t h e f u n c t i o n i n g of s e l e c t e d systems, u n i t s , o r i n s t rumen t s i n o r d e r t o h e l p e s t a b l i s h t h e o r i g i n of t h e s e f o r c e s .



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Manual of A i r c r a f t Accident i nves t ipaci.oli _. --- 111-4-2

4.2.3 S e l e c t i o n of parameters

Determination of t h e f l i g h t p a t h of an a i r c r a f t i s achieved from t h e record-

The dynamic loading of t h e a i r c r a f t i n t h e p lane normal i n g s of t h e parameters of i n d i c a t e d a l t i t u d e , i n d i c a t e d a i r s p e e d and magnetic heading i n r e l a t i o n t o a recorded t i m e base. t o t h e a i r c r a f t ( l o c a l v e r t i c a l ) is recorded from an acce lerometer i n s t a l l e d w i t h i n t h e p e r m i s s i b l e t rave l of t h e a i r c r a f t ' s c e n t r e of g r a v i t y . t o any f l i g h t r eco rde r system in tended t o be used f o r a c c i d e n t i n v e s t i g a t i o n purposes. Experience h a s shown t h a t t h e a d d i t i o n of p i t c h and r o l l a n g l e parameters t o d e f i n e t h e a t t i t u d e of t h e a i r c r a f t can be very h e l p f u l , indeed impor tan t . of rates of p i t c h and r o l l can be used f o r the same purpose bu t datum de te rmina t ion might prove d i f f i c u l t i n some cases.) parameters has been t h e s u b j e c t of some deba te but i n g e n e r a l terms it is nex t most impor tan t t o have r eco rd ings of t h e d e f l e c t i o n ang le s of t h e primary f l i g h t c o n t r o l s u r f a c e s (e le- v a t o r s , a i l e r o n s , rudder , v a r i a b l e inc idence t a i l p l a n e , s p o i l e r s , e t c . ) , f l a p s p o s i t i o n and engine power parameters. whether they are t u r b o - j e t s , t u r b o props or p i s t o n engines and t h e c h a r a c t e r i s t i c s of t h e engines . For example, a f t e r b u r n i n g (or r e -hea t ) , two o r t h r e e spoo l t u r b o - j e t s , t u r b o f a n and r e v e r s e t h r u s t must be taken i n t o c o n s i d e r a t i o n when dec id ing e x a c t l y what q u a n t i t y is t o be measured and recorded. It w i l l probably be found t h a t a ba re minimum of at least two parameters pe r engine w i l l be e s s e n t i a l b e f o r e a s u f f i c i e n t l y a c c u r a t e assessment of engine ou tpu t can be made. For t h e purpose of aerodynamic and eng ine power c a l c u l a t i o n s i t is a l s o necessary t o record t h e s t a t i c air temperature.

These parameters are fundamental

( A l t e r n a t i v e l y r eco rd ings

The o rde r of p r i o r i t y t o be a t t a c h e d t o any a d d i t i o n a l

Engine parameters w i l l depend upon t h e n a t u r e of t h e engines ;

Parameters t o f i l l any remaining f l i g h t r e c o r d e r capac i ty should be s e l e c t e d on a b a s i s of t h e p a r t i c u l a r a i r c r a f t type and i t s systems, having r ega rd t o t h e need a l s o t o r eco rd r a d i o nav iga t ion system s i g n a l s . This can i n c l u d e passage over 75 m c / s beacons, ILS d e v i a t i o n s i g n a l s , RMI p o i n t e r p o s i t i o n s e t c . The p r o v i s i o n of an even t marker t o i n d i c a t e t h e p o s i t i o n on t h e record where t h e p i l o t h a s i n d i c a t e d an even t of i n t e r e s t occur red is an advantage.

4.2.4 I n s t a l l a t i o n and p r o t e c t i o n

Most, i f no t a l l , f l i g h t d a t a r e c o r d e r s f i t t e d f o r a c c i d e n t i n v e s t i g a t i q n purposes inc lude c ra sh and f i r e p r o t e c t i o n f o r t h e r eco rd ing cassettes but t h e c ra sh environment i s one invo lv ing extremes of i n e r t i a , compression, p e n e t r a t i o n and hea t . It may be uneconomic i n terms of weight t o guard a g a i n s t t h e s e extremes by depending upon p r o t e c t i v e cas ing of t h e r e c o r d e r a lone and it is, t h e r e f o r e , d e s i r a b l e t o use t h e h igh p r o b a b i l i t y t h a t t h e d i r e c t i o n of impact w i l l be i n t h e d i r e c t i o n of normal f l i g h t by making use of t h e a i r c r a f t s t r u c t u r e t o absorb much of t h e energy of t h e impact and t o i n s t a l l t h e r eco rde r (or r eco rd ing c a s s e t t e ) i n t h e t a i l area of t h e a i r c r a f t . A survey of many a c c i d e n t s h a s a l s o shown t h a t t h e t a i l area i s less s u s c e p t i b l e t o damage by f i r e . T h i s should n o t be taken t o extremes s ince t h e l i g h t e r s t r u c t u r e of t h e t a i l cone is some- t i m e s detached i n a c r a s h , but t h e a r e a immediately a f t of t h e t a i l p l a n e spa r i n t h e fuse- l a g e i s normally most s u i t a b l e . a i rc raf t i n which case a p o s i t i o n nea r t h e r o o t of t h e f i n h a s been found t o be a r easonab le a l t e r n a t i v e . The ques t ion of i n e r t i a has been found t o be impor tan t p a r t i c u l a r l y as t h e r eco rde r mechanism u s u a l l y invo lves a high concen t r a t i on of weight and t h e p r o t e c t i v e cas ing adds t o it. an a f t i n s t a l l a t i o n i n a c r a s h , never t o be found i n s p i t e of t h e most i n t e n s i v e search. The attachment of t h e r eco rde r t o a heavy s t r u c t u r a l component i s most d e s i r a b l e and r e q u i r e s c a r e f u l des ign i n which s t r a p s , r a t h e r than b o l t e d a t t achmen t s which might be t h e focus of stress concen t r a t ion are used.

This may n o t be p r a c t i c a b l e i n some types of three-engined

Accidents have occurred where t h e r eco rde r ( c a s s e t t e ) h a s become detached from



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II I- 4- 3 --- ----- P a r t TI1.- The I n v e s t i g a t i o n - Cons ide ra t ion should a l s o be g iven i n t h e des ign of t h e p r o t e c t i v e c a s i n g of

a r eco rde r cassette t o i t s a b i l i t y t o resist t h e p e n e t r a t i o n of a sp iked o b j e c t posses s ing high i n e r t i a . t r a t i o n s and i n g e n e r a l terms i t is p r e f e r a b l e f o r a r e c o r d e r cassette c a s i n g t o have rounded e x t e r n a l s u r f a c e s r a t h e r t han sha rp co rne r s . by inc luding a h e a t r e f l e c t i n g s u r f a c e o r h e a t i n s u l a t i n g material o r bo th , bu t s i n c e a f l i g h t r eco rd ing may remain und i s tu rbed i n t h e burnt-out wreckage of an a i r c r a f t f o r a pe r iod of s e v e r a l hour s , o r days, i t is necessa ry t h a t t h e r eco rd ing should s u r v i v e t h e subsequent h e a t soak fo l lowing exposure t o ve ry h igh tempera tures over a s h o r t e r pe r iod . 'ïhe hea t soak s u r v i v a b i l i t y requi rement may r e f l e c t upon t h e r eco rd ing medium which is used but i n t h e case of s t a i n l e s s steel media be ing used i n connexion w i t h e l e c t r o m a g n e t i c r eco rd ing i t should be borne i n mind t h a t t h e magnetic q u a l i t i e s are l o s t when t h e tempera- t u r e exceeds about 4500 cen t ig rade . P r o t e c t i o n a g a i n s t t h e e f f e c t s of prolonged submersion i n sa l t water raises problems of r e t a i n i n g t h e waterproof q u a l i t i e s of t h e r e c o r d e r cassette where t h e r e c o r d i n g medium might s u f f e r damage from exposure t o s a l t water. F i n a l l y , t h e a b i l i t y of a f l i g h t r e c o r d i n g t o resist t h e e f f e c t s of chemicals l i k e l y t o be encountered i n a i r c r a f t c r a s h e s must be t aken i n t o account. Such chemica ls i n c l u d e f i r e e x t i n g u i s h a n t s , h y d r a u l i c f l u i d s , hydro-carbon f u e l s , etc.

Outer c a s i n g s of s p h e r i c a l des ign go a long way t o d e f l e c t i n g such pene-

F i r e p r o t e c t i o n is normally achieved

4.2.5 Recording systems

There are t h r e e b a s i c t y p e s of f l i g h t d a t a r eco rd ing sys tems i n u s e a t t h e p r e s e n t t i m e , namely t h e engraved f o i l , t h e photographic , and t h e e l e c t r o m a g n e t i c t ypes .

4.2 .5 .1 ' Engraved f o i l r e c o r d i n g system

The u n i t i s mostly s e l f - c o n t a i n e d and p r o t e c t e d i n a s p h e r i c a l c o n t a i n e r : t h e r e c o r d e r comprises a s h e e t of aluminium o r steel f o i l ( o r v a r i a n t s of t h e s e m e t a l s ) which i s drawn from a supply s p o o l o v e r a p l a t t e n and f e d on t o a take-up s p o o l a t a speed p r o p o r t i o n a l t o t i m e . During passage over t h e p l a t t e n s t y l i e i t h e r i n d e n t o r engrave t h e f o i l w i th a d isp lacement from t h e edge of t h e f o i l o r from a marked datum; t h i s d i sp lacement is p r o p o r t i o n a l t o t h e v a l u e of t h e parameter t o which it is r e l a t e d . The movement of t h e s t y l i is e i t h e r e l e c t r i c a l o r mechanical and t h e s p o o l movement i s e l e c t r i c a l . Its advan- t a g e s a r e s i m p l i c i t y , no r eadou t p r o c e s s i n g necessa ry (though readout a p p a r a t u s is d e s i r a b l e ) and immediate g r a p h i c a l t ype p r e s e n t a t i o n of t h e d a t a , Amongst i t s shor tcomings i s a l a c k of f l e x i b i l i t y , a v u l n e r a b i l i t y once t h e o u t e r p r o t e c t i v e cover i s damaged and i n some t y p e s d i f f e r e n t t i m e bases f o r each parameter make i t d i f f i c u l t t o r ead . L i m i t a t i o n s can a l s o be inposed by t h e i n e r t i a e f f e c t caused by us ing mechanically ope ra t ed s t y l i . system does no t lend i t s e l f t o au tomat i c d a t a p rocess ing .

The

4.2 .5 .2 Photographic r e c o r d i n g sys t em

The photographic r e c o r d e r and t h e engraved f o i l r eco rde r are based on similar p r i n c i p l e s ; t h e main d i f f e r e n c e between t h e two i s t h a t t h e metal f o i l i s r e p l a c e d by a p h o t o s e n s i t i v e paper and t h e s t y l i by t i n y m i r r o r s which focus l i g h t from a l i g h t source on t o t h e paper . The angu la r d i sp lacement of t h e m i r r o r s i s p r o p o r t i o n a l t o t h e v a l u e of t h e paramzter be ing measured. low speed phases of t h e f l i g h t , such as take-off and landing which has t h e e f f e c t of i n c r e a s i n s t h e reading accuracy by a f a c t o r of 10 t o 15. s i m p l i c i t y , r e l i a b i l i t y and t h e a v a i l a b i l i t y of a g r a p h i c a l readout fo l lowing a s imple deve loping process . F u r t h e r , t h e i n e r t i a of t h e m i r r o r system is lower than t h a t of t h e mechanical s t y l i of t h e f o i l r e c o r d i n g system. b i l i t y t o damage by f i r e . Even i n a w e l l - p r s t e c t e d r e c o r d e r , i t i s d i f f i c u l t t o o b t a i n

Th i s sys tem has an a b i l i t y t o expand t h e t i m e scale f o r t h e

Advantages of t h e s y s t e m i n c l u d e

I t s ch ie f shortcoming l i e s i n i t s vulnera-



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I II- 4- 4 Manual of A i rc ra f t Accident h v e s t i g a t i o n

EXAMPLE OF PROPER INSTALLATION OF FLIGHT DATA RECORDER



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I I I- 4-5 _- Part 111.- The I n v e s t i g a t i o n

EXAMPLES OF PROPER INSTALLATION OF FLIGHT DATA RECORDER



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adequate h e a t soak p r o p e r t i e s ; t h photographic paper can become reduced t o a sh i n t h e even t of a n i n t e n s e f i r e and t h e subsequent h e a t soak. A lower h e a t i n t e n s i t y can have t h e e f f e c t of changing t h e chemical p r o p e r t i e s of t h e p h o t o s e n s i t i v e paper w i t h t h e r e s u l t t h a t t h e a b i l i t y t o r e a d t h e r e c o r d i n g may b e pre judiced . T h e r e f o r e , i t i s p a r t i c u l a r l y important t o l o c a t e t h i s t y p e of recorder i n a p o s i t i o n i n t h e a i r c r a f t which h a s been demonstrated t o be t h e l e a s t a f f e c t e d by h e a t . magnitude of t h e parameters be ing recorded are sometimes i n d i s t i n c t o r even l o s t because of t h e s h o r t e r t i m e of exposure t o t h e l i g h t source. F i n a l l y , as w i t h t h e f o i l system, t h e photographic method does n o t lend i t s e l f t o f u l l y a u t o m a t i c d a t a p r o c e s s i n g ; however, a semi-automatic method is p o s s i b l e . The photographic r e c o r d i n g system i s used e x t e n s i v e l y i n r e s e a r c h and development work i n a d d i t i o n t o i t s u s e as a d a t a r e c o r d e r f o r f l i g h t s a f e t y purposes , w e l l away from s t r o n g r a d i o - a c t i v e sources .

Also, r a p i d e x c u r s i o n s of more t h a n normal

It is important t o remember t h a t t h e p h o t o s e n s i t i v e paper should be kept

4 . 2 . 5 . 3 Elec t romagnet ic r e c o r d i n g system

Elec t romagnet ic r e c o r d e r s can be d iv ided broadly i n t o two types ; f requency modulated and d i g i t a l systems. The record ing media can be p l a s t i c magnetic t a p e , s t e e l t a p e o r wire. I n p r i n c i p l e e l e c t r i c a l t r a n s d u c e r s , u s u a l l y p o t e n t i o m e t e r s o r s y n c h r o n i z e r s , are used t o measure t h e parameter and t h e s i g n a l p a s s e s through a c o n d i t i o n i n g u n i t which c o n v e r t s i t i n t o t h e a p p r o p r i a t e form f o r record ing on t h e r e c o r d i n g medium. Advantages of e l e c t r o - magnetic r e c o r d i n g i n c l u d e a h i g h p r o b a b i l i t y of c r a s h , f i r e and water submersion surv iv- a b i l i t y , e s p e c i a l l y when s tee l t a p e o r w i r e i s used, an e a s e of remote ( t a i l a r e a ) i n s t a l l a t i o n on t h e a i r c r a f t f u r t h e r t o improve s u r v i v a b i l i t y wi thout having t o use lengthy P i t o t and s t a t i c l i n e s , and t h e f a c i l i t y , wi th a p p r o p r i a t e i n t e r f a c e u n i t s , t o p r o c e s s t h e data a u t o m a t i c a l l y . The main d isadvantages are h igh c o s t , compl ica t ion and t h e need f o r a complete readout f a c i l i t y i n r e s p e c t of each e l e c t r o m a g n e t i c r e c o r d i n g system. S ince t h e concept i s newer t h a n t h e two systems mentioned above, more exper ience i s necessary t o improve r e l i a b i l i t y bu t t h i s t y p e of system l e n d s i t s e l f t o a c o n s i d e r a b l e e x t e n s i o n of t h e amount of d a t a t h a t can be recorded f o r a given weight p e n a l t y and t h e numerical accuracy of each recorded v a l u e can be h igh p a r t i c u l a r l y i n t h e d i g i t a l systems. It i s p o s s i b l e t o use a cont inuous loop type of record ing wi th e l e c t r o m a g n e t i c r e c o r d e r s but t h i s p r e v e n t s t h e i n v e s t i g a t o r examining ear l ie r r e c o r d i n g s i n s imilar c i rcumstances u n l e s s t h e d u r a t i o n of t h e loop i s of substant ia1l .y g r e a t e r d u r a t i o n t h a n t h e maximum d u r a t i o n of t h e a i r c r a f t t o which i t i s f i t t e d .

4.2.6 Removal and handl ing of recorded mediums

The fo l lowing p r e c a u t i o n s must be observed i n removal and subsequent handl ing of recorded mediums. I r r e s p e c t i v e of t he type of record ing system no a t tempt should be made t o e f f e c t a read-out a t t h e acc ident s i t e ; i n s t e a d t h e r e c o r d should be shipped e x p e d i t i o u s l y t o t h e a u t h o r i z e d read-out f a c i l i t y where s u i t a b l e process ing by q u a l i f i e d personnel can t a k e p l ace .

4 .2 .6 .1 Engraved f o i l record ing system

1. No a t tempt should be made a t t h e a c c i d e n t s i t e t o e x t r a c t t h e engraved f o i l record from t h e r e c o r d e r ; t h e e n t i r e u n i t should, be packed c a r e f u l l y f o r shipment.



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III- 4- 7 _- - P a r t III.- The I n v e s t i g a t i o n

2. These p r e c a u t i o n s a r e important s i n c e extreme care must be e x e r c i s e d when removing t h e medium from t h e r e c o r d e r t o p r e v e n t w r i n k l i n g , t e a r i n g , s c r a t c h i n g o r gouging by t h e r eco rd ing s t y l i . Tea r ing and wr ink l ing cause d i s t o r t i o n which cannot be completely removed. Unwanted s t y l u s s c r a t c h i n g and gouging r e s u l t i n erroneous i n d i c a t i o n s and t e n d t o con- f u s e t h e recorded traces. used i n engraved f o i l r e c o r d i n g system.

This is e s p e c i a l l y t r u e f o r t h e aluminium f o i l

3 . I f , a t a later s t a g e , t h e medium is t o be sh ipped do n o t c u t o f f j u s t t h e p o r t i o n t o be r e a d , send t h e en t i r e f o i l . Th i s is n e c e s s a r y because of t h e p o s s i b l e need t o review p rev ious f l i g h t s on t h e f o i l f o r c a l i b r a - t i o n and /o r c o r r e c t i o n da ta . f o i l s . Tape c a u s e s w r i n k l e s which cannot be smoothed out . I n s t e a d , wrap t h e s p o o l and f o i l with paper b e f o r e u s i n g tape . p r o t e c t t h e f o i l from damage w h i l e handl ing.

D o n o t use masking t a p e o r Scotch t a p e on

T h i s w i l l a l s o

4.2 .6 .2

4 . 2 . 6 . 3

Pho t o n r a p h i c r e c o r d i n g sy 8 t e m

1. Extreme c a r e must be e x e r c i s e d when e x t r a c t i n g t h e r e c o r d e r from t h e wreckage t o e n s u r e t h a t i t s o u t e r c a s i n g is not d i s t o r t e d so t h a t it pe rmi t s l i g h t t o p e n e t r a t e and obscure t h e r eco rd .

2. I n t h o s e cases when t h e r e c o r d e r case h a s been damaged from impact f o r c e s it shou ld be covered as soon a s p o s s i b l e w i t h opaque material t o prevent f u r t h e r p e n e t r a t i o n of l i g h t .

3. N o a t t empt should be made a t t h e acc iden t s i te t o e x t r a c t t h e photographic r e c o r d from t h e r e c o r d e r ; t h e e n t i r e u n i t should be packed c a r e f u l l y f o r shipment .

Elec t romagne t i c r e c o r d i n v systems

1. It is most impor t an t t h a t mine d e t e c t o r s and s i m i l a r d e v i c e s should not be used i n any s e a r c h f o r an electro-magnet ic f l i g h t r e c o r d e r since t h i s might r e s u l t i n t h e e r a s u r e of t h e record .

2. Some t y p e s of e l ec t ro -magne t i c r e c o r d e r s , p a r t i c u l a r l y t h o s e u t i l i z i n g w i r e as t h e r e c o r d i n g medium are equipped w i t h s e p a r a b l e cassettes. It is most d e s i r a b l e t o release t h e c a s s e t t e and a l l o w t h e brake t o be a p p l i e d t o t h e w i r e t r a v e l l i n g mechanism t o p reven t w i r e breakage during shipment.

4.2.7 F l i g h t Data Recorders: read-out and a n a l y s i s

There are two c l e a r l y d e f i n e d s t a g e s which must be observed by t h e acc iden t i n v e s t i g a t o r i n u s i n g a f l i g h t d a t a r e c o r d i n g . s tage .

They are t h e read-out s t a g e and t h e a n a l y s i s

4.2.7.1 Read-out

The purpose of t h e read-out s t a g e is t o provide an a c c u r a t e r e p r e s e n t a t i o n

To do t h i s i t is necessa ry t o a p p r e c i a t e t h e c h a r a c t e r i s t i c s and t h e magnitude of i n numerical terms of t h e pa rame te r s r eco rded i n e i t h e r a g r a p h i c a l o r a t a b u l a t e d numerical form.



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t h e c o r r e c t i o n s which must be a p p l i e d t o t h e raw d a t a which n e c e s s a r i l y r e q u i r e s a knowledge of t h e record ing system normally possessed only by t h e manufacturers o r s p e c i a l i s t o rganiza t ions . Correc t ions such a s compensation f o r c a l i b r a t i o n of t r a n s d u c e r s , instrument e r r o r , and p o s i t i o n e r r o r r e l a t i n g t o p i t o t and s t a t i c measurement parameters need t o be considered. p a r t i c u l a r a i r c r a f t i n s t a l l a t i o n , i t i s almost i n v a r i a b l y p r e f e r a b l e t o c o n s t r u c t a graph- i c a l r e p r e s e n t a t i o n of t h e recorded parameters on a s i n g l e common t i m e base; however, where i t is p o s s i b l e a t a b u l a t e d numerical p r e s e n t a t i o n is f r e q u e n t l y very h e l p f u l . F i n a l l y , i t may be p o s s i b l e t o r e t a i n the c o r r e c t e d informat ion on punch ca rd o r magnetic t a p e f o r subsequent computer processing and p l o t t i n g .

When a l l c o r r e c t i o n s have been a p p l i e d , i n c l u d i n g t h o s e a p p l i c a b l e t o a

I n d e a l i n g with record ings of any type i t w i l l only be p o s s i b l e t o o b t a i n read-outs of t h e raw d a t a from those o r g a n i z a t i o n s which have a p p r o p r i a t e read-out equipment. t i o n of t h e S t a t e conduct ing t h e i n v e s t i g a t i o n t o do t h i s , i n which case i t should be made t h e r e s p o n s i b i l i t y of t h e a c c r e d i t e d r e p r e s e n t a t i v e of t h e State i n which t h e read-out can be made t o ensure t h a t t h e a p p r o p r i a t e degree of p r i o r i t y and s e c u r i t y is a t t a c h e d t o o b t a i n i n g a read-out. conducting t h e i n v e s t i g a t i o n with a complete read-out i n due course t o g e t h e r w i t h a n i n d i c a t i o n of t h e working method used t o o b t a i n i t .

This may n e c e s s i t a t e a l lowing t h e f l i g h t record ing t o be taken o u t s i d e t h e j u r i s d i c -

I n t h i s event t h e a c c r e d i t e d r e p r e s e n t a t i v e should provide t h e State

An example of a F l i g h t Recorder Playback Cent re is provided i n Appendix 13 and t y p i c a l examples of f l i g h t d a t a record ing read-out are conta ined i n Appendix 4 .

Engraved f o i l r e c o r d i n g

I n t h e case of f o i l r e c o r d e r s i t i s d e s i r a b l e t h a t a p p r o p r i a t e equipment, u s u a l l y involving b inocular microscope OK smaller m a g n i f i c a t i o n c a p a b i l i t y , i s used i n o rde r t o determine parameter v a l u e s with s u f f i c i e n t accuracy i n r e l a t i o n t o t h e i r datum markers and t h e t i m e base. The provis ion of a d i g i t a l d e f i n i t i o n i n r e l a t i o n t o t h e X and Y Co-ordinates is a f a c i l i t y t h a t r e p r e s e n t s t h e i d e a l i n t h i s r e s p e c t . Correc t ions may be necessary i n r e s p e c t of d i sp laced t i m e bases f o r each parameter and knowledge of t h e engraving system, t h a t is t o say whether i t is on a cont inuous o r on a sampling base , i s necessary.

Photographic r e c o r d i n q

The photographic type of r e c o r d i n g r e q u i r e s knowledge of t h e s t e p response rates of t h e record ing mechanism and c o n s i d e r a t i o n s of t h e photographic l i m i t a t i o n s regard- i ng exposure t i m e where s u b s t a n t i a l excurs ions from t h e norm have taken p l ace .

E le c t r O m a Rne t i c r e cord i n g

I n t h e case of frequency modulated systems, c o r t e c t i o n s should be a p p l i e d where a p p r o p r i a t e i n r e s p e c t of datum s h i f t s and s t e p responses , t a k i n g i n t o account acceptab le background n o i s e levels. a c c u r a t e except where drop-outs of except iona l magnitude have taken p l a c e and t h e i r i n d i c a t i o n i s obvious.

With d i g i t a l systems t h e raw d a t a read-out i s u s u a l l y

4.2.7.2 Ana lys i s

The a n a l y s i s s t a g e , as d i s t i n c t from t h e read-out s t a g e , i s u s u a l l y c a r r i e d o u t by t h e a c c i d e n t i n v e s t i g a t o r i n c o n s u l t a t i o n wi th aerodynamists and o t h e r e x p e r t s r a t h e r than by t h e t e c h n o l o g i s t who i s f a m i l i a r wi th f l i g h t r e c o r d e r techniques . It may

3015177 N o . 7



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III- 4-9 _- P a r t 111.- The I n v e s t i g a t i o n -- be necessa ry , and i t is f r e q u e n t l y i l l u m i n a t i n g i n any even t , t o c o n s t r u c t a graph of t h e t o t a l energy of t h e a i r c r a f t i n o r d e r t o d e r i v e f u r t h e r i n fo rma t ion , such as changes of engine power and a i r c r a f t c o n f i g u r a t i o n , w h i l s t t a k i n g i n t o c o n s i d e r a t i o n o t h e r recorded informat ion n o t involved i n t h e energy c a l c u l a t i o n s . It i s necessa ry t o make a prolonged and d e t a i l e d examinat ion of t h e c o r r e c t e d read-out t o ensu re t h a t t h e r e is t h e proper cor- r e l a t i o n between t h e de f ined pa rame te r s o r t o e s t a b l i s h t h e r e a s o n s why t h e recorded va lues do n o t c o r r e l a t e . The r e c o n s t r u c t i o n of t h e f l i g h t p a t h on a l a r g e - s c a l e map t o g e t h e r w i th an i n d i c a t i o n of t h e r e l e v a n t h e i g h t s o r a l t i t u d e s is impor t an t , bu t g r e a t c a r e should be used i n p l o t t i n g t u r n s p a r t i c u l a r l y i f t h e rate of t u r n is i r r e g u l a r . A t a subsequent s t a g e i t is necessa ry f o r t h e Opera t ions Group o r Inves t iga tor - in-Charge t o re late ev idence acqu i red from s o u r c e s o t h e r t h a n t h e f l i g h t r e c o r d i n g t o t h e r e c o n s t r u c t e d f l i g h t pa th and t o e s t a b l i s h t h e r e a s o n s f o r d ive rgences i n t h e o v e r a l l r e c o n s t r u c t i o n from t h e o r i g i n a l l y in t ended f l i g h t pa th .

4.2.8 F u r t h e r developments

The v a l u e of f l i g h t d a t a r e c o r d i n g h a s been amply demonst ra ted and t h e r e can be no doubt t h a t t h e spectrum of f l i g h t d a t a r e c o r d i n g w i l l i n c r e a s e as t i m e goes on. It is t h e r e f o r e impor tan t t o keep i n mind t h a t a g e n e r a l deg ree of c o m p a t i b i l i t y between t h e v a r i o u s f l i g h t d a t a r e c o r d i n g sys tems should be a b a s i c o b j e c t i v e . The a v a i l a b i l i t y i n due cour se of more recorded i n f o r m a t i o n w i l l i n e v i t a b l y r e s u l t i n a n i n c r e a s e i n t h e e f f o r t necessa ry t o read-out and a n a l y s e t h e d a t a . Cons ide ra t ion w i l l , t h e r e f o r e , have t o be g iven t o improved methods of do ing t h i s . The f i r s t s t a g e might be i n t h e d i r e c t i o n of au tomat ic d a t a r e a d i n g and d a t a c o r r e c t i o n fo l lowed by au tomat i c p l o t t i n g and, t o some e x t e n t a t least , computerized a n a l y s i s . Later developments could l e a d t o a system where t h e f l i g h t d a t a r e c o r d e r ou tpu t , a f t e r any necessa ry i n t e r m e d i a t e p r o c e s s i n g , is f e d as t h e inpu t t o t h e a p p r o p r i a t e f l i g h t s i m u l a t o r s o t h a t a r e c o n s t r u c t i o n of t h e e v e n t s t h a t l e d up t o t h e a c c i d e n t could be w i t n e s s e d i n a manner similar t o t h a t i n which they took p l ace .

4 . 3 Cockpit Voice Recorders

4 . 3 . 1 Genera l

The d e s i r a b i l i t y of i n s t a l l i n g cockp i t v o i c e r e c o r d e r s on t r a n s p o r t air- c r a f t r e s u l t s from t h e f a c t t h a t i n s e v e r a l a c c i d e n t s c h a r a c t e r i z e d by sudden and extreme emergencies t h e f l i g h t c r e w could n o t communicate wi th ground f a c i l i t i e s . I n t h e s e cases where t h e crew d i d no t s u r v i v e , i n f o r m a t i o n t h a t t hey may have been a b l e t o g ive concerning t h e cause and n a t u r e of t h e emergency w a s l o s t . S t u d i e s condu.cted i n 1960 i n d i c a t e d t h a t , w i th s u i t a b l e microphone and f i l t e r equipment, i t w a s p o s s i b l e t o o b t a i n r easonab ly i n t e l l i g i b l e r e c o r d i n g s from a cockpit-mounted area microphone under r a t h e r s eve re cockpi t n o i s e c o n d i t i o n s . Some S t a t e s r e q u i r e t h e i n s t a l l a t i o n of c o c k p i t v o i c e r e c o r d e r s i n a l l l a r g e turbine-powered and p r e s s u r i z e d r e c i p r o c a t i n g four-engine t r a n s p o r t aeroplanes . Desc r ip t ion of some t y p e s of cockp i t v o i c e r e c o r d e r s a t p r e s e n t i n use is g iven a t Appen- d i x 3 . The r equ i r emen t s normal ly i n c l u d e r u l e s f o r t h e o p e r a t i o n of t h e r e c o r d e r s , s t anda rds of performance f o r t h e i r a p p r o v a l and s t a n d a r d s govern ing t h e method of i n s t a l l a - t i o n on an ae rop lane .

4 . 3 . 2 Purpose of t h e Cockpit Voice Recorder

The primary purpose of t h e c o c k p i t v o i c e r e c o r d e r is t o p rov ide t h e acc iden t i n v e s t i g a t o r w i t h f i r s t -hand in fo rma t ion of t h e f l i g h t crews' o b s e r v a t i o n and a n a l y s i s of c o n d i t i o n s aboard t h e a i r c r a f t and t h e p rocedures employed by them i n a t t empt ing t o handle t h e emergency.



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Experience has shown t h a t o t h e r s i g n i f i c a n t sounds are a l s o recorded, e.g. swi tches being a c t u a t e d , f l a p and landing gea r s e l e c t o r s be ing ope ra t ed , a u r a l warning s i g n a l s , engine n o i s e , cockpi t no i se a s s o c i a t e d wi th changes i n a i r s p e e d , etc. of information i s of cons iderable a s s i s t a n c e t o t h e i n v e s t i g a t o r , e s p e c i a l l y when t h e p r e c i s e t i m e of each sound can be determined from t h e record ing .

4 . 3 . 3 S e l e c t i o n of parameters

Th i s t ype

Cockpit vo ice r eco rde r s should normally record t h e fo l lowing:

vo ice communications t r a n s m i t t e d from o r r ece ived i n t h e aeroplane by r a d i o

vo ice communications of f l i g h t crew members on t h e f l i g h t deck

vo ice communications of f l i g h t crew members on t h e f l i g h t deck us ing the a i r c r a f t ' s in te rphone system

vo ice o r audio s i g n a l s i d e n t i f y i n g nav iga t ion o r approach a i d s in t roduced i n t o a headse t o r speaker

vo ice communications of f l i g h t crew members using t h e passenger loud speaker system, when t h e r e is such a system and t h e f o u r t h record ing channel i s not i n use.

To record e f f e c t i v e l y t h e v o i c e s o f f l i g h t crew members o n t h e f l i g h t deck, a cockpit-mounted area microphone i s i n s t a l l e d i r i trie b e s t p o s i t i o n t o record v o i c r communicat ions o r i g i n a t i n g a t t h e f i r s t and second p i l u t s t a t i o n s a s .vel1 as voice communications of o t h e r crew members on t h e f l i g h t deck when d i r e c t ( - d t o t h o s r s t d c i c n s . Care must be taken i n l o c a t i n g t h e microphone and a d j u s t i n g o r supplementirig ( h e pre- a m p l i f i e r s and f i l t e r s of t h e r eco rde r t o a s s u r e a h igh l e v e l of i n t e l l i g i b i l i t y of t h e recorded communications when recorded under cockp i t n o i s e cond i t i ons i n f l i g h t .

Cockpit vo ice r eco rde r s should be i n s t a l l e d s o t h a t each source o! in format ion descr ibed above be recorded on a s e p a r a t e channel . This cculd be achieved as f c , l l u r u s :

f o r t h e f i r s t channel , from each microphone, headse t o r speaker used a t t h e f i r s t p i l o t p o s i t i o n ;

f o r t h e second channel , from each microphone, headse t o r speaker used a t t h e second p i l o t s t a t i o n ;

f o r t h e t h i r d channel , from t h e cockpit-mounted area microphone;

f o r t h e f o u r t h channel , from - i ) each microphone, headse t , o r speaker used a t t h e s t a t i o n f o r t h e

t h i r d o r f o u r t h crew members; o r when not i n use f o r t h i s purpose, from

microphones a s s o c i a t e d wi th t h e ae rop lane ' s loud speaker system. i i )



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P a r t III.- The I n v e s t i g a t i o n 111-4-11 .--

4 . 3 . 4 I n s t a l l a t i o n and p r o t e c t i o n

I n s t a l l a t i o n of a c o c k p i t v o i c e r e c o r d e r should be made so t h a t :

a ) it r e c e i v e s i ts e l e c t r i c a l power from t h e bus b a r t h a t p r o v i d e s t h e maximum r e l i a b i l i t y f o r o p e r a t i o n of t h e r e c o r d e r w i thou t j e o p a r d i z i n g s e r v i c e t o s a t i s f y o t h e r e s s e n t i a l o r emergency l o a d s ;

b) t h e r e is an a u t o m a t i c means t o s t o p each e r a s u r e f e a t u r e from f u n c t i o n i n g a t t h e i n s t a n t of c r a s h impact; and

t h e r e is an a u r a l o r v i s u a l means f o r p r e f l i g h t checking of t h e r e c o r d e r f o r proper o p e r a t i on ;

t h e p r o b a b i l i t y of i n a d v e r t e n t a c t u a t i o n and o p e r a t i o n of t h e bu lk e r a s u r e dev ice d u r i n g c r a s h impact i s minimized.

c )

d)

The r eco rd c o n t a i n e r shou ld be l o c a t e d and.mounted so as t o minimize t h e p o s s i b i l i t y of c o n t a i n e r r u p t u r e r e s u l t i n g from c r a s h impact and subsequent damage t o t h e r eco rd ing from f i r e . I n meeting t h i s r equ i r emen t , t h e r e c o r d c o n t a i n e r should be as f a r a f t as p r a c t i c a b l e but should no t be l o c a t e d where aft-mounted eng ines may c rush i t upon impact.

4 . 3 . 5 Removal and h a n d l i n g

The utmost c a r e shou ld be e x e r c i s e d i n handl ing a c o c k p i t v o i c e r eco rde r . It should never be opened, bu t packed w i t h g r e a t care i n t h e s h i p p i n g c o n t a i n e r normally provided by t h e manufac turer and sh ipped t o t h e a u t h o r i z e d l a b o r a t o r y f o r read-out.

4 . 3 . 6

4 . 3 . 6 . 1

Cockpit Voice Recorders : read-out and a n a l y s i s

Genera l

There are t h r e e s t a g e s which must be observed by t h e a c c i d e n t i n v e s t i g a t o r i n us ing a cockp i t v o i c e r eco rd ing . f u n c t i o n , and t h e s t a g e wherein c o r r e l a t i o n wi th t h e f l i g h t d a t a r e c o r d e r is accomplished.

These are t h e r e a d - o u t / t r a n s c r i p t i o n s t a g e , t h e t iming

The purpose of t h e read-out s t a g e i s t o provide as a c c u r a t e as p o s s i b l e a w r i t t e n t r a n s c r i p t i o n of t h e words and sounds recorded on t h e t ape . I n o r d e r t o accomplish t h i s end, i t i s necessa ry t o employ s p e c i a l i z e d t a p e playback equipment des igned . ( u s u a l l y by t h e manufac turer ) t o reproduce t h e t a p e from a s p e c i f i c t y p e of cockp i t v o i c e r eco rde r . i n some c a s e s t h i s equipment w i l l n o t b e r e a d i l y a v a i l a b l e t o t h e i n v e s t i g a t o r , and i t nay be necessa ry t o a l low t h e r e c o r d e r t o be removed from t h e j u r i s d i c t i o n of t h e S ta te conduc t ing t h e i n v e s t i g a t i o n t o accompl ish a t least t h e i n i t i a l read-out of t h e record ing . A s i n t h e case of t h e f l i g h t d a t a r e c o r d e r ( s e e paragraph 4.2.7.1) i t should be made t h e r e s p o n s i b i l i t y of t h e a c c r e d i t e d r e p r e s e n t a t i v e of t h e State i n which t h e read-out can be made t o e n s u r e t h a t t h e a p p r o p r i a t e deg ree of p r i o r i t y and s e c u r i t y i s a t t a c h e d t o obta in- i n g a read-out. conducting t h e i n v e s t i g a t i o n wi th a t r a n s c r i p t of p e r t i n e n t communications, and a re- r eco rd ing of each r e c o r d i n g channe l i n i t s e n t i r e t y i n due cour se , t o g e t h e r w i t h a r e p o r t o u t l i n i n g ehe equipment and t e c h n i q u e s u t i l i z e d t o produce them.

I n this even t t h e a c c r e d i t e d r e p r e s e n t a t i v e should p rov ide t h e S t a t e s



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1-4-12 Manual of Ai rcraf t Accident I n v e s t i g a t i o n

The second, o r t iming s t a g e , i nvo lves t h e a s c e r t a i n i n g of p r e c i s e t i m e > p l i c a b l e t o t h e r a d i o telephone communications on t h e t a p e as w e l l a s rhe de t e rmina t ion . ie ther t h e r eco rde r was ope ra t ing a t i t s nominal t a p e t r a v e l speed. The former determina- Lon may be made by comparing t h e r ad io t e l ephone r e c o r d i n g channe l s t o ground-based record- igs a t a i r t r a f f i c c o n t r o l u n i t s which g e n e r a l l y have some form of superimposed o r o r r e l a t e d r a d i o t i m e s i g n a l on t h e tape . e.g. seismograph r e c o r d s ) t h e i n v e s t i g a t o r may e s t a b l i s h t i m e r e f e r e n c e p o i n t s on t h e ackp i t v o i c e r eco rde r t a p e which can be used t o re la te t o in t r a -cockp i t communications c sounds.

By t h e s e methods as w e l l as by o t h e r means

Determinat ion of tape speed accuracy may a l s o be made by t h e above method. 1 t h o s e cases where e i t h e r a t i m e s i g n a l o r r ad io t e l ephone communications have not e x i s t e d i i r ing t h e pe r iod of t h e cockp i t vo ice r eco rde r o p e r a t i o n , accuracy of e l a p s e d t i m e d a t a ay be achieved by a d j u s t i n g playback tape t r a v e l speed so as t o s t a b i l i z e a t p r e c i s e l y O0 Hz t h e inducted s i g n a l a t t h a t frequency which appea r s on most o r i g i n a l tapes .

Once t h e foregoing s t a g e s have been completed it is then p o s s i b l e , having j t a b l i s h e d a n a c t u a l t i m e ( o r an elapsed t i m e v a l u e from a r e f e r e n c e p o i n t ) , t o c o r r e l a t e i e d a t a obtained form t h e cockpi t vo ice r eco rde r w i th t h o s e gained from t h e € l i g h t d a t a ?corder read-out.

', 3 . 7 Technical n o t e s

It should b e borne i n m i n d t h a t ttivre is o f t e n a cons ide rab le ,aformation s t o r e d on t h e cockpi t v c i c - r eco rde r t ape a p a r t from t h e spoken ich as switches k i n g thrown, f l a p handles and unde -ca r r i age l e v e r s being ~ r n i n g s ig i ia l s , et:. , are o f t e n r e a d i l s i d e n t i f i a b l e .

h f u r t h e r i . t e m of d a t a which may be r e t r i e v e d from conic3 t a p e s i t e of t g r b i n e enTinec. This d a t a source has be?n e f f e c t i v e on a i r c r a f t w ..~d-rriountec! t..ngi.:!es. The method of rc : r ieval i s ? o p r ~ p a r e an ai.riotated c a rom anot!ier a i r c r a f t equipped with t h e same tvpe cF buth e r g i n e s and vo ice

wealth of word. >bunds c t u a t e d , a u r a l

i s t h e rpm t l i wing o r wing ibrntio:: r SF.' ri;.cordeir. ïh- .

:z i l ibrat ion t ape s h o u l d be made w-i . th a s i k n t c o c k p i t , i i i f i i g l i t , w i t 5 t n c !.;iriab!e.; oi: qgine rpin d i c t a t e d on t o one of t h e channels J t h e r t han t h e cockp i t area micru;ih.gtit- :?jan- 21. Eie tape s i g n a i s are then sub jec t ed t o spec t rog raph ic a n a l y s i s , t hus providing it

h u a 1 c a l i b r a t i o n record a g a i n s t which t o compare t h e s i g n a l s of unknown value from t h e ,:cident a i r c r a f t t ape . (See Appendix A . )

I n a t t empt ing t o s e p a r a t e i n t e l l i g e n t speech sounds from accompanying i n t e r - I rence such as may be caused by ambient cockpi t n o i s e , a u r a l warning s i g n a l s , o r o t h e r .>urCes, i t o f t e n becomes necessary t o apply e l e c t r o n i c f i l t e r i n g t echn iques t o the c o c k p i t >ice r eco rde r t a p e s i g n a l . i l t e r i n c e r t a i n frequency s p e c t r a , s i n c e such h igh - l eve l a t t e n u a t i o n w i l l almost h e v i t a b l y cause some degree of d i s t o r t i o n of speech sounds and t h u s l ead t o p o s s i b l e i c o r r e c t assessment of t h e con ten t of voice communications w i t h i n t h e cockp i t .

I n t h e s e cases , care should be e x e r c i s e d s o as no t t o over-

An example of a F l i g h t Recorder Playback Cen t re i s provided i n Appendix 13.

9/51 7 7 ' 40 . 7



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PART I I I

CHAPTER 5. - STRUCTURES INVESTIGATION



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111-5-1 -- P a r t III. - The I n v e s t i g a t i o n -. ---

CHAPTER 5

STRUCTURES It4VEST IGAT ION

The S t r u c t u r e s I n v e s t i g a t i o n covers t h e i n v e s t i g a t i n g and r e p o r t i n g upon t h e This i n c l u d e s pr imary and secondary s t r u c t u r e , l i f t and c o n t r o l a i r f r ame of t h e a i r c r a f t .

su r f aces .

P a r t III, Chapter 2 , I n i t i a t i o n of t h e Wreckage I n v e s t i g a t i o n d e a l s w i th t h e e a r l y s t a g e s of t h e s t r u c t u r a l i n v e s t i g a t i o n . t h e s u b j e c t s of Photography, Wreckage D i s t r i b u t i o n Char t s , Examination of Impact Marks and Debris and t h e hand l ing of Wreckage i n t h e Water. be d i scussed i n t h i s chap te r .

5.1 Recons t ruc t ion of Wreckane

Subsec t ions of t h a t c h a p t e r d e a l with,

Consequently, t h o s e s u b j e c t s w i l l no t

5 . 1 . 1 Genera 1

The " recons t ruc t ion" t echn ique is one of t h e most u s e f u l procedures a v a i l a b l e t o t h e i n v e s t i g a t o r f o r t h e i s o l a t i o n of t h e cause of a s t r u c t u r a l f a i l u r e . By "recon- s t r u c t i o n " , is meant t h e assembl ing of the v a r i o u s p i e c e s of wreckage i n t h e i r r e l a t i v e p o s i t i o n before f a i l u r e . Gene ra l ly , t h i s t echn ique is employed only f o r s p e c i f i c components such a s a wing panel , t a i l s u r f a c e o r c o n t r o l system a l though i n rare i n s t a n c e s it h a s been found necessa ry t o r e c o n s t r u c t a lmost a l l of t h e major components. procedure i s a twofold p r o p o s i t i o n . F i r s t , t h e v a r i o u s p i e c e s are i d e n t i f i e d and arranged i n t h e i r r e l a t i v e p o s i t i o n s . each p i e c e and t h e r e l a t i o n s h i p of t h i s damage t o t h e damage on o t h e r a d j a c e n t o r a s soc ia t ed pieces is e s t a b l i s h e d . T h i s l a t t e r work is t h e ch ie f purpose behind t h e r econs t ruc t ion .

The r e c o n s t r u c t i o n

Secondly, a d e t a i l e d examinat ion is made of t h e damage t o

When examining t h e wreckage of an a i r c r a f t keep i n mind t h a t an a i r c r a f t obeys t h e l a w of phys i c s j u s t a s p r e c i s e l y du r ing break-up a s it does d u r i n g normal f l i g h t .

5.1.2 I d e n t i f i c a t i o n of pieces

The ch ie f d i f f i c u l t y i n r e c o n s t r u c t i n g a component such as a wing l ies i n t h e i d e n t i f i c a t i o n of t h e v a r i o u s wreckage p i eces . I f t h e wing h a s broken up i n t o a r e l a t i v e l y few l a r g e p i e c e s , t h e t a s k i s much s i m p l i f i e d . I f i t h a s broken up int.0 a l a r g e number of small p i e c e s ( a s i t would i f t h e c o n t a c t speed had been h i g h ) , t h e recon- s t r u c t i o n j o b may be ex t remely d i f f i c u l t . The most p o s i t i v e means of i d e n t i f i c a t i o n is through p a r t numbers which a r e stamped on most a i r c r a f t p a r t s . checked a g a i n s t t h e a i r c r a f t p a r t s ca t a logue . When p a r t numbers are unreadable o r not found, i n d i r e c t methods must be r e s o r t e d t o f o r i d e n t i f i c a t i o n . The c o l o u r i n g ( e i t h e r p a i n t o r p r i m e r ) , t h e type of material and c o n s t r u c t i o n , external markings, r i v e t o r screw s i z e and spac ing , a l l can be used t o assist i n t h e i d e n t i f i c a t i o n of d i f f e r e n t p a r t s . For l a r g e s e c t i o n s , such a s s p a r chords , i t is o f t e n p o s s i b l e t o match t h e two ha lves of t he f r a c t u r e . The i d e n t i f i c a t i o n p r o c e s s is sometimes puzz l ing , s i n c e normally f l a t pieces a r e o f t e n found curved , and normally curved p i e c e s are o f t e n found f l a t . The i n v e s t i g a t o r soon l e a r n s no t be confused by t h e t o r n , ' t w i s t e d , buckled c o n d i t i o n of a piece of wreckage, and t o sea rch f o r t h e i d e n t i f i a b l e f e a t u r e s po in t ed out above.

These can e a s i l y be



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5.1 .3 Examination of p i e c e s

The chief purpose of r e c o n s t r u c t i n g t h e a i r c r a f t o r one of t he major compo- n e n t s i s t o permit a d e t a i l e d examination of t h e v a r i o u s wreckage p i e c e s . When the v a r i o u s p a r t s a r e placed i n t h e i r c o r r e c t r e l a t i v e p o s i t i o n s , i t is p o s s i b l e t o s tudy t h e c o n t i n u i t y o r l a c k of c o n t i n u i t y of damage on a s s o c i a t e d p i e c e s . I f wr inkles i n one s k i n p a n e l s e c t i o n are cont inuous a c r o s s a tear o r break i n t o a n o t h e r p a n e l , t hen d e t e r - minat ion of t h e f o r c e s causing wrinkl ing o r deformation is most u s e f u l i n d i f f e r e n t i a t i n g between i n - f l i g h t damage and impact damage, o r between primary and secondary f a i l u r e s . The c o n t i n u i t y of smears and s c o r e s a c r o s s breaks a r e a d d i t i o n a l p o i n t s t o no te dur ing t h e d e t a i l e d examination. I n - f l i g h t f i r e v e r s u s ground f i r e can be d i s t i n g u i s h e d i n t h i s saqe g e n e r a l manner. Over-all f a i l u r e p a t t e r n s , i n c l u d i n g d i r e c t i o n a l i n d i c a t i o n s of t he f o r c e s involved, can i n a lmost a l l ca ses be determined by r e l a t i n g t h e damage of i n d i v i d u a l p i e c e s . The manner and d i r e c t i o n i n which r i v e t s , screws and b o l t s a r e sheared is a u s e f u l i n d i c a t i o n i n t h i s work. Good n o t e s and ske tches should be made throughout t h i s d e t a i l e d examination. When i t w i l l add t c the c l a r i t y of t h e a c c i d e n t r e p o r t , photographs of t h e r e c o n s t r u c t i o n , i n c l u d i n g close-ups of s i g n i f i c a n t d e t a i l s , should be made.

5.1.4 Reconstruct ion a t t h e a c c i d e n t s i t e

The " recons t ruc t ion" technique p a r t i c u l a r l y i n r e s p e c t of cpecif i c components i s f r e q u e n t l y employed a t t h e a c c i d e n t scene. Th i s is e s p e c i a l l y t r u e i f t h e a c c i d e n t has occurred i n a r e l a t i v e l y open a r e a and t h e weather i s no t unusual ly inclement . Before t h e r eco r i s t ruc t ion work i s begun, t h e procedures o u t l i n e d i n Part I I I , Chapter 2 , should be fol lowed, i .e . , o v e r a l l photographs made, wreckage d i s t r i b u t i o n c h a r t completed, a walk- around inspec t ion made, and adequate n o t e s made on t h e manner i n which t h e v a r i o u s p i e c e s were f i r s t found. P a r t s from t h e suspected a r e a a r e c o l l e c t e d , i d e n t i f i e d , and arranged on t h e ground i n t h e i r r e l a t i v e p o s i t i o n s . Major components such a s t h e wing, t a i l and f u s e l a g e are genera l ly l a i d out s e p a r a t e l y f r o n one another f o r e a s e of l a t e r examination. I f t h e suspected a r e a i s a t t h e j u n c t i o n of t h e major components, t h e s e a r e a s a r e sometimes recons t ruc ted s e p a r a t e l y . I n d i v i d u a l cab le runs with t h e i r a s s o c i a t e d b e l l c r anks , i d l e r s and quadrants a r e u s u a l l y l a i d out s e p a r a t e l y , a g a i n f o r e a s e of examination. i c a n t markings a r e found on any of t h e s e l a t t e r i t e m s , corresponding markings can be sought ou t i n t h e r e l a t i v e p o s i t i o n i n t h e wing, f u s e l a g e , e t c . Recons t ruc t ion work a t t h e acci- den t s i t e is f a i r l y s t r a i g h t f o r w a r d and no g r e a t d i f f i c u l t y is normally encountered u n l e s s t h e a c c i d e n t h a s been very seve re and t h e r e a I n t h i s case i d e n t i f i c a t i o n i s d i f f i c u l t and t i m e consuming, but t h e r e s u l t s are , i n most caces , extremely worthwhile.

5.1.5 Reconstruct ion away from the a c c i d e n t s i t e

I f s i g n i f -

a l a r g e number of small p i e c e s of wreckage.

Very o f t e n t h e l o c a t i o n of t h e a c c i d e n t o r t h e p r e v a i l i n g weather c o n d i t i o n s prec lude t h e r e c o n s t r u c t i o n of suspected componentt 't t h e a c c i d e n t scene. I n t h i s c a s e , t h e i n v e s t i g a t o r must dec ide whether o r n o t i t is warranted o r necessary t o t r a n s p o r t t h e wreckage o r p o r t i o n s thereof t o a n o t h e r l o c a t i o n f o r f u r t h e r examinat ion. should be based on a c o n s i d e r a t i o n of t h e type of a c c i d e n t , t h e f a c t s developed a s of t h a t t ime, and the type of

This d e c i s i o n

information t h a t could be developed from t h e r e c o n s t r u c t i o n procedure.

Since a d d i t i o n a l damage w i l l p o s s i b l y be done t o t h e v a r i o u s wreckage p i e c e s d u r i n g t r a n s p o r t a t i o n , t h e i n v e s t i g a t o r should ensure t h a t h e h a s a complete set of n o t e s on a l l s i g n i f i c a n t smears, s c o r e s , tears, e t c . i d e n t i f i e d and keyed t o t h e wreckage d i s t r i b u t i o n c h a r t . The minimum amount of disassem- b l i n g should be done. I f i t is found necessary t o d isconnec t b o l t e d assembl ies , a record

A l l major p i e c e s should be s u i t a b l y tagged,



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I II- 5- 3 --- - . P a r t III.-- Tlie lnvec t i j i a t i» : i -.I_

R

Wreckage reconstruction a t scene o f accident involving mid-air co l l i s ion of two a ircra f t

SZmpZe "deveZopment" layout of upper and Zower surfaces of a mainphne i n a hangar PARTIAL RECONSTRUCTION OF WRECKAGE



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Manual of Aircraft Accident invest iga!:io'.i I I I- 5-4

General view of wing mock-up



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II 1-5-5 _______~-------- -. P a r t - III.- The Inves t iga t ion _.

View o f right-hand wing upper surface a t outboard f a i l u r e

View of right-hand Q i q g upper surface a t ii&oa.rd faiZure



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111-5-6 Manuâì of Aircraft Accident Inves t iga t i cn -

View of right-hand wing lower surface a t outboard fa i lu re

V L . i of r;gh:-hand wing Zower surface a t inboard f a i lu re



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111-5-7 -

Part III.-

The

Inv

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Copyright International C

ivil Aviation O

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rovided by IHS

under license with IC

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Not for R

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itted without license from

IHS

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Manual of Ai rcraf t Accident I n v e s t i g a t i o n 111-5-8 -- -

Genera l view of the wreckage reconstruction.

Detailed view of the r i g h t s ide of t he cabin forward of seat no. 6.

MAJOR RECONS'rRUCTION OF WRECKAGE



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I II- 5-9 ______ __-.- --- - P a r t III.- The I n v e s t i g a t i o n -

should be made of t h e sequence of t h e v a r i o u s washers, s p a c e r s , n u t s , e tc . c o n t r o l c a b l e s w i l l have t o be c u t t o s e p a r a t e p o r t i o n s of t h e wreckage. done, c a r e should be t aken t o i d e n t i f y and t a g a l l c u t s . a r e fo l lowed, v a l u a b l e ev idence may be l o s t o r t h e i n v e s t i g a t o r ' s t a s k cons ide rab ly magnified. A s i n o t h e r s t a g e s of t h e i n v e s t i g a t i o n , s h o r t c u t s should be suspec ted u n t i l they are e s t a b l i s h e d as r e a l l y be ing s h o r t c u t s .

I n many cases

Unless t h e s e s imple p recau t ions When t h i s is

When t h e r e c o n s t r u c t i o n is done away from t h e a c c i d e n t s i te i n a hangar , f o i P a r t s can be example, it is u s u a l l y p o s s i b l e t o do a more complete j o b of r e c o n s t r u c t i o n .

hung on mock-ups o r frameworks, o r suspended from above t o a c h i e v e a more three-d imens iona l arrangement which resembles more c l o s e l y t h e u n f a i l e d a i r c r a f t . It is most h e l p f u l t o have a v a i l a b l e a n a i r c ra f t of t h e same t y p e f o r comparison purposes . I f t h e p a r t s are ar ranged on frameworks off t h e f l o o r , i t is p o s s i b l e t o examine t h e upper and lower s i d e s wi thout a d d i t i o n a l r ea r r ang ing . Aside from t h e p o s s i b l e use of mock-ups, framework, etc., recon- s t r u c t i o n away from t h e a c c i d e n t s c e n e is t h e same a s t h e r e c o n s t r u c t i o n a t t h e a c c i d e n t s i t e . of t h e v a r i o u s p i e c e s of wreckage.

I n a l l of t h i s work, t h e g o a l i s t o permi t a more d e t a i l e d examinat ion and a n a l y s i s

5 . 2 Types of Material F a i l u r e

5 . 2 . 1 Ma j o r component f a i l u r e

The r e l a t i v e inc idence of i n - f l i g h t f a i l u r e s o r s e p a r a t i o n of some major component such as t h e wing, t a i l s u r f a c e , a i l e r o n , c o n t r o l sys tem o r f u s e l a g e is approximately in t h a t o r d e r , w i t h major f a i l u r e s of t h e f u s e l a g e or c o n t r o l sys tem o c c u r r i n g ve ry i n f r e q u e n t l y . I n g e n e r a l , major component f a i l u r e s r e s u l t from e i t h e r (1) inadequate des ign s t r e n g t h , o r ( 2 ) e x c e s s i v e l o a d s imposed upon t h e component, o r (3) d e t e r i o r a t i o n of s t a t i c s t r e n g t h through f a t i g u e o r c o r r o s i o n .

S ince a l l c i v i l a i r c r a f t are des igned and t e s t e d t o a t least t h e minimum s t a n d a r d s of t h e p e r t i n e n t n a t i o n a l r e g u l a t i o n s , f a i l u r e s d i r e c t l y a t t r i b u t a b l e t o inadequa te des ign s t r e n g t h are remote i f t h e a i r c r a f t i s ope ra t ed w i t h i n i t s d e s i g n l i m i t a t i o n s . Sometimes, however, e s p e c i a l l y when t h e a i r c r a f t is f i r s t i n t r o d u c e d , d i f f e r e n t l oad ings are exper ienced from t h o s e a n t i c i p a t e d and s t a t i c f a i l u r e s occur w i t h i n t h e o p e r a t i n g l i m i t a t i o n s . be d i r e c t e d t o f a i l u r e s invo lv ing new d e s i g n s . Most of t h e component f a i l u r e s a t t r i b u t a b l e t o inadequate d e s i g n s t r e n g t h are u s u a l l y a s s o c i a t e d wi th d e f i c i e n t r e p a i r o r mod i f i ca t ion work, o r w i t h a n improperly manufactured p a r t o r component. S ince t h e manufac tu re r ' s s t a n d a r d s and procedures a r e s u p e r v i s e d by government and i n d u s t r y a g e n t s , major manufac- t u r i n g mis t akes are kept t o a minimum. F a u l t y r e p a i r o r m o d i f i c a t i o n work is re spons ib l e f o r a l a r g e p r o p o r t i o n of f a i l u r e s i n t h i s grouping.

Th i s occur s i n f r e q u e n t l y bu t a c e r t a i n amount of s u s p i c i o n should always

Excess ive l o a d s are developed when a n a i r c r a f t i s o p e r a t i n g o u t s i d e of i t s Very o f t e n t h e s e l a r g e l o a d s are imposed inad-

A t o t h e r t imed\ \ the p i l o t may perform s e v e r e manoeuvres I n e i t h e r case, t h e l o a d i n g on t h e wing, t a i l ,

l i m i t a t i o n s of load f a c t o r a n d / o r speed . v e r t e n t l y such as du r ing t h e recovery f o l l o w i n g a l o s s of c o n t r o l a t h e i g h t where t h e a i r c r a f t e n t e r s a r ap id descen t . f o r which t h e a i r c r a f t was no t des igned . f u s e l a g e , etc., b u i l d s u p t o a v a l u e i n e x c e s s of t h e des ign l i m i t and s t a t i c f a i l u r e r e s u l t s . The c i rcumstances immediately p reced ing t h e f a i l u r e as developed from wi tnesses ' s t a t e m e n t s can be most h e l p f u l i n e s t a b l i s h i n g e x c e s s i v e l o a d s as t h e d i r e c t cause.



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Fat igue f a i l u r e s cont inue t o be one of t h e major causes of s t r u c t u r a l f a i l u r e s of a i r c r a f t p a r t s and components. This b a s i c cause should always be s t rong ly suspec ted u n t i l o t h e r f a c t s o r c i rcumstances are developed t o d isprove it a s be ing a f a c t o r . A s i nd ica t ed i n t h e s e c t i o n on "Fatigue", t h i s type of f a i l u r e can r e s u l t from a number of causes . I n gene ra l , f a t i g u e f a i l u r e s a r e due t o e i t h e r (1) inadequate des ign , o r ( 2 ) poor maintenance, o r ( 3 ) d e f e c t i v e manufactur ing, o r ( 4 ) a l t e r n a t i n g loadings no t a n t i c i p a t e d -by t h e des igner . The ma jo r i ty of f a t i g u e f a i l u r e s r e s u l t from imperfec t d e t a i l des ign and from improper i n s t a l l a t i o n o r handl ing of t h e p a r t . Since f a t i g u e is u s u a l l y a s s o c i a t e d wi th l a r g e numbers of cyc le s of r e p e t i t i v e load ing , t h i s type of f a i l u r e i s r a r e l y found in new a i r c r a f t wi th low service t i m e .

I n a d d i t i o n t o t h e t h r e e b a s i c causes f o r i n - f l i g h t s t r u c t u r a l f a i l u r e c i t e d above, t h e r e i s a s p e c i a l type of f a i l u r e a s s o c i a t e d wi th f l u t t e r . F l u t t e r is a n i n s t a b i l - i t y type of phenomenon involv ing a s e l f - e x c i t e d o s c i l l a t o r y system and i ts occurrence i s dependent upon t h e i n t e r - r e l a t i o n s h i p of t h e aerodynamic f o r c e s , i n e r t i a f o r c e s and e l a s t i c f o r c e s of t h e system. When f l u t t e r does occur t h e ampli tude of t h e o s c i l l a t i o n may b u i l d up and extremely h igh loads may develop, r e s u l t i n g gene ra l ly i n s t r u c t u r a l f a i l u r e of t h e a i r c r a f t o r one of i ts components. For t h i s reason , f l u t t e r can be considered a s a s p e c i a l v a r i a t i o n of excess ive loading and can be handled by t h e i n v e s t i g a t o r i n t h e same g e n e r a l manner a s f o r t h a t ca tegory of f a i l u r e . Modern a i r c r a f t are des igned and t e s t e d du r ing c e r t i f i c a t i o n t o avoid t h e p o s s i b i l i t y of f l u t t e r i n normal use. However, f l u t t e r can occur i n s e r v i c e , i f t h e o r i g i n a l des ign o r component s t i f f n e s s i s a l t e r e d by r e p a i r o r modi f ica t ion work o r i f excess ive f r e e p lay develops .

I n t h e preceding paragraphs, t h e b a s i c causes and c o n t r i b u t i n g f a c t o r s which are a s soc ia t ed wi th i n - f l i g h t s t r u c t u r a l f a i l u r e s of majcr components have been b r i e f l y reviewed. These p o i n t s should be of a s s i s t a n c e t o the acc iden t i n v e s t i g a t o r i n h i s evalu- a t i o n of a f a i l u r e a f t e r i t is found. The i n v e s t i g a t o r i s confronted wi th t h e cask of determining which component f a i l e d f i r s t ; € o r t u n a t e l y f a i l u r e of a major component i s r e l a t i v e l y easy t o sea rch ou t a f t e r such an a c c i d e n t . Th i s i s t r u e because i n almost every case , t he component s e p a r a t e s from the a i r c r a f t a f t e r f a i l u r e and si-nce sepa ra t ion gene ra l ly r e s u l t s , t h e f a i l e d component is found some d i s t a n c e from t h e main wreckage. When a component o r components s e p a r a t e a t a low a l t i t u d e , they are s t rewn a long t h e f l i g h t pa th approximately i n the order of t h e i r s epa ra t ion . When a component o r compo- nen t s s epa ra t e a t a h igh a l t i t u d e , t h e i n t e r r e l a t i o n s h i p of component mass, aerodynamic shape, speed a t s e p a r a t i o n and winds a l o f t a l l a f f e c t t h e t r a j e c t o r y of t h e p a r t and c a r e f u l s tudy of t hese f a c t o r s i s requi red t o determine the o r d e r of s e p a r a t i o n from t h e ground wreckage t r a i l . p a r t s , and i n v e s t i g a t o r s have had cons iderable success i n e v a l u a t i n g t h e s i g n i f i c a n c e of wreckage t r a i l s i n a c c i d e n t s of t h i s type. r econs t ruc t ion of t h e a i r c r a f t p l ay a s i g n i f i c a n t r o l e i n t h e de t e rmina t ion of t h e sequence of f a i l u r e . se c t ion s.

Methods are a v a i l a b l e t o approximate t h e t r a j e c t o r i e s of wreckage

The s tudy of t h e wreckage d i s t r i b u t i o n and

Other techniques are a l s o a v a i l a b l e and they are r e f e r r e d t o i n subsequent



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111-5-11 - P a r t III.- The Investigation -

WRECKAGE TRAIL ANALYSIS



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Manual of A i r c r a f t Acc ident Jiivect ip!. i o i . -__ ______._ __II--- 111-5-12

5.2'.2 P a r t i a l f a i l u r e o r mal func t ioning

Accidents i n t h i s g e n e r a l ca tegory are by f a r t h e more d i f f i c u l t t o i n v e s t i - g a t e , s i n c e no obvious evidence such as a wing being found two m i l e s from t h e main wreckage scene is usua l ly a v a i l a b l e on which t o make a r ap id de t e rmina t ion . malfunctioning of a major component g e n e r a l l y r e s u l t s i n a l t e r e d f l i g h t c h a r a c t e r i s t i c s and these i n t u r n are re spons ib l e f o r t h e a c c i d e n t . den t s i n t h i s ca tegory are jammed c o n t r o l s , improper d i s t r i b u t i o n of load on board, c o n t r o l s u r f a c e no t r igged p rope r ly , i n c o r r e c t i n s t a l l a t i o n of p a r t s , hard-over s i g n a l s from auto- p i l o t s , etc. Accidents of t h i s t ype a r e f r e q u e n t l y a s s o c i a t e d wi th recent r e p a i r o r al ter- a t i o n work; t h e r e f o r e t h e i n v e s t i g a t o r can o f t e n d i scove r v a l u a b l e c l u e s by s tudy ing t h e a i r c r a f t ' s h i s t o r y as r e f l e c t e d by l o g book e n t r i e s , p i l o t r e p o r t s and by o t h e r sources .

Pa r t i a l f a i l u r e o r

Some of t h e gene ra l causes of acci-

The gene ra l procedure used f o r a c c i d e n t s i n t h i s ca t egory i s t o f o l l o w r o u t i n e i n v e s t i g a t o r y p r a c t i c e s , s y s t e m a t i c a l l y checking out v a r i o u s l e a d s and c l u e s u n t i l t h e cause is determined. Ce r t a in techniques are a v a i l a b l e t o reduce t h e amount of work r equ i r ed t o complete t h e i n v e s t i g a t i o n ; of t hese , t h e e l i m i n a t i o n technique i s one of t h e most u s e f u l . I n most a c c i d e n t s , an experienced i n v e s t i g a t o r can quick ly e l i m i n a t e u n l i k e l y p o s s i b i l i t i e s , e .g . by r e fe rence t o t h e type o f ' i m p a c t , and can i s o l a t e t h e g e n e r a l area i n which t h e i n i t i a l d i f f i c u l t y i s loca ted . of t h e i n v e s t i g a t i o n .

The r e c o n s t r u c t i o n technique i s most h e l p f u l a t t h i s s t a g e

5.3 Examination of t h e Airframe inc lud ing Undercarriage and F l i g h t Cont ro ls

.5.3.1 Smears and s c o r i n g

In h i s pre l iminary examination a t t h e a c c i d e n t scene, t h e i n v e s t i g a t o r ' s immediate concern is t o determine i f a s t r u c t u r a l f a i l u r e had occurred be fo re impact. Toward t h i s end, h i s chief i n t e r e s t i n i t i a l l y is i n s e p a r a t i n g ground impact damage from i n - f l i g h t fa i lure . I n t h i s r ega rd , much va luab le informat ion can be ga thered from a c a r e f u l s tudy of t h e v a r i o u s smears and s c o r e s found on d i f f e r e n t p a r t s of t h e wreckage. When p o s s i b l e , t h i s s tudy should be made before t h e wreckage is d i s t u r b e d s i n c e movement of t h e wreckage may d e s t r o y va luab le c l u e s o r c r e a t e mis leading ones. The s tudy and a n a l y s i s of wreckage smears and s c o r e s is a n extremely va luab le a i d i n t h e i n v e s t i g a t i o n of c o l l i s i o n acc iden t s . t h a t can be learned from a s tudy of smears and s c o r i n g marks are presented .

I n t h e fo l lowing paragraphs of t h i s s e c t i o n some of t h e p o i n t s

A smear can be de f ined as a d e p o s i t of p a i n t , p r imer , o r o i l f i l m t r a n s f e r r e d from one p a r t t o ano the r p a r t du r ing t h e process of t h e two s l i d i n g o r rubbing a c r o s s each o t h e r . f a i l u r e . of t h e fuse l age o r t a i l s e c t i o n . co lou r , it would be normal t o f i n d coloured smears on t h e f u s e l a g e o r t a i l components. These p a i n t smears u s u a l l y p i l e up a g a i n s t p ro tuberances , such a s r i v e t heads o r s k i n l aps . The d i r e c t i o n of t h e smearing f o r c e can gene ra l ly be determined from t h e f a c t t h a t t h e p i le -up of p a i n t w i l l be found on t h e s i d e of t h e pro tuberance away from t h e d i r e c t i o n of t h e app l i ed fo rce . I n some cases , excess d e p o s i t s are pushed out from t h e ends of t h e s l o t s and d e f l e c t e d over i n t h e d i r e c t i o n of t h e smearing f o r c e . i f t h e i n v e s t i g a t o r cannot make a p re l imi - nary de te rmina t ion and i f he b e l i e v e s t h a t t h e smears may con ta in va luab le clues, he can r e s o r t t o l abora to ry examinations. of t h e smear subs t ance , and can u s u a l l y p inpoin t t h e d i r e c t i o n of t h e smearing f o r c e .

This s l i d i n g o r rubbing a c t i o n f r e q u e n t l y occurs a f t e r a n i n - f l i g h t s t r u c t u r a l For example, a f a i l e d wing panel o f t e n makes such a con tac t w i th t h e rear p o r t i o n

I f t h e wing panel had been pa in t ed with a d i s t i n c t i v e

Smear d e p o s i t s are sometimes found i n t h e recessed s l o t s of screws.

Th i s type of examination can u s u a l l y r e v e a l t h e n a t u r e



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111-5-13 P a r t III.- The I n v e s t i g a t i o n _.--

Score marks are produced when one p a r t s l i d e s o r s c r a p e s a c r o s s ano the r . The s c o r e marks r e s u l t when some s h a r p edge on one of t h e p i e c e s gouges t h e o t h e r piece. Sometimes only t h e p a i n t f i l m i s gouged, whi le more f r e q u e n t l y a c t u a l metal is gouged and an i n d e n t a t i o n or t rough is formed. magnifying g l a s s o r microscope w i l l r e v e a l d i r e c t i o n a l markings and metal r e s i d u e which is deformed i n t h e d i r e c t i o n of t h e s c o r i n g f o r c e . When a . s k i n p a n e l c o n t a i n i n g a pro- t rud ing head r i v e t seam s t r i k e s a g l a n c i n g blow i n a pa in ted s k i n p a n e l , a series of p a r a l l e l s c o r e markings i n t h e p a i n t e d f i l m i s u s u a l l y produced. If corresponding smear d e p o s i t s can be found on a p a r t i c u l a r row of r i v e t s , and knowing t h e r i v e t p i t c h , t h e r e l a t i v e p o s i t i o n of t h e two bodies d u r i n g c o n t a c t can u s u a l l y be e s t a b l i s h e d . This type of de t e rmina t ion is o f t e n h e l p f u l i n many i n v e s t i g a t i o n s . t o e s t a b l i s h t h a t t h e damage occur red p r i o r t o impact and n o t a f t e r w a r d s . I f s c o r e marks a r e found on s e v e r a l r e l a t e d p i e c e s of wreckage, t h e cons i s t ency and c o n t i n u i t y of t h e sco res a c r o s s t h e p i e c e s a f t e r they are p laced i n t h e i r r e l a t i v e p o s i t i o n s w i l l show t h a t t h e s c o r i n g w a s made b e f o r e t h e p i e c e s were t o m a p a r t . be used t o e s t a b l i s h t h a t t h e sco red component s t r u c k o r was s t r u c k by a n o t h e r component, t hus l ead ing t o a l o g i c a l sequence of i n - f l i g h t break-up.

Close examination of t h e s c o r e marking under a

Score marks can o f t e n be used

Th i s t ype of ev idence can o f t e n

Many o t h e r d i s t i n c t i v e markings are o f t e n found on p i e c e s of wreckage and a c a r e f u l s tudy of such markings w i l l v e r y o f t e n provide many v a l u a b l e c l u e s . When a r o t a t i n g p r o p e l l e r c u t s through me ta l , i t l e a v e s a ve ry d i s t i n c t i v e saw-toothed p a t t e r n . The j agged " tee th" are deformed i n t h e d i r e c t i o n of t h e c u t t i n g f o r c e and c u r l e d over i n an e a s i l y d i s t i n g u i s h a b l e manner. The amount of c u r l i n g , t h e e x t e n t of t h e j aggedness , t h e l eng th and width of t h e c u t , a l l p rov ide i n d i c a t i o n s of t h e p r o p e l l e r t o rque and forward speed du r ing t h e c u t t i n g i n t e r v a l . An a i r c r a f t c o n t r o l c a b l e i s a n o t h e r i t e m which produces a d i s t i n c t i v e marking when i t s t r i k e s o r i s dragged a c r o s s a s k i n pane l . I n t h i s case, t h e gene ra l i n d i c a t i o n i s a series of t i n y p a r a l l e l l i n e s . The e x a c t shape and s i z e of t h e s e cab le markings can o f t e n be used t o de te rmine t h e d i r e c t i o n i n which t h e c a b l e w a s moving when t h e markings w e r e made. P e c u l i a r l y shaped i n d e n t a t i o n s on p a r t s o r on s k i n p a n e l s can sometimes be matched wi th t h e p i e c e which made t h e marking and the reby p rov ide a c l u e t o t h e sequence of f a i l u r e . F u r t h e r , i t is sometimes p o s s i b l e t o be mis l ed by c u t t i n g marks produced by an axe o r hacksaw used i n t h e sa lvage o p e r a t i o n , and t h e i n v e s t i g a t o r should l e a r n t o be f a m i l i a r w i th t h i s t ype of marking and to d i s t i n g u i s h t h i s t ype from t h e o t h e r s desc r ibed .



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111-5- 14 Manual of Aircraft Accident Invest igat ion --

Note deposit bulld up against obstacles such as screw heaàs a d skin lap joints

Direction of application

shape of smear on a smooth audace

;L? Note curl of rear end in a section of a typical smear

Direction of application

SMEARS



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I II- 5- 15 P a r t III.- The i n v e s t i g a t i o n _ _

Note even p i t ch of scoring suggesting tha t it was made by a l ine o f r i v e t heads and end of scoring a t fracture indicating tha t the fracture occwred before the scoring.

SCORE MARKS Copyright International Civil Aviation Organization Provided by IHS under license with ICAO


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111-5-16 Manual of A i r c r a f t Accident Inves t iga t ion ---..I-_.__ --

m e cabZe which caused the scoring ( top ) has been iden t i f i ed by matching it with the damaged surface (S igh t ) ,

SCORE MARKS



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III- 5- 17 __I_. .___

P a r t III.- The Investigation ---_.

O

EXAMPLE OF SMEARING AND SCORING



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Manual of A i r c r a f t Accident inves t iga t ion ___-.--- 111-5-18 - 5.3.2 Main planes, fuse lage and t a i l u n i t

A s s t a t e d previously, one of t he main f i r s t endeavours i n t h e s t r u c t u r e examination i s t o determine whether there is evidence t h a t any main p a r t of t h e s t r u c t u r e was not i n i t s cor rec t r e l a t i v e pos i t ion a t the t i m e of impact, With t h i s i n mind, each component i s examined. components of t en provide valuable c lues . pieces , p a r t i c u l a r l y of overstressed metal shee t o r plywood is a l s o q u i t e he lpfu l .

Wreckage d i s t r i b u t i o n marks on the ground and te lescoping of Evidence of " f lu t te red" f a b r i c and missing

Components such as cables , pu l leys , hinges , and balance and t a b mechanisms should be examined c lose ly t o determine whether observed f a i l u r e s a r e t h e r e s u l t of design def ic ienc ies , wear, inadequate maintenance o r impact.

Examination of t he main port ion of t he fuselage should include an assessment of the a c t u a l load d i s t r i b u t i o n i n s o f a r a s possible . The f i g u r e s thus obtained should be cross-checked aga ins t t he weight .and balance shee t .

5.3.3 Unde rca rr iage

The l i n k mechanism, up and down locks and pos i t ion of t he operat ing j a c k s o r ac tua t ing cy l inders should be examined t o a s c e r t a i n whether the undercarr iage w a s up o r down, I f t h e gear has f a i l e d o r separated, no te t h e d i r e c t i o n of t h e f o r c e which caused the f a i l u r e o r separat ion.

5.3.4 F l igh t cont ro ls

To the maximum exten t poss ib le , a l l controls ,both manually and power operated, should be t raced out and inspected c a r e f u l l y t o assure t h a t a l l component p a r t s are accounted for .

Tai lplane incidence, t a b and f l a p s e t t i n g s should be noted and compared w i t h t h e i r respect ive s e t t i n g ind ica tors i n the cockpit .

A l l operat ing levers and the attachment of c o n t r o l rods o r cables t o these levers should be checked t o determine whether they were properly assembled, adequately lubricated and not jammed.

EXAMPLE OF SIGNIFICANT EVIDENCE

has exceeded i t s normal range of travel . The control lever has elongated the s l o t , indicating t h a t the elevator



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I II- 5- 19 - . - ____--_I-

P J r t III.- The I n v e s t i g a t i o n - __-

S p o i l e r s , where i n s t a l l e d , should be examined t o de te rmine whether they were extended a t t h e t i m e of impact and whether any f a i l u r e occurred i n t h e i r mountings.

5.3.5 Co c kp i t

The n o t i n g and photographing of t h e p o s i t i o n ' a n d s e t t i n g of a l l cockpi t con- t r o l s , swi t ches and c o n t a c t b r e a k e r s i s a f u n c t i o n normally a s s o c i a t e d a l s o wi th t h e systems and o p e r a t i o n s phases of t h e i n v e s t i g a t i o n .

Determina t ion of t h e i n s t a l l a t i o n and state of u se of seat b e l t s , shoulder ha rnesses , oxygen masks and o t h e r s a f e t y equipment i s a f u n c t i o n normally a s s o c i a t e d also wi th t h e human f a c t o r s phase of t h e i n v e s t i g a t i o n .

5.4 Recognit i on of Fa t i gue F a i l u r e s

5.4.1 Genera l

The term " f a t i g u e f a i l u r e " i s normally app l i ed t o t h o s e f r a c t u r e s t h a t are caused by r e p e a t e d load ing a t a c a l c u l a t e d stress cons iderably lower than would be r equ i r ed t o cause f a i l u r e under a s i n g l e load a p p l i c a t i o n . The complete s t o r y of a f a t i g u e f a i l u r e i s i n almost a l l c a s e s s e t f o r t h on t h e f a c e of t h e f r a c t u r e . I n o t h e r words, much v a l u a b l e informat ion r e l a t i v e t o t h e magnitude and d i r e c t i o n of loading and t o t h e presence o r absence of stress c o n c e n t r a t i o n s can be developed through a c a r e f u l s tudy of t h e f r a c t u r e d ,surfaces. I n t e r p r e t a t i o n of t h e f r a c t u r e , however, may not always be a simple matter, Lecause each c a s e may be in f luenced by many v a r i a b l e s . Some of t h e v a r i a b l e s have been c r i e f l y touched upon i n p rev ious s e c t ions . Some c o n t r i b u t i n g f a c t o r s , l i k e deca rbur i za t ion , i m onlv be v e r i f i e d by l abora to ry examination. I n many c a s e s , on t h e o t h e r hand, t h e cause c a n be p inpo in ted i n t h e f i e l d by c a r e f u l s tudy of t h e f r a c t u r e a lone .

Fa t igue f a i l m e s occur wi thout p e r c e p t i b l e d u c t i l i t y , as c o n t r a s t e d a g a i n s t stti:. i c f a i l u r e s where cons ide rab le d u c t i l i t y or "necking down" g e n e r a l l y t a k e s p lace . This < ! i s t i n c t i o n j.s o f t e n h e l p f u l ir, i s o l a t i n g a par: which has f a i l e d from f a t i g u e . A l l b r i t t l e : 2 i l u r e s , however, a r e not n e c e s s a r i l y f a t i g u e f a i l u r e s and t h i s f e a t u r e must be used wi th o the r f e a t u r e s t o be desc r ibed b e f o r e a f i n a l de te rmina t ion is made. I n a d d i t i o n , most f a t i g u e f a i l u r e s (some t o r s i o n f a t i g u e f a i l u r e s excepted) occur on p l anes which are a t r i g h t ang le s o r n e a r l y a t r i g h t a n g l e s t o t h e loading . On a l a r g e number of p a r t s t h e f a t i g u e p lane w i l l be pe rpend icu la r t o t h e a x i s of t h e p a r t , and i n t h e f a t i g u e area t h e f r a c t u r e w i l l g e n e r a l l y be i n one p l ane . I r r e g u l a r f r a c t u r e s , t h e r e f o r e , when t h e f r a c t u r e s l i p s from one p l ane t o ano the r and when t h e s e p l a n e s are very much d i f f e r e n t from a p lane pe rpend icu la r t o t h e load ing o r t o t h e a x i s of t h e p a r t , are ve ry probably not f a t i g u e f r a c t u r e s a l though c l o s e examination i s o f t e n r e q u i r e d t o s e e i f some small a r e a on t h e f r a c t u r e does n o t conform t o t h e b a s i c r e q u i s i t e s . The two f e a t u r e s of a f a t i g u e f r a c t u r e r e f e r r e d t o i n t h i s paragraph a r e ex t remely u s e f u l i n a s c e r t a i n i n g a f a t i g u e f a i l u r e from a l a r g e number of f a i l u r e s . I n f a c t , i n t hose c a s e s when t h e f r a c t u r e d s u r f a c e s are mut i l a t ed from subsequent damage, t h e s e f e a t u r e s may be t h e only ones a v a i l a b l e t o d is - t i n g u i s h between f a t i g u e and s t a t i c f a i l u r e s . It i s most d e s i r a b l e t h a t , i n making de ter - mina t ions of t h i s t y p e , both h a l v e s of t h e f r a c t u r e are a v a i l a b l e f o r examination.

- .

A s i n d i c a t e d p r e v i o u s l y , t h e most va luab le informat ion is conta ined on t h e f r a c t u r e s u r f a c e i t s e l f . The a c t u a l f a t i g u e f r a c t u r e s u r f a c e i s composed of two d i s t i n c t r eg ions : one smooth and v e l v e t y - t h e f a t i g u e zone; and t h e o t h e r , c o a r s e and c r y s t a l - l i n e - t h e i n s t a n t a n e o u s zone. The smooth v e l v e t y appearance of t h e f a t i g u e zone is caused by rubbing o f t h e m a t i n g s u r f a c e s as t h e c rack opens and c l o s e s under r epea ted



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111-5-20 Manuaì of A i r c r a f t Accident I n v e s t i g a t i o n

loading. " c r y s t a l l i z a t i o n theory". For many y e a r s , people i n examining a f a t i g u e f r a c t u r e o r i n d i scuss ing them were accustomed t o say ing t h a t t h e p a r t had "c rys t a l l i zed" . t h a t t h i s e r roneous b e l i e f sprang from t h e coarse appearance of t h e in s t an taneous zone. M e t a l l u r g i c a l l y , i t i s unt rue t h a t t h e p a r t o r t h e meta l i n t h e p a r t does c r y s t a l l i z e under f a t i g u e loading .

The coa r se appearance of t h e in s t an taneous zone has given r ise t o t h e e r roneous

We now know

The f i r s t t a s k , then , i n searching ou t a f a t i g u e f a i l u r e is t o look f o r t h e two d i s t i n c t types of zones on t h e f r a c t u r e - t h e f a t i g u e zone and t h e in s t an taneous zone. I n many f r a c t u r e s , more than one f a t i g u e zone w i l l o f t e n be found, i n d i c a t i n g t h a t s e v e r a l f a t i g u e c racks had developed and were progress ing a t t h e t i m e of t h e f i n a l f a i l u r e . each f a t i g u e zone, t h e o r i g i n of t h e f a t i g u e c rack can be found by l o c a t i n g t h e p o i n t from which t h e c rack f r o n t progress ion marks r a d i a t e . These f a t i g u e p rogres s ion marks are curved l i n e s on t h e f r a c t u r e s u r f a c e v a r i o u s l y known as "clamshells", "oys te r s h e l l s " , "beach" o r "stop marks", and are found i n almost every s e r v i c e f a t i g u e f a i l u r e . It should be noted he re t h a t under some loading cond i t ions , p a r t i c u l a r l y where t h e load c y c l e s are r e l a t i v e l y c o n s t a n t , t h e f a t i g u e c rack may grow wi thout l eav ing d i s t i n c t i v e p rogres s ion marks. I n t h e s e cases , t h e f a t i g u e f r a c t u r e can u s u a l l y be i d e n t i f i e d b y i t s smooth, v e l v e t y appearance o r by s i n g l e f r a c t u r e p l anes approximately pe rpend icu la r t o t h e d i r e c t i o n of loading and by t h e absence of evidence of d u c t i l i t y . should be r e f e r r e d t o a s p e c i a l i s t f o r conf i rmat ion .

I n

Any s u s p i c i o u s o r dubious f r a c t u r e s

The many crack f r o n t marks i n a t y p i c a l f a t i g u e f r a c t u r e t h a t occu r s i n s e r v i c e are caused by v a r i o u s degrees of rubbing as t h e c rack e i t h e r s t o p s f o r c e r t a i n pe r iods o r as i t p rogres ses a t a vary ing ra te under d i f f e r e n t stress l e v e l s . For t h i s reason , t h e t e r m "stop marks" as i t is app l i ed t o t h e c rack f r o n t marks i s perhaps more p i c t o r i a l t han t h e o t h e r commonly used expres s ions s i n c e i t i n d i c a t e s a h e s i t a n c y i n t h e c rack progress ion . because most f a t i g u e tests are conducted with a c o n s t a n t load amplitude. "Stop marks" are u s u a l l y concave toward t h e f r a c t u r e o r i g i n but t h e cu rva tu re v a r i e s g r e a t l y , depending on t h e shape of t h e p a r t , t h e degree of stress concen t r a t ion , and t h e t y p e of loading.

Laboratory f a t i g u e specimen f a i l u r e s very seldom show "stop marks"

I n t h e fo l lowing s e c t i o n s , t h e appearance of t h e f a t i g u e f r a c t u r e under v a r i o u s types of loadings i s i l l u s t r a t e d , and t h e informat ion t h a t can be learned from an a n a l y s i s - o f t h e markings i s b r i e f l y d iscussed . It should be r e i t e r a t e d t h a t f r a c t u r e a n a l y s i s a s such is a complex problem and t h a t t h i s p r e s e n t a t i o n cannot hope t o cover a l l of t h e coun t l e s s v a r i a t i o n s . t i o n s should enable t h e i n v e s t i g a t o r t o recognize and diagnose t h e ma jo r i ty of s e r v i c e f a t i g u e f a i l u r e s t h a t he is l i k e l y t o encounter.

However, knowledge of t h e material i n t h e s e fo l lowing sec-

5.4.2 Bending f a t i g u e f a i l u r e s

Bending f a t i g u e f a i l u r e s can be d iv ided i n t o t h r e e g e n e r a l c l a s s i f i c a t i o n s according t o t h e type of bending load imposed. two-way bending, and r o t a r y bending. Most bending f a t i g u e f a i l u r e s i n s e r v i c e w i l l f a l l i n t o one of t h e s e ca t egor i e s .

These t h r e e types a r e one-way bending,

One-way bending f a t i g u e f r a c t u r e s occur when a f l u c t u a t i n g bending load produces s t r e s s e s above t h e endurance l i m i t of t h e material only on one s i d e of a p a r t . Under t h i s type of loading , t h e stress is g e n e r a l l y a t a maximum a t one po in t on t h e o u t e r s u r f a c e of t h e p i e c e and a f a t i g u e c rack w i l l s t a r t he re i f t h e stress is above t h e endurance l i m i t and i f i t i s repea ted long enough. stresses occur on both s i d e s of t h e n e u t r a l a x i s and, when t h e stress level and number of

Under two-way bending loads , t e n s i l e



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l’art III.- Tiie I n v e s t i g a t i o n III-5-2L- ’

loadings a r e of t h e r i g h t o r d e r a s b e f o r e , c r a c k s w i l l s t a r t on bo th s i d e s of t h e p a r t and p rogres s toward t h e c e n t r e . Rotary bending occur s when a p a r t is r o t a t e d whi le under a bending loading . r a i l r o a d a x l e under service loading .

A t y p i c a l example of r o t a r y bending would be an eng ine c r a n k s h a f t o r a

I n each case, t h e stress l e v e l a f f e c t s t h e r e l a t i v e s i z e of t h e f a t i g u e and in s t an taneous zones. When t h e stress l e v e l is low, t h e f a t i g u e zone is l a r g e and v i c e versa . S t r e s s c o n c e n t r a t i o n a f f e c t s t h e g e n e r a l c u r v a t u r e of t h e f a t i g u e s t o p marks. P o i n t sources of stress c o n c e n t r a t i o n t e n d t o d e c r e a s e t h e r a d i u s of c u r v a t u r e c l o s e t o t h e o r i g i n and l i n e s o u r c e s t e n d t o r e s u l t i n m u l t i p l e c racks t h a t j o i n t o form a crack f r o n t roughly p a r a l l e l t o t h e l i n e of stress concen t r a t ion .

These g e n e r a l f e a t u r e s , t hen , can be used t o de te rmine t h e type of bending loading a p p l i e d , and, q u a l i t a t i v e l y , t h e stress l e v e l and presence o r absence of stress concen t r a t ions . I f t h e c r o s s - s e c t i o n under c o n s i d e r a t i o n d i f f e r s w ide ly from a symmetrical s e c t i o n , t h e a c t u a l s i g n i f i c a n c e of t h e markings as r e l a t e d t o stress leve l and stress c o n c e n t r a t i o n s may be somewhat a l t e r e d , b u t , i n gene ra l , t h e same r e a s o n i n g s t i l l a p p l i e s .

5 . 4 . 3 Tension f a t i m e f a i l u r e s

Because of i n i t i a l e c c e n t r i c i t i e s i n a p a r t o r because of e c c e n t r i c loading , pure t e n s i o n load ing as such r a r e l y occur s i n s e r v i c e . Usually some amount of bending accompanies tension. on axial loading . However, enough f a t i g u e f a i l u r e s under predominantly a x i a l loading do occur i n s e r v i c e t o war ran t l e a r n i n g how t o d i s t i n g u i s h t h e s e f a i l u r e s from bending and t o r s i o n a l f a i l u r e s . Tension f a t i g u e f a i l u r e s c a n g e n e r a l l y be recognized by the manner i n which t h e c r a c k h a s p rogres sed i n t o t h e p a r t . P a r a l l e l o r c o n s t a n t cur- v a t u r e s t o p markings are c h a r a c t e r i s t i c of f a t i g u e f a i l u r e s r e s u l t i n g from s t r a i g h t t e n s i o n loading. A s i n bending f a t i g u e f a i l u r e s , t h e r e l a t i v e s i z e of t h e f a t i g u e zone and t h e in s t an taneous zone can be used as a measure of t h e stress l e v e l which produced t h e f a i l u r e .

5 . 4 . 4 Tors ion f a t i g u e f a i l u r e s

Tor s ion f a t i g u e f a i l u r e s occur i n e i t h e r of two b a s i c modes: ( a ) h e l i c a l , a t approximately 450 t o t h e a x i s of t h e s h a f t , a long t h e p l a n e of maximum t e n s i o n , o r (b) shear . such as absence of d u c t i l i t y and obse rv ing t h e ang le of t h e f a i l u r e p l ane must o f t e n be used t o i d e n t i f y f a i l u r e s of t h i s t ype . from t h e rubbing of t h e two h a l v e s of t h e f r a c t u r e be fo re fina.1 s e p a r a t i o n and t h i s c h a r a c t e r i s t i c can be used t o i s o l a t e t h i s type. u r e s , t h e i n i t i a l c r a c k w i l l s tart i n one p l ane and then s l i p o f f i n t o ano the r . Helical f r a c t u r e s g e n e r a l l y occur when p o i n t sou rces of stress c o n c e n t r a t i o n s are p resen t . c r a c k s t end t o f o l l o w t h e d i r e c t i o n of l i n e sou rces of s t r e s s c o n c e n t r a t i o n . out t o r s i o n f a t i g u e f a i l u r e s , t h e i n v e s t i g a t o r i s u s u a l l y a ided by t h e knowledge t h a t t o r s i o n loading is p r e s e n t i n t h e s e r v i c e a p p l i c a t i o n . should be suspec ted when examining f a i l u r e s of c r a n k s h a f t s , f l a p d r i v e t o r q u e tubes , c o i l s p r i n g s , s p l i n e d s h a f t members, etc. Many p a r t s t h a t are s u b j e c t e d t o t o r s i o n loads may be case hardened and t h e f r a c t u r e i n t h i s case (hard s u r f a c e l a y e r ) may resemble f a t i g u e even when i t is caused by a g r o s s over load .

l o n g i t u d i n a l o r t r a n s v e r s e , t o t h e a x i s of t h e s h a f t , a long t h e p l a n e s of maximum F a t i g u e s t o p markings may n o t always be found on t h e f r a c t u r e , and secondary means

Transverse f r a c t u r e s are u s u a l l y ve ry smooth

I n many service t o r s i o n a l f a t i g u e f a i l -

Fa t igue I n sea rch ing

I n t h i s r e g a r d , t o r s i o n f a t i g u e



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111-5- 22 Manual of Aircraft Accident I n v e s t i g a t i o n

5.5 Recognition of S t a t i c F a i l u r e ~ s

5.5.1 General

For purpose of t h i s document, a s t a t i c f a i l u r e i s de f ined a s a f a i l u r e r e s u l t - ing from one or a small number of load a p p l i c a t i o n s . permanent d i s t o r t i o n o r r u p t u r e of t h e member as a r e s u l t of stresses i n excess of t h e y i e l d po in t of t h e material. by y i e l d i n g over a cons ide rab le p o r t i o n of t h e member i n t h e r e g i o n of t h e f a i l u r e . The phenomenon is commonly r e f e r r e d t o as "necking" i n t h e f a i l u r e of a convent iona l t e n s i l e test specimen. a lumin iumal loys u l t r a h igh s t r e n g t h steels, and most c a s t i n g s , may not show any appre- c i a b l e amount of necking o r d i s t o r t i o n .

. ca se of s t a t i c loading where t h e speed of load a p p l i c a t i o n a f f e c t s t h e magnitude of load.

The f a i l u r e is c h a r a c t e r i z e d by

I n d u c t i l e materials t h i s t ype of f a i l u r e can be recognized

Materials t h a t have r e l a t i v e l y l i t t l e d u c t i l i t y , such as t h e h igh s t r e n g t h

Impact loading may be cons idered as a s p e c i a l

S t a t i c f a i l u r e w i l l occur when loads i n excess of u l t i m a t e loads are imposed on t h e a i r c r a f t o r some component of the a i r c r a f t . I n f l i g h t , t h i s can happen when t h e a i r c r a f t is manoeuvred t o o seve re ly or a t t oo high a speed. I n landing or on t h e ground, t h i s can occur when t h e a i r c r a f t is landed too hard o r when t h e a i r c r a f t is t a x i e d over an obs t ruc t ion . The damage t h a t r e s u l t s when an a i r c r a f t s t r i k e s t h e ground is of t h e s t a t i c t ype , wi th impact l oad ing be ing an important cons ide ra t ion .

5.5.2 Common f r a c t u r e s i n metal

The y i e l d i n g or "neckíng" e f f e c t found i n most metal f r a c t u r e s is an ind ica - t i o n of a s t a t i c type of f a i l u r e . Deta i led examination of t h e deformation w i l l d i s c l o s e i n d i c a t i o n s of t h e type of loading ( i . e . , bending, t e n s i o n , e t c . ) and t h e d i r e c t i o n of loading. I n most cases, t h e two ha lves of t h e f r a c t u r e w i l l m a t e w i th one another o r can be recognized as a p a i r .

5.5.2.1 T e n s i l e

I n a t e n s i l e f a i l u r e , p a r t or a l l of t h e f r a c t u r e d s u r f a c e is usua l ly made up of a series of p l anes i n c l i n e d approximately 45-60 .degrees t o t h e d i r e c t i o n of loading. In a t h i n p a r t , such as s h e e t metal, t h e r e may be only one such i n c l i n e d plane. Frequent ly f r a c t u r e s on an i n c l i n e d p lane are c a l l e d " s l a n t f r a c t u r e s ' ' o r " t e n s i l e shear f r a c t u r e s " , while those on a p lane pe rpend icu la r t o the loading d i r e c t i o n a r e o f t e n c a l l e d " f l a t f r a c t u r e s " . t h e s l a n t f r a c t u r e s are c a l l e d shear l i p s . Cons iderable l o c a l deformation o r "necking" with a r educ t ion of c r o s s - s e c t i o n a l area i s a l s o g e n e r a l l y ev iden t i n d u c t i l e materials. If t h e f r a c t u r e is pure t ens ion a lone , t h e two h a l v e s of t h e f r a c t u r e s w i l l p a r t c l e a n l y and t h e r e w i l l be no evidence of rubbing.

When a predominantly f l a t f r a c t u r e h a s s m a l l s l a n t f r a c t u r e s a long t h e edges ,

5.5.2.2 Compres s i o n

Compression f a i l u r e s occur in two g e n e r a l forms - block compression and buckling. found i n long, l i g h t e r s e c t i o n s . When buckling occurs l o c a l l y , it i s r e f e r r e d t o a s c r i p p l i n g . as column buckling. p a r t i n a l l ca ses is bent from i t s o r i g i n a l shape.

Block compression is gene ra l ly found i n heavy s h o r t s e c t i o n s whereas buckl ing i s

When i t occurs i n such a way t h a t t h e whole p i e c e buckles , i t i s r e f e r r e d t o Local buckling and column buckl ing are e a s i l y recognized s i n c e t h e



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I n b lock compression f a i l u r e s , t h e p i e c e s e p a r a t e s on o b l i q u e p l anes as i n t e n s i o n , except t h a t t h e r e is rubbing of t h e two h a l v e s of t h e f r c i c tu re du r ing s e p a r a t i o n . I n a d d i t i o n , i n some materials t h e r e is a l o c a l i n c r e a s e i n c r o s s - s e c t i o n a l area where che mater ia 1 h a s y i e l d e d . 5.5.2.3 Bending

Bending is r e s i s t e d by t e n s i l e stresses on one s i d e of t h e member and by compression on t h e o p p o s i t e s i d e . is as o u t l i n e d under t e n s i o n and compression above. caus ing f a i l u r e can always be determined from l o c a l d i s t o r t i o n i n t h e f r a c t u r e area. t h e p a r t f i n a l l y s e p a r a t e s , l i pped edges may be found on t h e i n s i d e o r compression f a c e of t h e f r a c t u r e . f a i l u r e on t h e compression s i d e may be i n shea r r a t h e r t han i n compression.

The appearance of t h e f r a c t u r e i n t h e r e s p e c t i v e areas The d i r e c t i o n of t h e bending moment

A s

T h i s l i p p i g g occur s because a f t e r t h e i n i t i a l t e n s i o n f a i l u r e , t h e f i n a l

5.5.2.4 Shear

A s i n compression f a i l u r e s , s h e a r f a i l u r e s can occur i n two d i s t i n c t ways - block s h e a r and s h e a r buckl ing . ' I n t h e former type of f a i l u r e , t h e two halves of t h e f r a c t u r e w i l l s l i d e a c r o s s t h e o t h e r and t h e f r a c t u r e w i l l appear rubbed, po l i shed o r scored. fo rce .

The d i r e c t i o n of s c o r i n g w i l l g i v e a c l u e t o t h e d i r e c t i o n of t h e a p p l i e d s h e a r i n g

Shear buck l ing g e n e r a l l y occur s i n t h i n s h e e t metal such as wing s k i n o r s p a r webs. t i o n can be t o l d from t h e appearance of t h e buckle .

The s h e e t w i l l buckle i n a d i a g o n a l f a s h i o n and t h e d i r e c t i o n of f o r c e app l i ca -

When r i v e t s , screws, o r b o l t s f a i l i n s h e a r , t h e f a i l u r e i s u s u a l l y accompanied by e l o n g a t i o n of t h e h o l e and t h e r e w i l l appear behind t h e r i v e t a new moon o r c r e s c e n t shape open space. Th i s r e s u l t can be used t o de te rmine t h e d i r e c t i o n of t h e shea r ing f o r c e .

5.5.2.5 Tors iün

S ince t o r s i o n is a form of shea r t h e f a i l u r e from t o r s i o n ove r load w i l l be somewhat similar t o t h e shea r f a i l u r e , Evidence of t h e d i r e c t i o n of t o rque can be seen on t h e f r a c t u r e d s u r f a c e by observ ing t h e s c o r i n g marks. Most p a r t s r e t a i n a permanent t w i s t and t h i s can be used as an i n d i c a t i o n . I n tub ing members o r a ' l a r g e open s e c t i o n , l i k e t h e wing, t o r s i o n f a i l u r e s o f t e n occur as i n s t a b i l i t y f a i l u r e s i n a buckl ing manner. Again t h e d i r e c t i o n of t w i s t can be determined by c l o s e examination of t h e buckle .

5.5.2.6 T e a r i n g

Tear ing f a i l u r e s i n s h e e t metal, or h e a v i e r s e c t i o n s f o r t h a t matter, gener- a l l y occur i n two d i s t i n c t forms - s h e a r t e a r i n g and t e n s i l e t e a r i n g .

Shear t e a r i n g occurs when t h e a p p l i e d f o r c e s a r e a c t i n g ou t of t h e p l ane of These f a i l u r e s are c h a r a c t e r i z e d by a l i p p i n g of material on t h e edges of t h e

The concavi ty of t h e s c o r i n g can be t h e s h e e t . s h e e t and by s c o r i n g l i n e s on t h e f r a c t u r e d s u r f a c e . used t o t e l l t h e d i r e c t i o n of t e a r i n g . The d i r e c t i o n of t e a r i n g i s from convex t o concave. Sometimes i f t h e r e ' is a heavy p a i n t f i l m , t h e saw-toothed breaking of t h e p a i n t f i l m can be used t o t e l l t h e d i r e c t i o n of t e a r i n g .



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Tens i l e t e a r i n g occurs when t h e s h e e t tears under t e n s i l e f o r c e s i n t h e This type of f r a c t u r e is q u i t e common. p l ane of t h e s h e e t o r member. Except i n t h i n s h e e t

material examination of t h e f r a c t u r e w i l l d i s c l o s e "herringbone" marks wi th t h e head of t h e her r ingbone p o i n t i n g back t o t h e o r i g i n of t h e tear.

5.5.3 Common f r a c t u r e s i n f a b r i c

5.5.3.1 T e n s i l e

A s would be expected, f a b r i c f a i l u r e s r e s u l t from an over load of t h e i n d i v i - d u a l t h reads . t h e ou t s t and ing th read ends which have a b r u s h l i k e appearance w i l l not be deformed from the l i n e of t h e load. t h r e a d s a t t h e f r a c t u r e w i l l be deformed i n l i n e with t h e load.

I f t h e app l i ed t e n s i l e f o r c e i s p a r a l l e l t o t h e t h r e a d s i n t h e c l o t h , t hen

If t h e app l i ed t e n s i l e f o r c e is a t an a n g l e t o t h e th reads , t h e

5.5.3.2 Tear ing

Under t e a r i n g loads, t h e i n d i v i d u a l t h r e a d s f a i l i n t e n s i o n , bu t t h e t h r e a d s are u s u a l l y deformed i n t h e d i r e c t i o n of t h e tear. f a m i l i a r brush- l ike appearance. t h a n t h a t which is found i n t ens ion loading a t an ang le t o t h e t h r e a d l i ne .

The ends of t h e th read p resen t t h e The deformation of t h e t h r e a d s is much more pronounced

5.5.3.3 Teas ing

Teasing is t h e term app l i ed t o t h e appearance of f a b r i c f r a c t u r e s which have been f l a p p i n g i n t h e airstream a f t e r f a i l u r e . The f a b r i c becomes un rave l l ed , f l u f f y , and sometimes even t i e d up i n knots. Sometimes t h i s can be used as i n d i c a t i o n of i n - f l i g h t f a i l u r e . Th i s cond i t ion can, however, be encountered on t h e ground under h igh wind condi- t i o n s , and cau t ion must be used i n apply ing t h i s p a r t i c u l a r c h a r a c t e r i s t i c . Some i d e a of t h e t i m e of exposure can be determined from t h e amount of t e a s i n g p resen t . Large amounts of t e a s i n g might i n d i c a t e long exposure and/or h igh airstream v e l o c i t y .

5.5.4 Common f r a c t u r e s i n p l a s t i c s

5.5*4.1 General

F a i l u r e s i n p l a s t i c windows a r e d i f f i c u l t t o e v a l u a t e because i n most cases only a s m a l l number of fragments are a v a i l a b l e f o r examination. The more p i e c e s t h a t are recovered, ' t h e b e t t e r is t h e chance of de te rmining t h e cause. The g e n e r a l p rocedures used i n s tudying f a i l u r e s i n p l a s t i c s is t o p i ece toge the r t h e a v a i l a b l e fragments and then by c o r r e l a t i n g t h e i n d i v i d u a l f a i l u r e p a t t e r n s t o i s o l a t e t h e i n i t i a l f a i l u r e . I n t h e f o l - lowing subsec t ion , in format ion is presented on t h e appearance of t y p i c a l t e n s i l e , bending and t e a r i n g type of f r a c t u r e s . assist in i s o l a t i n g t h e i n i t i a l f a i l u r e . edge of t h e pane l and is gene ra l ly a smooth curve. end on o t h e r breaks can be dismissed as be ing secondary f a i l u r e s . c a r e f u l l y examined f o r evidence of bubbles , s c r a t c h e s , n i c k s o r gouges. gene ra l , a c t as s t r e s s raisers, and i n i t i a t e t h e f a i l u r e .

In a d d i t i o n , t h e r e are a few g e n e r a l p r i n c i p l e s which A f i r s t pa th of f a i l u r e t e rmina te s only a t an

All breaks should be These w i l l , i n

The re fo re , b reaks o r f r a c t u r e s which

Two gene ra l t ypes of markings i n g l a s s o r p l a s t i c f r a c t u r e s have been i d e n t i f i e d and a r e i n gene ra l use. Rib marks are s i m i l a r t o t h e f a m i l i a r f a t i g u e c l amshe l l o r beach marks and are curved l i n e s r a d i a t i n g i n t h e d i r e c t i o n of t h e f r a c t u r e propagat ion .

These two markings are " r i b marks" and "hackle marks".

The f r a c t u r e d i r e c t i o n approaches



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a r i b mark on t h e concave s i d e and l e a v e s t h e convex s i d e . Although r i b marks are found on g l a s s and p l a s t i c f r a c t u r e s i n i t i a t e d by impact , they can be produced by r e l a t i v e l y slow t e a r i n g of g l a s s o r p l a s t i c . similar t o t h e f a t i g u e " r a t c h e t marks" which i n d i c a t e m u l t i p l e c r a c k s j o i n i n g wi th one another . Hackle marks are v a l u a b l e i n i d e n t i f y i n g t h e o r i g i n of t h e f r a c t u r e s i n c e they always p o i n t i n t h e d i r e c t i o n of t h e i n i t i a l c rack . I f t h e source of t h e f a i l u r e is a bubble o r o t h e r f low, t h e hack le marks w i l l ve ry o f t e n spread out i n r a y - l i k e f a s h i o n from t h e flow.

Hackle marks are perpendicular t o t h e r i b marka and are

5.5.4.2 Tensile

Because of t h e i r l o w d u c t i l i t y , P l e x i g l a s s and o t h e r similar p l a s t i c s f a i l i n a b r i t t l e manner. The f a i l u r e s g e n e r a l l y o r i g i n a t e a t some l o c a l weak p o i n t i n t h e material or a t a s c r a t c h o r gouge. h igh ly pol i shed . Marks resembling t h e "herringbone" markings found i n metal t e a r i n g f r ac - t u r e s r a d i a t e from t h e o r i g i n of t h e t e n s i l e f a i l u r e . g e t d i f f e r e n t l i g h t i n g on it w i l l sometimes h e l p t o make t h e markings more e a s i l y discernible.

The i n i t i a l f a i l u r e zone is u s u a l l y f l a t , smooth,

Moving t h e p i e c e back and f o r t h t o

5.5.4.3 Bending

The o u t e r o r t e n s i l e s i d e of t h e bend can g e n e r a l l y be determined by looking f o r t h e f l a t s i d e of t h e f r a c t u r e which is roughly perpendicular t o t h e su r face . On the compression s i d e , t h e f a i l u r e is u s u a l l y on an ob l ique p l ane and t h e compression edge is e i t h e r l i pped o r rounded o f f .

5.5.4.4 T e a r i n g

Tea r ing i n p l a s t i c s is e s s e n t i a l l y a t e n s i l e t e a r i n g under loads i n o r n e a r l y i n t h e p l ane of t h e s u r f a c e . Very o f t e n bending e f f e c t s combined w i t h t e n s i o n e f f e c t s are found i n t e a r i n g f r a c t u r e s . Curved, wave-like l i n e s can be seen on t h e f r a c t u r e r a d i 8 t i n g from t h e p o i n t where t h e tear s t a r t e d . These curved l i n e s are u s u a l l y pe rpend icu la r t o t h e t e n s i o n edge of t h e f r a c t u r e and curve r a p i d l y u n t i l they appear t o r u n t angen t t o t h e COP

p r e s s i o n edge. These marks resemble t h e f a m i l i a r c l amshe l l o r beach marks found i n metal f a t i g u e f a i l u r e s and are g e n e r a l l y r e f e r r e d t o in p l a s t i c f r a c t u r e s as " r ib" markings.

5 .6 Sequence of F a i l u r e

5.6.1 Genera 1

When a s t r u c t u r a l p a r t o r component f a i l s i n f l i g h t , g e n e r a l l y a cha in of even t s is s t a r t e d du r ing which o t h e r p a r t s o r components f a i l . Thus, when a wing pane l f a i l s and de taches i t s e l f from t h e a i r c r a f t , ve ry o f t e n t h e severed pane l w i l l s t r i k e and de tach p o r t i o n s of t h e f u s e l a g e o r t a i l s e c t i o n . The s e p a r a t i o n of t h e wing pane l f a i l u r e is g e n e r a l l y r e f e r r e d t o a s t h e " i n i t i a l " f a i l u r e , whereas t h e f u s e l a g e o r t a i l f a i l u r e s a r e r e f e r r e d t o a s "subsequent" f a i l u r e s . I n a d d i t i o n , when t h e a i r c r a f t o r i t s sepa ra t ed components s t r i k e t h e ground, s u b s t a n t i a l impact damage usua l ly r e s u l t s . t a s k , then , is f i r s t t o s e p a r a t e t h e i n - f l i g h t damage from t h e ground impact damage. Next, he must s ea rch out among t h e i n - f l i g h t f a i l u r e s t h e one i n i t i a l f a i l u r e . F i n a l l y , h e must i s o l a t e t h e exac t cause f o r t h i s i n i t i a l f a i l u r e .

The i n v e s t i g a t o r ' s

I n o t h e r s e c t i o n s of t h i s c h a p t e r , background m a t e r i a l h a s been presented f o r t h e i n v e s t i g a t o r ' s guidance i n , d e v e l o p i n g - p e r t i n e n t f a c t s r e l a t i n g t o s t r u c t u r a l f a i l u r e acc iden t s . As t h e v a r i o u s p o i n t s a r e developed, t h e i n v e s t i g a t o r should c o n s t a n t l y i n t e g r a t e



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t h e new evidence. d e t a i l e d examination has been performed with thoroughness, d e f i n i t e modes of f a i l u r e w i l l become evident . It w i l l be found t h a t c e r t a i n f a i l u r e s must have preceded o t h e r s f o r t h e

f a i l u r e w i l l be e s t a b l i s h e d .

I f t h e i n v e s t i g a t i o n has been proceeding s y s t e m a t i c a l l y and i f t h e

4 observed damage t o have been made. As t h e work p rogres ses f u r t h e r , a d e f i n i t e sequence of

5.6.2 Primary and secondary f a i l u r e s

I n determining the sequence of f a i l u r e , i t is extremely h e l p f u l t o have a thorough understanding of primary and secondary-type f a i l u r e s . A primary-type f a i l u r e is one which occurs whi le ad jacen t or a s soc ia t ed p a r t s a r e i n t a c t and when a loading similar t o t h e des ign loading has been app l i ed t o t h e f a i l e d p iece . Thus, a primary-type f a i l u r e of one of t h e wing main s p a r s would involve t h e compression f a i l u r e of -one spa r chord, and/or buckl ing of t h e spar web, and/or t h e t e n s i o n f a i l u r e of t h e o the r spar chord. secondary-type of f a i l u r e i s one which occurs when t h e i n t e g r i t y of ad jacent p a r t s h a s been des t royed by previous f a i l u r e s . In gene ra l , t h e loading which produces such f a i l u r e d i f f e r s from t h e des ign loading i n type. Thus, i f bo th spa r chords of a wing spa r are found f a i l e d by t w i s t i n g o r bending fo rces , t h e f a i l u r e s would be secondary. l edge of t h e des ign func t ions o f t h e va r ious a i r c r a f t s t r u c t u r a l p a r t s is necessary t o make de termina t ions of t h i s type. w i th t h e i n i t i a l and subsequent i n - f l i g h t f a i l u r e s , wh i l e t h e secondary-type f a i l u r e s are more f r equen t ly a s soc ia t ed with ground impact f a i l u r e s o r damage.

A

Some know-

I n gene ra l primary-type f a i l u r e s a r e usua l ly a s s o c i a t e d

5.6.3 A i r c r a f t a t t i t u d e j u s t before f a i l u r e

Some of t h e more important procedures and methods f o r i s o l a t i n g t h e v a r i o u s types of f a i l u r e s have been presented. I f t h e i n v e s t i g a t o r fo l lows t h e procedures o u t l i n e d h e should be a b l e , f o r example, t o determine t h a t t h e l e f t wing pane l had f a i l e d i n f l i g h t . However, it s t i l l remains f o r him t o determine why t h e wing pane l f a i l e d and i f t h e f a i l u r e w a s c o n s i s t e n t with t h e f l i g h t a t t i t u d e at t h e i n s t a n t of f a i l u r e . Th i s kind of determina- t i o n is necessary i n o rde r t o r u l e out t h e p o s s i b i l i t y of a des ign de f i c i ency o r t o e s t a b l i s h t h e impos i t ion of excess ive loads. eyewi tnesses , no g r e a t amount of work may be n e c e s s a r y l t o r e c o n c i l e t h e s t r u c t u r a l damage t o t h e f l i g h t a t t i t u d e . When wi tnesses are not a v a i l a b l e , t h e i n v e s t i g a t o r must compare t h e f a i l u r e loading wi th known loadings f o r v a r i o u s f l i g h t a t t i t u d e s t o a r r i v e a t some i n d i c a t i o n of t h e speed of t h e a i r c r a f t and t h e manoeuvre being performed a t t h e t i m e of breakup. The information presented i n t h e fo l lowing s e c t i o n s should be of a s s i s t a n c e t o t h e i n v e s t i g a t o r i n t h i s eva lua t ion work.

I f t h e acc iden t has been observed by ground o r a i r

5.7 Modes of Load Appl ica t ion

5.7.1 General

The manner o r "mode" of , load a p p l i c a t i o n has an extremely important bea r ing on t h e way i n which a p a r t f a i l s i n s e rv i ce . loading a p p l i c a t i o n s is a t bes t only a r b i t r a r y s i n c e , i n gene ra l , t h e d i f f e r e n c e between d i f f e r e n t t ypes is r e a l l y only one of degree. Thus one mode of load a p p l i c a t i o n b lends i n t o another a s r a t e of loading is decreased o r increased . Changes i n t h e frequency of loading w i l l result also i n a change of t h e mode. I n r e a l i t y , no hard o r f a s t r u l e can be s t a t e d . However, f o r purposes of i n v e s t i g a t i o n work i t is sometimes convenient t o look upon a p a r t i c u l a r loading a s one type or o the r . For t h i s reason , i n t h e fol lowing d i s - cuss ion t h e va r ious modes a r e a r b i t r a r i l y d iv ided i n t o t h r e e types : dynamic.

Any breakdown o r typ ing of v a r i a t i o n s i n

s t a t i c , r epea ted and



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5.7.2 S t a t i c l o a d i n g

S t a t i c l oad ing can be f u r t h e r d iv ided i n t o shor t - t ime s ta t ic loading and long-time s t a t i c loading:

5.7.2.1 Short- t ime load ing

I n sho r t - t ime s t a t i c l oad ing , t h e load is a p p l i e d so g r a d u a l l y t h a t a l l p a r t s are a t any i n s t a n t e s s e n t i a l l y i n equ i l ib r ium, i.e., t h e s imple , conven t iona l stress for - mulas can be used d i r e c t l y . r e s u l t s and t h e t o t a l t i m e r e q u i r e d t o produce f a i l u r e is no t more than a few minutes. s e r v i c e , t h e load i s inc reased p r o g r e s s i v e l y up t o i t s maximum v a l u e , is main ta ined a t t h a t maximum v a l u e but f o r a l i m i t e d t i m e , and is n o t re -appl ied o f t e n enough t o make f a t i g u e a cons ide ra t ion . The u l t i m a t e s t r e n g t h , e las t ic l i m i t , y i e l d p o i n t , y i e l d s t r e n g t h , and modulus of e l a s t i c i t y of a material are u s u a l l y determined by shor t - t ime s ta t ic tests. w i l l . be exp la ined more f u l l y l a t e r , t h i s is t h e type of loading a p p l i c a t i o n used i n con- j u n c t i o n wi th present-day des ign cri teria. Loads imposed upon t h e a i r c r a f t by v a r i o u s manoeuvres o r by i s o l a t e d peak g u s t s are g e n e r a l l y cons idered as s t a t i c loads.

5.7.2.2 Long-t i m e l o a d i n g

I n t e s t i n g , t h e load is inc reased p r o g r e s s i v e l y u n t i l f a i l u r e In

As

I n long-time s t a t i c load ing , t h e maximum load is a p p l i e d g r a d u a l l y as be fo re , but t h e load is main ta ined . enable i t s probable f i n a l e g f e c t t o be p red ic t ed . o r i n t e r m i t t e n t l y d u r i n g t h e l i f e of t h e s t r u c t u r e . m a t e r i a l and i t s p robab le permanent s t r e n g t h are determined by long-time tests a t t h e tem- p e r a t u r e p r e v a i l i n g under s e r v i c e cond i t ions . only important a t e l e v a t e d tempera tures . When a p a r t i s loaded f o r a r e l a t i v e l y long t i m e a t h ighe r t h a n normal t empera tu res , i t w i l l begin t o c reep o r d i s t o r t a t a more or less uniform r a t e . The s t r e n g t h of t h e p a r t is reduced from i t s room t empera ture va lue . p r e s e n t t i m e , t h e r e are few a p p l i c a t i o n s of t h i s type of loading i n c i v i l a i r c r a f t . How- e v e r , a s a i r c r a f t speeds i n c r e a s e and s k i n tempera tures are s u f f i c i e n t l y h igh , t h i s type of loading w i l l t a k e on i n c r e a s e d s i g n i f i c a n c e .

I n t e s t i n g , i t i s maintained f o r a s u f f i c i e n t l y long time t o I n service, i t is main ta ined cont inuous ly

The creep or f l o w c h a r a c t e r i s t i c s of a

This t ype of l oad ing a p p l i c a t i o n is gene ra l ly

A t the

5.7.3 Repeated load in&

In r e p e a t e d load ing , t h e load o r stress i s a p p l i e d and wholly o r p a r t i a l l y removed or i nc reased many t i m e s i n r a p i d success ion . This i s t h e t y p e of loading appl ica- t i o n which is a s s o c i a t e d wi th f a t i g u e . Genera l ly speaking , r e p e a t e d loading impl i e s a l a r g e number of load a p p l i c a t i o n s . However, under c e r t a i n c o n d i t i o n s , r e p e a t e d loading of only a r e l a t i v e l y few c y c l e s can produce a similar e f f e c t t o a l a r g e number of cyc le s . This po in t w i l l be exp lo red f u r t h e r i n t h e d i s c u s s i o n l a t e r on f a t i g u e . The important po in t t o remember a t t h e moment is t h a t t h e s t r e n g t h of a p a r t i s reduced from i ts s t a t i c s t r e n g t h va lue when t h e p a r t i s loaded r e p e a t e d l y . The a c t u a l amount of t h e r e d u c t i o n v a r i e s w i th t h e stress l e v e l and t h e number of r e p e t i t i o n s . A t y p i c a l example h e r e w i l l i l l u s t r a t e t h i s po in t . I f a round ba r of 2014-T6aluminiumalloy i s loaded i n t e n s i o n , t h e f a i l u r e stress w i l l be 60,000 p s i . Y e t i f t h i s same p a r t had been loaded through 100,000,000 cyc le s of reversed bending load , t h e f a i l u r e stress would be only 20,000 p s i . Cycles of t h i s o rde r of magnitude can be and o f t e n are encountered w i t h i n t h e l i f e - t i m e of an a i r c r a f t . Atmospheric g u s t s and v i b r a t i o n produce a repea ted type of loading: f o r some a i r c r a f t , manoeuvre loads a r e s i g n i f i c a n t .



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5.7.4 Dynamic load ing

I n t h e two previous ly mentioned types of loading , a state of equ i l ib r ium e x i s t e d , i.e., t h e e x t e r n a l loads were i n balance with t h e i n t e r n a l loads . I n dynamic loading, t h e loaded member i s i n a s ta te of v i b r a t i o n and s t a t i c equ i l ib r ium does n o t e x i s t f o r a t i m e . load ing and impact loading.

I n broad terms, t h e r e are two classes of dynamic loading - sudden

5.7.4.1 Sudden l o a d i n g

. Sudden loading occurs when a weight or "dead load", n o t i n motion, is suddenly placed upon a member of s t r u c t u r e . suspended by a cord which allowed t h e weight j u s t t o touch t h e beam, and t h e cord was t h e n cut . The stress and d e f l e c t i o n so produced would be approximately twice as g r e a t as i f t h e weight were easedon t o t h e beam as i n s t a t i c loading. mately twice as much stress and deformation when app l i ed suddenly as when a p p l i e d progres- s i v e l y . The a c t u a l magnitude of t h e "magnification f a c t o r " depends f o r t h e most p a r t upon t h e p a r t i c u l a r type of f o r c e of load being cons idered and upon t h e s t i f f n e s s of t h e sys- t e m . I n t h e a i r c r a f t f i e l d , gus t l oads a r e forms of sudden load ing a l though, a s w i l l be noted later, they are t r e a t e d as s t a t i c loads .

A beam would be t h u s loaded i f a weight were

Any f o r c e w i l l cause approxi-

5.7.4.2 Impact l o a d i n g

Impact is gene ra l ly a s s o c i a t e d wi th motion as when one body s t r i k e s ano the r . Unusually high f o r c e s can be developed under impact loading . Th i s t ype of loading h a s no d i r e c t p l ace i n a i r c r a f t des ign (a p o s s i b l e except ion would, perhaps , be i n des ign f o r c r a sh s u r v i v a l ) bu t i t i s important i n a i r c r a f t acc iden t i n v e s t i g a t i o n work. Materials which. o r d i n a r i l y f a i l i n a d u c t i l e manner under s t a t i c loading can be made t o f a i l i n a b r i t t l e manner i f t h e rate of loading i s h igh enough. I n t h i s connexion t h e ra te of l oad ing has te be apprec iab ly g r e a t e r than 50 f t p e r second (15 m / s > f o r t h i s type of loading t o be s i g n i f i c a n t . I t should be remembered t h a t even when a n a i r c r a f t s t r i k e s t h e ground a t high speed, because of e l a s t i c i t y i n t h e a i r c r a f t s t r u c t u r e and t h e load absorbing charac- terist ics of t h e ground, many p a r t s are loaded at r a t e s cons iderably lower than t h e a c t u a l impact r a t e .

5.?.5 Design load c r i t e r i a

It i s not p o s s i b l e w i t h i n t h e conf ines of t h i s manual t o d i s c u s s i n d e t a i l Nor t h e des ign load cri teria conta ined i n the va r ious S t a t e r e g u l a t i o n s on t h e sub jec t .

is i t p o s s i b l e t o set f o r t h such c r i t e r i a w i th r e s p e c t t o t h e d e s i g n of a l l a i r c r a f t . eve r an acc ident occurs i n which s t r u c t u r a l i n t e g r i t y i s s u s p e c t , t h e i n v e s t i g a t o r should f a m i l i a r i z e himself w i th t h e r e l evan t r e g u l a t i o n s and des ign c r i t e r i a .

5.8 Specialist Examinations

When-

Some of t h e more f r equen t ly conducted tests a r e (1) tests on m e t a l l i c p a r t s f o r evidence of f a t i g u e c racking , poor 'welding, subs tandard m a t e r i a l p r o p e r t i e s , poor h e a t t r ea tmen t , stress co r ros ion c racking , inadequate dimensional p r o p e r t i e s , e t c . , and (2) tests on smears, sco res , c u t s , e t c . , t o determine t h e n a t u r e of t h e subs t ance and d i r e c t i o n of app l i ed f o r c e s , e tc .



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II 1-54! 9 P d r t I I I . - Tlic T n v e s t i g a t i o n

( ince t h e sample h a s been r e c e i v e d i n t h e l a b o r a t o r y , a v a r i e t y of tests can be accompiished a s appropri-ate . a s s i s t i n t h e d e f i n i t i o n of c a u s a t i o n w i t h r e spec t t o s t r u c t u r a l f a i l u r e . It i s p o s s i b l e through such t e s t i n g t o i d e n t i f y f a t i g u e o r c-orrosion c r a c k i n g , inadequate welding, poor ‘rient t rea tment , cubst; indard material p r o p e r t i e s , inadequate dimensional’ p r o p e r t i e s , etc. i,ikewise chemical a n a l y s e s can be employed e f f e c t i v e l y on material samples and are par- t i c u l a r l y u s e f u l i n t h e i d e n t i f i c a t i o n of smears.

Micrnscopic examinat ion, hea t and loading experiments

Tests are f r e q u e n t l y performed i n r e l a t i o n t o t h e s t r e n g t h of t h e a i r c r a f t s t r u c t u r e and t h i s involves t e s t i n g of s t r u c t u r a l l o a d s through t h e medium of s t r a i n gauges, a p p r o p r i a t e l y placed f o r e i t h e r f l i g h t t e s t i n g o r s t a t i c t e s t i n g on t h e ground. Tes t ing o€ p o s s i b l e system e r r o r s by means of v a r i o u s r e c o r d i n g d e v i c e s may a l s o be cons i d e r r d.

Where damage i s s u s p e c t e d t o be t h e r e s u l t of unusua l c i rcumstances , such a s t h e d e t o n a t i o n of an e x p l o s i v e dev ice , many samples of d e b r i s : d u s t , cushion, fu r - n i s h i n g , smears, p i e c e s of paper , w i r e s , e t c . , w i l l be necessary . The smallest i t e m of a s u s p i c i o u s n a t u r e o r appearance should n o t be neglec ted . c a r e f u l l y s e a l e d i n c l e a n c o n t a i n e r s , f u l l y l a b e l l e d and da tea .

A l l p a r t s o r i t e m s sliould be

Note (1 ) : Refer t o P a r t II , Chapter 2 , S e c t i o n 2 .5 , f o r d e t a i l s concern- i n g t h e c o n s i d e r a t i o n s and a c t i o n t o be taken with regard t o s p e c i a l i s t examinations.

Note ( 2 ) : T y p i c a l examples of f r a c t u r e a n a l y s e s are g iven a t Appendix 5 a n d examples of dett-rrniriation of sequence of f r a c t u r e are given a t Appendix 6.

- Note ( 3 ) : I is d e s c r i b e d hereunder .

Fractography, which i s p a r t of t h e “ S p e c i a l i s t Examination“ I 5 . 9 Fractography

1 5 .9 .1 Gen r ra 1

. Examination and a n a l y s i s of t h e a c t u a l f r a c t u r e f a c e s , known as f r a c t o g r a p h i c a n a l y s i s o r more commonly f r a c t o g r a p h y , w i l l normally enable t h e i n v e s t i g a t o r t o i d e n t i f y t h e mode and cause of f a i l u r e . T h i s technique re l ies f o r i t s s u c c e s s on t h e f a c t t h a t p r e c i s e i n d e n t i f i c a t i o n of t h e macro and microscopic topography o f t h e f r a c t u r e s u r f a c e s can be used t o p o s i t i v e l y i d e n t i f y t h e mode of f r a c t u r e (ove r load , f a t i g u e , stress corro- s i o n , e t c . ) . deformation, environment and so f o r t h can l e a d t o deduct ion of t h e cause and sequence of f a i l u r e .

Having i d e n t i f i e d t h e mode of f a i l u r e , a n a l y s i s of t h e l o a d i n g , geometry,

5 .9 .2 I n i t i a l examinat ion

I n i t i a l examinat ion by eye a l o n e can sometimes g i v e a s u f f i c i e n t l y a c c u r a t e a n a l y s i s t o i d e n t i f v t h e cause of f a i l u r e i f t h e f a i l e d component is l a r g e enough. However i t is more normal f o r t h e i n v e s t i g a t o r i n t h e f i e l d t o u s e a pocket magnifying g l a s s of perhaps l o x magnifi.catiion power. camera f o r permanent record ing of t h e d e t a i . i s ) w i l l u s u a l l y enable t h e f i e l d i n v e s t i g a t o r t o i d e n t i f y and s e l e c t f a i l e d components suspec ted of be ing a primary cause of t h e a c c i d e n t .

This t o o l ( t o g e t h e r w i t h a macro-closeup

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III-5-29a Manual of A i r c r a f t Accident I n v e s t i g a t i o n

i. 9 . 3 Laboratory examination

i . 9 . 3 . 1 Stereomicroscope

To o b t a i n more p r e c i s e a n a l y s i s t h e suspec t components would be forwarded I O a l a b o r a t o r y , o r a t least t h e i n v e s t i g a t o r s o f f i c e , f o r c l o s e r examination. , p t i c a l stereomicroscope w i l l a l low macro-examination t o t y p i c a l l y 50x l i f e s i z e , and G i l l a l s o a l low f u l l c o l o r photography o f t h e revea led d e t a i l s . :o lor is of t en of p a r t i c u l a r importance i n record ing d e t a i l s of c o r r o s i o n products and/or l a i n t c h i p s and smears a s s o c i a t e d wi th f r a c t u r e f aces .

A good

The a v a i l a b i l i t y of

j . 9 . 3 . 2 Scanning e l e c t r o n microscope (SEM)

For many engineer ing m e t a l s , p o s i t i v e a n a l y s i s of t h e f r a c t u r e mode r e q u i r e s 2xamination of t h e micro-topography ( t h e shape of t h e s u r f a c e of t h e f r a c t u r e a c r o s s 1/1 000ths of a cent imeter r a t h e r t h a n a c r o s s c e n t i m e t e r s ) . n icroscopes a r e capable of examination of f l a t s u r f a c e s up t o 2 - 3 OOOx l i f e s i z e ( t l i i s c a p a b i l i t y is e x t e n s i v e l y used f o r example i.n metal lography, where t h e i n v e s t i g a t o r is examining a pol ished and etched f l a t s e c t h i c u t from t h e component t o i d e n t i f y i.ts s t r u c t u r e , and can hence d e r i v e i t s metiiod of manufactiire and hea t t r ea tmen t , and possih1.e subsequent environmental exposure). magnifi .cation is inc reased t h e depth of f i e l d i s reduced. s i z e p r a c t i c a l l y a l l of t h e f r a c t u r e s u r f a c e w i l l be out of focus and hence no t r u e a n a l y s i s and understanding of t h e f rac tography can be de r ived .

Laboratory q u a l i t y o p t i c a l

Unfortunately f r a c t u r e s are seldom f l a t , and as t h e A s a r e s u l t a t 1 0 0 0 ~ l i f e

This problem can u s u a l l y be reso lved by use of t h e scanning e l e c t r o n micrcscope (CEM). The SEM examines the sample under a vacuum, bu t t h i s i s not normal1.y a problem f o r inorganic (dead) samples. It o p e r a t e s by scanning a f i n e e l e c t r o n beam a c r o s s the sample, and picking up r e su l t i . ng e l e c t r o n s e j e c t e d from t h e s u r f a c e . The r e s u l t i n g s i g n a l i.s used t o modulate t h e b r i g h t n e s s o f a beam c r e a t i n g a T.V. image scanning a t t h e saine r a t e as t h e sample scanning beam. The observed p i c t u r e is q u i t e s i m i l a r i n appearanc-e t o an o p t i c a l image, but has a depth of f i e l d r e l a t i v e l y 30Ox t o 5Oox a s g r e a t as t he o p t i c a l image a t s i m i l a r magniEicat iuns. Ili theory tfic magnif i - c a t i o n can be increaseci i n d e f i n i t e l y , a s i t is m e r e l y t h e r a t i o of t h e ou tpu t T.V. screeri area compared t o t h e a r e a being scanned on t h e samp1.e. Since t h e a r e a scanned on t h e s a m p l e can be reduced t o very small l e v e l s , i n p r a c t i c e SEM examinat ions can cover t h e range from perhaps 5x l i f e s i z e t o 50 OOOx magnif icat ion. Most f rac tography a n a l y s i s can b e performed e f f e c t i v e l y i n t h e range of 1 O O x t o 10 OOOx magni f ica t ion .

5 . 9 . 3 . 3 Transmission e l e c t r o n microscope (TEM)

Occassional ly i t i s necessary t o e n l a r g e t h e sample image even more than t h e l i m i t f o r t h e SEM. t ransmiss ion e l e c t r o n microscope (TEM). I n t e r e s t i n g l y t h e TEM is o l d e r than t h e SEM, which has only been a v a i l a b l e f o r perhaps 10 t o 15 yea r s . The l i m i t a t i o n s f o r t h e TEM are t h a t i t looks a t a r e p l i c a of t h e sample and no t t h e s a m p l e i t s e l f , and i t can o n l y look a t a t i n y a r e a (perhaps 2mm x 2mm) which may hence n o t be r e p r e s e n t a t i v e and l e a d t o t h e wrong conclusion. i n t o a moldable p l a s t i c , removing t h e p l - a s t i c , "shadowing" i t wi th a very t h i n c o a t of metal, d i s s o l v i n g away t h e p l a s t i c and then passing a wide a r e a beam of e l e c t r o n s through t h e metal f i l m ( t h e rep l ica of t h e f r a c t u r e s u r f a c e ) . t h e e l e c t r o n s which passed through t h e r e p l i c a can be i n t e r p r e t e d t o deduce t h e micro- f ractography of t h e sample ( t h e image i s no t very similar t o a n o p t i c a l image, but i s more l i k e an x-ray p r i n t o r shadowgraph). S ince t h e TEM i s u s i n g e l e c t r o n s i n s t e a d of v i s i b l e l i g h t , t h e l i m i t a t i o n i s t h e wavelength ( a s wi th l i g h t ) of e l e c t r o n s , hence magni f ica t ions of up t o 1 O00 OOOx l i f e s i z e are poss ib l e .

In t h i s ca se the next resource f o r t h e i n v e s t i g a t o r i s t h e

I n p r a c t i c e a p l a s t i c model i s m a d e by impressing t h e f r a c t u r e

The image produced by c c l l e c t i n g

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Part 111.- The Investigation III-5-29b

5 . 9 . 4 Conclusion

In real life the investigator would progress from naked eye through magnifier to optical stereomicroscope to SEM and possibly TEM as necessary to deduce the fracture mode. The great advantage of all these techniques is that the sample is not damaged in any way by any of the techniques (at least this is true for engineering a l loys ) and thus the sample is still available for further examination in its original state.

18/6/78 No. 9 Copyright International Civil Aviation Organization


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II 1-5-3 O Manual of A i r c r a f t A c c i d e n t Invest igat ion

FATIGUE FRACTURE

Note the smooth velvety appearance of the fat igue zone with clear stop marks and the coarse appearance of the instantaneous zone.

M A I N TYPES OF FRACTURE



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II 1-5-3 1 ____-- -__--- -_-- - -- -l__l-

P a r t III.- The Investigation - _---- 1

S ta t i c fracture of the upper ear caused by overload following the fa i lure of the lower ear.

Fatigue fracture of the l e f t s ide o f the lower ear ( B ) ; note the nucleus arid l im i t s of the fa t igue zone a t arrows B and C respective (below). S t a t i c t ens i l e tearing fracture of the r igh t side of the lower ear followed.

( A

l Y

t I

EXAMPLE OF THE TWO TYPES OF FRACTURE ON THE SAME PIECE OF WRECKAGE



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111-5- 32 Manual of A i r c r a f t A c c i d e n t I n v e s t i g a t i o n

FATIGUE FRACTURE OF HOLLOW ALUMINIUM ALLOY PROPELLER

f lote typical di f ference of appearance betzjeen fat igue zone and instantaneous zone.



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P a r t III.- The I n v e s t i g a t i o n I I I- 5-3 3 ’ -_ ___.__---

L

of the p a r t of the

t- e O

iiI

b h d e showing wear pat tern near the fracture. X 1.

llll-_l_-pllll--

Appearance of the fractured Portion of fracture and surface. Fatigde fracture adjacent surface showing originated a t arrow rrarr and the re la t ion of dark areas extended t o arrows “b”. X 1. (arrows) on the fracture

t o those on the e x t e r m l siAi-face. X 2.

i. i f 1 UiJi;. FRACTURE OF SOLID ALUNNILX ALLOY PROPELLER



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..

1 1 1 - 5 - 3 4 Manual of A i r c r a f t Accident Invest igat ion

EXAMPLES OF STATIC TENSION FRACTURE I N TUBULAR SECTION

Note 45-degree plane of fracture and the Zack of dis tor t ion o r burring o f edges.



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111-5-35 P a r t 111.- The I n v e s t i g a t i o n ___--- - . II

Skin c o l l a p e d due t o loading applied in the directions of the arrows

I

/

Buckling Co nipression

"A" - "A" length shortened due t o

Tube bursting outward local ly longitudinal cracks

compression

n

EXAMPLES OF STATIC COMPRESSION FAILURE



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I I 1-5- 3 6 Manual of Aircraft Accident Investigation

I Flange bent upwards

Bending i n plane of l e g - l e g i n compression.

Flange bent upwards -7-- i- Bending i n plane of leg - l eg i n compression.

EXAMPLES OF STATIC BENDING FRACTURES IN TEE-CROSS SECTION



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Part 111.- Tne Investigation ~

r 1

No distortion or burring of edges

Tension

Top of leg shows bending signs

Tensile characteristics in leg fracture

Flange bent down locally at fracture

Bending - downwards

Bending-in of flange

~_II_

Bending - upwards-

I II- 5-3 7

COMPARISON OF STATIC TEMSION AND BENDING FRACTURES I N ANGLE SECTION



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III-5-.38 Manual of A i r c r a f t A c c i d e n t Invest igat ion

T e d e characteristics

Bending.

CornDression side ” IT

Compression ( s t r u t f a i l u r e ) .

STATIC BENDING AND COMPRESSION FRACTURES I N TUBULAR SECTION

Note s imi lar i ty .



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Part III.- T h e I n v e s t i g a t i o n -. 111-5-49-

Tensile characteristics

I /------------

Suiral fracture surface 1

' ""yyTensile characteristics along this surface

(7 -- Torsion . -

MPARISON OF STATIC BENDING AND TORSION FRACTURES I N TUBULAR? CTION



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111-5-40 M

anual of A

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ent

Investigation

STATIC

SHEAR FRA

CTURES IN

R

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ivil Aviation O

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rovided by IHS


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IHS

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II 1-5-1 ____ ~

Far t 111.- Tlie I n v e s t i g a t i o n _-___-

A luminiun a 7, L O ~ .

SteeZ bolt. TYPICAL STATIC SHEAR FAILURE

Note characteristic bright hal f moon indicated by an arrow.



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111-5- 42 Manual of Aircraft Accident Invest igat ion

CONNECTING STRUCTURE

TENSION NOTE 'NECKING'

BUT NO BENDRJG

UPWARD AND BACKWARD BENDING

ANALYSIS OF FRACTURES I N A WING SPAR



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--`,,```,,,,````-`-`,,`,,`,`,,`---

111-5- 44 M

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I 11-5-4 5 I-_____I_ _______I.

P a r t 111.- T:le Investigation ---__ -..-__.I__

Tension

Microscopic examination would show strands thus.

I

1 ' ' RLE FRACTURES



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- 111-5-46 Manual of Aircraft Accident Investigation

- All strands broken at common

points in cable. Ends of strands would appear thus

Ø

I

Tens ion plus cutting (Localising fracture)

CABLE FRACTURES



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111-5-47 P a r t III.- T h e Investigation - ~.

Bushy appearance, f i b res s traight Tension Bushy appearance, f i b res turned along threads locally a t fracture across threads

Teasing. Fracture before being heZd i n airstream



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111-5- 48 Manual of Aircraft -- Accident Investigation

Fibres aìi straight, fractare e x t d s ov& appreciable length of member.

Tension along grain. ~~

Mirror at 45 degrees to show side view of fiabure, surface fibres lifted in different directions.

Tension across grain.

Mark of compression fracture of the fibres on a finest quality spruce spar base plate.

I I \

Compression.

ZXAMPLES OF STATIC TENSION AND COMPRESSION FRACTURES IN WOOD



--`,,```,,,,````-`-`,,`,,`,`,,`---

111-5-49 _. - P a r t III.- The I n v e s t i g a t i o n

Tensile characteristics

/ Compression characteristics

BENDING FRACTURE O F A WING SPAR.

The base pLates of the wing spar are made of Laminated spruce.

DYNAMIC BENDING FRACTURE OF A LAMINATED SPRUCE SAMPLE



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111-5- 50 Manual of A i rc ra f t Accident Inves t iga t ion

Finest quality.

First qua Zity.

Second qua Zit y.

EVOLUTION OF DYNAMIC BENDING FRACTURE I N SAMPLES OF SPRUCE OF DIFFERING QUALITIES

Note that the lower the quality the Zess marked the difference between the tension and the compression characteristics.



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PART III

CHAPTER 6. - POWERPLANT INVESTIGATION



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-- IT I- 6-1 _ _ Part III.- The I n v e s t i g a t i o n -

CHAPTER 6

P W E R P L A N T INVESTIGATION

6 . 1 Genera l

The Powerplant i n v e s t i g a t i o n normally i n c l u d e s t h e eng ine , t h e f u e l , o i l and coo lan t sys tems, p r o p e l l e r and i t s c o n t r o l u n i t , j e t p i p e and p r o p e l l i n g n o z z l e , t h r u s t r e v e r s e r ( a s a p p r o p r i a t e ) , mountings of t h e eng ine , and where t h e eng ine i s b u i l t i n t o a u n i t , t h e a t t achmen t s of t h e u n i t t o t h e a i r f r a m e s t r u c t u r e , f i r e w a l l s and cowl ings , a u x i l i a r y g e a r box, c o n s t a n t speed d r i v e u n i t , engine and p r o p e l l e r a n t i - i c i n g sys tem, engine f i r e d e t e c t i o n and e x t i n g u i s h i n g systems, powerplant c o n t r o l s .

Powerplant f a i l u r e s o r ma l func t ions are f r e q u e n t c a u s a l f a c t o r s i n a i r c r a f t a c c i d e n t s . For t h i s reason i t is e s s e n t i a l t h a t a c a r e f u l examinat ion of t h e powerplan ts and t h e i r a s s o c i a t e d components be made t o de te rmine whether they are involved as a causa f a c t o r i n t h e p a r t i c u l a r a c c i d e n t under i n v e s t i g a t i o n . i nc lude a n e g a t i v e s t a t emen t i n t h e r e p o r t r ega rd ing t h e powerplant i f i t i s determined t h a t f a i l u r e o r ma l func t ion were n o t c a u s a l f a c t o r s .

i t is e s p e c i a l l y impor tan t t o b

i n most c a s e s a complete o r even p a r t i a l s t r i p o r teardown of e i t h e r a p i s t o n o r t u r b i n e engine w i l l n o t be p o s s i b l e a t t h e scene of t h e a c c i d e n t , indeed w i t h modem complex eng ines t h i s i s most u n d e s i r a b l e . Only i n ve ry s m a l l and s imple types of engines and where a b s o l u t e l y necessa ry should t h i s be a t tempted .

Only a s u p e r f i c i a l examination should be a t tempted a t t h e s i t e of t h e a c c i d e n t paying p a r t i c u l a r a t t e n t i o n t o t h o s e i t e m s of c o n t r o l o r f u e l f e e d s connec t ing t h e engine t o t h e airframe. u s e f u l where i n - f l i g h t o i l l eakages and /o r f i r e are suspec ted .

Photography should be f r e e l y used and c o l o u r photography i s

It i s most h e l p f u l and indeed necessa ry wi th modern and complex eng ines t o e n l i s t a s u i t a b l y q u a l i f i e d engine maker 's r e p r e s e n t a t i v e , p r e f e r a b l y someone who has expe r i ence of a i r c r a f t a c c i d e n t procedure and t echn iques , i n t o t h e Powerplant I n v e s t i g a t i o n Group.

.After a p r e l i m i n a r y s t u d y on t h e s i t e of t h e a c c i d e n t qrrangements should be made t o t r a n s p o r t t h e powerplant t o an a p p r o p r i a t e and approved b a s e f o r f u r t h e r d e t a i l e d examination and tests.

Always c o n s i d e r whether t h e eng ine can be bench- tes ted under c o n t r o l l e d c o n d i t i o n s , b e f o r e s t r i p p i n g o r removing any accesso ry , i f such an exercise is a p p r o p r i a t e o r necessa ry having r ega rd t o t h e c i r c u m s t a n t i a l ev idence of t h e a c c i d e n t .

6 .1 .1 E x t e r n a l Damage

The f i r s t and most obvious i n s p e c t i o n a t t h e scene o f t h e a c c i d e n t is f o r damage and whether t h i s damege i s c o n s i s t e n t w i th t h e crash impact o r n o t .



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Manual of Airc ra f t Accident Investigation I 11-6-2 .--_I-

Impact under power.

impact not under powel- ífZame-out).

JET ENGINE COMPRESSORS



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Parli III.- The I n v e s t i g a t i o n I II- 6- 3

Very g e n e r a l l y , impact damage should be appa ren t t o t h e i n v e s t i g a t o r ; c r a s h impact damage w i t h hard t e r r a i n o r b u i l d i n g s w i l l c ause inward p e n e t r a t i o n s o f t h e engine c a s i n g s o r t e a r i n g o f f of a c c e s s o r i e s , w h i l s t i n - f l i g h t f a i l u r e such a s compressor o r t u r b i n e ma l func t ion can cause e x t e r n a l p e n e t r a t i o n s , t h a t is t o s a y p a r t s of t h e compressor o r t u r b i n e may w e l l be e j e c t e d from t h e eng ine and make a number of p e n e t r a t i o n s of t h e engine o r a d j a c e n t a i r f r a m e . These i n d i c a t i o n s are of a n X n i t i a l and g e n e r a l c h a r a c t e r and no c o n c l u s i o n s should b e drawn a t t h i s s t a g e of t h e i n v e s t i g a t i o n .

6.1.2 Power a t imvact

It is n e a r l y always a n u r g e n t requirement t o know whether t h e eng ine , be it a p i s t o n e n g i n e o r t u r b i n e e n g i n e , w a s under power when i t s t r u c k t h e ground. Th i s is not always e a s y t o a e s e s s and no s t r a i g h t f o r w a r d o r qu ick formulas are a v a i l a b l e t o assess t h i s a t t h e scene of t h e a c c i d e n t .

6.1.2.1 Jet enp ines

I n some i n s t a n c e s t h e f a c t t h a t j e t e n g i n e s w e r e under power o r no t a t impact is easy t o determine ( s e e f i g u r e s on page 111-6-2). The upper f i g u r e shows a com- p r e s s o r which had a high degree of r o t a t i o n a l energy on impact w h i l s t t h e lower f i g u r e r e p r e s e n t s a compressor not under power on impact, but p o s s i b l y r o t a t i n g under windmil l ing c o n d i t i o n s only . These photographs are, however, examples of extreme condi t ' ions . I n moat i n s t a n c e s , p a r t i c u l a r l y i n t h e absence of a s u r v i v i n g f l i g h t crew o r of i n d i c a t i o n s of engine power from f l i g h t r e c o r d e r s , s e v e r a l f a c t o r s must be t a k e n i n t o account and examined before an assessment can be made. Such a s ses smen t s can only be approximate and no sound technique e x i s t s where an e x a c t power o r rpm of an engine can be g iven because, i n t h e absence of a r e c o r d e r , t h e r e are so many v a r i a b l e and unknown f a c t o r s t o be t aken i n t o cons ide ra t ion . For i n s t a n c e i f a j e t a i r c r a f t s u f f e r s loss of power, say on take-off and s t r i k e s t h e ground immediately, t h e windmi l l i ng o r run-down of t h e t u r b i n e and compressor rpm w i l l have been reduced on ly s l i g h t l y and t h e evidence of high-speed r o t a t i o n at impact could be ve ry misleading. There are, of course , occas ions where t h e engine c a s i n g is not damaged so no d i s t o r t i o n of b l a d e s o r rubbing of compressors appea r s t o a s s i s t t h e i n v e s t i g a t o r . The l a c k of v i s u a l r o t a t i o n a l damage is n o t , t h e r e f o r e , immediate evidence of low power. The c i r cums tances of c r a s h impact, p i l o t a c t i o n s b e f o r e impact, s e t t i n g of f u e l and o i l v a l v e s , speed of impact , n a t u r e of impact t e r r a i n o r water etc. must a l l be considered. f i r m conc lus ion can be reached w i t h t u r b i n e engines .

F u l l s t r i p i n v e s t i g a t i o n of t h e engine is necessa ry i n a l l cases b e f o r e any

6.1.2.2 P i s t o n and t u r b i n e l p r o p e l ler e n g i n e s

A d i f f e r e n t t echn ique i s r e q u i r e d t o determine i f a p i s t o n o r t u rb ine /p ro - p e l l e r eng ine w a s under power a t t h e t i m e of impact. Here a g a i n a l a c k of power may appear t o be obvious a t f i r s t i n s p e c t i o n ( s e e f i g u r e s on pages 111-6-7 t o 111-6-10) t h e p r o p e l l e r may even be f e a t h e r e d but t h i s i s n o t conc lus ive evidence of l a c k of power a v a i l a b l e at t h e engine. Acc iden t s have been caused by crew f e a t h e r i n g t h e 'good' eng ine i n mis t ake f o r t h e d e f e c t i v e one, so p r o p e l l e r examinat ion must a l s o go a l o n g w i t h e n g i n e examination. it is v e r y unwise t o t r y and conclude upon power o u t p u t of a p i s t o n , o r t u r b i n e / p r o p e l l e r engine a t t h e scene of an a c c i d e n t . P r o p e l l e r s must always be t aken t o an approved work- shop or l a b o r a t o r y f o r e x p e r t examinat ion.

Again



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6.2 Evidence Obta inable from P r o p e l l e r Examination

When p rope r ly c o r r e l a t e d w i t h ev idence ob ta ined from t h e engine , examina- t h n of t h e p r o p e l l e r can produce v a l u a b l e ev idence such as:

1.

2.

r evea l ing whether power w a s be ing produceâ a t t i m e of impact

rpm ef t h e engine ( i n some cases)

3. p r o p e l l e r b lade ang le

4 . ground speed of t h e a i r c r a f t ( i n some cases).

5.2.1 Examination of b l ades

The f i r s t s t e p i n p r o p e l l e r examination is t o account f o r a l l t h e b l a d e s , p a r t i c u l a r l y t h e i n t e g r i t y of t h e t i p s . t u r e s on t h e recovered p o r t i o n should be examined wi th a magnifying g l a s s t o de te rmine whether t h e break occurred i n f l i g h t o r a t impact. should be c a r e f u l l y noted.

I f any p o r t i o n of t h e b l ade is miss ing , t h e f r a c -

Evidence of f a t i g u e o r t e n s i o n b r e a k s

6 .2 .2 Determination of power a t impact

The next s t e p should be an examination t o de termine whether power was b e i n g developed a t t h e t i m e of impact. The most t y p i c a l i n d i c a t i o n s are as fo l lows:

a ) b l ades bent forward nea r t h e t i p i n d i c a t e h i g h power a t t i m e of impact. Blade p i t c h angle w i l l normally be i n t h e c o n s t a n t speed range;

b ) b l ades bent s l i g h t l y rearwards i n d i c a t e r o t a t i o n of t h e p r o p e l l e r a t t i m e of impact b u t low o r no power. Th i s is u s u a l l y a s s o c i a t e d w i t h a windmill ing cond i t ion . Blade p i t c h a n g l e w i l l normally be on t h e f i n e p i t c h s top .

However, a word of warning - t h e i n v e s t i g a t o r i n t h e f i e l d must treat w i t h g r e a t r e s e r v e t h e damage and d i s t o r t i o n he may see i n p r o p e l l e r b l ades a f t e r t hey have s t r u c k t h e ground. It is a l l too easy t o reach a h a s t y conc lus ion t h a t an engine has been under power when t h e acc iden t occur red because t h e p r o p e l l e r is g r e a t l y bent o r daniaged. Evidence adduced from examination of t h e p r o p e l l e r b l a d e s w i l l normally be Co-related w i t h o t h e r evidence b e f o r e i t is p o s s i b l e t o form a p rope r conclus ion .

A s a p recau t ion a g a i n s t t h e l o s s of impor tan t ev idence i t i s a good p r a c t i c e t o mark t h e p o s i t i o n of t h e b l ade shank wi th r e s p e c t t o t h e p r o p e l l e r hub b u t where t h e d r i v e between t h e b l ade and t h e p i t c h change mechanism i s seve red as a r e s u l t of impact, t h e s i g n i f i c a n c e of t h e s e marks w i l l have t o be a s s e s s e d du r ing d e t a i l e d in spec t ion . f a c t o r s must be taken i n t o cons ide ra t ion , and each a c c i d e n t a s s e s s e d accord ingly . of impact, t h e n a t u r e of t h e ground, speed o f impact, t h e material of t h e p r o p e l l e r be i t aluminium a l l o y , s tee l o r wood, a l l i n f l u e n c e t h e assessment . I n s h o r t , i t is n o t s u f f i - c i e n t t o examine a p r o p e l l e r by i t s e l f and t h e n assess whether o r n o t t h e engine w a s under power. The p r o p e l l e r b lades form only one l i n k i n t h e c h a i n of ev idence , which, when coupled wi th o t h e r f e a t u r e s such a s p i t c h a n g l e of t h e b l a d e s i n r e l a t i o n t o t h e known phase of ope ra t ion a t t h e t i m e of t h e a c c i d e n t , t h e t w i s t i n g , i f any, i n t h e p r o p e l l e r s h a f t

Many The a n g l e



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111-6-5 .-I __--. -.-- P a r t III.- The I n v e s t i g a t i o n

and t h e c o n d i t i o n of t h e eng ine and f u e l v a l v e s e t c . may l ead t o sounder conc lus ions regard ing t h e deg ree of engine power be ing developed a t t h e t i m e of impact. of t h e p i t c h s e t t i n g may be a s c e r t a i n e d by s t r i p p i n g t h e p r o p e l l e r governor head and checking t h e p o s i t i o n of the p i t c h change mechanism i n con junc t ion wi th . impact markings o r impress ions o f t e n made a c r o s s t h e base of t h e b l ade on th.e s o f t copper shims o r packing plates. The markings o r impress ions can g ive v a l u a b l e and r e l i a b l e c l u e s as t o t h e p i t c h ang le of t h e b l a d e s a t t h e t i m e t h e b l a d e s t r i k e s t h e ground. w i th c a r e i n con junc t ion w i t h an e x p e r t from t h e p r o p e l l e r manufac tu re r s o r o t h e r s k i l l e d person exper ienced i n t h i s t ype of i n v e s t i g a t i o n .

Determinat ion

Th i s work must be done

Wooden b l a d e s under power load ing w i l l s h a t t e r and t h e i r p i e c e s w i l l be s c a t t e r e d a c o n s i d e r a b l e d i s t a n c e e i t h e r s i d e of the p a t h made by the a i r c r a f t ( s e e f i g u r e s on page 111-6-8).

P r o p e l l e r s which are f e a t h e r e d on impact may, depending upon the n a t u r e of t h e c r a s h , leave d i s t i n c t i v e l i n e markinggon t h e ground i n l i n e w i t h t h e p a t h of t h e a i r c r a f t . P r o p e l l e r s r o t a t i n g leave c h a r a c t e r i s t i c s l a s h marks a t s h o r t i n t e r v a l s o r spac ings upon which c e r t a i n c a l c u l a t i o n s can be made ( s e e paragraph 6.2.3 below). case of p r o p e l l e r s of some l i g h t a i r c r a f t which are ope ra t ed by governor o i l p r e s s u r e a g a i n s t a s p r i n g o r compressed a i r , it does n o t n e c e s s a r i l y f o l l o w t h a t i f t h i s t y p e of p r o p e l l e r is found i n t h e f e a t h e r e d p o s i t i o n t h a t t h e p r o p e l l e r was f e a t h e r e d p r i o r t o impact. impact.

I n t h e

I n some c i rcumstances t h e s e p r o p e l l e r s can run i n t o t h e f e a t h e r e d p o s i t i o n a f t e r

It should always be remembered t h a t ev idence of l a c k of engine power on impact as shown by t h e p r o p e l l e r does n o t n e c e s s a r i l y imply eng ine f a i l u r e s i n c e t h e p i l o t may c l o s e t h e t h r o t t l e of an eng ine , o r t u r n t h e swi t ches o f f b e f o r e impact i f h e is i n a p o s i t i o n t o do so.

6.2.3 Determina t ion of Pround speed a t impact

The spac ing of the i n i t i a l cuts o r bites of t h e b l a d e s of a p r o p e l l e r i n

The fo l lowing formulas may b e used t o de te rmine t h e ground may p rov ide u s e f u l ev idence p a r t i c u l a r l y i f t h e ground speed of t h e a i r c r a f t a t impact is known ( o r can b e e s t i m a t e d ) . approximately t h e p r o p e l l e r speed i n r e v o l u t i o n s p e r minute a t t h e t ime of impact w i t h t h e ground:

31 x groundspeed ( k t s a) speed mm = Dis tance between c u t s - in metres x number of b l ades

o r

101 x proundspeed ( k t s ) D i s t ance between c u t s i n f e e t x number of b l ades

The engine s h a f t speed can be ob ta ined by i n v e r s e l y app ly ing t h e r educ t ion gea r r a t i o t o t h e p r o p e l l e r speed. is known t h e formula can be used t o o b t a i n t h e approximate ground speed a t impact.

A l t e r n a t i v e l y , i f t h e p r o p e l l e r speed ( o r engine speed)

Ground speed ( k t s ) = Prop speed ( r p m ) x d i s t a n c e between c u t s x number of b l ades 31 (me t r i c u n i t s ) o r 101 ( f e e t )



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6.2.4 P r o p e l l e r f a i i u r e i n f l i p h t

Accidents have occurred due t o b l ade f a i l u r e i n f l i g h t , u s u a l l y as a r e s u l t of f a t i g u e c racks . t o r n ou t of i t s mountings o r t h e reduct ion gea r cas ing i s t o r n from the' engine. P r o p e l l e r f a i l u r e i n f l i g h t may no t o r i g i n a t e i n t h e p r o p e l l e r i t s e l f and c a r e f u l examination of i t s c o n t r o l l e r , o i l system, engine and reduct ion gea r is e s s e n t i a l .

Such f a i l u r e s cause excess ive v i b r a t i o n and f r e q u e n t l y t h e engine is

6.2.5 Overspeedinn of p r o p e l l e r s

ûverspeeding p r o p e l l e r s , which have d e f i e d a t t empt s by t h e f l i g h t crew t o f e a t h e r them, have a l s o been a f a i r l y common f a c t o r i n a c c i d e n t s . F a i l u r e of t h e r e d u c t i o n gea r may i n some i n s t a l l a t i o n s uncouple t h e p r o p e l l e r and t h e f r e e sp inn ing p r o p e l l e r may overspeed v i o l e n t l y due t o windmil l ing a t h igh a i r s p e e d s t o such a n ex ten t t h a t b l ades may be f lung out of t h e hub under enormous c e n t r i f u g a l f o r c e s loading . resource t h e f l i g h t crew have of c o n t r o l l i n g an overspeeding o r run-away p r o p e l l e r is t o c l o s t h e t h r o t t l e and raise t h e nose of t h e a i r c r a f t i n o r d e r t o reduce t h e a i r speed .

Very o f t e n t h e only



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P a r t 111.- The Investigation 111-6-7

Light a i rc ra f t : propeller not under power a t impact.

Fracture analysis shows propeller f a i l e d i n backward bending, suggesting that propeller was not under power a t impact.

WOODEN PROPELLERS



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111-6- 8 Manual of Airc.raf t Accident Investigation __-

Propeller windmilling a t impact.

Propeller under power on impact.

METAL PROPELLERS



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III- 6-9 -_._- - - Part 111.- The Inves t iga t ion

Prope Z Zer under power a t impact.

t

BZadec 3 and 4 of the above propeller.

METAL PROPELLERS



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111-6-10 Manual of Aircraft Accident Investigation -- -

T i p of b l a d e no. 1 of same p r o p e l l e r .

METAL PROPELLERS (Cont d)



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P a r t III.- The I n v e s t i g a t i o n 111-6- 11- - 6.3 Opera t iona l C a p a b i l i t i e s of t h e Engine a t Impact

The i n v e s t i g a t o r must, b e f o r e removal of any eng ine from t h e scene of an a c c i d e n t , s a t i s f y h i m s e l f , so f a r as t h e wreckage w i l l p e r m i t , t h a t t h e eng ine w a s capable of producing power. I n a d d i t i o n t o t h e fo rego ing examination i t i s j u s t as important t o e s t a b l i s h t h a t t h e engine is p r o p e r l y connected t o a s o u r c e ’ o f f u e l and o i l and t h a t t h e a p p r o p r i a t e f u e l v a l v e s are c o r r e c t l y s e b t h e p i p e s and l i n e s clear of o b s t r u c t i o n and t h e f u e l and o i l t ank c l e a n and u n o b s t r u c t e d , n o t only o u t l e t s b u t inward a i r v e n t s as w e l l . The t h r o t t l e connexions should be examined f o r c o r r e c t connexions and t h e i g n i t i o n ( i f p i s t o n engine) checked from t h e s w i t c h e s t o t h e d i s t r i b u t o r . from d i r t y and o b s t r u c t e d f u e l f i l t e r s which have caused a l o s s of power. s t r i p examinat ion of t h e mechanical p a r t s of t h e eng ine w i l l r e v e a l no evidence of mechanical d e f e c t o r f a i l u r e .

Many a c c i d e n t s have a r i s e n I n t h e s e cases

6.3.1 Determinat ion of ma l func t ion o r f a i l u r e of p i s t o n e n p i n e s

I n de t e rmin ing f a i l u r e o r ma l func t ion of a p i s t o n e n g i n e any evidence re-

The fo l lowing most common symptoms of engine m a l f u n c t i o n and t h e i r ceived from eyewi tnesses should f i r s t be cons ide red i n o r d e r t o l o c a l i z e t h e t y p e of f a i l u r e involved. causes are l i s t e d f o r i n fo rma t ion . The f a c t t h a t several of t h e s e symptoms are similar should forewarn t h e i n v e s t i g a t o r of t h e , p o s s i b i l i t y of a s s i g n i n g wrong c a u s a l f a c t o r s i f a c a r e f u l p h y s i c a l examinat ion is n o t derformed.

6.3.1.1 C a r b u r e t t o r i c i n g

Th i s is experienced more f r e q u e n t l y w i t h t h e s m a l l p i s t o n eng ine than w i t h t h e l a r g e r p i s t o n eng ines and is u s u a l l y i n d i c a t e d by a g r a d u a l d e c r e a s e i n power, s p u t t e r i n g , e r r a t i c i n c r e a s e s and d e c r e a s e s i n r p w i n t e r m i t t e n t rough o p e r a t i o n , exhaus t o f t e n e m i t - t i n g b l a c k ( o v e r r i c h mixture) smoke. t h e re la t ive humidi ty is f a i r l y h i g h (above 60 p e r c e n t ) i n f i n e , sunny and o f t e n warm weather (15/20OC - 60/70°F). need not be p r e v a i l i n g f o r c a r b u r e t t o r ice t o form. me teo ro log ica l c o n d i t i o n s and assess t h e s e c o n d i t i o n s wi th h i s f i n d i n g s i n t h e wreckage i.e., t h e s e t t i n g of t h e h o t and c o l d a i r i n t a k e v a l v e s o r s h u t t e r s bo th a t t h e engine and cock- p i t . Checks should be made f o r p o s s i b l e f a i l u r e of t h e s h u t t e r s themselves o r disconnexion of t h e c o n t r o l .

I n some eng ines c a r b u r e t t o r i c i n g w i l l occu r when

It must be borne i n mind t h a t c o n d i t i o n s f o r a i r f r a m e i c i n g The i n v e s t i g a t o r must s t u d y t h e

6 . 3 . 1 . 2 I g n i t i o n t r o u b l e

I g n i t i o n f a u l t s are o f t e n i n d i c a t e d by i n t e r m i t t e n t l y rough o p e r a t i o n of t h e engine. and t iming are a l l p o i n t s worthy of i n s p e c t i o n . i n g and may i n d i c a t e o t h e r t r o u b l e s such as i n c o r r e c t mix tu re o r abnormal l e a d d e p o s i t s . The i n v e s t i g a t o r must check t h a t t h e t y p e of s p a r k p l u g is a p p r o p r i a t e and t h a t t h e p lugs are t i g h t i n t h e c y l i n d e r s . t h e engine etc.

Electr ic h a r n e s s , magneto w i r i n g t o t h e c o c k p i t s w i t c h e s , magneto d r i v e s The s p a r k p l u g p o i n t s may be v e r y reveal-

H e must also check t h a t t h e f u e l w a s t h e c o r r e c t grade f o r



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Manual of A i r c r a f t Accident I n v e s t i g a t i o n --- 111-6-12

6.3.1.3 Running o u t of f u e l o r f u e l s t a r v a t i o n t o t h e eng ine

This is o f t e n i n d i c a t e d by s p u t t e r i n g o r erratic i n c r e a s e s and dec reases of power, b u t on occas ions , depending upon t h e type of c a r b u r e t t o r o r f u e l i n j e c t i o n system, t h e r e may be no a u d i b l e o r n o t i c e a b l e warnings except a s i l e n t f a d i n g away of t h e engine. On multi-engined a i r c r a f t , e s p e c i a l l y when f l y i n g on in s t rumen t s o r a t n i g h t and where c o n s t a n t speed p r o p e l l e r s are i n use, f a i l u r e may be d i f f i c u l t t o d e t e c t f o r some t i m e . Fuel p r e s s u r e 9nd f u e l flow meters g ive t h e most r e l € & b l e i n d i c a t i o n of f u e l S t a r v a t i o n caus ing an engine loss of power. I n c o r r e c t f u e l va lve s e t t i n g o r f u e l system mismanagement p a r t i c u l a r l y ' o n multi-engined a i r c r a f t has caused more a c c i d e n t s t han running o u t of f u e l i n t h e normal sense. found i n t h e wreckage whether he cons ide r s them r e l e v a n t o r r e l i a b l e o r no t . c o n t r o l l e d va lves normally g ive r e l i a b l e pre-crash i n d i c a t i o n of t h e l a s t s e t t i n g of t h e valve. r e scue and sa lvage a t t empt s and t h i s type of c o n t r o l should t h e r e f o r e be viewed wi th susp ic io i as t o r e l i a b i l i t y of pre-crash s e t t i n g .

The i n v e s t i g a t o r must ensu re t o record a l l f u e l v a l v e s e t t i n g s as E l e c t r i c a l l y

Cable o r rod ope ra t ed f u e l va lves may move du r ing t h e c r a s h impact o r du r ing

I n s p e c t i o n of i u e l t anks , p i p e l i n e s and f u e l v e n t s is e s s e n t i a l t o ensu re t h a t o b s t r u c t i o n , leakage, chaf ing , punctured o r corroded tanks d i d n o t e x i s t . The inves- t i g a t o r must check back t o t h e las t r e f u e l l i n g source and i n s p e c t t h e r e l e v a n t documents. S to rage and usage of t h e a i r c r a f t t o g e t h e r w i t h f u e l l i n g p r a c t i c e may r e q u i r e examination f o r it is p o s s i b l e f o r water condensation t o c o l l e c t i n tanks and c a r b u r e t t o r s .

,

S t r i p i n s p e c t i o n of f u e l i n j e c t o r s and c a r b u r e t t o r s should be performed by . s p e c i a l i s t s a t a s u i t a b l e base o r l a b o r a t o r y . P o i n t s t o remember du r ing t h i s i n v e s t i g a t i o n

are, proper s i z e of j e t i n s t a l l e d , s t i c k i n g o r punctured f l o a t , c l e a n l i n e s s , c o r r o s i o n of j e t w e l l s , f o r e i g n matter i n t h e f u e l chamber, evidence of w a t e r and t h e c o r r e c t s e t t i n g s of mixture and t h r o t t l e c o n t r o l s . must be c a r e f u l l y inspec ted . With both i n j e c t o r and c a r b u r e t t o r systems it is o f t e n b e t t e r t o r i g test f i r s t , i f t h i s i s p h y s i c a l l y p o s s i b l e , r a t h e r t han s t r i p ; t h i s a l s o a p p l i e s t o such i t e m s a s f u e l pumps. p o s s i b l e contamination is n o t l o s t when i n i t i a t i n g f u n c t i o n a l t e s t i n g .

With i n j e c t o r s t h e c o n t r o l v a l v e s , c u t of f and pump

Precau t ions should be t aken t o e n s u r e t h a t evidence of any

6.3.1.4 Lubr i ca t ion

Often it w i l l be obvious i f l a c k of l u b r i c a t i o n h a s played any p a r t i n t h e f a i l u r e , but i n some eng ines o i l p r e s s u r e from the normal engine system is used f o r o t h e r purpqses such as servo systems, o i l hea t ing of c a r b u r e t t o r s , f e e d i n g p r o p e l l e r c o n t r o l u n i t s etc. O i l systems t h e r e f o r e from tank t o engine must be examined f o r o b s t r u c t i n g d i r t , l o o s e o r f a i l e d p i p e s , leakages e t c . n o t be forgot ten . All o i l f i l t e r s should be examined wi th g r e a t care and i f necessary chemical ly analysed. and t o d e t e c t any divergence from c o r r e c t s p e c i f i c a t i o n o r impending f a i l u r e . o p e r a t o r s conduct chemical a n a l y s i s a s a normal maintenance procedure.

6.3.1.5 Mechanical i n t e g r i t y

The c o r r e c t q u a n t i t y and q u a l i t y of o i l should

Chemical a n a l y s i s i s a modem technique employed t o c o n t r o l f a i l u r e s Many major

With t h e except ion of very s m a l l and s imple p i s t o n eng ines , s t r i p examina- t i o n s should be undertaken only a t t h e manufac tu re r ' s approved engine overhaul o r i n v e s t i - g a t i o n base. expe r i ence and background of d e f e c t s and f a i l u r e s is i n v a l u a b l e t o t h e success of t h e i n v e s t i g a t i o n . t h e s t r i p i n v e s t i g a t i o n .

The manufacturer should always be consu l t ed a t a n e a r l y s t a g e because h i s

The i n v e s t i g a t o r should normally be s u f f i c i e n t l y q u a l i f i e d t o s u p e r v i s e Any susp ic ious f r a c t u r e s o r f a i l u r e s should always be examined



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P a r t 111.- The I n v e s t i g a t i o n I I I- 6- 13

by an e x p e r t i n f r a c t u r e a n a l y s i s o r by a q u a l i f i e d m e t a l l u r g i s t . type of f a i l u r e i n connect ing r o d s , g e a r t e e t h , r o c k e r s , camshafts , c y l i n d e r ho ld down s t u d s , p i s t o n s , s p r i n g s and c r a n k s h a f t s and is u s u a l l y w e l l and t y p i c a l l y d e f i n e d a t t h e f r a c t u r e s u r f a c e .

6.3.2

F a t i g u e is t h e u s u a l

Determinat ion of ma l func t ion o r f a i l u r e o f ' jet eng ines

The modem j e t eng ine is u s u a l l y so complex and of s p e c i a l c o n s t r u c t i o n wi th cr i t ical f i t s and c l e a r a n c e s t h a t ve ry l i t t l e can , o r shou ld , be a t t empted a t s t r i p examination a t t h e scene of t h e a c c i d e n t . Where it is a b s o l u t e l y necessa ry o r where s a l - vage appea r s t o be u n l i k e l y due t o d i s t a n c e o r d i f f i c u l t t e r r a i n etc., t h e n a l i m i t e d v i s u a l i n s p e c t i o n such a s removal of p r e s s u r e o i l f i l t e r s o r a n i n t e r n a l probe i n s p e c t i o n of t u r b i n e o r compressor may be undertaken. For s u c c e s s f u l i n v e s t i g a t i o n , however, it is e s s e n t i a l t h a t t h e manufacturer of t h e engine be brought i n t o t h e i n v e s t i g a t i o n a t an e a r l y s t a g e and made a member of t h e Powerplant I n v e s t i g a t i o n Group. Supe rv i s ion and c o n t r o l are of cour se e s s e n t i a l by t h e chairman of t h e Group o r t h e Investigator-in-Charge. It is u s u a l l y necessa ry t o remove t h e complete eng ine t o a s u i t a b l y equipped and approved base , normally t h e eng ine manufac tu re r ' s , where f u l l f a c i l i t i e s , s p e c i a l t o o l s and r i g s are a v a i l a b l e . engine is i n a f i t s ta te f o r a bench test run o r is only s u i t a b l e f o r teardown i n s p e c t i o n . There are, however, a few obvious p o i n t e r s which may assist t h e i n v e s t i g a t o r a t t h e scene of t h e a c c i d e n t . F i r s t l y , h e w i l l be concerned t o know, w a s t h e t u r b i n e r o t a t i n g a t a high speed, a low (windmil l ing) speed , o r s topped a t t h e moment of impact? Here i t must be b o m e i n mind t h a t t h e r e are o f t e n no clear c u t formulas t o assess such c o n d i t i o n s (see paragraph 6.1.2) and care must be e x e r c i s e d from t h e s tar t n o t t o form any firm conc lus ions however tempting t h e ev idence may appea r , because r o t a t i o n a l ev idence is only a p o r t i o n of t h e evidence t o be cons ide red : w a s i n f ac t "burning turning".

I f p r a c t i c a b l e , t h e i n v e s t i g a t o r should d e c i d e a t t h e s i te whether t h e

t h e i n v e s t i g a t o r must know whether t h e engine

One t echn ique which may be a p p l i e d i f t h e eng ine flame tubes are s e v e r e l y buckled i s t h e m e t a l l u r g i c a l examinat ion of t h e material i n o r d e r t o e s t a b l i s h whether t h e buck l ing occur red when t h e m e t a l w a s h o t o r co ld . Some eng ine manufacturers have developed t h i s t echn ique , w i t h c o n t r o l l e d specimens under expe r imen ta l tests, t o such an e x t e n t t h a t combustion t empera tu re a t c r a s h impact can be e s t a b l i s h e d w i t h i n c l o s e l i m i t s .

Mechanical f a i l u r e i n t h e modem h i g h t h r u s t t u r b i n e is u s u a l l y obvious The d i s i n t e g r a t i o n of a and o f t e n c a t a s t r o p h i c so f a r as t h e powerplant i s concerned.

h i g h speed t u r b i n e causes damage and d e s t r u c t i o n n o t u n l i k e -a l o c a l i z e d "explosion". Damage t o t h e a i r f r a m e as w e l l as eng ine can be expected. Engine p a r t s may be s c a t t e r e d over many m i l e s a long t h e f l i g h t t r a c k and a l l have got t o be found, p l o t t e d on a l a rge - scale map, and recovered t o t h e i n v e s t i g a t i o n base . It i s o f t e n i n t h e s e e a r l y de t a t ch - ments t h a t t h e c l u e t o i n i t i a l f a i l u r e is t o be found.

6.3.2.1 Compressor f a i l u r e s

Axial f low and o f t e n c e n t r i f u g a l compressor f a i l u r e i n f l i g h t may be a s c e r t a i n e d by s e v e r a l p o s i t i v e i n d i c a t i o n s w i t h i n Che engine. c a t i o n of i n - f l i g h t compressor f a i l u r e is t h e heavy d e p o s i t s of aluminium o r t i t a n i u m a l l o y on t h e v a r i o u s hot i n t e r n a l s u r f a c e s downstream i n t h e engine. u s u a l l y o r i g i n a t e from t h e f a i l i n g compressor b l a d i n g me ta l from t h e compressor c a s i n g . i t s e l f may b e s e r i o u s l y rup tu red and f l y i n g d e b r i s from t h e compressor may cause o t h e r

The most p o s i t i v e i n d i -

These d e p o s i t s

I n s e r i o u s cases of compressor f a i l u r e t h e c a s i n g s c r a p i n g o r c u t t i n g p a r t i c l e s of



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111-6- 14 Manual of A i r c r a f t Accident. Inves t i ga t i a t i

f a i l u r e s such as severance o r displacement of f u e l o r o i l p i p e s wi th consequent r i s k of f i r e due t o i g n i t i o n of f r e e f u e l o r o i l . o r combustion chambers may r evea l a build-up of semi-molten aluminium a l l o y which has streamed back i n t h e a i r flow from t h e f a i l e d compressor and impinged upon t h e h o t s u r f a c e s . The e x t e n t of t h i s build-up w i l l o f t e n provide a c l u e as t o t h e l eng th of t i m e o r d u r a t i o n of t h e f a i l u r e . from o t h e r sou rces , of i t s o r i g i n . and f a i l u r e t h a t occurs a f t e r impact wi th t h e ground is seldom d i f f i c u l t , p r imar i ly t h e r e w i l l be only l i g h t d e p o s i t s of aluminium a l l o y d e p o s i t s on t h e h o t s e c t i o n s of t h e engine when a compressor f a i l u r e occurs a f t e r ground impact. compressor r o t o r space r r i n g s , whi le deep, w i l l be few i n number and i n t e r m i t t e n t around t h e pe r iphe ry of t h e space r r ings . mountings but w i l l o f t e n remain wi th in t h e engine . It i s seldom t h a t compressor f a i l u r e i n f l i g h t w i l l c ause b lades t o be e j e c t e d o r thrown forward of t h e a i r i n l e t b u t a com- p r e s s o r f a i l u r e w h i l s t t h e engine i s running on t h e ground can cause b l ades t o be e j e c t e d up t o one hundred f e e t i n f r o n t of t h e engine a i r i n l e t . s u r g e s , it i s p o s s i b l e t h a t t h i s may a l s o occur i n f l i g h t w i th t h e a t t e n d a n t r i s k t h a t t h e e j e c t e d d e b r i s may be inges ted i n t o t h e a d j a c e n t engine caus ing t h a t engine t o f a i l a l s o .

I n s p e c t i o n of t h e "hot s ec t ions" of t h e t u r b i n e

Analys is of t h e bui l t -up material may g i v e a c l u e , i f i t is no t obvious D i f f e r e n t i a t i n g between compressor f a i l u r e i n f l i g h t

The s c o r i n g and gouging of t h e

Many compressor vanes and b l a d e s may be t o r n from t h e i r

On rare occas ions , dur ing v i o l e n t

6 . 3 . 2 . 2 I n g e s t ion

I n g e s t i o n of fo re ign matter has caused, and con t inues t o cause , many mecha- n i c a l f a i l u r e s of cornpressors. b i r d s a t a t ime wi thout damage but l a r g e b i r d s can cause s e r i o u s f a i l u r e . Flocks of migra t ing b i r d s can be impacted i n f l i g h t and such occurrences may r e s u l t i n s e v e r a l o r a l l engines be ing a f f e c t e d . Often wi th s i n g l e b i r d i n g e s t i o n no t r a c e of t h e b i r d i s immediately v i s i b l e upon i n i t i a l i n spec t ion of t h e engine a l though t h e r e i s a d i s r u p t i o n of t h e compressor. S m a l l and f i n e d e p o s i t s of b i r d remains however a r e o f t e n trapped i n t h e a i r b l eeds and tappings o f f t h e compressor and o f t e n microscopic examination of t h e d e b r i s i s necessary t o determine t h a t i t was i n f a c t a b i r d . S t a i n s on compressor b l a d e s should be c a r e f u l l y preserved as these may well g ive a c l u e when chemically and microsco- p i c a l l y analysed a s t o b i r d impact ( i . e . , b i r d blood ev idence) .

The modem compressor is designed t o cope wi th many small

Apart from b i r d s , i n g e s t i o n of o t h e r materials such as r ivets , n u t s , b o l t s , p i e c e s of c l o t h and pebbles from runways o r taxi-ways can a l s o cause damage t o compressors, p a r t i c u l a r l y t h e a x i a l f low type. Often t h e inges t ed o b j e c t w i l l l eave i t s mark o r impr in t i n t h e f i r s t s t a g e of t h e compressor. and undamaged it can be taken t h a t i n g e s t i o n of a s o l i d o b j e c t has n o t taken place. I f t h e in t e rmed ia t e o r l a t t e r s t a g e s of t he compressor are damaged, bu t not t h e f i r s t s t a g e s , t h i s could i n d i c a t e t h a t a primary mechanical f a i l u r e i n t h e compressor has occurred not connec ted wi th inges t ion . The t ime, p l ace and r e s p o n s i b i l i t y f o r damage t o t h e compressor can o f t e n be e s t a b l i s h e d from the type of damage. i n d i c a t e t h a t t he damage was i n i t i a t e d du r ing take-off o r t a x i i n g from an unswept o r poor ly maintained a i r f i e l d . i n spec t ion and c l e a n l i n e s s a t t h e manufacturers. (although damage from t h e l a t te r i s very r a r e ) will i n d i c a t e t h a t damage occurred dur ing t5e f l i g h t s t age .

Normally i f t h e f i r s t s t a g e r o t a t i n g b lades a r e c l e a n

For i n s t a n c e , damage from pebbles could

Damage by r i v e t i n g e s t i o n could sugges t poor maintenance or l a c k of I n g e s t i o n of b i r d s , trees, h a i l s t o n e s

I n - f l i g h t f a i l u r e s of c e n t r i f u g a l compressors a r e rare and t h i s type of des ign i s o f t e n more capable of i nges t ing v a r i o u s s p e c i e s of b i r d and o t h e r d e b r i s w i thou t damage. However, i n both t h e a x i a l and c e n t r i f u g a l compressors f a t i g u e of b l ades , d i s c o r s h a f t can cause s e r i o u s f a i l u r e s and every f r a c t u r e must be examined wi th t h i s i n mind.



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111-6-15 -.

P a r t 111.- T h e I n v e s t i g a t i o n

6.3.3 Turbine f a i l u r e s

In- f l igh t tu rb ine d i sc blade f a i l u r e can cause major damage and of ten f i r e . Fatigue is of ten the root cause of blade o r d i sc f a i l u r e . days because of increased use of automatic f u e l and temperature control . d i sc i t s e l f is not now a frequent o r common f a i l u r e , but can be ca tas t rophic when i t does occur. overheating o r mechanical abrasion due t o abnormal wear o r malascembly r e s u l t i n g i n inadequate running clearances a r e causes of turbine blade f a i l u r e s . of blades may be caused by:

Creep f a i l u r e s are rare these Fa i lure of t he

Fatigue due t o minor machining o r f in i sh ing processes , over-s t ress ing following

Separation of port ions

a) thermal compressor s t a l l where a i r flow through the compressor is r e s t r i c t e d i .e . , sometimes by ingest ion of material o r b i rds ;

b) i c ing of a i r i n l e t s (although r a r e ) ;

c) dis turbance o r unstable combustion condi t ions o r f a i l u r e of combustion tubes.

A s with t h e compressor the turbine, o f ten with seve ra l s tapes , i s a most c r i t i c a l and highly s t ressed p a r t of the turbine engine. The manufacture, assembly and working condi t ions are a l l complex and i n t r i c a t e and c lose co l labora t ion with the manufac- t u r e r of t h e engine i s e s s e n t i a l a t a l l s tages of t he inves t iga t ion i n t o any suspect f a i l u r e .

6.3.4 Flame-out

The predominant cause f o r in - f l igh t flame-out of modem turb ine engines i s the malfunction o r f a i l u r e of the f u e l supply o r cont ro l regulator . I f t he f u e l con t ro l l e r o r pumps are suspected and condi t ions permit, r i g t e s t ing on a cont ro l led r i g is the bes t method of determining the cause of malfunction. The re - l igh t system should a l s o be examined. The inves t iga tor must always bear i n mind tha t flame-out of tu rb ine engines can be caused by mismanagement of the f u e l system, turning off of the wrong f u e l valve, leaving a f u e l valve open t o an empty tank o r simply running out of fue l . A l l of these matters should be examined and eliminated before concluding the engine equipment w a s a t f a u l t .

6.3.5 Type and qua l i ty of f u e l

Jet engines a r e not normally very sens i t i ve t o the type o r qua l i ty of f u e l and most engines are approved t o run on severa l types o r grades of fue l : kerosene, and pe t ro l mixtures o r even, during emergencies pure pe t ro l . Fuel is normally w e l l control led f o r qua l i ty a t t he r e fue l l i ng base before the a i r c r a f t i s r e fue l l ed and i t is rare f o r f a i l u r e s o r accidents t o occur due t o poor qua l i ty of f u e l i n tu rb ine engines. excess water content can cause f reez ing and blockage of f i l t e r s although automatic heating arrangements are normally embodied i n most modem j e t powerplants.

However,

The inves t iga to r should always record the type and qua l i ty of the f u e l used (obtaining a chemical ana lys i s repor t i f considered necessary) . important when f i re fexplos ion occurs on the ground and surv iva l of occupants i s involved. Because of the opportunity of building-up knowledge on the inf luence of f u e l type on surv iva l , t h i s is a l s o important when f u e l is s p i l l e d but f i r e does not occur or spread very slow. Therefore, i n a l l cases, the inves t iga tor should c o l l e c t :

This i s pa r t i cu la r ly

a) data on the f u e l a t the accident s i t e including type(s ) , quan t i t i e s and loca t ion , f i r e spread, i gn i t i on source, e tc . ;

b) da ta on the r e fue l l i ng of the a i r c r a f t / fype(s ) , quan t i t i e s and loca t ion within the a i r c r a f t 7 , as w e l l as in - f l igh t f u e l management. These da ta should be col lected not only f o r t he l a s t f l i g h t o r f l i g h t s tage , but a l s o f o r the immediately preceding f l i g h t s o r f l i g h t s tages . Operational da ta f o r the accident f l i g h t i t s e l f , as ca l l ed f o r i n Sect ions 3.13 and 3.14, Chapter 3, of P a r t III, are v i t a l l y important i n assessing such things as the f u e l temperature a t impact.

3015177 No. 7



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111-6-16 Manual of Aircraft Acciiient Znrrct iga:.icin

6.4 Ef fec t iveness of F i r e Ext inpuisher Systems

I n many a i r c r a f t acc iden t i n v e s t i g a t i o n s wi tnes ses w i l l s t a t e t h a t they observed t h e a i r c r a f t on f i r e p r i o r t o impact. r e l a t i v e l y rare. O r d i s r u p t i o n i n t h e power p l a n t and t h e r e l e a s e of f r e e f u e l i n t o t h e engine bay. i n g t h e c o r r e c t d r i l l s a r e taken promptly most f i r e s can be brought under c o n t r o l and ex t ingu i shed i n f l i g h t . of f u e l and o i l t o t h e engines: t anks . g e n e r a l l y e x t i n g u i s h i t s e l f . a s s o c i a t e d d r i l l s be ing c a r r i e d ou t qu ick ly and i n c o r r e c t sequence, f o r i n s t a n c e i n p r o p e l l e r powerplants t h e p r o p e l l e r must be f ea the red be fo re t h e f i r e e x t i n g u i s h e r system can be e f f e c t i v e . o f f , b e f o r e t h e f i r e ex t ingu i she r system can be e f f e c t i v e .

The a c t u a l occur rence of i n - f l i g h t f i r e is The ma jo r i ty of i n - f l i g h t f i r e s a r e due t o major mechanical breakdown

Provid-

The most important p a r t of t h e f i r e d r i l l is t o shu t o f f t h e f low t h i s i s normally t h e low p r e s s u r e f u e l supply from t h e

I f t h i s p a r t of t h e d r i l l is c a r r i e d o u t promptly and c o r r e c t l y t h e f i r e w i l l F i r e e x t i n g u i s h e r systems r e l y t o a l a r g e degree i n t h e

i n t u r b i n e engines t h e low p r e s s u r e f u e l must b e s h u t o f f , and kep t s h u t

S p e c i a l t echniques may be necessa ry a f t e r a major f i r e a c c i d e n t t o de te rmine whether t h e f i r e e x t i n g u i s h e r b o t t l e c a r t r i d g e w a s opera ted by t h e crew e l e c t r i c a l l y o r by t h e subsequent f i r e , whether i n - f l i g h t o r on t h e ground, i .e . , by spontaneous i g n i t i o n of t h e ope ra t ing charge i n t h e b o t t l e head by t h e f i r e . The method employed u s u a l l y v a r i e s w i t h t h e make and des ign of t h e b o t t l e bu t i n c l u d e s a c l o s e s tudy of t h e e l e c t r i c d e t o n a t o r f i l a m e n t , t h e manner i n which t h e d i scha rge s l u g has been e j e c t e d , t h e manner i n which t h e e x p l o s i v e medium h a s been detonated o r b u r n t (completely o r p a r t i a l l y ) and v a r i o u s o t h e r f e a t u r e s a s soc ia t ed wi th t h e p a r t i c u l a r des ign . r e l i e f are most d i f f i c u l t t o ana lyse . open i n a characteristic way i f s u b j e c t t o external f i r e and t h i s would i n d i c a t e immediate- l y e lec t r ica l de tona t ion . A i r c r a f t f i t t e d w i t h c r a s h c i r c u i t s connected t o t h e f i r e e x t i n - gu i she r b o t t l e s can f u r t h e r compl ica te t h e i n v e s t i g a t i o n i f f i r e i n t h e a i r i s involved , because if the b o t t l e s are not d i scharged i n f l i g h t they may subsequent ly be d ischarged du r ing c ra sh impacts. Cross over o r second s h o t systems a l s o invo lve two s e t s of power- p l a n t f i r e e x t i n g u i s h e r s and it is e s s e n t i a l t o check both systems t o a s c e r t a i n whether t h e c o r r e c t heads have been d ischarged i n both systems.

Modem f i r e e x t i n g u i s h e r b o t t l e s w i t h p r e s s u r e The o l d type wi thout p r e s s u r e r e l i e f would b u r s t

t o t h e i n v e s t i g a t o r t h a t t h e b o t t l e had no t been 'discharged i n f l i g h t by t h e normal

Another method, i f c i rcumstances pe rmi t , i s t o ana lyse e lec t ro-chemica l ly t h e i n s i d e of t h e d i scha rge o r spray p i p e s and nozz le s t o a s c e r t a i n whether t h e chemical ex t ingu i shan t has passed through the system. F i r e e x t i n g u i s h e r systems and f i r e warning systems are becoming complex and s p e c i a l i z e d and t h e prompt co-opera t ion of t h e manufac turer is e s s e n t i a l t o a s u c c e s s f u l i n v e s t i g a t i o n i n t o any f i r e e x t i n g u i s h e r system.

6.5 Taking of Samvles

The m i n purpose of t ak ing samples is t o i d e n t i f y subs t ances found on a i r - c r a f t components, and t o assess t h e bulk o r main f u e l o r o i l supply a g a i n s t t h e c o r r e c t s p e c i f i c a t i o n . Sometimes i n a i r c r a f t acc iden t i n v e s t i g a t i o n t h i s is n o t always p o s s i b l e and o f t e n d i f f i - c u l t y w i l l be experienced i n ob ta in ing a sample a t a l l .

Care should t h e r e f o r e be taken t o t a k e a f a i r sample o r an average sample.

Taking samples of o i l from t h e powerplant and f u e l from t h e main tanks o r

(Glass o r p l a s t i c c o n t a i n e r s l e t powerplant should always be attempted. used. i n l i g h t which may s p o i l t h e sample: t h e p l a s t i c . ) ment of f u e l is t o be made i n a l abora to ry . w i t h a i r c r a f t number, d a t e , and p o s i t i o n of sample taken. g e t t i n g samples t o t h e l abora to ry .

Clean and uncontaminated c o n t a i n e r s must always be Fuel samples should be f n s u i t a b l y s e a l e d t i n s .

f u e l may a l s o absorb some of t h e c o n s t i t u e n t s of

The c o n t a i n e r s should be c l e a r l y l a b e l l e d There should be no de lay i n

A t l e a s t h a l f a ga l lon o r two l i t res should be ob ta ined i f a proper assess-



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111-6-17 ' P a r t 111.- T h e I n v e s t i g a t i o n __-____ Taking samples of o t h e r materials such as smoke o r s o o t smears.may be

j u s t i f i e d . a n a l y s i s i n t h e l a b o r a t o r y i n t h e i n t e r e s t of de t e rmin ing t h e p o s s i b l e sou rce , e . g . b i r d o r o t h e r f o r e i g n p a r t i c l e i n g e s t i o n .

Contaminants o r smears on compressor b l ades should be s u b j e c t e d t o chemical

6.6 S p e c i a l i s t Examinations

Fue l and o i l samples must be examined by f u e l and o i l s p e c i a l i s t s t o t h e r e l e v a n t s p e c i f i c a t i o n s . Some of t h e contaminants t h a t may be found i n t h e o i l system are metall ic o r carbon p a r t i c l e s , f o r e i g n f l u i d s , and s ludge. The metall ic p a r t i c l e s may be e i t h e r f e r r o u s o r non-fer rous . Fe r rous p a r t i c l e s i n d i c a t e some f a i l u r e of s t ee l p a r t s w i t h i n t h e eng ine and t h e s i z e and shape can g i v e a c l u e a s t o what f a i l e d . The most probable sou rces of s tee l shav ings are c y l i n d e r w a l l s , p i s t o n r i n g s and gea r s .

Non-ferrous p a r t i c l e s u s u a l l y i n d i c a t e f a i l u r e of s l e e v e b e a r i n g s , bushings, p i s t o n s o r some o t h e r aluminium, magnesium o r bronze p a r t of t h e engine .

Excess ive s ludge o r carbon may cause f u e l s t a r v a t i o n and eng ine f a i l u r e . Fore ign f l u i d s such as water o r f u e l are n o t t o o p r e v a l e n t i n t h e o i l system, bu t t h e i r p resence i f e x c e s s i v e w i l l change t h e l u b r i c a t i n g q u a l i t i e s of t h e o i l and cause t r o u b l e i n t h e engine . Another p o s s i b i l i t y of eng ine f a i l u r e is t h e wrong type of o i l . This can cause s e r i o u s ove rhea t ing and eng ine mal func t ion t o t h e p o i n t of complete s toppage . Conse- quen t ly , a d e t a i l e d p h y s i c a l and chemica l a n a l y s i s of t h e f u e l and o i l and any contaminants i n t h e s e systems can be most u s e f u l .

T e s t i n g of powerplan ts , a c c e s s o r i e s o r i n s t rumen t s i f p o s s i b l e should always be cons idered i n p re fe rence t o primary s t r i p i n s p e c t i o n . Th i s should be c l e a r l y i n d i c a t e d from t h e start and a l l such i t e m s c l e a r l y l a b e l l e d . Very o f t e n t h e complete powerplant cannot be bench t e s t e d but many of i ts a c c e s s o r i e s can and t h e s e should be removed f o r r i g t e s t i n g . A s u b s t i t u t e f o r bench t e s t i n g can o f t e n be found by mounting t h e engine on a similar a i r f r a m e and t h i s can e x p e d i t e t h e i n v e s t i g a t i o n .

F l i g h t tests should only be cons idered i f i t is a b s o l u t e l y necessa ry . T h i s w i l l on ly be on rare occas ions , f o r w i th powerplan ts o r t h e i r a c c e s s o r i e s bench and r i g t e s t i n g wi th s imula ted f l i g h t environments is commonplace. However, i n i n - f l i g h t f i r e cases where leakage of f u e l o r o i l is s u s p e c t i t may be necessa ry t o have a f l i g h t test wi th s u i t a b l y "whitewashed" a i r c r a f t and cameras etc. i n o r d e r t o s t u d y f u e l and a i r f lows etc.



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PART I I I

CHAPTER 7. - SYSTEMS INVESTIGATION



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Par t III.- 'rile i n v e s t i g a t i o n 111-7- 1 .

7 . 1

CHAPTER, 7

S Y S T E K INVESTIGATION

Genera l

The Systems I n v e s t i g a t i o n cove r s i n v e s t i g a t i n g and r e p o r t i n g on t h o s e systems of t h e a i r c r a f t which, u n l i k e f u e l and o i l systems which come under "powerplant" and f l y i n g c o n t r o l s which come under "s t ructure" , are not i nc luded under o t h e r headings . i n e v i t a b l y a degree of o v e r l a p , a s f o r i n s t a n c e i n t h e case of h y d r a u l i c a l l y ope ra t ed f l y i n g c o n t r o l s where t h e power g e n e r a t i o n and r e g u l a t i o n of t h e h y d r a u l i c sys tem c o n s t i t u t e s p a r t of t h e systems i n v e s t i g a t i o n w h i l s t h y d r a u l i c o p e r a t i o n of t h e c o n t r o l s u r f a c e s comes w i t h i n t h e coverage of t h e s t r u c t u r e s i n v e s t i g a t i o n . Gene ra l ly , t h e f o l l o w i n g systems are con- s ide red t o f a l l under t h e heading of t h e systems i n v e s t i g a t i o n : h y d r a u l i c s , e l e c t r i c s and e l e c t r o n i c pneumatics, vacuum, p r e s s u r i z a t i o n and a i r c o n d i t i o n i n g , ice and r a i n p r o t e c t i o n , i n s t rumen t s , a i r d a t a computer, f l i g h t d i r e c t o r , s t a l l warning and r ecove ry , r a d i o commu- n i c a t i o n and n a v i g a t i o n sys tems, a u t o p i l o t , f i r e d e t e c t i o n and p r o t e c t i o n system, oxygen system.

There is

The a i r c r a f t systems i n v e s t i g a t i o n p r e s e n t s a somewhat d i f f i c u l t t a s k owing t o t h e d i v e r s i t y and complexity of modern equipment. The re fo re , s i n c e a l l systems and t h e i r o p e r a t i o n can be r e l a t e d t o t h r e e b a s i c a r e a s , - i t is impera t ive t h a t t h e i n v e s t i g a t o r have a good working knowledge of h y d r a u l i c s , e l e c t r i c i t y / e l e c t r o n i c s , and pneumatics i n o r d e r adequate ly t o deve lop and a n a l y s e t h e a v a i l a b l e f a c t s .

The i n v e s t i g a t o r should a v a i l h imsel f of a p p r o p r i a t e d e t a i l e d schemat ic diagrams o r working drawings t o de te rmine what components are inc luded i n each system, t h e n make eve ry e f f o r t t o account f o r a l l of t h e s e components. These diagrams o r drawings w i l l a l s o be h e l p f u l i n a n a l y s i n g t h e e f f e c t of a mal func t ioning component on t h e remainder of a system.

Each a i r c r a f t system must be accorded t h e same degree of importance regard-

J u s t as impor t an t , less of t h e a c c i d e n t c i rcumstances . s h i p of any sys tem t o t h e c a u s a l area wi thout a thorough examination. d a t a developed by t h e examinat ion of one system may be h e l p f u l i n proving o r d i sp rov ing t h e i n t e g r i t y of o t h e r s y s t e m s . th'an examinat ion of components i n s i t u , i t can invo lve t h e f u n c t i o n a l t e s t i n g of a complete system, t h e t e s t i n g of i n d i v i d u a l components of a system, o r r e - i n s t a l l a t i o n of equipment i n an a i r c r a f t of t h e same type f o r f l i g h t tests t o de te rmine t h e c a p a b i l i t i e s of t h e components i n normal f l i g h t and under c o n d i t i o n s s p e c i f i e d by t h e i n v e s t i g a t o r .

There is no way t o de te rmine adequa te ly t h e r e l a t i o n -

The examination of t h e system w i l l g e n e r a l l y invo lve more

Each system can be broken down i n t o s i x areas which should assist i n account- ing f o r components. These areas are (1) supply , ( 2 ) p r e s s u r e , ( 3 ) c o n t r o l , ( 4 ) p r o t e c t i o n , (5) d i s t r i b u t i o n and (6) a p p l i c a t i o n . Documentation of components should inc lude nomen- c l a t u r e , manufac turer , p a r t number, se r ia l number and, where provided , t h e s p e c i f i c a t i o n tiumber. t h e same system, e s p e c i a l l y i n t h e h y d r a u l i c and pneumatic systems. The re fo re , i t w i l l be necessary t o o b t a i n an up-to-date l i s t i n g from t h e o p e r a t o r showing t h e a c t u a l l o c a t i o n of t h e s e components i n t h e system by serial number. T h i s i n fo rma t ion may be ob ta ined from t h e manufac turer i n t h e case of a new a i r c r a f t .

Some components having t h e same p a r t number may be used i n v a r i o u s p o r t i o n s of



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Documentation of t h e systems and components should no t merely c o n s i s t i n ca t a logu ing o r l i s t i n g s . appearance and cond i t ion of t h e components as w e l l as t h e p o s i t i o n of any movable p a r t s . Complete sen tences should be used r a t h e r t han terse, c r y p t i c ph rases .

Rather , i t should comprise a f a i r l y d e t a i l e d d e s c r i p t i o n of t h e

One of t h e f i rs t items t o be documented should be t h e p o s i t i o n s of swi t ches and c o n t r o l s i n t h e cockp i t wreckage. ins t ruments . Such documentation, supplemented by photographs, should be accomplished a s sodn as p o s s i b l e i n Co-ordination wi th t h e Opera t ions Group. i n v e s t i g a t i n g team should be asked t o s t a y out of t h e cockpi t area u n t i l t h e h a s been completed.

Also, document t h e r ead ings on a l l a v a i l a b l e

Other members of t h e documentation

7.2 Hydraul ic Systems

7.2.1 Rese rvo i r s and f l u i d

The i n v e s t i g a t o r should l e a r n t o r ecogn ize t h e v a r i o u s f l u i d s by co lou r so t h a t he can r a p i d l y determine i f t h e proper f l u i d w a s used i n t h e a i r c r a f t involved i n t h e acc iden t . and contamination count. The r e s e r v o i r s should be examined t o determine t h e q u a n t i t y of f l u i d remaining and t o determine t h e f l u i d l e v e l p r i o r t o t h e acc iden t ; check t h e r e s e r v o i r d r a i n va lves f o r being c losed and s a f e - t i e d , t h e f l u i d i n l e t f i l t e r s f o r contamination, and t h e s e c u r i t y of t h e f i l l e r neck cap. e l e c t r i c a l l y opera ted ; check them f o r being open o r c losed and re la te t h e f i n d i n g s t o nor- m a l or emergency opera t ion .

Samples of f l u i d should be ob ta ined from v a r i o u s a r e a s of t h e system f o r a n a l y s i s

F lu id s u c t i o n shut-off v a l v e s may be manually o r

7.2.2 Hydraulic pumps

The main h y d r a u l i c pumps may be engine-driven o r e l e c t r i c motor-driven; a u x i l i a r y pumps w i l l gene ra l ly be d r iven by e l e c t r i c motors. i n t e g r i t y : examination of t h e f r a c t u r e s u r f a c e s of a sheared coupl ing can provide opera- t i o n a l evidence. A b a t t e r e d and somewhat po l i shed appearance of t h e mating f r a c t u r e sur - f a c e s i n d i c a t e s t h a t t h e coupl ing f a i l e d w h i l e t h e pump was be ing opera ted and t h e d r i v i n g source continued t o ope ra t e and t h e two s u r f a c e s were b a t t e r e d toge the r . Clean and o the r - w i s e undamaged f r a c t u r e s u r f a c e s would i n d i c a t e t h a t t h e pump and d r i v i n g source were s t a t i c a t t h e time of- f a i l u r e . Such a f a i l u r e would most l i k e l y be t h e r e s u l t of c r a sh f o r c e s . This cond i t ion would apply t o any component opera ted i n l i k e manner. A pump wi th a sheared coupling and damaged f r a c t u r e s u r f a c e s should be examined f o r l u b r i c a t i o n , wear, looseness , or overheat . t i o n o r a c t u a l f a i l u r e . should be examined f o r t rapped evidence of impending or a c t u a l pump f a i l u r e .

7.2.3 Hydraulic accumulators

Check t h e d r i v e coupl ing

Examine t h e i n t e r n a l mechanism f o r ev idence of ove rhea t , c a v i t a - F i l t e r s a r e i n s t a l l e d i n t h e case d r a i n l i n e s of some pumps and

I n s p h e r i c a l accumulators a rubber b ladder o r diaphragm s e p a r a t e s t h e charge a i r from t h e f l u i d while i n t h e c y l i n d r i c a l accumula tors a f l o a t i n g p i s t o n is used f o r t h e same purpose. Hydraulic accumulators should be examined f o r r e t e n t i o n of t h e a i r p re load and t h e amount, if any, should be checked wi th a s u i t a b l e gauge. The b ladder o r diaphragm should be examined f o r l eaks and t h e f l o a t i n g p i s t o n should be checked f o r i t s p o s i t i o n i n r e l a t i o n t o t h e a i r o r f l u i d ends of the c y l i n d e r . Th i s can be r e l a t e d t o t h e sequence of a i r and hydrau l i c p re s su re lo s s . 3000 p s i (60-210 kg/cm*) and, t h e r e f o r e , c o n s t i t u t e a hazard t o t h e a i r c r a f t i n f l i g h t and

The p r e s s u r e s i n t h e s e accumula tors range from 850 -



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t o personnel on t h e ground should t h e p r e s s u r e v e s s e l f a i l : e x p l o s i v e r u p t u r e ; accumulators should be handled wi th c a u t i o n .

7.2 .4 P r e s s u r e r e g u l a t o r s and r e l i e f v a l v e s

examine them f o r ev idence of

Regula tors and re l ie f v a l v e s should be examined f o r s t i c k i n g open o r c l o s e d and they may be t e s t e d t o de te rmine t h e i r r e g u l a t o r y s e t t i n g s . These u n i t s may i n c o r p o r a t e heavy s p r i n g s and should only be disassembled by q u a l i f i e d p e r s o n n e l u s i n g proper equipment t o avoid p e r s o n a l i n j u r i e s .

7.2.5 Manifolds and p r e s s u r e modules

These d i s t r i b u t i o n centres should be examined f o r t h e p o s i t i o n of any incorpora ted s e l e c t o r v a l v e s . P r e s s u r e modules are u s u a l l y c o n t r o l l e d manually o r by a n e l ec t r i c motor. Thei r p o s i t i o n s as found should be r e l a t e d t o normal or emergency o p e r a t i o n . Asso- c i a t e d e l e c t r i c a l connec tors and w i r i n g should be checked f o r s e c u r i t y , i n s t a l l a t i o n and e l e c t r i c a l l y caused damage.

7.2.6 S e l e c t o r v a l v e s and a c t u a t o r s

S e l e c t o r v a l v e s should be examined f o r p o s i t i o n and i n t e g r i t y of c o n t r o l l i nkages . Some s e l e c t o r v a l v e s are opera ted d i r e c t l y from t h e c o c k p i t by c a b l e s . The p o s i t i o n of such v a l v e s should be regarded w i t h c a u t i o n because a i r c r a f t break-up can p u l l t h e c a b l e s o r break them t h u s r e n d e r i n g v a l v e p o s i t i o n s q u e s t i o n a b l e . A c t u a t o r r o d s and screw j a c k s should be measured f o r e x t e n s i o n and mechanical l i n k a g e p o s i t i o n s should be marked o r s c r i b e d as found f o r f u t u r e r e f e r e n c e . These f i n d i n g s can be d u p l i c a t e d i n an i n t a c t a i r c r a f t of t h e same type t o determine t h e e q u i v a l e n t component p o s i t i o n s . The p o s i t i o n s of v a l v e s and a c t u a t o r s can be determined by X-ray where component damage pre- c l u d e s measurements o r o t h e r techniques . A l l a c t u a t o r rod bending should be measured and a check should be made f o r impress ions on t h e rod s u r f a c e made by c o n t a c t w i t h t h e end of t h e a c t u a t i n g c y l i n d e r at t h e t i m e bending occurred.

7.2.7 F i l t e r s and plumbing

F i l t e r s should be examined f o r t h e amount and t y p e of contaminat ion which may be p r e s e n t . The i n v e s t i g a t o r should s p e c i a l l y look f o r s ea l and gaske t mater ia l and meta l p a r t i c l e s which might i n d i c a t e impending o r e x i s t i n g f a i l u r e i n some component, Hydraul ic l i n e s and f i t t i n g s should be examined f o r s e c u r i t y , ev idence of l eak ing and o t h e r evidence of f a i l u r e which may have occurred p r i o r t o t h e a c c i d e n t . Also, check f o r improper i n s t a l l a t i o n , bogus f i t t i n g s and improper t u b i n g materials.

7 .2 .8 Hydraul ic and pneumatic components: f u n c t i o n a l t e s t i n g

P r i o r t o beginning tests of h y d r a u l i c components, o b t a i n samples of f l u i d t o be ana lysed f o r contaminat ion, a c i d and water conten t and type of f l u i d . ponent i s mounted i n a t es t f i x t u r e and p r e s s u r e hoses are a t t a c h e d , t h e u n i t w i l l be e x e r c i s e d t o purge t h e passages of air . The f i r s t f l u i d which i s s u e s from t h e r e t u r n p o r t s should be caught i n a s u i t a b l e c o n t a i n e r and examined f o r f o r e i g n m a t e r i a l which may be p r e s e n t i n t h e u n i t . A p i e c e of sea l m a t e r i a l o r o t h e r d e b r i s may have lodged i n v a l v e s o r passages and could be d is lodged dur ing purging. component and ensure t h a t t he t es t equipment can supply adequate p r e s s u r e and ra te of f l u i d flow.

Once a com-

A s c e r t a i n t h e working p r e s s u r e of t h e

T e s t i n g of h y d r a u l i c and pneumatic components should cover o p e r a t i o n of check v a l v e s , r e l i e f v a l v e s , shut-off v a l v e s and leakage r a t e s . Actua tor p i s t o n r o d s should be checked f o r break-away f o r c e s r e q u i r e d f o r i n i t i a l movement from t h e s t a t i c p o s i t i o n . Look f o r ev idence of e x c e s s i v e i n t e r n a l leakage o r by-passing. Disassembly and i n t e r n a l examina-



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t i o n should be accomplished i f condi t ions warrant . Look e s p e c i a l l y a t t h e condi t ion of sea ls and v a l v e s , evidence of overheat ing, c a v i t a t i o n and e x c e s s i v e l y worn parts. The f a c i l i t y ' s package f u n c t i o n a l test procedure w i l l be v e r y d e t a i l e d and w i l l include a l l necessary t o l e r a n c e s . These procedures should be fol lowed c a r e f u l l y .

A i r systems of l a r g e pressure and a i r f low capacit ies w i l l be requi red when t e s t i n g pneumatic system components. be found i n t h e a i r c r a f t maintenance manuals and w i l l i n c l u d e o p e r a t i n g p r e s s u r e s and a i r f low volumes as w e l l as t h e requi red v o l t a g e s f o r e l e c t r i c a l l y opera ted po r t ions . c o n t r o l v a l v e c a p a b i l i t i e s w i l l be most important because t h e y a r e t h e h e a r t of t h e system. However, t h e s e are backed up by t h e temperature and p r e s s u r e s e n s o r s ( the rmos ta t s and pres- s u r e swi t ches ) which react t o normal and a d v e r s e cond i t ions . .The la t te r may be e s p e c i a l l y s i g n i f i c a n t when a malfunct ion i s suspected. f low c o n t r o l components.

S p e c i f i c a t i o n s f o r t h e s e components w i l l g e n e r a l l y

Flow ,

Therefore , they are as important as t h e

7.3 Electr ical Sys tems

7.3.1 Generators , a l t e r n a t o r s and i n v e r t e r s

Examine these components f o r evidence of a r c i n g , burning, f a u l t y brushes, improper w i r e o r c a b l e connexions and over-heat ing. d e t e c t s i g n s of excess ive output . When a g e n e r a t o r o p e r a t e s under excess ive load f o r more t h a n a r e l a t i v e l y s h o r t pe r iod , t h e i n c r e a s e i n h e a t w i l l cause d i s c o l o u r a t i o n of t h e commutator b a r s o r mel t ing of so lde r . I n s e v e r e cases, t h e commutator b a r s may rise t o a p o i n t where t h e b a r s i n t e r f e r e wi th t h e brushes and t h e brushes are broken off and c a r r i e d away. I f such a condi t ion is found, i t is apparent t h a t t h e o u t p u t of t h e gene ra to r was pass ing through a pa th of lower r e s i s t a n c e than in tended and s t r o n g l y s a g g e s t s t h e presence of a s h o r t c i r c u i t somewhere i n t h e e lec t r ic power system.

V i s u a l examinat ion of g e n e r a t o r s may

Occasional ly , a dangerous malfunct ion occurs which is known as an "overvoltage" condi t ion . This r e s u l t s from t h e a p p l i c a t i o n of g e n e r a t o r o u t p u t t o t h e f i e l d c i r c u i t of t h e genera tor without con t ro l . I t is g e n e r a l l y t h e r e s u l t of a d i r e c t s h o r t c i r c u i t withi i i t h e genera tor from armature output t o the g e n e r a t o r f i e l d t e rmina l . Th i s r e s u l t s i n an u n c o n t r o l l a b l e high v o l t a g e output and e x c e s s i v e c u r r e n t , f o l loved by a n almost i n s t a n t a n e c u s burning out of f i l a m e n t s i n l i g h t bulbs and r a d i o tubes . The g e n e r a t o r switch i s turned o f f t o disconnect t h e offending gene ra to r from t h e c i r c u i t , t h u s c a u s i n g t h e genera tor r e v e r s e c u r r e n t cut-out r e l a y t o open. However, i f t h e output of t h e g e n e r a t o r is too high, t h e r e v e r s e cu r ren t r e l a y may be unable t o i n t e r r u p t t h e c u r r e n t f low and t h e cu r ren t cont inues t o flow i n t h e form of an arc a c r o s s t h e r e l a y c o n t a c t s . T h i s r e s u l t s i n mel t ing of t h e con tac t p o i n t s and p o s s i b l e d e s t r u c t i o n of t h e e n t i r e r e l a y assembly. prolonged, i t may i g n i t e o t h e r m a t e r i a l s i n t h e same g e n e r a l l o c a t i o n .

I f t h e c o n d i t i o n is

Bearings should be examined f o r l u b r i c a t i o n , wear, looseness and roughness. Worn o r loose bear ings can cause the armature o r r o t o r t o c o n t a c t t h e f i e l d o r s t a t o r windings and cause o t h e r i n t e r n a l damage. a l l y s u f f i c i e n t t o i n d i c a t e opera t ion but i s no t prima f a c i e evidence of e lec t r ic power output . determinat ion. These u n i t s should be t e s t e d , c o n d i t i o n s permi t t ing .

Heavy s c o r i n g o r s c u f f i n g i n a r o t a t i n g device i s gener-

When a l l of t h e system h a s been examined, t h e f a c t s can be analysed t o make t h i s

7.3.2 Bat t e r i e s

I n t a c t lead-acid b a t t e r i e s should be f i r s t checked w i t h a Jo l tme te r a c r o s s each c e l l and second with a hydrometer t o determine spec . i f i c g r a v i t y of t he e l e c t r o l y t e . These readings w i l l i n d i c a t e the s t a t e of charge. I f t h e e l e c t r o l y t e tias drained out of t h e b a t t e r y and/or t h e p l a t e s are broken, t h e r e a r e means of examining and t e s t i n g t h e p l a t e s t o determine t h e i r a b i l i t y t o acccpt and h o l d a cha rge , and t h e s t a t e o f t h e charge a t t h e time of impact. The nickel-cadmium ( a l k a l i n e ) b a t t e r y i s d i f f e r e n t i n t h a t t h e r e i s no s p e c i f i c g r a v i t y check. determine t h e i r condi t ion.

The ind iv id i l a l c e l l s must be checked w i t h a vo l tmeter t o



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7.3.3 Transformer r e c t i f i e r u n i t s

These u n i t s convert . a l te rna t ing cur ren t t o d i r e c t cur ren t e l e c t r i c power and are u t i l i z e d where t h e bas i c e lec t r ic power system i s supplied by a l t e rna to r s . These u n i t s are s o l i d s t a t e and t h e i r condi t ion and a b i l i t y t o func t ion can only be ascer ta ined by t e s t ing . i nd ica t e s not only t h a t DC e l e c t r i c power w a s ava i l ab le but t h a t t h e AC system w a s opera- t i o n a l as w e l l .

I n systems of t h i s type, evidence of operation i n DC-powered compoiients

7.3.4 Generators, a l t e r n a t o r and inve r t e r con t ro l

This area includes vol tage r egu la to r s , frequency r egu la to r s , reverse cur ren t cut-out r e l ays and s o l i d state generator con t ro l o r p ro tec t ion panels. I n t a c t u n i t s should be t e s t e d t o determine t h e i r p r i o r con t ro l s e t t i n g s and a b i l i t y t o func t ion as designed. Relay contac ts and c o i l s may be examined f o r evidence of malfunction and i n t e r n a l c i r c u i t r y should be t e s t e d f o r i n t e g r i t y . o r d i screpancies are noted.

The u n i t s should be examined i n d e t a i l when malfunctions

7.3.5 Dis t r ibu t ion Centres

A l l bus bars , t e rmina l s t r i p s and junc t ion boxes should be examined f o r s igns of damage t o cable and wiring connexions. of loose s tuds , a r c ing between adjacent te rmina ls , overheat and burning. Improper connexions can r e s u l t i n s u f f i c i e n t hea t t o m e l t bus bars and the te rmina l s t r i p s around s tud bases: t h i s could lead t o l o s s of por t ions of t h e e l e c t r i c a l system o r even complete l o s s of e l e c t r i c power. t he ground. The p o s s i b i l i t y t h a t fo re ign ob jec t s may have f a l l e n across te rmina ls , r e s u l t - ing i n d i r e c t s h o r t s and f i r e s , should a l s o be examined.

The inves t iga to r should a l s o look f o r evidence

These condi t ions have a l s o led t o e l e c t r i c a l f i r e s i n f l i g h t and on

X-ray photograph revealed e l ec t r i ca l short i n capsulated assembly.



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II I- 7- 6 &nua1 of A i r c r a f t Accident I n v e s t i g a t i o n

7.3 .6 C i r c u i t P r o t e c t o r s

Th i s i nc ludes f u s e s , c i r c u i t b reake r s and c u r r e n t limiters. These dev ices a r e i n s t a l l e d t o p r o t e c t w i r ing only. i n t e g r a l p r o t e c t i o n i f deemed necessary by t h e manufacturer. be examined f o r t r i p p i n g o r me l t ing of t h e f u s i b l e s t r i p s . C i r c u i t b reake r s may t r i p i f sub jec t ed t o e x t e r n a l l y app l i ed hea t such as i n pos t -c rash f i r e and may a l s o t r i p when sub jec t ed t o heavy p h y s i c a l shock. mal func t ion t o t h e unwary i n v e s t i g a t o r ; t h e r e f o r e , t h a t c i r c u i t should be examined f u r t h e r be fo re making a d i a g n o s i s , c i r c u i t mal func t ion occurs i f t h e e l e c t r i c a l f a u l t is removed r a p i d l y . For i n s t a n c e , a power l e a d may s h o r t t o ground on a i r c r a f t s t r u c t u r e and burn through r a p i d l y before t h e p r o t e c t o r h a s an oppor tun i ty t o r e a c t . C i r c u i t b r e a k e r s are prone t o d e t e r i o r a t i o n wi th t i m e and t h e i r r a t i n g s may change. and would not t r i p a t a l l . The r e s u l t of such c o n d i t i o n s could t u r n an e l e c t r i c a l f a u l t i n t o a s e r i o u s problem.

7.3.7 Relays and so leno ids

E l e c t r i c a l l y ope ra t ed components w i l l u s u a l l y have A l l c i r c u i t p r o t e c t o r s should

This could provide an e r roneous i n d i c a t i o n of a c i r c u i t

Fuses and c u r r e n t l imi te rs may remain i n t a c t even though a

Some b reake r s have been found with i n t e r n a l c o r r o s i o n

Relay c o n t a c t s should be examined f o r burn ing and p i t t i n g . They may even be found welded t o g e t h e r . Also, check f o r weak or broken r e l a y s p r i n g s and open, sho r t ed o r burned c o i l s . Solenoids should be examined f o r over -hea t ing o r f a i l e d c o i l s . These f i n d i n g s may l ead t o d e t e c t i o n of r e l a t e d c i r c u i t mal func t ions .

7 i 3 . 8 E l e c t r i c motors

E l e c t r i c motors should be examined f o r ev idence of e l e c t r i c a l d i s t r e s s and evidence of' o p e r a t i o n a t impact. Examine wi r ing , b rushes , commutators o r s l i p r i n g s , and f i e l d a rmature windings: look f o r ev idence of over -hea t ing , burn ing , a r c i n g , f a u l t y connexions and open o r sho r t ed windings. Examine t h e component be ing d r iven by t h e motor t o determine i t s c o n d i t i o n , looking e s p e c i a l l y f o r a mal func t ion which could be d e t r i m e n t a l t o motor ope ra t ion . Check t h e d r i v e coupl ing o r connexion f o r be ing sheared or i n t a c t . The motors may d r i v e f a n s o r o t h e r r o t a b l e components which could y i e l d o p e r a t i o n a l ev idence through s c o r i n g o r bending of f a n blades, o r s c r a p i n g of a r o t a t i n g component when i t sepa ra t ed from i ts housing. There may be impress ions on r o t a t i n g components which would i n d i c a t e t h a t t h e u n i t w a s a t rest o r o therwise n o t o p e r a t i n g when p h y s i c a l damage occurred . Motor bea r ings should be examined f o r wear o r l ooseness which would a l l o w t h e armature t o c o n t a c t or r u b a g a i n s t t h e f i e l d winding p o s t p i eces . The commutator and brushes should be examined f o r copper b r idg ing , broken brushes o r l oose brush wi r ing .

7.3.9 Electr ic w i r i n g

E l e c t r i c c a b l e s and wir ing should be examined f o r ev idence of over-heating, cha f ing of w i r e bundles a g a i n s t b racke t s o r a d j a c e n t s t r u c t u r e , and a r c i n g o r burning. D i sco loura t ion of i n s u l a t i o n is not n e c e s s a r i l y ev idence of over-heat bu t cou_ld be merely a r e s u l t of aging. Over-heat may be evidenced by embr i t t l ement of i n s u l a t i o n and r e s i s t a n c e t o bending. It i s w i s e t o s e p a r a t e wi re s i n a bundle f o r e a s i e r examination. One w i r e i n t h e bundle may be over-heating and a f f e c t i n g a d j a c e n t wires. Any evidence of burning should be explored f u r t h e r t o determine whether i t s source is e x t e r n a l o r e lec t r ica l . Ex te rna l burning of s t r a n d s i s evidenced by a dark s u r f a c e wi th b r i g h t w i r e underneath. burning is evidenced by d i s c o l o u r a t i o n throughout t h e s t r a n d c r o s s s e c t i o n . of broken o r cu t w i re s t r a n d s f o r evidence of e l e c t r i c power a p p l i c a t i o n when s e p a r a t i o n occurred. welding toge the r .of s t r a n d s o r by smoothly rounded s t r a n d 2 n d ~ .

E l e c t r i c a l Examine t h e ends

This w i l l u s u a l l y be i n d i c a t e d by melted g lobu les o r nodes on t h e end of s t r a n d s ,



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111-7-7 :',lrt III.-- The I n v e s t i g a t i o n

7.3.10 E l e c t r i c a l components: f u n c t i o n a l t e s t i n g

The more s imple tests may c o n s i s t of running g e n e r a t o r s , a l t e r n a t o r s and i n v e r t e r s on a test bench t o de te rmine t h e i r a b i l i t y t o p rov ide s u i t a b l e e l e c t r i c power under c o n d i t i o n s of no-load and f u l l load. The mated v o l t a g e and f requency r e g u l a t o r s o r c o n t r o l p a n e l s should be used du r ing these tes ts i f t h e i r c o n d i t i o n pe rmi t s .

E l e c t r i c motors should be examined f o r s h o r t e d o r open f i e l d and armature v indings , bad b rushes and commutators o r ev idence of malopera t ion which would cause them t o draw e x c e s s i v e c u r r e n t . B e s u r e t o use e lec t r ica l power of t h e p rope r v o l t a g e and phase when t e s t i n g t h e s e components. Relays and r e g u l a t o r s , as w e l l as b l a c k box electrical sys- t e m c o n t r o l components, w i l l r e q u i r e more d e t a i l e d t e s t i n g . s p e c i f i c o p e r a t i n g s e t t i n g s and t h e s e should be determined from manuals on t h e system involved o r from in fo rma t ion supp l i ed by t h e manufac turer , must be a s c e r t a i n e d when seek ing t h e s e s p e c i f i c a t i o n s .

Relays w i l l g e n e r a l l y have

The r e l a y t y p e and model number

Vol tage and f requency r e g u l a t o r s of t h e carbon p i l e t ype should have t h e carbon s t a c k c o n d i t i o n examined a f t e r they are t e s t e d t o de te rmine t h e i r r e g u l a t o r y capa- b i l i t i e s . S t a c k d e t e r i o r a t i o n w i l l cause t h e r e g u l a t o r s t o ma l func t ion . Genera tor and a l t e r n a t o r p r o t e c t i o n and c o n t r o l p a n e l s are mainly e l e c t r o n i c i n n a t u r e and w i l l r e q u i r e s p e c i a l t e s t i n g equipment. Ensure d e t a i l e d c i r c u i t diagrams and s p e c i f i c a t i o n s are ob ta ined f o r t h e t e s t i n g and t r o u b l e s h o o t i n g of t h e s e components. F a i l u r e s i n r e l a y s and r e g u l a t i n g '

components have r e s u l t e d i n many cases where e s s e n t i a l electrical s e r v i c e w a s l o s t due t o overhea t ing of equipment, ove rvo l t age and excess c u r r e n t draw and even d e s t r u c t i v e e l e c t r i c a l f i r e s .

7.3.11 L igh t bu lbs and r a d i o tubes

A good source of i n fo rma t ion is t h e l i g h t bulb, e s p e c i a l l y warning l i g h t bulbs. i t would be v e r y h e l p f u l i f i t could be determined t h a t a warning l i g h t w a s i l l umina ted a t t h e t i m e of t h e a c c i d e n t . I t a l s o may be impor tan t t o de te rmine whether cockp i t l i g h t i n g was a v a i l a b l e . Other bu lbs , such as from t h e c a b i n o r e x t e r n a l l i g h t s , can a s s i s t i n de t e rmin ing t h e p re sence of e l e c t r i c power a t impact. Every e f f o r t should . be made t o r ecove r bu lbs from l and ing l i g h t s , p o s i t i o n o r n a v i g a t i o n l i g h t s , wing i l lumina- t i o n o r ice l i g h t s and r o t a t i n g a n t i - c o l l i s i o n l i g h t s . Each bulb and tube must be care- f u l l y and p r o p e r l y l a b e l l e d .

Bulb f i l a m e n t s should be examined us ing a magnifying g l a s s . When an u n l i t bu lb i s s u b j e c t e d t o p h y s i c a l shock, t h e r e is no a p p r e c i a b l e s t r e t c h i n g of t h e f i l a m e n t s , even when t h e load is s u f f i c i e n t t o cause f i l amen t f a i l u r e . However, when t h e bulb i s i l l umina ted a p h y s i c a l shock causes s t r e t c h i n g of t h e h o t f i l a m e n t a t l o a d s f a r below t h a t caus ing f a i l u r e . The f i l a m e n t s of most bu lbs are t i g h t l y wound c o i l s , and i n t h e s e bu lbs t h e s t r e t c h i n g r e s u l t s i n t h e c o i l s opening up, l i k e those of a t e n s i o n s p r i n g s t r e t c h e d beyond t h e e l a s t i c l i m i t . The i n c r e a s e d l eng th a l s o causes d i s t o r t i o n of t h e normal loop Eormed by t h e f i l a m e n t .

The amount of f i l a m e n t s t r e t c h depends on t h e magnitude of t h e shock load and may be g e n e r a l o r l o c a l i z e d , u s u a l l y nea r t h e end a t tachment p o l e s o r a t t h e bends of t h e f i l amen t over t h e suppor t hangers w i th only a s l i g h t opening up of t h e windings. There is not much i n c r e a s e i n l e n g t h , and, consequent ly , on ly s l i g h t d i s t o r t i o n of t h e loop i n such cases . Where t h e g l a s s envelope i s broken i n t h e a c c i d e n t and p o r t i o n s of t he f i l amen t may b e mi s s ing , c a r d i i l examination can d e t e c t ev idence of t h e b u l b be ing i l l u m i n a t e d t-tirough s t r e t c h i n g of t h e remain ing f i l amen t nea r i t s a t tachment p o i n t s . There i s a l s o a



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n o t i c e a b l e d isco loura t ion of t h e f i l amen t i n such c a s e s a s a r e s u l t of o x i d a t i o n of t h e tungs ten w i r e which does no t occur when t h e f i l amen t is cold.

I f a f i l amen t is found broken but i ts appearance i s c l e a n and b r i g h t and no s t r e t c h is noted i n t h e f i lament c o i l , t h i s is evidence t h a t t he f a i l u r e occurred w h i l e t h e f i l amen t was cold. appears c l ean , as though i t snapped o f f , a g a i n t h i s i s evidence t h a t t h e f i lament w a s cold. g l a s s envelope is s l i g h t l y d i sco lou red , t h i s i s an i n d i c a t i o n t h a t t h e f i l amen t burned o u t and t h i s most probably occurred p r i o r t o t h e acc iden t .

Also examine c l o s e l y the broken ends of t h e f i l amen t ; i f t h e break

I f , on t h e o t h e r hand, t h e r e i s a melted g lobule o r node on t h e broken end and the

Radio vacuum tubes w i l l e x h i b i t somewhat similar i n d i c a t i o n s . A t u b e t h a t is

A cracked o r broken. t ube wi th a normal appear ing envelope i n d i c a t e s t h a t cracked and is smoked on t h e i n s i d e of t h e envelope i n d i c a t e s t h a t t h e tube was h o t a t t h e t i m e of breakage. no e lectr ic power w a s being a p p l i e d t o t h e tube f i l a m e n t s a t t h e t i m e of breakage.

7 . 3 . 1 2 Examp les

Typica l examples of examinat ion of e l ec t r i ca l systems are given a t Appendix 7.

7.4 P r e s s u r i z a t i o n and A i r Condi t ioning Systems

7.4.1 Superchargers and compressors

These u n i t s supply charge a i r f o r a i r c o n d i t i o n i n g and p r e s s u r i z a t i o n . Both types of components a r e genera l ly dr iven by engine accessory d r i v e s o r gear boxes and may be disengaged i n f l i g h t i n case of malfunct ion. They can only be re-engaged a f t e r complete engine shut down. Both types should be examined f o r evidence of disengagement o r d r i v e f a i l u r e , f o r proper l u b r i c a t i o n , and f o r evidence of bear ing f a i l u r e o r over-heat ing. The i n p e l l e r s should be examined f o r blade damage which would i n d i c a t e o p e r a t i o n a t t h e t i m e of t h e acc iden t .

7.4.2 Turbine engine bleed a i r system

A i r i s bled from t h e compressor s e c t i o n of t u r b i n e engines i n c o n t r o l l e d amounts t o provide a i r condi t ion ing and p r e s s u r i z a t i o n , and i c e and r a i n p r o t e c t i o n . Auxi l ia ry power u n i t s u t i l i z i n g t u r b i n e engines b a s i c a l l y supply a i r f o r engine s t a r t i n g but may a l s o be used t o supplement t h e a i r condi t ion ing system, p a r t i c u l a r l y f o r ground operat ion. Pneumatic flow c o n t r o l va lves , such as shut-off o r , i s o l a t i o n v a l v e s , a i r d e l i v e r y v a l v e s , p r e s s u r e reducing o r modulating v a l v e s , c r o s s f e e d v a l v e s , temperature con- t r o l v a l v e s and non-return o r check v a l v e s , should be examined f o r v a l v e p l a t e p o s i t i o n s and a s s o c i a t e d duc t ing connexion i n t e g r i t y . The va lve p l a t e p o s i t i o n s should be r e l a t e d t o cockpi t c o n t r o l p o s i t i o n s . and examined f o r i n t e g r i t y . Cont ro l components such as over-temperature and over -pressure swi tches and thermosta t s should be loca ted and preserved f o r f u r t h e r s tudy should t h e need a r i s e .

Bleed a i r p r e s s u r e r e l i e f v a l v e s o r pane ls should be l o c a t e d

I f cab in fumes o r carbon monoxide contaminat ion a r e suspected a s a f e a t u r e i n t h e acc iden t t h e a i r duc t ing , p a r t i c u l a r l y t h a t c l o s e s t t o t h e engine bleed, should be examined f o r smoke o r o i l depos i t s . A l so t h o s e r e s p o n s i b l e f o r powerplant i n v e s t i g a t i o n should be a l e r t e d t o t h e need t o examine t h e engine o i l s e a l s . Human Fac to r s group i s necessary i n t h i s s i t u a t i o n .

Co-ordination wi th t h e



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111-7- 9 ____p---.---- I ' i i r t 111.- T h e I n v e s t i g a t i o n

7.4.3 A i r Cond i t ion ing System

T h i s w i l l i n c l u d e a l l f low c o n t r o l v a l v e s such as t h e c a b i n mixing va lve , a i r d e l i v e r y v a l v e s , pack v a l v e s and tempera ture c o n t r o l va lves . p r e s s o r s , condensers and e v a p o r a t o r s ; a i r c y c l e machines o r c o o l i n g t u r b i n e s ; turbo- compressors, water s e p a r a t o r s and h e a t exchangers. should be documented and r e l a t e d t o cockp i t c o n t r o l p o s i t i o n s . turbo-compressors should be examined f o r ev idence of o p e r a t i o n o r mal func t ion . t i o n of t h e b e a r i n g s and i m p e l l e r s and t h e i r p roper l u b r i c a t i o n , as w e l l as t h e duc t ing connexions a t t h e s e u n i t s , should be examined.

Also inc luded are f r e o n com-

A l l v a l v e p o s i t i o n s and t h e i r c o n d i t i o n A i r c y c l e machines and

The condi-

Flow c o n t r o l v a l v e s are u s u a l l y of two types; t h o s e which are ope ra t ed by e l e c t r i c motors and t h o s e which are e l e c t r i c a l l y c o n t r o l l e d b u t pneumat i ca l ly ac tua t ed . The l a t t e r type w i l l , i n g e n e r a l , r e t u r n t o t h e c losed p o s i t i o n i f e lec t r ic power is removed. It w i l l be impor t an t t o i d e n t i f y each of t h e s e v a l v e s i n o r d e r t o relate t h e i r p o s i t i o n s t o cockpi t c o n t r o l s . The v a r i o u s e lec t r ica l components of t h e c o n t r o l and warning c i r c u i t s , such as thermocouples, mercury swi t ches and p r e s s u r e swi t ches should be r ecove red , i d e n t i f i e d , l a b e l l e d and p r e s e r v e d f o r t e s t i n g or d e t a i l e d examination should t h e need arise.

7.4.4 P r e s s u r i z a t i o n

The h e a r t of t h i s sys tem w i l l be t h e p r e s s u r e c o n t r o l and r e l i e f v a l v e s , and t h e mechanical and e l e c t r i c a l c o n t r o l components. The l a t t e r w i l l u s u a l l y be found i n t h e cockpi t and e l ec t r i ca l equipment r acks . The former w i l l c o n s i s t of t h e p r e s s u r e c o n t r o l va lve , ou t f low v a l v e s and emergency d e p r e s s u r i z a t i o n va lves . These v a l v e s should be examined f o r c o n d i t i o n and p o s i t i o n , i n t e g r i t y of mechanical l i n k a g e , e lec t r ica l connec to r s and p r e s s u r e s e n s i n g l i n e f i t t i n g s . Look f o r any evidence of ma l func t ion such as s t i c k i n g va lves or f a i l u r e s i n diaphragms. Some p r e s s u r e c o n t r o l v a l v e s can be t r i p p e d c l o s e d du r ing emergency c o n d i t i o n s such as f i g h t i n g an unde r f loo r compartment f i r e . The p o s i t i o n of i t s l inkage may p o i n t t o such an occurrence .

7.4.5 D u c t i n g

A l l d u c t i n g should be recovered and examined f o r be ing r u p t u r e d from over- p re s su re o r mater ia l d e f e c t s and d u c t j o i n t clamps should be checked f o r i n t e g r i t y . Heated a i r from a l e a k i n g or s e p a r a t e d duc t j o i n t can have an adve r se e f f e c t on a d j a c e n t equipment, e l e c t r i c . w i r i n g o r f l u i d - c a r r y i n g plumbing. Heat e f f e c t on w i r i n g can r e s u l t i n erratic o p e r a t i o n of e l e c t r i c a l l y ope ra t ed components. Ducting i n t e r i o r s should be examined f o r evidence of smokeor o t h e r d e p o s i t s . Duct i n s u l a t i o n should be examined f o r d i s c o l o u r a t i o n which might i n d i c a t e over -hea t ing , and f o r t h e presence of f u e l or h y d r a u l i c f l u i d satura- t i o n r e s u l t i n g from l e a k s i n plumbing a d j a c e n t t o t h e duc t ing . The l a t t e r could r e s u l t i n a f i r e .

7 , 5 , I c e and Ra in P r o t e c t i o n Systems

T h i s i n c l u d e s pneumatics and thermal de- ic ing equipment, w indsh ie ld wipe r s and r a i n r e p e l l e n t .

7.5.1 Pneumatic de - i c ing equipment

Pneumatic a i r from vacuum pumps is used ' i n t h e o l d e r a i r f o i l de-icing systems.

Examine t h e vacuum pump d r i v e coupl ing and t h e f u s i b l e p lug f o r i n t e g r i t y and Examine t h e c o n d i t i o n of de- ic ing boo t s , t h e i r supply l i n e s and t h e p o s i t i o n of t h e i r con- t r o l va lves . t h e pump i t s e l f f o r ev idence of o p e r a t i o n a t t h e t i m e of t h e a c c i d e n t .



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Manual of A i r c r a f t Accident Inves t igat ioi i -- 111-7-10 -

7.5.2 Thermal de-icing equipment

A i r f o i l thermal a n t i - i c i n g i s provided by h e a t e d a i r suppl ied by gasol ine- f i r e d h e a t e r s o r by t u r b i n e engine bleed a i r . f o r burn-through o r s i g n s of f i r e from l e a k i n g f u e l . w i l l have flow c o n t r o l v a l v e s f o r wing and empennage and t h e i r p o s i t i o n s should b e documented and r e l a t e d t o cockp i t c o n t r o l s e t t i n g s . A i r f o i l a n t i - i c i n g duc t ing should be examined f o r ev idence of f a i l u r e o r l oose j o i n t s which could a l low h o t a i r t o be d i r e c t e d a g a i n s t w i r i n g bundles, f l u i d l i n e s and o t h e r components which could malfunct ion as t h e r e s u l t of e x c e s s i v e h e a t . There have been c a s e s where t h i s hea ted a i r h a s c h a r r e d t h e i n s u l a t i o n on e l ec t r i c wi r ing .

The combustion h e a t e r s should be examined The engine b l e e d , a i r a n t i - i c e system

7.5.3 Windshield w i p e r s and r a i n r e p e l l e n t

Windshield wipers may be h y d r a u l i c a l l y o r e l e c t r i c a l l y operated. Check t h e p o s i t i o n of wiper arms and check t h e p o s i t i o n of wiper c o n t r o l s . There have been cases where malfunct ioning hydraul ic wiper motors have d e p l e t e d a v a i l a b l e p r e s s u r e t o t h e p o i n t where landing g e a r s could not be lowered and locked down i n emergency s i t u a t i o n s . Rain r e p e l l e n t may be bleed a i r a c r o s s t h e windshie lds o r may be provided by a chemical from aerosol- type d i spense r s . b u r s t i n g i n f l i g h t . should they b u r s t , even though t h e substance is non-toxic.

These d ispensers should be recovered and examined f o r ev idence of They a r e u s u a l l y mounted i n t h e cockp i t and thereby c o n s t i t u t e a hazard

7.6 Instruments

7.6.1 Genera 1

A l l ins t ruments should be recovered, t h e i r r e a d i n g s and c o n d i t i o n documented and t h e i r connexions examined. Pressure instrument hoses should be examined f o r ev idence of leakage o r poor connexions; e l e c t r i c a l connectors should be examined f o r l o o s e p i n s o r poor s o l d e r i n g of wir ing; and wir ing bundles behind instrument pane ls should be examined f o r s h o r t s , over-heating o r chafed i n s u l a t i o n . Clamped bundles should be examined under t h e clamps s i n c e t h i s i s a l i k e l y place t o f i n d worn i n s u l a t i o n .

7.6.2 P i t o t and s t a t i c pressure s y s t e m s

P i t o t heads should be examined f o r o b s t r u c t i o n s and an ohmmeter used t o test t h e c o n t i n u i t y of t h e P i t o t h e a t e r element. One way t o check f o r P i t o t h e a t e r o p e r a t i o n a t impact i s t o look f o r v e g e t a t i o n o r woody material packed i n t o t h e tube a t i m p a c t . I f t h i s mater ia l is charred o r discoloured by h e a t , t hen i t i s an i n d i c a t i o n t h a t t h e h e a t e r may have been i n ope ra t ion . Examine s t a t i c p o r t s f o r blockage by t ape o r o t h e r o b s t r u c t i o n s such a s gasket s e a l i n g m a t e r i a l which may have been extruded i n t o t h e p o r t a t i n s t a l l a t i o n . The P i t o t and s t a t i c pressure plumbing should be examined f o r evidence of blockage due t o i c e and/or water as w e l l a s f o r adequacy of drainage. i n t h i s connexion, t h e des ign of t h e P i t o t s t a t i c system may warrant a d e t a i l e d review. The plumbing should a l s o be examined f o r evidence of breakage o r loose f i t t i n g s . Some c a s e s have been found where t u b i n g w a s buckled o r tw i s t ed near a f i t t i n g because of improper i n s t a l l a t i o n o r r e p a i r t echniques . Examine f l e x i b l e hoses behind t h e instrument pane ls f o r being kinked and f o r h o l e s being c r e a t e d by aging of t h e hoses. The p o s i t i o n of t h e s t a t i c source s e l e c t o r f o r normal o r a l t e r n a t e sources should be recorded.



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P a r t III.- The I n v e s t i g a t i o n 111-7- 11

7.6.3 A l t i m e t er s

The most r e l i a b l e r e a d i n g obtained from an a l t i m e t e r w i l l be t h e ba romet r i c p re s su re s e t t i n g . f l i g h t crew t o determine i f it w a s c o r r e c t . recorded and t h e v a l u e should compare t o t h e e l e v a t i o n of t h e a c c i d e n t s i te; however, t h e i n t e r n a l mechanism may have been d i s r u p t e d du r ing t h e a c c i d e n t and t h e r e a d i n g may be i n v a l i d . S ince t h e ba romet r i c scale is gear-dr iven by an a d j u s t i n g knob, t h e a d j u s t i n g mechanism should be examined f o r s i g n s of damage, a d j u s t i n g mechanism was n o t locked fo l lowing a shop adjustment and t h e altimeter p o i n t e r s were d i sconnec ted from t h e ba romet r i c s e t t i n g mechanism. t o be reset wi thou t a cor re spond ing change i n p o i n t e r p o s i t i o n s .

T h i s r e a d i n g shou ld be compared wi th t h e last s e t t i n g provided t o t h e The p o s i t i o n of t h e hands o r drum should be

There have been instances where t h e

T h i s a l lowed t h e ba romet r i c scale

7.6.4 A i r speed i n d i c a t o r s

Airspeed i n d i c a t o r s and Machmeters should be examined c a r e f u l l y t o e s t a b l i s h whether t hey have been jammed by impact a t t h e r e p r e s e n t a t i v e r e a d i n g o r t o determine t h e d i r e c t i o n of f a i l u r e of t h e i n d i c a t o r need le sp indle . Gene ra l ly , t h e i n d i c a t i o n of t h e instrument as found i n t h e wreckage is not t o be r e l i e d on, but photography of t h e f a c e i n u l t r a - v i o l e t l i g h t (b l ack l i g h t ) may r e v e a l a s i g n i f i c a n t r ead ing . The in s t rumen t may have t o be checked i n t h e l a b o r a t o r y f o r mechanical f a i l u r e , o r i f t h e damage is minimal i t may be p o s s i b l e t o c a l i b r a t e it and check its h y s t e r e s i s .

7.6.5 Compass systems

Determine r e a d i n g s on heading i n d i c a t i n g in s t rumen t s such as t h e magnetic compass, t h e cour se d i r e c t o r i n d i c a t o r (CDI), t h e r a d i o magnet ic d i r e c t i o n i n d i c a t o r (RMDI) t h e gyrosyn compass and t h e a i r - d r i v e n d i r e c t i o n a l gyro.. Record t h e s e l e c t e d cour se and t h e s e t t i n g index. Some of t h e s e u n i t s w i l l i n c o r p o r a t e i n t e g r a l gyroscopes wh i l e o t h e r s w i l l be f e d by remote d i r e c t i o n a l gyros. operat ion. Disassemble t h e u n i t and look f o r r o t a t i o n a l s c o r i n g on t h e r o t o r and t h e i n s i d e of t h e r o t o r housing from c o n t a c t a t t h e t i m e of t h e acc iden t . In s t rumen t r e a d i n g s should be r e l a t e d t o t h e a i r c r a f t heading a t impact. The r ead ings may n o t a g r e e , i n which case t h e compass system may have become i n o p e r a t i v e a t some t i m e p r i o r t o t h e a c c i d e n t . It may a l s o be t h e r e s u l t of damage i n c u r r e d du r ing t h e crash. A l l of t h e s e c o n d i t i o n s should be considered.

The gyros should be examined f o r evidence of

Some ins t rumen t s such as C D I w i l l have mileage i n d i c a t o r s i n one corner of t h e instrument wh i l e t h e a i r c r a f t may have a s e p a r a t e m i l e a g e . i n d i c a t o r on t h e instrument panel. These mileage r e a d i n g s shou ld be checked a g a i n s t t h e d i s t a n c e between t h e acc iden t s i t e and s e l e c t e d f a c i l i t y . Omnibearing i n d i c a t o r s can y i e l d in fo rma t ion as t o t h e . a i r c r a f t ' s b e a r i n g from a s e l e c t e d VOR f a c i l i t y . Th i s i n fo rma t ion may a l s o be ob ta ined from t h e p o i n t e r s on t h e RMDI. and w i l l be s e l e c t e d by swi t ches on t h e instrument panel. The s e l e c t e d f u n c t i o n s should be determined t o make a d e f i n i t e c o r r e l a t i o n wi th a s e l e c t e d f a c i l i t y .

The ñMDI p o i n t e r s may be used f o r both VOR and ADF bea r ings

The magnetic compass should be examined f o r evidence of p r i o r unservice- a b i l i t y such a s a n i n c o r r e c t amount of f l u i d , and a l s o f o r improper i n s t a l l a t i o n . be determined t h a t t h e compass d i r e c t i o n ca rd is c u r r e n t , and i t ,should be borne i n mind t h a t t h e o p e r a t i o n of t h e compass can be in f luenced by t h e c l o s e p rox imi ty of f e r r o u s mat e r ia1 .

It should



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111-7-12 Nanual - of Aircrnf t Accident I n v e s t i g a t i o n

7.6.6 A t t i t u d e ins t ruments

P i t c h and r o l l i n d i c a t i o n s should be recorded. It i s p o s s i b l e t o de te rmine t h e p i t c h and r o l l , when t h e p i c t o r i a l d i s p l a y s have been o b l i t e r a t e d , by examination of t h e small se rvos . The a r t i f i c i a l hor izon and t u r n and s l i p i n d i c a t o r m ~ y c o n t a i n i n t e g r a l gyros o r a l l gyro informat ion may be fed t o the in s t rumen t s from a remote v e r t i c a l gyro. A l l gyros should be examined as i n d i c a t e d i n paragraph 7.6.5 above.

7.6.7 I n t e g r a t e d instrument systems

The components of t h e i n t e g r a t e d ins t rument systems should be. recovered f o r p o s s i b l e t e s t i n g . Examination of t h e s e components must be conducted under l a b o r a t o r y con- d i t i o n s because of t h e s p e c i a l i z e d test equipment r e q u i r e d f o r such examination. Systems of t h i s type may become important i n landing a c c i d e n t s w i t h t h e new automated l and ing systems now being i n s t a l l e d i n t r a n s p o r t a i r c r a f t .

A s t h e s e systems a r e developed i t is expected they w i l l become f u r t h e r i n t e g r a t e d wi th t h e nav iga t ion systems.

7.6.8 Navigation components

These w i l l inc lude components of t h e i n t e g r a t e d f l i g h t instrument systems as w e l l as s i n g l e components i n a i r c r a f t not s o equipped. While t h e va r ious in s t rumen t s may not be i n a cond i t ion f o r a c t u a l t e s t i n g , t h e r e are f e a t u r e s b u i l t i n t o t h e in s t rumen t s which can provide important da ta . The e l e c t r o n i c o r b l ack box components w i l l be ve ry h e l p f u l i n t h i s r e s p e c t a l so .

Many ins t ruments r e c e i v e t h e i r s i g n a l s from remote sources and u t i l i z e small synchronous se rvos f e d by servo t r a n s m i t t e r s . These se rvos w i l l a i d i n provid ing heading , p i t c h and r o l l a t t i t u d e and f l i g h t c o n t r o l s u r f a c e p o s i t i o n in fo rma t ion which can be ve ry important depending on t h e acc iden t circumstances. Un i t s con ta in ing such dev ices should be recovered and placed i n p r o t e c t i v e s t o r a g e u n t i l they can be a f fo rded s p e c i a l examination, Such examination can bes t be accomplished a t t h e f a c i l i t i e s of t h e manufacturer. The aggrega te d a t a obta ined from t h e examination of a l l such s e r v o s i n a g iven s y s t e m w i l l provide a s o l i d base f o r a n a l y s i s of t he p r e v a i l i n g c i rcumstances p r i o r t o t h e acc iden t . Examination of damage t o gyro gimbals can sometimes provide informat ion as t o p i t c h and r o l l a t t i t u d e s a t t h e t i m e of impact.

7.6.9 Enp i n e ins t ruments

Engine ins t ruments should be documented f o r r e a d i n g s and condi t ions . Some ins t ruments such a s t h e t u r b i n e i n l e t temperature i n d i c a t o r may c o n t a i n c a l i b r a t e d t a p e which can y i e l d informat ion as t o p r i o r readings . r a t i o t r a n s m i t t e r which may con ta in information as t o p r i o r engine output .

Another component i s t h e engine p r e s s u r e

7.7 Radio Communication and Radio Navigation Equipment

7.7.1 T ransmi t t e r s and r e c e i v e r s

During cockpi t documentation, t h e frequency s e l e c t o r pane l s should be examined f o r s e l e c t e d f r equenc ie s . t h e a rea . audio s e l e c t o r pane l s t o determine t h e amount of volume set on t h e equipment.

These f r equenc ie s should be c o r r e l a t e d wi th r a d i o f a c i l i t i e s i n Also, check volume c o n t r o l knob p o s i t i o n s on both t h e s e l e c t o r pane l s and t h e



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The VHF r a d i o equipment f o r both communication and n a v i g a t i o n can be examined v i s u a l l y t o de te rmine p re - se l ec t ed f r equenc ie s by removing t h e f r o n t cover and r ead ing t h e frequency on two i n d i c a t o r s . Should t h e f r o n t pane l be miss ing , t h e c r y s t a l bank s e l e c t o r swi tches should be examined t o determine which c r y s t a l s were s e l e c t e d . The two c r y s t a l va lues can t h e n be g iven t o t h e manufacturer who can then supply t h e s e l e c t e d frequency. Another method is t o examine t h e frequency s e l e c t o r rods and cam p o s i t i o n s , a l s o t ak ing no te of t h e p o s i t i o n s of t h e tun ing s lugs . shop, it can be channel led u n t i l t h e cams and s l u g s ag ree i n p o s i t i o n t o t h e component i n ques t ion ; t h e n t h e f requency can be r ead o f f t h e good u n i t .

When s i m i l a r equipment is a v a i l a b l e i n a r a d i o

The latest VHF r a d i o equipment is of s o l i d state c o n s t r u c t i o n u t i l i z i n g e l e c t r o n i c swi t ch ing and no moving p a r t s . t h e above in fo rma t ion i s r e t r i e v a b l e through a p h y s i c a l examinat ion.

7.7.2 Automatic d i r e c t i o n f i n d e r s

Th i s equipment has no "memory" and t h u s none of

Determine t h e band and frequency s e l e c t e d from t h e ADF c o n t r o l pane l , then endeavour t o c o r r e l a t e t h e s e f i n d i n g s wi th a nearby low f requency f a c i l i t y . The ADF equipment i t s e l f h a s no i n d i c a t i o n s of f requency such as i n some of t h e VHF equipment And i ts frequency can on ly be ob ta ined by a c t u a l ope ra t ion . Depending on t h e component cond i t ion t h e band and f requency may be determined by use of a s i g n a l gene ra to r . I f t h e ADF is no t operable , t h e p o s i t i o n s of t h e v a r i a b l e tun ing condensers should be r eco rded by s c r i b i n g on t h e condenser p l a t e s t o ho ld t h e r e l a t i o n s h i p , t hen ano the r r e c e i v e r of t h e same type can be tuned u n t i l t h e condenser p l a t e s are i n t h e same r e l a t i o n s h i p and a good approximation of t h e f requency can be obta ined .

The ADF need le on t h e ñMDI can be documented as t o an i n d i c a t e d bear ing and t h i s can be r e l a t e d t o t h e bea r ing of t h e acc iden t s i t e t o t h e s e l e c t e d f a c i l i t y . This can be accomplished i n con junc t ion w i t h t h e VOR needle b e a r i n g s i n d i c a t e d and t h u s provide a check of t h e n a v i g a t i o n by t h e f l i g h t crew, p a r t i c u l a r l y on en-route acc iden t s . It may be p o s s i b l e t o d e r i v e b e a r i n g in fo rma t ion from t h e p o s i t i o n of t h e movable ADF loops depending on t h e i r c o n d i t i o n .

7.7.3 Di s t ance measuring equipment

The cockp i t channel s e l e c t o r p o s i t i o n should be recorded . The d i s t a n c e module i n t h e f r o n t p o r t i o n of t h e u n i t can provide a mi leage i n d i c a t i o n : some u n i t s w i l l a l s o provide an i n d i c a t i o n of t h e s e l e c t e d channel b u t t h i s w i l l n o t be t r u e of s o l i d state equipment. whether o r n o t t h e u n i t w a s locked on t o a channel o r w a s i n t h e p r o c e s s of channel l ing .

Equipment u t i l i z i n g moving components can a l s o provide an i n d i c a t i o n as t o

Determine t h e f requency s e l e c t e d f o r VOR f a c i l i t i e s and check t o see i f t h a t f a c i l i t y is equipped f o r DME response . be compared t o t h a t found on t h e DME equipment. t h e d i s t a n c e between t h e a c c i d e n t s i t e and t h e s e l e c t e d f a c i l i t y .

The DME channel a s s igned t o t h a t f requency can then Compare t h e d i s t a n c e found on t h e DME t o

7 .7 .4 Antennas and c a b l e s

Antenna c a b l e connexions should be examined €o r s i g n s of damage or poor connexions. s t a t i c d i scha rges .

T r a n s m i t t e r an tennas should be examined f o r evidence of l i g h t n i n g s t r i k e s o r



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7 .8 F l i g h t Control Sys tem

7 .8 .1 Power c o n t r o l u n i t s

The h y d r a u l i c a l l y opera ted components should be examined .for evidence of leakage, proper e lec t r ica l connexions and l i n e f i t t i n g s f o r s e c u r i t y . of mechanical l i nkages and a c t u a t o r rods a s found f o r l a t e r r e f e r e n c e . and t h e s u r f a c e they o p e r a t e a r e i n t a c t , i t may be p o s s i b l e t o test t h e component where i t l i e s i f e lec t r ic and h y d r a u l i c power sou rces are r e a d i l y a v a i l a b l e . t h e most v a l i d t e s t of f u n c t i o n s s i n c e t h e same plumbing i n s t a l l a t i o n is being used. I f t h i s i s no t p o s s i b l e , t h e u n i t s should be removed from t h e wreckage f o r t e s t i n g a t a l a te r t i m e . a t t h e t i m e a connexion is broken t o prec lude i n t r o d u c i n g unwanted contaminat ion i n t o t h e u n i t .

Mark t h e p o s i t i o n I f t h e components

This would p r o v i d e

Take care when removing the u n i t s t h a t a l l hoses and p o r t s are capped o r plugged

7.8.2 S t a b i l i z e r screw jack

The h y d r a u l i c a l l y opera ted h o r i z o n t a l s t a b i l i z e r screw j a c k should be examined and a l l l i n e s , f i t t i n g s and mechanical l i n k a g e checked f o r s i g n s of damage. p o s i t i o n s of l e v e r arms, cab le drums, e t c . , so t h a t t hey can be r e a l i g n e d i f changed d u r i n g handl ing. Measure t h e gimbal nu t p o s i t i o n on t h e screw j a c k t o a s c e r t a i n t h e p o s i t i o n of the s t a b i l i z e r a t impact.

Mark t h e

7.8.3 Miscellaneous component s

E l e c t r i c a l l y operated components such as t r i m t a b s , s o l e n o i d v a l v e s , c o n t r o l v a l v e s and warning c i r c u i t s should be examined a l s o . Some v a l v e s w i l l be opera ted auto- m a t i c a l l y when a power c o n t r o l u n i t o r o t h e r device mal func t ions o r f a i l s . These v a l v e s should be recovered and t h e i r p o s i t i o n s documented. Document t h e c o n d i t i o n of t h e art i- f i c i a l f e e l system and t h e rudder yaw damper.

7.8.4 Automatic p i l o t s y s t e m

P o s i t i o n s of a u t o p i l o t c o n t r o l s i n t h e cockpi t and t h e c o n d i t i o n of t h e s e r v o motors and t h e i r attachment t o t h e f l i g h t c o n t r o l system should be recorded. An a t tempt should be made t o determine whether o r no t t h e a u t o p i l o t w a s i n o p e r a t i o n a t t h e t i m e of t h e accident .

7.8.5 F l i g h t c o n t r o l components - f u n c t i o n a l t e s t i n g

Hydro-mechanical and electro-hydro-mechanical components such as power c o n t r o l u n i t s , c o n t r o l boost u n i t s and s t a b i l i z e r screw j a c k s may be g iven complete package func- t i o n a l test s.

S p e c i a l tests may be devised which w i l l p rovide more informat ion than t h e s tandard tests. An example would be t e s t i n g t h e c a p a b i l i t i e s of t h e s t a b i l i z e r screw j a c k under c e r t a i n condi t ions of t a i l loading. test f i x t u r e , t h e screw j a c k can be s t a t i c a l l y loaded i n t e n s i o n and compression t o simula-ce t h e a p p l i c a t i o n of f u l l e l e v a t o r d e f l e c t i o n i n both d i r e c t i o n s a t assumed a i r speeds. h y d r a u l i c , e l e c t r i c a l and mechanical c o n t r o l s can then be e x e r c i s e d t o determine t h e a b i l i t y of t h e screw j a c k t o o p e r a t e under such cond i t ions .

When t h e screw j a c k assembly is mounted i n t h e

The

Note; Precaut ions t o be considered b e f o r e under tak ing t h e t e s t i n g of - hydraul ic components a r e contained i n paragraph 7.2.8 above; f o r d e t a i l s concerning t h e cons idera t ions and a c t i o n t o be taken w i t h regard t o s p e c i a l i s t i n v e s t i g a t i o n s refer t o P a r t II, Chapter 2 , S e c t i o n 2.5.



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Part III.- The i n v e s t i g a t i o n 111-7- 15

7.9 F i r e D e t e c t i o n and P r o t e c t i o n Systems

7.9.1 F i r e d e t e c t o r s

F i r e d e t e c t o r s may be of t h e ? f i r e w i r e ? t ype o r t hey may be i q d i v i d u a l d e t e c t o r s wi red i n s e r i e s . The f i r e warning c i r c u i t s should be checked f o r c o n t i n u i t y , grounding o r s h o r t i n g and t h e d e t e c t o r r e l a y boxes should be t e s t e d f o r o p e r a t i o n .

- Note: F i r e d e t e c t i o n and e x t i n g u i s h e r systems are becoming i n c r e a s i n g l y complex, t h e r e f o r e c o n s i d e r a t i o n may need t o be g iven t o u s i n g t h e s p e c i a l i z e d knowledge and tes t equipment of t h e manufacturer .

7 .9 .2 F i r e e x t i n p u i s h e r systems

These systems may u t i l i z e carbon d i o x i d e o r f r e o n . Usual ly , f i r e p r o t e c t i o n is provided f o r the e n g i n e s and t h e a u x i l i a r y power u n i t s ; however, many of t h e o l d e r air- c r a f t a l s o provide p r o t e c t i o n f o r u n d e r f l o o r compartments. A i r c r a f t u t i l i z i n g combustion h e a t e r s f o r a i r c o n d i t i o n i n g and thermal a n t i - i c i n g w i l l have h e a t e r f i r e p r o t e c t i o n a l s o . The l a t t e r w i l l u s u a l l y be of t h e carbon d ioxide type.

F i r e e x t i n g u i s h e r b o t t l e s should be recovered and examined f o r t h e i r s t a t e of charge. I f t hey are found t o be charged, arrangements should be made f o r s a f e s t o r a g e t o prec lude p e r s o n n e l i n j u r y . I f they are d ischarged , t h e c o n t r o l heads should be examined t o determine whether o r n o t t h e d i s c h a r g e w a s i n t e n t i o n a l . P r o v i s i o n s are made f o r thermal r e l e a s e and t h i s f u n c t i o n should a l s o be examined. I n d i c a t o r d i s c s a r e provided i n t h e a i r c r a f t s k i n of t h e f u s e l a g e o r engine pylons near t h e e x t i n g u i s h e r i n s t a l l a t i o n area t o provide ev idence of i n t e n t i o n a l o r thermal discharge. These should h e checked f o r cond i t ion .

7.9.3 P o r t a b l e e x t i n g u i s h e r s

P o r t a b l e e x t i n g u i s h e r s u s e carbon d ioxide and a l s o water. They should a l s o be recovered and examined i n o r d e r t o determine whether o r no t t hey were used. I f used, every a t tempt should be made t o determine whether u se occurred b e f o r e the a c c i d e n t o r dur ing t h e rescue o p e r a t i o n s .

7.10 Oxygen Systems

7.10.1 Oxygen c y l i n d e r s

C r e w and passenger b r e a t h i n g oxygen c y l i n d e r s should be accounted f o r t o ensure t h a t none of them had b u r s t p r i o r t o t h e a c c i d e n t . This w i l l i n c l u d e both p o r t a b l e and f i r s t a i d oxygen c y l i n d e r s . Any c y l i n d e r which remains charged should be placed i n s a f e s t o r a g e t o p r e v e n t personnel i n j u r y . Where p o s s i b l e , check t h e c y l i n d e r c o n t e n t s t o ensure t h a t t h e gas i s oxygen and n o t some t o x i c m a t e r i a l .

7 .10.2 Plumbing and f i t t i n g s

Examine a l l plumbing f o r evidence of f a i l u r e under p r e s s u r e . Control v a l v e s should be examined f o r e r o s i o n caused by h igh p r e s s u r e r a p i d flow. T h i s might i n d i c a t e t h a t t!ie oxygen had been r e l e a s e d t o o f a s t by l i n e f a i l u r e or v a l v e f a i l u r e . Regulator v a l v e s should be checked t o see i f they are c l o s e d , open o r p a r t i a l l y open.



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PART I I I

CHAPTER 8. - MAINTENANCE INVESTIGATION



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CHAPTER 8

MAINTENAMCE INVESTIWTION

8.1 General

The purpose of t h e maintenance i n v e s t i g a t i o n is t o review t h e maintenance h i s t o r y of t h e a i r c r a f t t o determine:

a ) in fo rma t ion which could have some bea r ing on t h e a c c i d e n t o r which could p o i n t t o a p a r t i c u l a r area of s i g n i f i c a n c e f o r i n v e s t i g a t i o n ;

b) . whether t h e a i r c r a f t h a s been maintained i n accordance wi th t h e s p e c i f i e d s t a n d a r d s ;

c ) whether , having r ega rd t o information gained d u r i n g t h e a c c i d e n t i n v e s t i g a t i o n , t h e s p e c i f i e d s t a n d a r d s are s a t i s f a c t o r y .

The i n v e s t i g a t i o n can cove r a wide a r e a and e n t a i l s t h e c a r e f u l examination of a g r e a t volume of d e t a i l , p a r t i c u l a r l y i n t h e case of a c c i d e n t s i n v o l v i n g l a r g e t r a n s p o r t a i r c r a f t . The f o l l o w i n g i n d i c a t e s t h e main areas t o be examined:

a) t o determine t h e o p e r a t i n g h i s t o r y of t h e a i r f r a m e , e n g i n e s , and compo- n e n t s ; hour s flown and a l s o , where a p p r o p r i a t e , t h e number of l and ings made ;

b) t o pe ruse t h e h i s t o r y of a c c i d e n t s , d e f e c t s and i r r e g u l a r o r abnormal o p e r a t i o n s which have been r epor t ed o r which become known d u r i n g t h e i n v e s t i g a t i o n and t o review t h e subsequent r e c t i f i c a t i o n o r o t h e r a c t i o n taken;

c) t o determine from t h e r e c o r d s t h a t mandatory m o d i f i c a t i o n s have been i n c o r p o r a t e d i n t h e a i r c r a f t and t h a t t e c h n i c a l o r d e r s have been complied w i t h ;

t o determine from t h e r e c o r d s t h a t any o t h e r m o d i f i c a t i o n s inco rpora t ed i n t h e a i r c r a f t w e r e performed i n a p rope r manner and , if a p p l i c a b l e , approved by t h e a p p r o p r i a t e a u t h o r i t y ;

t o a s c e r t a i n t h e f u n c t i o n a l procedure of t h e maintenance system employed by t h e o p e r a t o r and t o e s t a b l i s h t h a t it i s i n accordance wi th t h e main- t enance system approved by t h e l i c e n s i n g a u t h o r i t y ;

to a s c e r t a i n from t h e maintenance r e c o r d s whether o r no t t h e maintenance system h a s been fol lowed c o r r e c t l y and t o r eco rd any d i s c r e p a n c i e s o r omissions.

d )

e )

f )



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Manual of A i r c r a f t Accident Tiwest i g a t i o n II 1-8-2 -- 7

8.2 Large Transport A i r c r a f t

The maintenance r eco rds of l a r g e t r a n s p o r t a i r c r a f t a r e voluminous and an understanding of t h e o p e r a t o r ' s maintenance system and r eco rd ing procedures i s e s s e n t i a l f o r a s a t i s f a c t o r y i n v e s t i g a t i o n . necessary t o e n l i s t t h e a s s i s t a n c e of t he o p e r a t o r and, i n t h e case of a c c i d e n t s i nvo lv ing a i rc raf t of ano the r S t a t e , t h i s w i l l r e q u i r e Co-ordination wi th t h e S t a t e of Regis t ry . The t a s k of perus ing t h e maintenance r eco rds w i l l normally be conducted a t t h e maintenance base of t h e ope ra to r bu t i t is a l s o important t o determine what r eco rds were c a r r i e d i n t h e a i r c r a f t and t o secure them, i f p o s s i b l e , t o g e t h e r w i th t h e r eco rds he ld a t t r a n s i t bases through which t h e a i r c r a f t passed.

To achieve t h i s unders tanding it w i l l normally be

I n a d d i t i o n t o t h e records which t h e o p e r a t o r is obl iged t o keep i n accordance wi th t h e approved maintenance system, t h e r e may be o t h e r opera. t iona1 r eco rds which could conta in v a l u a b l e informat ion . The i n v e s t i g a t o r should f i n d out whether t h e r e are any such r eco rds and study them c a r e f u l l y , f o r they may h e l p t o r e so lve whether t h e r e h a s been any abnormal ope ra t ion of t h e a i r c r a f t .

The maintenance i n v e s t i g a t i o n w i l l sometimes e n t a i l t h e in t e rv i ewing of maintenance and o t h e r personnel i n o rde r t o co r robora t e important d e t a i l s conta ined i n t h e maintenance r eco rds and t o de te rmine , i n p a r t i c u l a r areas, t h e e x t e n t of i n spec t ions and o t h e r work and how p a r t i c u l a r tasks were c a r r i e d o u t , i n spec ted and c e r t i f i e d . In a d d i t i o n , i t may be necessary t o ob ta in f r o m t h e f l i g h t crew in fo rma t ion r ega rd ing t h e performance of t h e a i r c r a f t on previous s t a g e s of t h e f l i g h t o r p rev ious f l i g h t s .

8.3 Smal l A i r c r a f t

I n t h e case of small a i r c r a f t , t h e same p r i n c i p l e s of i n v e s t i g a t i o n of t h e maintenance r eco rds should apply but t h e r e w i l l be many a c c i d e n t s i n which maintenance r eco rds of t he a i r c r a f t involved w i l l be ve ry scanty. Qui te o f t e n a l l t h e r eco rds of t h e a i r c r a f t are c a r r i e d i n t h e a i r c r a f t and may have been des t royed . t h e i n v e s t i g a t o r more d i f f i c u l t bu t a great weal th of in format ion may be obta ined by t h e c a r e f u l in te rv iewing of maintenance personnel and f l i g h t crew concerning work r e c e n t l y c a r r i e d out on t h e a i r c r a f t and t h e o t h e r a s p e c t s which are covered du r ing t h e normal maintenance i n v e s t i g a t i o n .

8.4 I n v e s t i g a t i o n Co-ordination

Th i s makes t h e t a s k of

P a r t i c u l a r emphasis is t o be given t o t h e need f o r t h e i n v e s t i g a t o r charged with t h e maintenance i n v e s t i g a t i o n t o main ta in ve ry c l o s e Co-ordinat ion wi th t h e Investigator-in-Charge. a p a r t i c u l a r area of s i g n i f i c a n c e f o r i n v e s t i g a t i o n by o t h e r s p e c i a l i s t s , and i n t u r n i t may be n e c e s s a r y f o r t h e maintenance i n v e s t i g a t i o n t o s tudy p a r t i c u l a r a s p e c t s which have come t o t h e a t t e n t i o n of othersengaged elsewhere i n t h e i n v e s t i g a t i o n .

The r e s u l t s of t h e maintenance i n v e s t i g a t i o n may w e l l p o i n t t o



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PART I I I

CHAPTER 9. - HUMAN FACTORS INVESTIGATION



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P a r t 111.- The I n v e s t i g a t i o n

CHAPTER 9

HUMAN FACTORS INVESTIGATION

Tab le of Contents

9.1 General .................................................................. 9.2 C o n t r i b u t i o n of t h e Human F a c t o r s I n v e s t i g a t i o n ..........................

9.2.1 Recons t ruc t ion of t h e circumstances ............................... 9.2.2 Human e n g i n e e r i n g and s u r v i v a l .................................... 9.2.3 I d e n t i f i c a t i o n ....................................................

9.3 B r i e f i n g t h e P a t h o l o g i s t ................................................. 9.4 Tasks a t t h e Accident S i t e ...............................................

9.4.1 F a c i l i t i e s and equipment .......................................... 9.4.2 Procedures t o be fol lowed dur ing t h e recovery phase ............... 9.4.3 Recommendations of t h e I n t e r n a t i o n a l Criminal P o l i c e Organ iza t ion .

9.5 Tasks a t t h e Mortuary .................................................... 9.5.1 F a c i l i t i e s ........................................................ 9.5.2 I d e n t i f i c a t i o n of t h e dead ........................................

9.5.2.1 P r i n c i p l e s ............................................... 9.5.2.2 I d e n t i f i c a t i o n procedures ................................ 9.5.2.3 The g a t h e r i n g of in fo rma t ion about t h o s e b e l i e v e d k i l l e d . 9.5.2.4 Comparison of r e c o r d s ....................................

9.6 Evidence to be Derived from t h e P a t h o l o g i c a l Examination ................. 9.6.2 The examinat ion of p a s s e n g e r s and c a b i n a t t e n d a n t s ................ 9.6.3 C o r r e l a t i o n w i t h t h e a i r c r a f t wreckage examination ................

9.6.3.1 The c o c k p i t .............................................. 9.6.4 The n a t u r e and cause of i n j u r i e s and t h e i r t iming ................. 9.6.5 The d e t e r m i n a t i o n of t h e cause of dea th of each p e r s o n ............

9. 7 Release of Human Remains and P e r s o n a l P rope r ty ...........................

9.6.1 D e t e c t i o n of d i s e a s e o r impaired e f f i c i e n c y i n t h e o p e r a t i n g crew .

9.6.3.2 The passenge r compartment ................................

9.8 The Survived Accident .................................................... 9.9 Other Aspects of t h e Human F a c t o r s I n v e s t i g a t i o n .........................

and p h y s i c a l h e a l t h ............................................. 9.9.2 The problems of t h e p a r t i c u l a r f l i g h t .............................

9.10 Summary ..................................................................

9.9.1 F l i g h t crew med ica l and p e r s o n a l r eco rds . Basic mental

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P a r t III.- The I n v e s t i g a t i o n I I I-9- 3

CHAPTER 9

HUMAN FACTORS INVESTIGATION

9.1 General

T h i s c h a p t e r of t h e Manual of A i r c r a f t Accident I n v e s t i g a t i o n is intended as a g e n e r a l g u i d e t o an a i r c r a f t a c c i d e n t i n v e s t i g a t o r on t h e c o n t r i b u t i o n medical , patho- l o g i c a l and human e n g i n e e r i n g s p e c i a l i s t s , i n s h o r t t h e v a r i o u s "human f a c t o r s n e x p e r t s , may be a b l e t o make t o a n a c c i d e n t i n v e s t i g a t i o n and t h e n a t u r e of t h e work involved i n t h e i r c o n t r i b u t i o n . More d e t a i l e d m a t e r i a l is provided f o r t h e medical s p e c i a l i s t s them- s e l v e s i n t h e I C A 0 medical manual* and i n o t h e r t e c h n i c a l pub l i ca t ions** which, w h i l s t tech- n i c a l i n c o n t e n t , could be of v a l u e t o a i r c r a f t a c c i d e n t i n v e s t i g a t o r s i n t e r e s t e d i n t h i s p a r t i c u l a r f i e l d .

The prime o b j e c t of t h e Human F a c t o r s i n v e s t i g a t i o n is t o o b t a i n evidence as t o t h e c a u s e , sequence and e f f e c t of t h e a c c i d e n t through an examinat ion of t h e o p e r a t i n g crew, t h e c a b i n a t t e n d a n t s and t h e pas senge r s . Co- inc iden ta l ly w i t h t h e i n v e s t i g a t i o n , evidence as t o i d e n t i f i c a t i o n w i l l a u t o m a t i c a l l y emerge p a r t i c u l a r l y i f each examination i s enhanced by t h e co-ordinated e f f o r t s of t h e Human F a c t o r s Group p a t h o l o g i s t , p o l i c e , odon- t o l o g i s t s , r a d i o l o g i s t s , etc.

I d e n t i f i c a t i o n of t h e v i c t i m s must n o t be regarded as a n end i n i t s e l f . I d e n t i f i c a t i o n is an e s s e n t i a l p a r t of t h e o v e r - a l l a i r c r a f t a c c i d e n t i n v e s t i g a t i o n and it is expedient t o i n t e g r a t e t h e i d e n t i f i c a t i o n of bod ie s w i t h t h e post-mortem and autopsy examinations. I t is f o r t h i s r e a s o n t h a t t h e s u b j e c t of i d e n t i f i c a t i o n is d e a l t w i th i n some d e t a i l i n t h i s c h a p t e r .

The importance of t h e human f a c t o r s i n v e s t i g a t i o n h a s been inadequa te ly a p p r e c i a t e d i n t h e p a s t ; t h e ev idence de r ived from t h e human b e i n g s concerned i n a n a i r c r a f t a c c i d e n t - be they crew o r pas senge r s , s u r v i v o r s o r non-survivors - r e p r e s e n t s an i n t e g r a l p a r t of t h e i n v e s t i g a t i o n a s a whole. The purpose of t h i s i n t r o d u c t i o n and S e c t i o n 9.2 i s t o o u t l i n e t h e v a l u e of t h e medical i n v e s t i g a t i o n t o a i r c r a f t a c c i d e n t i n v e s t i g a t o r s and t o c i v i l a v i a t i o n a d m i n i s t r a t i o n s .

It is r e a l i z e d t h a t t h e procedures t o be fol lowed and r e s p o n s i b i l i t i e s w i l l d i f f e r c o n s i d e r a b l y acco rd ing t o l o c a l or n a t i o n a l laws, r e g u l a t i o n s and p r a c t i c e s and, t h a t i n some S t a t e s t h e competent j u d i c i a l a u t h o r i t y is r e s p o n s i b l e f o r t h e i n v e s t i g a t i o n of a l l c a s e s of sudden d e a t h . However, from a n a i r c r a f t a c c i d e n t i n v e s t i g a t i o n p o i n t of view t h e o b j e c t i v e of t h e medical i n v e s t i g a t i o n should be:

* Manual of C i v i l Av ia t ion Medicine (Doc 8984-AN/895).

** The f o l l o w i n g p u b l i c a t i o n s a r e known t o be r e l e v a n t t o t h e s u b j e c t :

Mason J . K . , Av ia t ion Accident Pathology. London, 1962, Butterworth.

Reals W.J., Eledical I n v e s t i g a t i o n of Av ia t ion Accidents . Chicago, 1968, College of American P a t h o l o g i s t s .

Stevens P . J . , F a t a l C i v i l A i r c r a f t Accidents ; t h e i r Medical and P a t h o l o g i c a l I n v e s t i g a t i o n . B r i s t o l , 1970, Wright.

3015177 No. 7



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111-9-4 Planual of A i r c r a f t Accident I n v e s t i g a t i o n

a ) t o provide medical evidence of t e c h n i c a l v a l u e t o t h e Inves t iga to r - in - Charge i n t h e r e c o n s t r u c t i o n of t h e a c c i d e n t ;

b ) t o provide medical evidence of t e c h n i c a l v a l u e r e l a t e d t o human enginee r ing , s u r v i v a l a s p e c t s , e tc . ;

c ) Co-ordination of t h e fo rego ing ev idence wi th t h e c i v i l a u t h o r i t i e s f o r j u d i c i a l i d e n t i f i c a t i o n , c e r t i f i c a t i o n of d e a t h and r e l a t e d matters.

Experience i n d i c a t e s t h a t o f t e n almost t h e t o t a l Human F a c t o r s I n v e s t i g a t i o n h a s been d i r e c t e d towards ! i d e n t i f i c a t i o n t o t h e de t r imen t of any o t h e r t e c h n i c a l input of v a l u e t o t h e Investigator-in-Charge.

Genera l ly , t h e Investigator-in-Charge w i l l appo in t as head of t h e Human

I n t h e even t t h a t t h e r e are f a t a l i t i e s , he should a l s o appoin t a p a t h o l o g i s t ,

I f t h e p a t h o l o g i s t h a s

F a c t o r s Group a s p e c i a l i s t i n a v i a t i o n medicine wi th expe r i ence i n a i r c r a f t a c c i d e n t inves- t i g a t i o n . i d e a l l y w i t h exper ience i n a v i a t i o n pathology o r a t least i n f o r e n s i c pathology, t o per form necessa ry f u l l au topsy examinations on a l l t h o s e v i c t i m s k i l l e d . expe r i ence i n a v i a t i o n pathology, he may w e l l be appoin ted as head of t h e Human F a c t o r s Group bu t t h i s w i l l depend on t h e type of a c c i d e n t be ing i n v e s t i g a t e d and o t h e r Human F a c t o r c o n s i d e r a t i o n s . The f a t a l acc iden t is, g e n e r a l l y , more d i f f i c u l t t o i n v e s t i g a t e than t h e non- fa t a l a c c i d e n t and i t i s f o r t h i s reason t h a t t h e r o l e of t h e p’athologis t is s t r e s s e d i n t h i s c h a p t e r . I n t h e event t h a t no a v i a t i o n p a t h o l o g i s t is a v a i l a b l e i n t h e S ta te inves- t i g a t i n g a major f a t a l a c c i d e n t , t h e Inves t iga tor - in-Charge should cons ide r r e q u e s t i n g o t h e r S t a t e s t o provide t h e necessary s p e c i a l i s t ( s ) .

Depending upon whether t h e a c c i d e n t i n v o l v e s l a r g e o r small a i r c r a f t , t h e I n e i t h e r human f a c t o r s evidence w i l l d i f f e r mainly i n emphasis r a t h e r t han subs tance .

case i t w i l l n o t ach ieve maximum v a l u e i n t h e absence of pre-planning on t h e p a r t of t h e a v i a t i o n a u t h o r i t y and o the r l o c a l o r n a t i o n a l a u t h o r i t i e s ( s e e page 11-1-4). Such pre- p l ann ing should be on t h e b a s i s of t h e l a r g e s t p o s s i b l e d i s a s t e r ; a small acc iden t merely means u t i l i z i n g less of t h e a v a i l a b l e resources . The matters f o r concern a r e d e t a i l e d i n subsequent s e c t i o n s bu t may be summarized a s fo l lows :

a ) The l a r g e non-fa ta l acc iden t : t h e p l a n s must be concerned wi th t h e p rov i s ion of r e scue equipment, w i th t h e a v a i l a b i l i t y of h o s p i t a l f a c i l i - t i e s and wi th t h e in t e rv i ew and examination of t h e crew t o de te rmine p o s s i b l e medical and psycho log ica l f a c t o r s , and of both crew and pas- s enge r s wi th regard t o i n j u r i e s and t h e i r causes , and escape and s u r v i v a l a spec t s .

b ) The major f a t a l a c c i d e n t : t h e d i s a s t e r p l an w i l l i nc lude t r a i n i n g i n t h e mapping and recovery of bod ies , t h e p r o v i s i o n of mortuary and r e f r i g e r a t i o n f a c i l i t i e s and t h e e s t ab l i shmen t of a medical team of i n v e s t i g a t o r s to - ge the r with an i d e n t i f i c a t i o n s e c r e t a r i a t o r commission.

Th i s i s a cons ide rab le programme but t he b e n e f i t s l i k e l y t o a c c r u e from a human f a c t o r s i n v e s t i g a t i o n are a t least equal t o t h e b e n e f i t s de r ived from any o t h e r a spec t of t h e a i r - c r a f t acc iden t i n v e s t i g a t i o n .

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Part III.- The I n v e s t i g a t i o n 111-9-5 - 9.2 C o n t r i b u t i o n of t h e Human F a c t o r s I n v e s t i g a t i o n

9 .2 .1 Recons t ruc t ion of t h e c i r cums tances

Some medica l ev idence r e l a t i n g t o t h e r e c o n s t r u c t i o n of the c i rcumstances of t h e a c c i d e n t may come from s u r v i v i n g crew members or passengers . I n t h e main, however, medical ev idence a s s o c i a t e d w i t h t h e r e c o n s t r u c t i o n of t h e a c c i d e n t c i r cums tances is asso- c i a t e d w i t h t h e f a t a l a c c i d e n t .

I n f a t a l l i g h t a i r c r a f t a c c i d e n t s t h e examination of t h e p i l o t is l i k e l y t o c o n t r i b u t e most; h e r e t h e medical i n v e s t i g a t i o n s should be d i r e c t e d t o de t e rmin ing o r exc luding d i s e a s e and i t s p o s s i b l e a s s o c i a t i o n , and such a s p e c t s as de te rmin ing o r exc lud ing a l c o h o l , d rugs and t o x i c subs t ances as a c c i d e n t causes, The examinat ion of pas senge r s can- no t be ignored , however, even i n l i g h t a i r c r a f t ; i n d u a l c o n t r o l a i r c r a f t one cannot be c e r t a i n t h a t a "passenger" was n o t f l y i n g t h e a i r c r a f t and f u r t h e r , t o x i c o l o g i c a l e x a m i n a - t i o n of pas senge r s ' t i s s u e s may tend t o v a l i d a t e f i n d i n g s i n t h e p i l o t ' s body such as r a i s e d carbon monoxide l e v e 1s.

The p resence of two o r more p i l o t s on t h e f l i g h t deck of l a r g e r aircraft makes p i l o t i n c a p a c i t a t i o n from d i s e a s e o r d r u g s as a cause of a major a c c i d e n t less l i k e l y . Although t h i s i s n o t e n t i r e l y t r u e when t h e a c c i d e n t h a s occurred a t a c r i t i c a l phase of f l i g h t such as take-off or l and ing , n e v e r t h e l e s s t h e p a t h o l o g i s t may o f t e n f i n d it appro- p r i a t e i n a l a r g e a c c i d e n t t o c o n c e n t r a t e on t h e s e a r c h f o r ev idence of c o n d i t i o n s l i k e l y t o a f f e c t t h e whole c r e w - i n p a r t i c u l a r carbon monoxide o r o t h e r noxious fumes tha t may have contaminated t h e c o c k p i t . H e must a l s o seek ev idence t o e l i m i n a t e o r conf i rm t h e involvement of a c r i m i n a l ac t such as unlawful i n t e r f e r e n c e w i t h t h e o p e r a t i o n of t h e a i r - c r a f t . A f u l l examination of a l l the o p e r a t i n g crew may g ive v a l u a b l e ex idence about who w a s c o n t r o l l i n g t h e a i r c r a f t a t t h e t i m e of t h e c r a s h , and i n t h i s r e s p e c t i d e n t i f i c a t i o n has d i r e c t t e c h n i c a l v a l u e t o t h e i n v e s t i g a t i o n as d i s t i n c t from j u d i c i a l va lue .

I n t h e major f a t a l a i r c r a f t a c c i d e n t , however, t h e r e i s t h e p o s s i b i l i t y of d e r i v i n g ev idence from t h e c a b i n a t t e n d a n t s and passenge r s ; a main concern of t h i s c h a p t e r i s t o i l l u s t r a t e why t h e oppor tun i ty must n o t be l o s t . A f u l l examinat ion , p a r t i c u l a r l y when it can be based upon p rev ious e x p e r i e n c e , may r e v e a l ev idence as t o t h e sequence of e v e n t s , t h e s t a g e of f l i g h t and the d e g r e e of emergency a n t i c i p a t e d ; t h e p a t t e r n of i n j u r i e s m y i n d i c a t e c l e a r l y t h e type of a c c i d e n t - f i r e i n f l i g h t , s t r u c t u r a l f a i l u r e i n f l i g h t , sudden or g r a d u a l d e c e l e r a t i o n a t impact , e tc . ; and an examinat ion of t h e pas senge r s may be t h e prime method of demons t r a t ing sabo tage as a n a c c i d e n t cause.

9.2.2 Human e n g i n e e r i n g and s u r v i v a l

The Human F a c t o r s I n v e s t i g a t i o n may p rov ide medical ev idence which i s of g r e a t v a l u e i n r e l a t i o n t o human e n g i n e e r i n g and s u r v i v a l . r e l e v a n t i n both f a t a l and non- fa t a l a c c i d e n t s b u t a g a i n t h e r e may be a d i f f e r e n c e of emphasis acco rd ing t o whether t h e a c c i d e n t i n v o l v e s a l a r g e o r small a i r c r a f t .

Such ev idence w i l l be e q u a l l y

I n t h e case of t h e small a i r c r a f t t h e examination w i l l g e n e r a l l y be d i r e c t e d t o t h e p i l o t ( s ) ; however, whether t h e a i r c r a f t b e l a r g e o r small, one should c o n s i d e r such f a c t o r s as t h e r e l e v a n c e of t h e type of h a r n e s s r e s t r a i n t i n u s e , t h e p r o v i s i o n or l a c k of o t h e r items of s a f e t y equipment, and t h e i n j u r y producing p o t e n t i a l of t h e c o n t r o l s , i n s t r u - ments and o t h e r cockp i t s t r u c t u r e s .

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I 11-9-6 Plaiiual of A i r c r a f t Accident I n v e s t i g a t i o n

In t h e c a s e of t h e t r a n s p o r t a i r c ra f t acc iden t , i n t e r e s t w i l l i n e v i t a b l y -include t h e passengers and t h e Human Fac tors Group w i l l be s e a r c h i n g f o r evidence of i n j u r y r e s u l t i n g from seat s t r u c t u r e s - w i t h o r without adequate ha rness r e s t r a i n t - and the mis- s i l e e f f e c t of c o n t e n t s of t h e cabin . Medical o r pa tho log ica l evidence w i l l a l s o be a v a i l - a b l e as t o t h e adequacy o r inadequacv of walkways, e x i t s and s u r v i v a l ecuigment.

9.2.3 Iden t i f ica t i o n

I t is apparent t h a t t he u s e f u l i n t e r p r e t a t i o n of human f a c t o r f i n d i n g s is dependent upon a c c u r a t e i d e n t i f i c a t i o n of t h e c a s u a l t i e s involved. I d e n t i f i c a t i o n is , t h e r e f o r e , pre-eminently a t o o l of i n v e s t i g a t i o n but i t a l s o h a s major medico-legal s i g n i - f i c a n c e and j u d i c i a l a p p l i c a t i o n . f o r any evidence determined by members of h i s group a s a c c i d e n t i n v e s t i g a t o r s , p a r t i c u l a r l y t h e p a t h o l o g i s t , t o be used f o r medico-legal purposes . f o r e , have s p e c i a l needi; f o r Co-ordinat ion wi th l o c a l o r n a t i o n a l a u t h o r i t i e s w i th p a r t i c - u l a r regard t o i d e n t i f i c a t i o n . These needs should be recognized d u r i n g t h e pre-planning and should n o t be overlooked du r ing t h e i n v e s t i g a t i o n . There i s , however, n c c o n f l i c t of i n t e r e s t s - i n v e s t i g a t i o n and i d e n t i f i c a t i o n are in te r -dependent as recognized i n Annex 13 and, i n t h e fo l lowing s e c t i o n s of t h i s chap te r they are d i scussed t o g e t h e r under t h e same headings, in p a r t i c u l a r :

The head of t h e Human F a c t o r s Group must b e prepared

The Human Fac to r s Group w i l l , t he re -

a ) Tasks a t t h e acc iden t s i t e ,

b) Tasks a t the mortuary,

c) Evidence t o be der ived from t h e p a t h o l o g i c a l examinatiom.

9.3 Br i e f ing t h e P a t h o l o g i s t

Tdeall.y, t h e appcin ted p a t h o l o g i s t would obtclin a complete "cace h i s t o r y " before beginning .h i s examination: he should acqua in t himself wi th t h e d e t a i l s of t h e c i r - cumstances of t h e acc iden t , d e t a i l s of t h e o p e r a t i n g crew's medical and p e r s n n a l h i s t o r i e s , f a m i l i a r i z e himself wi th t h e i n t e r n a l layout of t h e cockp i t and passenger compar~meiits o í t h e a i r c r a f t type concerned, and make a thorough examinat ion of tlie a c c i d e n t s i t e - 211 before commencing h i s examinat ion of the bodies . Such an approach is r a r e l v , i f e v e r , p r a c t i c a b l e . The p r e s s u r e s t h a t e x i s t fo l lowing most f a t a l a i r c r a f t a c c i d e n t s are such t h a t examination and d i s p o s a l of t.he bodies must be handled a s quick ly a s p r a c t i c a b l e and unnecessary de lay avoided. Many f a c t o r s map n e c e s s i t a t e speed; t h e extreme example i s t h a t of a t r o p i c a l c l ima te w i t h no r e f r i g e r a t i o n f a c i l i t i e s .

A p r a c t i c a l approach has been fouiid t o be f o r t h e p a t h o l o g i s t t o he b r i e f e d a t t h e o u t s e t by t h e Invest igator- in-Charge concern ing t h e s a l i e n t f e a t u r e s of tlie acc iden t and t o be informed whether any p a r t i c u l a r i d e a s as t o t h e t y p e of a c c i d e n t "iay have been aroused. This does no t have t o be a lengthy o r d e t a i l e d b r i e f i n g b u t s u f f i c i e n t only t o a l low t h e pa tho log i s t an oppor tuni ty t o make a s p e c i a l p o i n t of s ea rch ing , du r ing t h e course of h i s normal complete examinat ion, f o r suppor t ing o r c o n t r a d i c t o r y ev idence r e l a t i v e t o any o t h e r evidence which may a l r e a d y be a v a i l a b l e t o t h e inves t iga tor - in-Charge . quent i n t e r v a l s d u r i n g the i n v e s t i g a t i o n t h e p a t h o l o g i s t and t h e head of t h e Human F a c t o r s Group, or t h e Invest igator- in-Charge as a p p r o p r i a t e , should c o n f e r . thus ge t an up-to-date p i c t u r e and l e a r n of developments which may bear upon h i s work; h e i n t u r n can r e p o r t any of h i s f i n d i n g s which could provide a l ead f o r members of o t h e r groups. This i s t h e p r i n c i p l e of t h e Group System i n which i t i s e s s e n t i a l t h a t t he human f a c t o r s team p lay a f u l l p a r t (see page II-2-3).

A t f r e -

The p a t h o l o g i s t can

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Part III.- The I n v e s t i g a t i o n 111-9- 7

9.4 - Tasks a t t h e Accident S i t e

9 . 4 . 1 F a c i l i t i e s and equipment

The equipment r e q u i r e d f o r t h e l o c a t i n g and recovery of t h e bod ies w i l l depend upon t h e n a t u r e of t h e a c c i d e n t . Much of t h i s equipment w i l l need t o be provided l o c a l l y arid t he v a l u e of pre-p lanning as mentioned i n P a r t II, Chapter 1, S e c t i o n 1.3, w i l l be r e f l e c t e d i n t h e speed wi th which i t i s provided . The m a j o r i t y of a c c i d e n t s occur w i t h i n a four -mi le zone of an a i r p o r t and i t i s i n such areas t h a t combined d i s a s t e r p l ann ing by a v i a t i o n and l o c a l a u t h o r i t i e s is p a r t i c u l a r l y impor tan t . S tocks of c e r t a i n i t e m s should be e s t a b l i s h e d and t h e a v a i l a b i l i t y of o t h e r equipment a s s e s s e d and kep t under c o n s t a n t review .

I n a c c i d e n t s which i n v o l v e c o l l i s i o n w i t h houses , f a c t o r i e s , etc., heavy equipment such as c r a n e s , b u l l d o z e r s , might be r e q u i r e d i n o r d e r t o clear t h e way and t o remove t h e d e b r i s s o t h a t t h e bod ies c a n be found. When t h e f i r s t s i g n of a body is uncovered, work must t hen proceed s lowly by hand. Where t h e a i r c r a f t c r a s h e s i n i s o l a t e d t e r r i t o r y such as mountainous d i s t r i c t s , d e s e r t s o r swamps, s p e c i a l equipment might be r e q u i r e d ; when v i c t i m s are thrown i n t o water, b o a t s and d i v i n g equipment may be necessa ry .

A l ist of b a s i c equipment f o r i n v e s t i g a t o r s is t o be found i n P a r t IhChap- t e r l, S e c t i o n 1 . 2 of t h i s Manual; t h e f o l l o w i n g i t e m s are more s p e c i f i c a l l y recommended f o r s a lvage of t h e a c c i d e n t v i c t i m s , t h e i r examinat ion and i d e n t i f i c a t i o n , and should be provide1 i n q u a n t i t i e s p r o p o r t i o n a t e t o t h e number of v i c t i m s :

F i r s t - a i d k i t s , b l a n k e t s and t r a n s p o r t f a c i l i t i e s f o r s u r v i v o r s ;

P l a s t i c o r canvas bags , b u r i a l pouches o r c o f f i n s f o r t r a n s p o r t of bodies ;

S t rong paper o r p l a s t i c bags o r o t h e r c o n t a i n e r s , one f o r each body, f o r s a fekeep ing of p e r s o n a l e f f e c t s ;

S t akes ;

Tags f o r marking b o d i e s , bags , remains o r p i e c e s of equipment o r s t a k e s a t t h e s i t e ;

Ropes, s t r i n g ;

Scotch t ape ;

I n d e l i b l e i n k , wax p e n c i l s ( b l u e , r e d ) ;

Rubber g loves , p r o t e c t i v e c l o t h i n g , such a s ap rons , rubber boo t s , e t c . , as a p p r o p r i a te;

Photographic equipment i n c l u d i n g f l a s h gear f o r t h e s p e c i f i c u se of t h e Human F a c t o r s Group;

Pocket l e n s o r microscope, microscope s l i d e s , s y r i n g e s and need le s ; measuring t a p e , d e n t a l wax, r e a g e n t s , a n t i s e p t i c s o l u t i o n s , etc. ;

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S u i t a b l e c o n t a i n e r s ( p l a s t i c bags) and t e s t - t u b e s (wi th p lugs ) f o r c o l l e c t i n g blood, t i s s u e , specimens o r small p i e c e s of material on which l abora to ry tests w i l l be made; and s u i t a b l e p r e s e r v a t i v e s .

C e r t a i n of t h e above, such a s t h e last two i t e m s w i l l normally be r equ i r ed .only i n t h e s p e c i a l i z e d es tab l i shment i n which t h e bodies of v i c t i m s w i l l be t aken f o r d e t a i l e d examina- t i o n and t o which r e f e r e n c e i s made i n Sec t ion 9.5.

9.4.2 Procedures t o be fol lowed d u r i n g t h e recovery phase

The f i r s t r e s p o n s i b i l i t y fo l lowing an a i r c r a f t a c c i d e n t i s always t o g i v e immediate a s s i s t a n c e t o t h e in ju red by whatever means can be made a v a i l a b l e . t h a t l i f e cannot be saved i n t h a t p a r t i c u l a r a c c i d e n t , t he nex t r e s p o n s i b i l i t i e s are t o save l i v e s i n f u t u r e a c c i d e n t s and t o save l i v e s by t r y i n g t o p reven t f u t u r e a c c i d e n t s . This is t h e p r i n c i p l e under ly ing t h e whole i n v e s t i g a t i o n of t h e a c c i d e n t and t h e b a s i s f o r t h e need f o r c l o s e Co-ordination between l o c a l o r n a t i o n a l a u t h o r i t i e s and the I n v e s t i g a t o r - in-Charge and h i s i n v e s t i g a t o r s , i n p a r t i c u l a r t h e appoin ted p a t h o l o g i s t .

I n t h e even t

9.4.3 Recommendations of t h e I n t e r n a t i o n a l Cr imina l P o l i c e Organiza t ion

The fo l lowing are based on recommendations by t h e I n t e r n a t i o n a l Cr imina l P o l i c e Organizat ion (INTERPOL). The INTERPOL recommendations are based p r imar i ly upon mass d i s a s t e r s of types o t h e r than a i r c r a f t a c c i d e n t s ; t h e r e f o r e , i n t h e fo l lowing sub-paragraphs, they have been modified t o take account of t h e s p e c i a l needs of a comprehensive medico- p a t h o l o g i c a l i n v e s t i g a t i o n of an a i r c r a f t d i s a s t e r . I t is suggested:

a ) Bodies should be l a b e l l e d and photographed i n s i t u a t t h e ac.cident s i t e . The photographs are intended as a record of t h e v i c t i m s ' c i rcumstances and l o c a t i o n a t t h e acc iden t s i t e , t h e bod ies ' a t t i t u d e s a114 r e l a t i o n - s h i p s t o ad jacen t o b j e c t s i nc lud ing o the r bod ie s and major p o r t i o n s of wreckage. (These photographs a re riot in tended p r i m a r i l y f o r i d e n t i f i c a t i o n purposes; f u r t h e r photography f o r t h i s purpose is d i s -us sed Ln sub-sect i o n 9.5.2.2). I n a d d i t i o n t o the photographs t h e p o s i t i o n s ci bodies r e l a t i v e t o o the r bodies and t o p i e c e s of a i r c r a f t wreckage should be mapped aiid/-)- t h e p o s i t i o n marked by s t a k i n g if the t e r r a i n i s s u i t a b l e . I f necessz r - . t h i s a c t i o n can be commenced bv t h e p o l i c e provided t h e need til p r e s e r v e and record a l l evidence of p o s s i b l e importance t o t h e medical and Lech- riical p a r t s of t h e a c c i d e n t i n q u i r y i s s t r i c t l y recognized. I d e a l l y i t should be performed i n co-operat ion w i t h t h e invest igator- i i i -Charge and h i s i n v e s t i g a t o r s , i n p a r t i c u l a r t h e p a t h o l o g i s t appoin ted t o conduct the medico-pathological i n v e s t i g a t i o n i f h i s a t t endance w e r e n o t unduly de ldved ( P a r t III, Chapters 1 and 2 a l s o r e f e r ) .

The bodies of v i c t ims should be p laced i n temporary c o f f i n s OK such o t h e r c o n t a i n e r s as might be a v a i l a b l e . Many of t h e types of p l a s t i c and canvas bags o r b u r i a l pouches t h a t are a v a i l a b l e a r e adequate provided t h a t no l o s s of conten t i s p o s s i b l e d u r i n g t r a n s i t . Poly thene s h e e t i n g h a s t h e d isadvantage of r e q u i r i n g care i n packing i f loss i n t r a n s i t i s t o be avoided; but i t can be used wi th c a r e . Labels should be a t t a c h e d t o loose a r t ic les and detached p o r t i o n s of bod ie s , they should be l i s t e d and t h e i r l o c a t i o n wi th r e s p e c t t o t h e numbered bodies recorded.

b)



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P a r t 111.- The I n v e s t i g a t i o n I I I- 9- 9

c ) Examination of bod ie s should be conducted a t t h e scene only t o t h e e x t e n t o u t l i n e d i n a ) above, bu t c o r p s e s should n o t be removed u n t i l a l l t h e procedures recommended have been c a r r i e d o u t . Each body, t h e c l o t h e s which a r e on i t and t h e p rope r ty i n t h a t c l o t h i n g should be t r a n s f e r r e d complete t o a c o n t a i n e r and thence t o t h e mortuary area.

d ) The l a b e l a t t a c h e d t o a co rpse must be numbered i n i n d e l i b l e crayon or i n k and should be a f f i x e d t o t h e body i t s e l f , n o t t o a s t r e t c h e r o r b l anke t . I t i s , however, convenient t o a t t a c h an a d d i t i o n a l l a b e l b e a r i n g t h e same number t o t h e c o n t a i n e r i n which t h e body is p laced f o r t r a n s i t . C e r t a i n body bags have a pocket on t h e o u t s i d e t o hold such a l a b e l .

e ) A s s t a t e d i n c ) above , i t is b e s t i f p e r s o n a l e f f e c t s a r e , n o t removed from t h e c o r p s e a t t h e s i t e , a c o n t a i n e r they should never be r ep laced bu t be pu t i n a s e p a r a t e con- t a i n e r and l a b e l l e d s o as t o i n d i c a t e t h e i r p robab le o r a lmost c e r t a i n ( i f t h i s be t r u e ) a s s o c i a t i o n w i t h a p a r t i c u l a r numbered body. Rescue workers should u s e extreme c a u t i o n i n r e c o v e r i n g t h e bod ies and i n g a t h e r i n g a l l p e r s o n a l be longings o r p r o p e r t y t h a t may belong t o t h e deceased , i n keeping t h e s e wi th t h e remains t o which they unequivoca l ly be long w h i l e they are be ing removed t o t h e mor tuary , bu t i n s e p a r a t e l y packaging and c a r e f u l l y l a b e l l i n g items t h e ownership of which is i n any way d o u b t f u l . An i n c o r r e c t l y a s s igned i t e m could c a u s e t h e i d e n t i f i c a t i o n team a g r e a t d e a l of a d d i t i o n a l work, and it could l e a d t o an e r r o r i n i d e n t i f i c a t i o n . The l o c a t i o n of a l l l oose p r o p e r t y , c l e a r l y shown i n r e l a t i o n t o t h e remains n e a r which i t w a s found, should be noted on t h e l a b e l a t t a c h e d t o each a r t i c l e .

I f e f f e c t s f a l l from a body be ing p l aced i n

f ) The bod ies of v i c t i m s should no t be d i s p e r s e d bu t brought t o g e t h e r by t h e q u i c k e s t means p o s s i b l e t o a s p e c i a l i z e d e s t a b l i s h m e n t o r , i n t h e absence of such e s t a b l i s h m e n t , t o t h e most s u i t a b l e p l a c e capab le of conserv ing them. There they can be r e t a i n e d , i n r e f r i g e r a t e d accommodation i f neces- s a r y and i f a v a i l a b l e , f o r t h e d e t a i l e d and s p e c i a l examinat ions which should be under taken t o complete t h e i d e n t i f i c a t i o n procedures and a t t h e same t i m e t o f i n a ev idence r e l a t i v e t o t h e a c c i d e n t i n v e s t i g a t i o n .

The success of t h e medico-pa thologica l i n v e s t i g a t i o n i n g e n e r a l and t h e i d e n t i f i c a t i o n of t h e v i c t i m s i n p a r t i c u l a r depends upon t h e thoroughness of t h e r e s c u e workers more than anyone e lse f o r i t i s t h e i r p r e l i m i n a r y work a t t h e scene which can f a c i l i t a t e t h e f u r t h e r i n v e s t i g a t i o n s o r j e o p a r d i z e them. These workers should be thoroughly i n s t r u c t e d i n t h e i r t a s k and i ts importance, bu t it i s s t r o n g l y urged t h a t t h e work a t t h e scene should always be superv ised by t h e Inves t iga tor - in-Charge and h i s i n v e s t i g a t o r s - i n p a r t i c u l a r t h e appoin ted p a t h o l o g i s t - o r , i n t h e i r absence , a n exper ienced p a t h o l o g i s t and /o r p y i c e o f f i c e r .

I n t h e even t t h a t c o l l e c t i o n and t r a n s f e r of t h e bod ies t o t h e mortuary h a s preceded t h e a r r i v a l of t h e Inves t iga tor - in-Charge , no harm w i l l have been done provided t h a t t h e p r a c t i c e s o u t l i n e d above have been fo l lowed. of p r e s e r v i n g ev idence f o r t h e i n v e s t i g a t i o n (both t h e t e c h n i c a l and t h e j u d i c i a l ) t h a t , once t h e bod ies are s e c u r e l y housed, d e t a i l e d examination of any s o r t must await t h e a r r i v a l of t h e p a t h o l o g i s t .

However, s o g r e a t i s t h e importance

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The Investigator-in-Charge should not h e s i t a t e t o use h i s i n f l u e n c e wi th l o c a l o r n a t i o n a l a u t h o r i t i e s t o persuade them of t h e importance of a l l t h e s e matters p a r t i c u l a r l y i f t h e l i a i s o n a s s o c i a t e d wi th t h e pre-planning i n t h e event of an acc iden t f a i l e d t o produce s t and ing ar.rangements.

9.5 Tasks a t t h e Mortuary

9.5.1 F a c i l i t i e s

A mortuary wi th t h e necessary f a c i l i t i e s o r a medico-legal i n s t i t u t e might be a v a i l a b l e i n t h e v i c i n i t y of many a i r p o r t s , p remises , such as t h e basement of a i r p o r t bu i ld ings , which may be s u i t a b l e f o r u se a s a mortuary i n case of a c c i d e n t , and t h e necessary equipment should be p laced i n r e a d i n e s s f o t u s e i n emergency. c r a f t d i s a s t e r p l ans might cons ide r b u i l d i n g s such a s pub l i c h a l l s , gymnasiums, o r l a r g e c o m e r c i a l s t o r a g e premises which, i f no t empty could be vaca ted a t s h o r t n o t i c e . I’erhaps t h e p r i m e r e q u i s i t e s are space , p r ivacy , l i g h t and running water i n t h a t o rde r of importance. I n a d d i t i o n t o t h e space needed f o r t h e work of examining bod ies , s e p a r a t e rooms should b e a v a i l a b l e where remains can be viewed, i f necessa ry , by relatives and o t h e r s . Sepa ra t e accommodation, p r e f e r a b l y c l o s e a t hand, i s needed f o r t h e in t e rv i ew of r e l a t i v e s and w i t - ne s ses and f o r c l e r i c a l work, a l s o i t i s extremelv impor tan t t o have a room which can a c t as a communications c e n t r e c l o s e t o t h e mortuary,

Otherwise, a survey should be undertaken of

Local a u t h o r i t i e s not i n t h e v i c i n i t y of a i r p o r t s bu t fo rmula t ing a i r -

Depending upon c l i m a t i c c o n d i t i o n s c o n s i d e r a t i o n should he given t o t h e a v a i l - a b i l i t y of ref r i g e r a t i o n f a c i l i t i e s . Re f r ige ra t ed s t o r a g e of bodies pendiiig examination i s necessary except i n t h e c o l d e s t c l ima tes , e s p e c i a l l y i f t h e r e a r e l a r g e ncimherc and thtair examination w i l l t ake many days. R a r e l y w i l l t h e r e be cuf f i c i en t - permanent r e f r i g e r a t e d mortuary accommodation nea r t h e s i t e of a l a r g e a c c i d e n t . When t h e r e i s riot, t h e b e s t so lu- t i o n may be t o h i r e r e f r i g e r a t e d t r u c k s which may be parhed w i t h i n t h e mair i mortuary p r e c i n c t s . Should such t r u c k s n o t be a v a i l a b l e b lock i c e may b e used Lut t h i s is a zela- t i v e l y i n e f f i c i e n t means of keeping bodies c o o l and s u p p l i e s i n s u f f i c i e n t q u e n t i t y may b e d i f f i c u l t t o ob ta in . Occas iona l ly spac ious r e f r i g e r a t e d accommodation ma\- bc7 folind dvai l a h l s t i n some f a c t o r y o r o t h e r commercial bu i ld ing w i t h i n a r easonab le d i s t a n c e (-f Lhe main mer- t ua ry and t h i s could be u t i l i z e d f o r temporary s to rage .

I f no f a c i l i t i e s can be made a v a i l a b l e where t h e remains can be kept cool i n t r o p i c a l c l i m a t e s , temporary b u r i a l might become necessa ry u n t i l a r rangements can be made f o r onward t r a n s p o r t a t i o n t o a p l ace s u i t a b l e f o r t h e d e t a i l e d i n v e s t i g a t i o n . i t is e s s e n t i a l t h a t every i t e m of in format ion t h a t can be obta ined a t t h e scene of t h e a c c i d e n t and from remains which might assist i n i d e n t i f i c a t i o n or t h e exp lana t ion of t h e a c c i d e n t , be immediately obta ined and c a r e f u l l y recorded. I n a n i s o l a t e d r eg ion where no f a c i l i t i e s a r e a v a i l a b l e it may be p o s s i b l e a f t e r c o n s u l t a t i o n and Co-ordination wi th t h e r e spons ib l e l o c a l o r n a t i o n a l a u t h o r i t i e s , t o r e t u r n t h e remains of a l l v i c t i m s t o t h e p o i n t of o r i g i n of t h e f l i g h t ( o r some o t h e r mutually convenient l o c a t i o n ) f o r examination, i d e n t i f i c a t i o n and d i s p o s a l , t o c e r t a i n cond i t ions and r e g u l a t i o n s . d e n t s , should ensu re co-operation as s p e c i f i e d i n Annex 1 2 , paragraph 2 .2 .

I n t h i s c a s e

It should be noted t h a t t h e t r a n s p o r t of co rpses i s s u b j e c t Con t rac t ing S t a t e s , i n t h e c a s e of a i r c r a f t a c c i -

The p a t h o l o g i s t w i t h i n t h e Human F a c t o r s Group should be aware of t h e e x t e n t t o which t h e a s s i s t a n c e of a medico-legal o r p a t h o l o g i c a l i n s t i t u t e w i l l be r equ i r ed f o r s p e c i a l medical, b i o l o g i c a l o r chemical tests r e l a t i v e t o i d e n t i f i c a t i o n o r t o o t h e r a s p e c t s of h i s i n v e s t i g a t i o n and he should c o l l e c t specimens acco rd ing ly . Co-ordination wi th t h e l o c a l o r n a t i o n a l a u t h o r i t i e s i s s t r e s s e d .

Again t h e importance of

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A medical i n s t i t u t e o r f u n e r a l d i r e c t o r may be a b l e t o p rov ide f a c i l i t i e s f o r embalming; some a i r l i n e s r e t a i n a f i r m of f u n e r a l d i r e c t o r s and they a r r a n g e r e p a t r i a - t i o n and u l t i m a t e d i s p o s a l a s a p p r o p r i a t e . i t i es should a s c e r t a i n t h e nearest i n s t i t u t e s and a i r l i n e s c a p a b l e of p rov id ing r e l e v a n t s e r v i c e s , and t h e amourit of h e l p they could g i v e i f r e q u i r e d .

It is suggested t h a t a v i a t i o n and l o c a l au tho r -

9.5.2

9.5.2.1

I d e n t i f i c a t i o n of t h e dead

P r i n c i p l e s

I d e n t i f i c a t i o n of t h e dead is of g r e a t importance f o r s o c i o l o g i c a l and l e g a l r easons t o t h e f a m i l i e s of t h e deceased. It p e r m i t s t h e i s s u e of t h e c e r t i f i c a t e of d e a t h necessa ry t o avoid t h e s e r i o u s l e g a l consequences and c o m p l i c a t i o n s i n c e r t a i n States f o r t h e next of k i n of a missing person. r e l e a s e d f o r p a t h o l o g i c a l examinat ion f o r a c c i d e n t i n v e s t i g a t i o n pu rposes only a f t e r t h e examination by t h e j u d i c i a l a u t h o r i t y f o r i d e n t i f i c a t i o n pu rposes had been completed since the r e s p o n s i b i l i t y f o r i d e n t i f i c a t i o n of t h e v i c t i m s of a mass d i s a s t e r i s o f t e n cons ide red by S t a t e s t o be s e p a r a t e from any t e c h n i c a l i n v e s t i g a t i o n i n t o t h a t d i s a s t e r . T h i s may be s a t i s f a c t o r y fo l lowing c e r t a i n t y p e s of a c c i d e n t o r n a t u r a l d i s a s t e r bu t i n a i r c r a f t acci- d e n t i n v e s t i g a t i o n i t is h i g h l y d e s i r a b l e t h a t t h e work of i d e n t i f i c a t i o n of t h e v i c t i m s be c l o s e l y Co-ordinated with t h e p a t h o l o g i c a l examinat ion of t h o s e v i c t i m s f o r i t i s essen- t i a l t o t h e i n t e r p r e t a t i o n of t h e p a t h o l o g i c a l and t h e t e c h n i c a l f i n d i n g s i n r e l a t i o n t o t h e a c c i d e n t .

I n some States it would be u s u a l f o r bod ie s t o be

It is always important f o r example, t o t h e t e c h n i c a l i n v e s t i g a t i o n t o i d e n t i f y and e s t a b l i s h t h e l o c a t i o n of t h e c r e w a t t h e t i m e of t h e a c c i d e n t , and whether o r n o t any o t h e r person w a s i n a l o c a t i o n l i k e l y t o have a f f e c t e d t h e f l i g h t and, i f so, h i s i d e n t i t y : i t is not a lways p r a c t i c a b l e whether t h e body be t h a t of a c r e w member o r a passenger t o d i f f e r e n t i a t e between t h e medical ev idence gained f o r j u d i c i a l i d e n t i f i c a t i o n and t h a t gained f o r c o n s i d e r a t i o n by t h e Human F a c t o r s Group. and f i r e is o f t e n such t h a t only s p e c i a l i s t examinat ion of t h e b o d i e s by p a t h o l o g i s t s , d e n t i s t s , r a d i o l o g i s t s and o t h e r e x p e r t s w i l l l ead t o t h e i r i d e n t i f i c a t i o n . An uncoordinated e f f o r t between l o c a l o r n a t i o n a l a u t h o r i t i e s and t h e Human F a c t o r s Group is u n s a t i s f a c t o r y on two c o u n t s - evidence e s s e n t i a l t o t h e a i r c r a f t a c c i d e n t i n v e s t i g a t i o n may u n w i t t i n g l y b e des t royed ; t o seek h e l p from t h e Human F a c t o r s Group only when d i f f i c u l t i e s arise o f t e n compl i ca t e s t h e t a s k .

Damage t o bod ies from a c c i d e n t f o r c e s

Although t h e p rocedures fol lowed d i f f e r acco rd ing t o l o c a l o r n a t i o n a l l a w s , r e g u l a t i o n s and p r a c t i c e s , where such l o c a l customs are s e r i o u s l y a t v a r i a n c e w i t h t h e p r i n c i p l e s set out i n t h i s c h a p t e r and Appendix 9 , n a t i o n a l and l o c a l a u t h o r i t i e s should be urged t o modify t h e i r practices a s f a r a s t hey can i n t h e c a s e of a i r c r a f t a c c i d e n t s i n t h e i n t e r e s t s of f u r t h e r i n g i n t e r n a t i o n a l a i r s a f e t y .

It is s t r o n g l y recommended t h a t on a l l occas ions t h e l o c a l o r n a t i o n a l au tho r - i t i e s should seek t h e co-operat ion of t h e p a t h o l o g i s t appo in ted by t h e Invest igator- in-Charge t o h i s Human F a c t o r s Group. t h a t is t h e i n v e s t i g a t i o n of f a t a l a i r c r a f t a c c i d e n t s , h e w i l l a l s o be e x p e r t i n matters of i d e n t i f i c a t i o n . F a i l i n g t h e a v a i l a b i l i t y of such a person, a f o r e n s i c p a t h o l o g i s t might be e n l i s t e d t o assist. Although h i s e x p e r i e n c e of a i r c r a f t a c c i d e n t s may n o t be g r e a t h e w i l l have t h e b e n e f i t of t h e a v i a t i o n e x p e r i e n c e of o t h e r members of t h e Human F a c t o r s Group and he w i l l have been t r a i n e d both i n i d e n t i f i c a t i o n p rocedures and i n t h e examinat ion of t h e bod ies of t h o s e who have d i e d a v i o l e n t and u n n a t u r a l d e a t h , w i t h a view t o c o n t r i b u t i n g t o t h e e x p l a n a t i o n of t h e c i r cums tances which l e d t o d e a t h . A n i d e n t i f i c a t i o n d i v i s i o n

I f t h a t p a t h o l o g i s t i s one expe r i enced i n a v i a t i o n pathology,

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such as t h e p o l i c e may be a b l e t o h e l p wi th i d e n t i f i c a t i o n problems themselves, bu t w i l l no t be competent t o pursue t h e wider comprehensive sea rch f o r medical evidence r e l a t i v e t o t h e t e c h n i c a l i n v e s t i g a t i o n of t h e a c c i d e n t which i s so ve ry impor tan t .

An i d e n t i f i c a t i o n commission might u s e f u l l y be appoin ted , . as is t h e p r a c t i c e i n some S t a t e s , comprising t h e p a t h o l o g i s t , a p o l i c e o f f i c e r o r person from t h e j u d i c i a l a u t h o r i t y wi th exper ience of i d e n t i f i c a t i o n , p l u s such o t h e r s p e c i a l i s t s ( o d o n t o l o g i s t s , a n t h r o p o l o g i s t s , r a d i o l o g i s t s , etc .) as c i r cums tances permi t o r r e q u i r e . I f p o s s i b l e t h e p a t h o l o g i s t should be chairman of such a commission, f o r o the rwise t h e r e arises t h e danger of t h e two a s p e c t s of t h e medico-pathological i n v e s t i g a t i o n becoming sepa ra t ed and i d e n t i f i- c a t i o n be ing pursued s o l e l y as an end i n i t s e l f and t o t h e exc lus ion of t h e a c c i d e n t inves- t i g a t i o n a s p e c t s . The chairman of such a commission may be charged wi th dec id ing , w i t h t h e he lp of t h e o t h e r members, when evidence of i d e n t i f i c a t i o n is conc lus ive o r he may be r equ i r ed t o a d v i s e t h e l o c a l j u d i c i a l a u t h o r i t y , o r a coroner and h i s j u r y of what ev idence h a s been found so t h a t a l e g a l o f f i c i a l may s i g n c e r t i f i c a t e s of i d e n t i f i c a t i o n ; t h e s e d e t a i l s are a matter of l o c a l procedure and custom.

9.5.2.2 I d e n t i f i c a t i o n procedures

There is a g r e a t d e a l t o commend t h e procedure whereby a team led by pa tholo- g i s t s ( i nc lud ing the Human Fac to r s Group p a t h o l o g i s t ( s ) ) and policemen o r o t h e r r e l e v a n t j u d i c i a l a u t h o r i t y , wi th c l e r i c a l a s s i s t a n t s , make a s i n g l e j o i n t thorough examination of each body i n t u r n . The s t e p s i n t h i s t a s k are o u t l i n e d below; g r e a t e r d e t a i l i s d i s c u s s e d i n t h e r e l e v a n t c h a p t e r s of t h e I C A 0 medical manual.

Both t h e j u d i c i a l a u t h o r i t y and t h e p a t h o l o g i s t have an i n t e r e s t i n t h e c l o t h i n g p resen t and i t s con ten t s . The ev idence t h e i e i n may l ead t o i d e n t i f i c a t i o n ( l aun- dry marks, d i s t i n c t i v e des igns , e t c . ) ; it may be s i g n i f i c a n t w i th regard t o t h e a c c i d e n t (drugs o r a d o c t o r ' s p r e s c r i p t i o n i n a f l i g h t crew meriber's pocke t , o r a l e t t e r i n a passenger ' s pocket , i n d i c a t i n g a d i s t u r b e d , perhaps s u i c i d a l s t a t e of mind). S t a i n s made by vomitus o r food may g ive c l u e s as t o the degree of eniergency; t e a r s i n c l o t h i n g may i n d i c a t e t h e cause of d e a t h and i t i s e s s e n t i a l t h a t t h e r e can be no confus ion between such tears and t h o s e made by t h e examiner. desc r ibed and ca ta logued i n t h e r e c o r d s r e l a t i n g t o t h e body i n q u e s t i o n , bo th the j u d i c i a l a u t h o r i t y and t h e p a t h o l o g i s t can observe t h e e x t e r n a l bod i ly evidence; a g a i n t h i s ev icence may lead t o i d e n t i f i c a t i o n ( s u r g i c a l s c a r s o r t a t t o e s , e t c . ) o r be of s i g n i f i c a n c e w i t h regard t o t h e acc iden t i t s e l f (e.g. sh rapne l i n j u r i e s from an exp los ive d e v i c e ) . Radiographs should be taken a t t h i s s t a g e i f f a c i l i t i e s are a v a i l a b l e , t h e i r number and t h e areas of a body s e l e c t e d w i l l depend upon t h e need t o sea rch f o r ev idence of sabotage i n t h e g iven a c c i d e n t and t h e need t o pursue , i f t h e r e be a p a u c i t y of o t h e r evidence, r ad iog raph ic evidence of i d e n t i t y .

When c l o t h i n g and j e w e l l e r y have been removed, f u l l y

T h e r e a f t e r t h e p a t h o l o g i s t should proceed w i t h h i s f u l l i n t e r n a l examination and c o l l e c t i o n of specimens of t i s s u e f o r s p e c i a l l a b o r a t o r y examination. The s p e c i a l l abo ra to ry examinations may be h i s t o l o g i c a l , des igned t o r e v e a l microscopic d i s e a s e o r evidence of t h e t iming of dea th , t o x i c o l o g i c a l i n a sea rch f o r t h e presence of a l c o h o l , d rugs o r noxious subs tances such as carbon monoxide and, p o s s i b l y , s e r o l o g i c a l w i th a view t o de te rmining blood groups t h a t might a s s i s t i n i d e n t i f i c a t i o n .

Photographic r eco rds of t he body c l o t h e d and undressed a r e h i g h l y d e s i r a b l e

The number of t h e body concerned should be c l e a r l y as are photographs of any p o s s i b l y s i g n i f i c a n t a b n o r m a l i t i e s noted i n t h e e x t e r n a l o r i n t e r n a l examinations of t he bodies. seen i n every photograph taken.

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Provided t h a t t h e j u d i c i a l a u t h o r i t y and t h e p a t h o l o g i s t (s) have c a r r i e d o u t a thorough comprehensive examinat ion i n c l u d i n g making a f u l l r e c o r d of f i n d i n g s , and f u l l y l a b e l l i n g and c a r e f u l l y p r e s e r v i n g a l l s u i t a b l e material ev idence f o r f u r t h e r r e f e r e n c e and f o r l a b o r a t o r y tests o r a n a l y s i s , t h e bod ies may then be p l aced i n c a s k e t s and, i f essen- t i a l embalmed. It is, however, a d v i s a b l e t h a t i n d i v i d u a l bod ie s should n o t be d i sposed of f i n a l l y u n t i l t h e p a t h o l o g i c a l p r o c e s s of i d e n t i f i c a t i o n and i n v e s t i g a t i o n is complete w i t h r e s p e c t t o t h e a c c i d e n t a s a whole and, i n view of t h e p o s s i b l e need t o re-examine bod ies , t h e c a s k e t s should be l e f t i n such a s ta te t h a t t hey can be re-opened i n necessa ry .

I n a l a r g e a c c i d e n t w i t h many f a t a l i t i e s t h e i n v e s t i g a t i o n s are l i k e l y t o take many days. t h e mortuary is c o n t r o l l e d ; f a t i g u e must be minimized b u t , a t t h e same t i m e , t h e major obse rve r s must remain unchanged u n t i l t h e end. p a t h o l o g i s t and j u d i c i a l a u t h o r i t y t o pay some a t t e n t i o n t o t h e paper work of i d e n t i f i c a t i o n a f t e r t h e d a y ' s a u t o p s i e s . I d e n t i f i c a t i o n b a s i c a l l y depends upon c o r r e l a t i o n of i n fo rma t ion about a known pe r son wi th evidence found from an examination of a body (see sub-sect ion 9.5.2.4); i t i s n e c e s s a r y , t h e r e f o r e , f o r an o r g a n i z a t i o n t o be i n s t i t u t e d f o r t h e c o l l e c - t i o n of i n fo rma t ion about t h e p e r s o n s aboard t h e a i r c r a f t .

I n t h e s e c i r cums tances , it is e s s e n t i a l t h a t t h e amount of work done i n

It i s u s u a l l y p o s s i b l e t h e r e f o r e f o r t h e

9.5.2.3 The g a t h e r i n g of i n f o r m a t i o n abou t t h o s e b e l i e v e d k i l l e d

I d e n t i f i c a t i o n of t h e m a j o r i t y of bod ie s f o l l o w i n g a n a i r c r a f t a c c i d e n t o f t e n depends upon t h e a v a i l a b i l i t y of i n fo rma t ion about t h o s e on board. Some in fo rma t ion may be a v a i l a b l e from t h e a i r l i n e concerned which should p r o v i d e a passenge r l ist as soon as p o s s i b l e with a d d i t i o n a l d e t a i l s i f a v a i l a b l e such as t r a v e l l i n g class, seat occupied, o r i g i n and des t ina t ion . , b u s i n e s s o r home a d d r e s s , t i c k e t number and baggage.

The most p r o f i t a b l e s o u r c e of i n fo rma t ion w i l l u s u a l l y be r e l a t i v e s or c l o s e f r i e n d s of t h e deceased and a n i n f o r m a t i o n s e r v i c e should b e i n s t i t u t e d w i t h o u t d e l a y a f t e r an a i r c r a f t a c c i d e n t . ûne approach is f o r a i r l i n e s t o i n c l u d e i n t h e i r d i s a s t e r p l a n s arrangements f o r s e t t i n g up a n i n f o r m a t i o n service as soon as n o t i f i c a t i o n is rece ived t h a t a d i s a s t e r h a s ove r t aken one of t h e i r a i r c r a f t . I n a t least one S t a t e t h e a i r l i n e s d e l e g a t e t h i s t a s k t o a f i r m of f u n e r a l d i r e c t o r s who a r e r e t a i n e d p r i m a r i l y f o r t h e purpose of a r r ang ing t h e u l t i m a t e d i s p o s a l of bod ie s . When no such service is provided by t h e a i r l i n e involved, ad hoc arrangements should be made through p o l i c e , Red Cross o r similar organiza- t i o n s ; t h e pre-planning f o r t h e p o s s i b i l i t y of a n a c c i d e n t must e n v i s a g e t h i s cont ingency The utmost tact and sympa the t i c unde r s t and ing must, of course,be shown by t h o s e engaged in t h i s work i n d e a l i n g wi th r e l a t i v e s .

Whoever unde r t akes t h e t a s k , i t i s e s s e n t i a l that , u s i n g t h e passenger l ist and addres ses s u p p l i e d by t h e a i r l i n e , c o n t a c t should be made w i t h r e l a t i v e s o r f r i e n d s by t h e s p e e d i e s t p o s s i b l e means; u s u a l l y t h i s w i l l b e by te lephone. F u l l d e t a i l s should be c o l l e c t e d from t h e s e c o n t a c t s abou t t h e p h y s i c a l c h a r a c t e r i s t i c s of t h e pas senge r o r crew member, h i s / h e r age , c l o t h i n g and p e r s o n a l posses s ions . The names of h i s / h e r d o c t o r and d e n t i s t should be recorded i f known; bo th t h e s e p e r s o n s should be c o n t a c t e d f o r f u r t h e r information abou t p h y s i c a l f e a t u r e s w i t h p a r t i c u l a r r e f e r e n c e t o any h i s t o r y of s u r g i c a l o p e r a t i o n s , c u r r e n t d i s e a s e , blood group, etc.; and p o s s i b l y most impor t an t of a l l , f u l l d e t a i l s are r e q u i r e d of t h e o d o n t o l o g i c a l state. The d e n t i s t should be asked t o supplement any in fo rma t ion he can g i v e over t h e t e l ephone , by sending r e c o r d c a r d s and d e n t a l X-rays t o t h e in fo rma t ion c o l l e c t i n g c e n t r e f o r u r g e n t onward t r a n s m i s s i o n t o t h o s e examining t h e bodies i n t h e d i s a s t e r mortuary. A good photograph of t h e deceased may sometimes be v e r y h e l p f u l , and depending upon t h e c o u n t r y of o r i g i n of t h e deceased, c i v i l i d e n t i f i c a t i o n f i l e s might p r o v i d e f i n g e r p r i n t s and f u r t h e r p e r s o n a l d a t a ,

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111-9-14 Manual of A i t c r a f t Accident I n v e s t i g a t i o n

There i s an i n f i n i t e v a r i e t y of i t e m s of i n fo rma t ion about a person t h a t The s o r t of i n fo rma t ion o u t l i n e d

I f one o r could provide a c l u e t o t h e i d e n t i t y of h i s / h e r body. above would be s u f f i c i e n t t o permi t i d e n t i f i c a t i o n i n t h e m a j o r i t y of cases. more bodies remain u n i d e n t i f i e d f u r t h e r h e l p may be r equ i r ed from t h e a p p r o p r i a t e r e l a t i v e s o r f r i e n d s , t h i s niay t a k e t h e form of a d d i t i o n a l in format ion on p a r t i c u l a r matters revea led by t h e examinations of t h e bod ies s t i l l t o b e i d e n t i f i e d , o r may invo lve r e l a t i v e s be ing asked i f they can recognize fragments of c l o t h i n g o r v a r i o u s pe r sona l posses s ions . It must never be f o r g o t t e n t h a t v i s u a l r e c o g n i t i o n , be i t of a t raumat ized o r bu rn t body, o r a p i e c e of garment o r o t h e r a r t ic le , may be e r roneous . been made both in a n e g a t i v e and p o s i t i v e sense by d i s t r a u g h t r e l a t i v e s . badly mut i l a t ed v i s u a l i d e n t i f i c a t i o n should be regarded only a s a c l u e t o i d e n t i t y and c o r r o b o r a t i v e ev idence should be sought. r e l a t i v e s t h i s should be done under c o n d i t i o n s g i v i n g due d e f e r e n c e t o both t h e deceased , and r e l a t i v e s themselves, t a k i n g i n t o account whenever p o s s i b l e t h e deceased ' s r e l i g i o n and t h e f u n e r a l rites p resc r ibed by it.

Many i n c o r r e c t v i s u a l i d e n t i f i c a t i o n s have When a body is

Whenever any bod i ly remains are p resen ted t o

9.5.2.4 Comparison of r e c o r d s

The t a s k of comparing t h e f i n d i n g s i n t h e bodies w i t h t h e in fo rma t ion provided about t hose be l i eved t o have been on board the a i r c r a f t is s t r a i g h t f o r w a r d bu t can be t i m e consuming. It can be pursued by c l e r i c a 1 a s s i s t a n t s w h i l e t h e work of examining t h e b o d i e s con t inues but any t e n t a t i v e r e s u l t s ob ta ined must be checked by t h o s e appoin ted t o make t h e f i n a l d e c i s i o n about t h e a c c e p t a b i l i t y of t h e evidence i n each case. S ince t h e i d e n t i f i c a - t i o n of bodies i s e s s e n t i a l f o r s o c i o l o g i c a l and l e g a l reasons and impor tan t (sometimes e s s e n t i a l ) t o the Human F a c t o r s Group i n v e s t i g a t i o n of t h e a c c i d e n t , t h e p a t h o l o g i s t h imsel f must be c l o s e l y involved i n t h e f i n a l d e c i s i o n s ; a s suggested p rev ious ly i t is d e s i r a b l e t h a t he be t h e chairman of any i d e n t i f i c a t i o n group o r commission.

One State h a s found i n p r a c t i c e t h a t i f t h e forms used t o record f h d i n g s and informat ion a r e co loured , o r c l e a r l y d i f f e r e n t i a t e d i n some o t h e r way, t h e work of comparison is f a c i l i t a t e d (see Appendix 9) .

it is convenient to d e a l f i r s t w i t h bod ie s having a d i r e c t c l u e t o s p e c i f i c i d e n t i t y a v a i l a b l e such as a n a m e on c l o t h i n g o r i n documents. Next, one can conven ien t ly t u r n t o those r eco rds which do no t have so s p e c i f i c a c l u e to, i d e n t i t y . body may have r e t a i n e d f ragments of crew-type of uniform bu t w i thou t an i n d i c a t i o n of rank. One by one i t w i l l be p o s s i b l e t o exclude t h e i d e n t i t y of t h e body as t h a t of a p a r t i c u l a r crew member u n t i l p o s i t i v e p o i n t s of comparison are found s u f f i c i e n t f o r f i r m p o s i t i v e i d e n t i f i c a t i o n .

For example, a male

As t h e p rocess con t inues a t t e n t i o n should be g iven t o r e c o r d s having no d i r e c t immediate c l u e t o i d e n t i t y bu t n e v e r t h e l e s s having some unusual f e a t u r e which may be taken as a c l u e upon which t o concen t r a t e ; t h i s might b e a d i s t i n c t i v e t a t t o o , a n o l d amputa t ion , a n unusual d e n t a l p r o s t h e s i s , o r perhaps a s p e c i a l o r d i s t i n c t i v e d e n t a l record . Many exc lu- s i o n s can be made q u i t e r a p i d l y , bu t occas iona l ly a record j u s t i f y i n g more c a r e f u l comparison of a d d i t i o n a l f e a t u r e s w i l l be found be fo re an exc lus ion can be made, I n due cour se t h e informat ion r eco rds w i l l be c o r r e l a t e d wi th t h e d e s c r i p t i o n of t h e p a r t i c u l a r f e a t u r e , and comparison of o the r d e t a i l s about t h e body and t h e known pe r son w i l l be found t o conf i rm i d en t i t y.

The easier i d e n t i f i c a t i o n s should be made f i r s t , l e a v i n g t i l l later those

When t h i s l a t e r s t a g e is reached the volume of t h e r e c o r d s which may be more d i f f i c u l t because t h e bod ies have revea led -fewer obvious p o t e n t i a l l y v a l u a b l e c l u e s t o i d e n t i t y . should have been reduced - i t w i l l be necessary p a i n s t a k i n g l y t o compare t h e r e c o r d s of a

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P a r t III.- The I n v e s t i g a t i o n III- 9- 15

body with the. r eco rds of each known p e r s o n of a p p r o p r i a t e sex , exc luding i d e n t i t y i f pos- s i b l e , r eco rd ing t h i s and working towards t h e s o l u t i o n of each i d e n t i f i c a t i o n problem. Often a t t h i s s t a g e an a p p r a i s a l of i n fo rma t ion a v a i l a b l e w i l l sugges t t h a t a body could be t h a t of one of two o r more pas senge r s and d i f f e r e n t i a t i o n may be p o s s i b l e only i f addi - t i o n a l in format ion is sought from t h e r e l a t i v e s of t h e p a r t i c u l a r persons be l i eved t o be involved.

9.6 Evidence to . be Derived from t h e P a t h o l o g i c a l Examination

9.6.1 Detec t ion of d i s e a s e o r impaired e f f i c i e n c y i n t h e o p e r a t i n g crew

As t h e j o i n t examinat ion of a body proceeds , t h e i d e n t i t y of t h a t body may become quick ly ev iden t and i.t may be a p p r e c i a t e d t h a t i t i s , o r a lmos t c e r t a i n l y is, a member of t h e o p e r a t i n g crew. e s p e c i a l l y d e t a i l e d from t h e p o i n t of view of d e t e c t i o n of d i s e a s e o r impaired e f f i c i e n c y . I f t h e o p e r a t i n g c r e w have no t y e t been i d e n t i f i e d , and t h e p o s s i b i l i t y cannot be excluded t h a t an u n i d e n t i f i e d body may be t h a t of a c r e w member, t h e examinat ion of t h a t body must be as complete as i f i t w e r e known t o be t h a t of a p i l o t .

i f t h i s is so, t h e p a t h o l o g i s t ' s examinat ion should be

I n t h i s c a s e , t h e p a t h o l o g i s t should make an e s p e c i a l l y c a r e f u l s e a r c h f o r evidence of p r e - e x i s t i n g d i s e a s e which could have caused sudden c o l l a p s e o r d e a t h o r which could have lowered e f f i c i e n c y i n g e n e r a l terms and h e should a l s o seek ev idence of impaired func t ion due t o a l c o h o l , d rugs o r envi ronmenta l contaminants such as carbon monoxide.

To t h i s end, t h e au topsy must i n c l u d e sampling of a l l major organs f o r microscopic examinat ion and o€ blood and u r i n e and s e l e c t e d t i s s u e s f o r chemica l examination. It w i l l g e n e r a l l y be p o s s i b l e f o r t h e p a t h o l o g i s t t o o b t a i n s u p p l i e s of t h e f i x a t i v e s o l u t i o n needed f o r p r e s e r v a t i o n of t h e t i s s u e f o r microscopic i n v e s t i g a t i o n (10 p e r c e n t formaldehyde) problems may however be encountered as t o s u i t a b l e c o n t a i n e r s and s t o r a g e of samples f o r chemical examinat ion. These samples cannot be preserved wi th f i x a t i v e s o l u t i o n s and must be f rozen ; no t a l l S t a t e s have l a b o r a t o r i e s w i t h f a c i l i t i e s f o r t h e s o p h i s t i c a t e d a n a l y s e s t h a t may be r equ i r ed . It may be cons idered a d v i s a b l e , t h e r e f o r e , s u b j e c t t o t h e agreement of l o c a l o r n a t i o n a l a u t h o r i t i e s , and co -o rd ina t ion through t h e Inves t iga tor - in-Charge , f o r such spec i - mens t o be s e n t t o one of t h e s p e c i a l i z e d l a b o r a t o r i e s t h a t a r e a v a i l a b l e f o r t h i s kind of work i n c e r t a i n S t a t e s .

It is important f o r t h e i n v e s t i g a t o r t o r e a l i z e t h a t , as i n o t h e r areas of t h e acc iden t i n v e s t i g a t i o n , ev idence t h a t a medical abnormal i ty is p r e s e n t i n a p i l o t i s a long way from proof t h a t t h a t abnorma l i ty w a s d i r e c t l y connected w i t h t h e a c c i d e n t . A p i l o t may be shown t o have d i s e a s e which could have caused h i s sudden c o l l a p s e o r dea th . It i s r a r e l y p o s s i b l e t o f i n d medica l ev idence which shows unequivoca l ly t h a t d i s e a s e d i d cause c o l l a p s e o r dea th ; t h a t i t probably d i d so is a conc lus ion which can normally be reached only a f t e r c o r r e l a t i o n of a l l t h e ev idence adduced by a l l t h e s p e c i a l i z e d inves t iga - t i n g groups - n o t merely t h a t of t h e Human F a c t o r s Group.

9.6.2 The examinat ion of pas senge r s and c a b i n a t t e n d a n t s

The volume of work involved i n an a c c i d e n t w i th a l a r g e number of f a t a l i t i e s d i c t a t e s t h a t t h e au topsy examinat ions and organ and t i s s u e sampling of bod ie s known t o be t h o s e of pas senge r s ' shou ld be less e x t e n s i v e than f o r t h e o p e r a t i n g c r e w on t h e f l i g h t deck o r i n t h e c o c k p i t . Neve r the l e s s , t h e r e are c e r t a i n p o i n t s which should n o t be overlooked in t h e examinat ion of any body.

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II I- 9- 16 Manual of A i r c r a f t Accident I n v e s t i g a t i o n

S u f f i c i e n t l y d e t a i l e d examination and sampling of t h e s e bodies are requ i r ed t o provide , i n a d d i t i o n t o t h e p r e c i s e cause of dea th :

an estimate of d e c e l e r a t i o n f o r c e s , der ived from t h e state of t h e h e a r t , a o r t a , diaphragm, l i v e r and sp leen toge the r w i th t h e presence of f r a c t u r e s i n sternum, s p i n e and p e l v i s ,

an assessment of any evidence of seat b e l t i n j u r y and a s s o c i a t e d c ran io- f a c i a l damage,

evidence of s u r v i v a l i n f i r e as shown by t h e presence of r a i s e d carboxyhaemoglobin l e v e l s i n blood o r t i s s u e s ,

t h e presence of microscopic changes i n t h e lungs r e l e v a n t t o ante-mortem i n j u r y , t o l i f e du r ing f i r e ; and p o s s i b l y t o such medico-legal ques t ions as su rv ivo r sh ip which may subsequent ly arise,

f o r medico-legal r easons n o t e must a l s o be taken of t he presence of any p re -ex i s t ing d i s e a s e if subsequent compensation c la ims a r e t o be s e t t l e d with equ i ty .

Examination of t he bodies of pas senge r s Gan e s t a b l i s h a p a t t e r n of i n j u r i e s . Such a p a t t e r n may be uniform o r d iscordant . s enge r s were subjec ted t o much t h e same type and degree of f o r c e .

. combination of c r a n i o - f a c i a l damage,seat b e l t i n j u r y ant3 c r a s h i n g of t h e lower l e g s asso- c i a t e d wi th passenger tie-down f a i l u r e in t h e c l a s s i c c ra sh s i t u a t i o n . in format ion may be der ived by comparing t h e p a t t e r n of i n j u r i e s i n t h e passengers w i t h t h e p a t t e r n i n t h e c a b i n c r e w - e.g. were t h e cab in a t t e n d a n t s braced f o r a n emergency o r w e r e they i n t h e i r normal ope ra t ing cond i t ions .

A uniform p a t t e r n i n d i c a t e s t h a t a l l t h e pas- A t y p i c a l example is t h e

Much a d d i t i o n a l

I n t h e d i scb rdan t p a t t e r n , one group of passengers may show i n j u r i e s d i s t i n c - t i v e from t h e remainder. This could i n d i c a t e some unusual i n c i d e n t and t h e i n t e r p r e t a t ï o n of t h e f i n d i n g s rests t o a l a r g e e x t e n t on a c c u r a t e i d e n t i f i c a t i o n and locationa i n t h e a i r c r a f t i n accordance wi th t h e passenger s e a t i n g p l an . The p o s s i b i l i t y of a s i n g l e body showing a d e v i a t i o n from t h e norm must always be remembered - i t may w e l l be t h a t i t is only by t h i s means t h a t a case of sabotage o r un lawful i n t e r f e r e n c e wi th t h e ope ra t ion of t h e aircraft is d i sc losed .

9.6.3 Cor re l a t ion wi th t h e aircraft wreckage examinat ion

9.6.3.1 The- cockpi t

Cor re l a t ion between t h e degree of cockp i t damage and t h e degree of i n j u r y t o t h e p i l o t is e s s e n t i a l . Anomalous f i n d i n g s may g ive a c l u e t o such acc iden t causes a s f a i l u r e of t h e au tomat ic p i l o t o r of a t tempted i n t e r f e r e n c e w i t h t h e normal o p e r a t i o n of t h e a i r c r a f t . I n j u r i e s discovered should be, whenever p o s s i b l e , r e l a t e d t o s p e c i f i c items of equipment i n t h e cockpi t . To t h i s end a sea rch should be made f o r t h e presence of blood and o t h e r t i s s u e s on t h e s e a t s , ins t ruments and c o n t r o l columns. I n c e r t a i n c i rcumstances i t may be necessary t o i d e n t i f y such evidence a s be ing r e l a t e d t o s p e c i f i c f l i g h t crew members o r , conceivably, t o show t h a t t h e t i s s u e s are n o t human - f o r example, ev idence of b i r d s t r i k e .

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P a r t III.- The I n v e s t i g a t i o n I I I- 9- 1 7

The damage t o and t h e g e n e r a l s t a t u s of t h e f l i g h t crew seats and s a f e t y ha rness should be recorded as be ing p e r t i n e n t t o t h e r e c o n s t r u c t i o n of e v e n t s i n t h e cock- p i t a t t h e t i m e of t h e a c c i d e n t , immediately a f t e r w a r d s , and t o t h e p o s s i b i l i t i e s of sur- v i v a l and escape.

9 . 6 . 3 . 2 The passenge r compartment

A d e t a i l e d examinat ion and d e s c r i p t i o n of a l l seats, t h e i r a t t achmen t s , seat b e l t s , and o t h e r s a f e t y equipment and su r round ing s t r u c t u r e s should be made. p r e r e q u i s i t e t o a s u r v i v a b i l i t y s tudy . themselves m y g ive a n i n d i c a t i o n of t h e f o r c e s involved. b e l t s should always be measured. occupant from such measurcment a l t h o u g h it should be borne i n mind t h a t seat b e l t a d j u s t - ments may va ry cons ide rab ly . enab le t h e i n v e s t i g a t o r t o d i s t i n g u i s h between a c a b i n which h a s been p repa red f o r an emergency l and ing and one i n which t h e pas senge r s have been s i t t i n g w i t h t h e i r b e l t s l i g h t l y f a s t e n e d a s a r o u t i n e . s e a t i n g p l a n s when a v a i l a b l e and w i t h t h e r e s u l t s of t h e au topsy examinat ions. When s e a t i n g p l a n s a r e not a v a i l a b l e and when l o c a l o r n a t i o n a l a u t h o r i t i e s have removed bod ies b u t d i d not record t h e i r l o c a t i o n , c l u e s may o f t e n be d i scove red as t o t h e s e a t i n g of passengers; f o r example, a book o r handbag found i n t h e compartment on a seat back w i l l s u g g e s t a pro- bab le l o c a t i o n of i t s owner. w i t h c l o t h i n g removed f rom bod ies may w e l l pe rmi t d e d u c t i o n s about t h e l o c a t i o n of bod ie s - a t l e a s t where t h e bod ies came t o rest, i f n o t t h e i r s e a t l o c a t i o n s .

It is a Displacement of f a s t e n e r s and evidence on t h e b e l t s

The s i z e of f a s t e n e d b u t t o f n i t might be p o s s i b l e t o deduce t h e s i z e of t h e seat

Of g r e a t e r importance, the o v e r a l l t i g h t n e s s of b e l t s should

F ind ings of t h i s n a t u r e must c e r t a i n l y be c o r r e l a t e d w i t h pas senge r

Fragments of f a b r i c , fu sed t o a i r c r a f t s t r u c t u r e , compared

9 . 6 . 4 The n a t u r e and cause of i n j u r i e s and t h e i r t i m i n g

Th i s r e f e r s i n p a r t i c u l a r t o a s i n g l e major l e t h a l i n j u r y s u s t a i n e d by a v i c t i m o r t o p o t e n t i a l l y i n c a p a c i t a t i n g i n j u r i e s which would have prevented a conscious and otherwise capab le pe r son from e f f e c t i n g h i s own escape. An assessment of t h e n a t u r e and cause of i n j u r i e s is r e q u i r e d so t h a t c o n s i d e r a t i o n can be g iven t o a p p r a i s i n g s a f e t y fea- t u r e s w i t h i n t h e a i r c r a f t and improving them. Examples i n c l u d e p e n e t r a t i n g head i n j u r i e s o r c rush ing f r a c t u r e s of t h e lower l e g s , bo th of which may i n d i c a t e an u n s a t i s f a c t o r y d e s i g n

. of t h e back of t h e seats i n r e l a t i o n t o t h e s e s i t u a t e d immediately behind them.

The c a u s e s of unusual t y p e s of i n j u r y need t o be f u l l y examined. ûn more than one occas ion c o n c l u s i o n s have been reached upon which p i l o t w a s a c t u a l l y a t t h e con- t r o l s of an a i r c r a f t when it c r a s h e d , based upon t h e n a t u r e of t h e i n j u r i e s t o t h e hands and w r i s t s o r f e e t and a n k l e s as determined bo th by naked eye . examina t ion a t au topsy and by r ad iog raphs .

Sabotage and t h e p o s s i b l e i n j u r i e s due t o b l a s t o r s h r a p n e l from e x p l o s i v e d e v i c e s must no t be missed. T i s s u e s from around any such s u s p e c t wounds should be preserved by t h e p a t h o l o g i s t f o r l a b o r a t o r y a n a l y s i s f o r t h e a p p r o p r i a t e trace evidence. I n j u r i e s so caused w i l l be r e f l e c t e d i n damage t o t h e c l o t h i n g ; t h e dange r s of premature removal of c l o t h i n g p u r e l y f o r t h e purpose of i d e n t i f i c a t i o n are, the reby , emphasized.

Radiographs are e s p e c i a l l y impor t an t i n c a s e s of suspec ted sabo tage and any sugges t ion of f o u l p l a y s h o u l d i n d i c a t e a need f o r e x t e n s i v e u s e of X-ray examinat ion, Th i s is a good example of t h e importance of u s i n g s p e c i a l t echn iques i n t h e v a r i o u s a s p e c t s of t h e i n v e s t i g a t i o n . autopsy t a b l e i n a s s e s s i n g s k e l e t a l i n j u r i e s , f o r a permanent r e c o r d of t h e s e w i l l be provided by t h e f i l m s . Simultaneously, t h e r ad iog raphs may r e v e a l f o r e i g n bod ies , o r s k e l e t a l a b n o r m a l i t i e s which are of v a l u e i n t h e p r o c e s s of i d e n t i f i c a t i o n .

The more r ad iog raphs can be used , t h e less t i m e need be s p e n t a t t h e

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9.6.5 The de termina t ion of t h e cause of dea th of each person

Many of t h e bodies from a n a i r c r a s h w i l l be e x t e n s i v e l y damaged by excess ive f o r c e s and by burns. c o n t r i b u t i o n t o a n a i r c r a f t acc iden t i n v e s t i g a t i o n t o a s c r i b e d e a t h t o burning o r t o mul t i - p l e i n j u r i e s on t h e b a s i s of a s u p e r f i c i a l e x t e r n a l post-mortem examiriaticm. produces so many a d d i t i o n a l f a c t o r s t h a t such an a n a l y s i s r e p r e s e n t s l i t t l e more than guess work; moreover, a s u p e r f i c i a l examination f a i l s t o d i s t i n g u i s h between ante-mortem and post-mortem i n j u r y . It is important t o determine, i f i t is a t a l l poss ib l e , t h e p r e c i s e cause of dea th i n each c a s e i n r e l a t i o n both t o t h e t e c h n i c a l a s p e c t s of t h e a c c i d e n t inves- t i g a t i o n and t o later medico-legal problems, A f e w examples are given t o i l l u s t r a t e t h e

It i s tempting f o r t h o s e no t aware of t h e va lue of t h e p a t h o l o g i c a l

A c o n f l a g r a t i o n

e s s e n t i a l n a t u r e

a )

C )

- .

of a f u l l i n t e r n a l autopsy:

In the event of t h e dea th of a p i l o t from h e a r t d i s e a s e w h i l s t a t t h e c o n t r o l s , a r e s u l t a n t c r a sh may cause m u l t i p l e i n j u r i e s which, i n t h e absence of i n t e r n a l examination, might be accepted a s t h e cause of dea th . Obviously i n t h i s c a s e t h e evidence important t o the t e c h n i c a l a c c i d e n t i n v e s t i g a t i o n would be missed.

I f a passenger s u s t a i n e d a seve re head i n j u r y of l e t h a l s e v e r i t y impor tan t conclus ions may be drawn a s t o t h e s u r v i v a b i l i t y of h i s environment. I f , however, i n t e r n a l examination showed he i n f a c t d ied from burning, t h e head i n j u r y may be a s c r i b a b l e t o t h e e f f e c t s of heat: and t h e i n t e r p r e t a - t i o n w i l l be q u i t e d i f f e r e n t .

A husband and wi fe may both appear t o have Sus ta ined m u l t i p l e i n j u r i e s and i n c i n e r a t i o n . But i f one has a c t u a l l y d i ed from asphyxia and t h e o the r from i n j u r y i t could be he ld t h a t t h e former survived t h e l a t t e r wi th f a r reaching medico-legal imp l i ca t ions . Of importance t o t h e tech- n i c a l acc iden t i n v e s t i g a t i o n would be t h e ev idence t h a t one may have survived t h e impact theref o r e t h e i n v e s t i g a t i o n would con t inue i n t o t h e human engineer ing and su rv iva€ a s p e c t s .

9.7 Release of Human Remains and Personal Proper ty

Although it is p r e f e r a b l e t o r e t a i n a l l bodies e i t h e r u n t i l a l l have been i d e n t i f i e d o r u n t i l no f u r t h e r i d e n t i f i c a t i o n s are p o s s i b l e , bod ie s should be r e l e a s e d t o the l o c a l o r n a t i o n a l a u t h o r i t i e s as soon a s p o s s i b l e provided:

a ) a l l t h e information r e l evan t t o t h e i n v e s t i g a t i o n has been d e r i v e d from t h e cadaver ,

b) t h e r e is no p o s s i b l e doubt a s t o t h e i d e n t i t y of a body.

A f t e r i d e n t i f i c a t i o n of a l l bodies has been e s t a b l i s h e d and t h e r e i s no f u r - t h e r need t o r e t a i n bodies from t h e po in t of view of t h e a c c i d e n t i n v e s t i g a t i o n , i t is normally t h e r e s p o n s i b i l i t y of t n e l o c a l o r n a t i o n a l a u t h o r i t i e s t o r e t u r n them t o t h e i r f a m i l i e s with a s u i t a b l e i d e n t i f i c a t i o n n o t i c e and d e a t h c e r t i f i c a t e . i s requi red , a d d i t i o n a l permi ts and c e r t i f i c a t e s might have t o be obta ined p e r m i t t i n g t h e t r a n s p o r t of t h e bodies o r remains t o o t h e r l o c a l i t i e s , d i s t r i c t s o r S t a t e s . )

(Where r e p a t r i a t i o n

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I 11-9-19 P a r t III.- The I n v e s t i g a t i o n -_ 9.8 The Survived Accident ,

Genera l ly , t h i s is a more s t r a i g h t f o r w a r d matter than t h e a c c i d e n t i n which a l l t h e a i r c r a f t occupants were k i l l e d f o r i t l a r g e l y invo lves t h e examinat ion of l i v i n g and probably Co-operative s u b j e c t s . E s s e n t i a l l y t h e Human F a c t o r s Group w i l l be look ing f o r t h e same type of evidence as t h a t d e r i v e d from t h e p a t h o l o g i c a l examinat ion of t h o s e k i l l e d ( s e e Sec t ions 9.6.1 t o 9.6.4).

A medical examinat ion, p r e f e r a b l y by an a v i a t i o n medical s p e c i a l i s t o r qua- lif i e d a v i a t i o n medical examiner, should be made on s u r v i v i n g f l i g h t crew members t o determine whether any p h y s i c a l , p h y s i o l o g i c a l o r p s y c h o l o g i c a l f a c t o r s i n t h e o p e r a t i n g c r e w had a b e a r i n g on t h e c i r cums tances of t h e a c c i d e n t . It might w e l l be d e s i r a b l e f o r blood and /o r u r i n e samples t o be t aken f o r a n a l y s i s both f o r t h e p re sence of t h e r a p e u t i c subs t ances and t o h e l p t o determine whether any abnormal state such as hypoglycaemia may have been p r e s e n t . Before t a k i n g such specimens, however, t h e i n v e s t i g a t o r should ensu re . t h a t t h e r e are no l o c a l l e g a l c o n t r a - i n d i c a t i o n s ; h e should a l s o have t h e consen t of t h e s u b j e c t and he would be w e l l a d v i s e d t o e x p l a i n t h e purpose of t h e tests b e f o r e under- t a k i n g them.

The crew should be in t e rv i ewed but t h i s should be Co-ordinated through t h e Invest igator- in-Charge t o ensu re t h a t t h e r e is no undue d u p l i c a t i o n because of t h e needs of t h e v a r i o u s Groups.

A d e t a i l e d record shou ld be made of i n j u r i e s t o a l l occupants w i t h a n assessment of t h e i r cause; t h e f i n d i n g s must be c o l l a t e d w i t h t h e i r seat p o s i t i o n , o r l o c a t i o n i n t h e a i r c r a f t , and a d j a c e n t environment i n o r d e r t h a t p r e v e n t i v e a c t i o n such as r e d e s i g n may be cons ide red .

I f t h e a i r c r a f t h a s been evacuated i n t h e p re sence of f i r e o r s i m i l a r haza rd (e.g. s i n k i n g i n t h e case of a d i t c h i n g ) a f u l l account of each pe r son’ s e scape is a v a l u a b l e c o n t r i b u t i o n t o an assessment of f a c t o r s i n f l u e n c i n g s u c c e s s o r f a i l u r e .

A s t h e a i m of a c c i d e n t i n v e s t i g a t i o n is p r e v e n t i o n , a t t e n t i o n should a l s o be given t o t h e psycho log ica l e f f e c t s of t h e a c c i d e n t upon t h e f l i g h t crew b e f o r e they are allowed t o r e t u r n t o f l y i n g d u t i e s .

9.9 Other Aspects of t h e Human F a c t o r s I n v e s t i g a t i o n

9.9.1 F l i g h t crew medical and p e r s o n a l r e c o r d s - Bas ic mental and p h y s i c a l h e a l t h

The medical r e c o r d s of t h e f l i g h t crew must be s t u d i e d t o de t e rmine whether any c o n d i t i o n w a s known t o e x i s t which might have p rec luded t h e i r s u c c e s s f u l completion of t h e demanded t a s k i n t h e p r e v a i l i n g c i r cums tances . P a r t i c u l a r a t t e n t i o n should be given t o any c o n d i t i o n l i k e l y t o have l e d t o i n c a p a c i t a t i o n i n f l i g h t o r t o a d e t e r i o r a t i o n in f i t n e s s and performance. The p o s s i b l e c a u s e s of i n c a p a c i t a t i o n o r lowered e f f i c i e n c y of performance is , t h e o r e t i c a l l y , t h e r ange of t h e d i s e a s e s of man b u t , w i t h adequa te medical s u p e r v i s i o n of crews, g r o s s a b n o r m a l i t i e s are u n l i k e l y t o be p r e s e n t .

Any in fo rma t ion ob ta ined from t h e medical r e c o r d s must be c o r r e l a t e d w i t h t h e p a t h o l o g i c a l f i n d i n g s . autopsy - e p i l e p s y being t h e prime example. a l s o be noted b u t , a g a i n , i t w i l l be t h e e s s e n t i a l l y n e g a t i v e p a t h o l o g i c a l f i n d i n g s i n an a c c i d e n t suspec ted of having a human f a c t o r s cause which w i l l f o c u s a t t e n t i o n on t h e s e s y s t e m s .

Many f u n c t i o n a l a b n o r m a l i t i e s however are n o t demonstrable a t V i s u a l and a u d i t o r y a c u i t y of t h e crew should

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I n c e r t a i n c i rcumstances , t h e f l i g h t crew background should be i n v e s t i g a t e d and t h i s w i l l i nc lude cons ide ra t ion of such matters a s mot iva t ion f o r f l y i n g , gene ra l i n t e l l i g e n c e , emotional s t a b i l i t y , c h a r a c t e r and behaviour. Again, however, well-documented a b n o r m a l i t i e s of t h i s s o r t are s c a r c e l y compatible w i t h modern f l i g h t crew s e l e c t i o n methods and it may w e l l be t h a t in format ion obta ined from f r i e n d s , r e l a t i v e s , acquafn tances , super- v i s o r s , i n s t r u c t o r s , p e r s o n a l phys i c i ans and o t h e r obse rve r s as t o both t h e r e c e n t a c t i v i t i e s and a t t i t u d e s of t h e f l i g h t crew and t o t h e i r long-term p e r s o n a l and f l y i n g h a b i t s , g e n e r a l h e a l t h and o rd ina ry behaviour may provide in fo rma t ion which i s of f a r g r e a t e r va lue .

The r ecogn i t ion and i n v e s t i g a t i o n of t h e psycho-physiological e lements under- l y i n g many acc iden t causes have n o t always been given t h e p rope r degree of a t t e n t i o n . elements of pe rcep t ion , judgement, d e c i s i o n , morale, mo t iva t ion , age ing , f a t i g u e , and i n c a p a c i t a t i o n are o f t e n r e l a t i v e l y i n t a n g i b l e , y e t h i g h l y p e r t i n e n t v a r i a b l e s . Even when d e t e c t e d , they are d i f f i c u l t t o measure and document and i t should be emphasized t h a t a p o s i t i v e a s s o c i a t i o n between any such abnormaï i ty d i scove red and t h e cause of t h e a c c i d e n t can seldom, i f eve r , be b e t t e r t han corrjectufe. must be made t o i n v e s t i g a t e and r e p o r t upon such human f a c t o r s as f u l l y as poss ib l e .

Human

Desp i t e t h e s e d i f f i c u l t i e s , every e f f o r t

9.9.2 The problems of t h e p a r t i c u l a r f l i p h t

Many matters which are n o t of a medical n a t u r e may be p e r t i n e n t t o t h e Human Fac to r s Group and it i s h e r e t h a t a c l o s e l i a i s o n wi th t h e Opera t ions Group is e s s e n t i a l .

Some of t h e g e n e r a l problems of t h ' i s t ype inc lude :

The f l i g h t p l an - wi th p a r t i c u l a r r e f e r e n c e t o instrucr.t$ons g iven and d e v i a t i o n s made from those i n s t r u c t i o n s .

The f l i g h t equipment - r ang ing from i t e m s such as t h e a i r c r a f t t ype , t o cockp i t l ayou t , mechanisms f o r cab in p r e s s u r i z a t i o n , v e n t i l a t i o n and tempera t ù r e con t r o i.

The n a v i g a t i o n a i d s - p a r t i c u l a r l y whether t hey w e r e used t o t h e i r f u l l e x t e n t .

The f l i g h t environmnent and f l i g h t phase - which should inc lude a con- s i d e r a t i o n of t h e p o s s i b l e p re sence of fumes from t h e eng ine f l u i d s and f u e l and a l s o of t o x i c subs t ances from t h e cargo .

Assessment of t h e workload of t h e crew a t t h e t i m e of t h e a c c i d e n t .

The importance of t h i s i n fo rma t ion t o t h e Human F a c t o r s Group is e s s e n t i a l l y t o guide them i n t o s i g n i f i c a n t areas of i n v e s t i g a t i o n on t h e i r own acco-unt. For example, a d e v i a t i o n from t h e f l i g h t pa th might i n d i c a t e a need f o r an examination f o r carbon monoxide i n t o x i c a t i o n ; a suspec t p r e s s u r i z a t i o n system might i n d i c a t e a need t o conf i rm o r exc lude hypoxia as a cause of t h e acc iden t . The i t e m i z a t i o n of l i k e l y t o x i c causes w i l l s i m p l i f y and d i r e c t t h e work of t h e a v i a t i o n t o x i c o l o g i s t . emphasize t h e need f o r f r equen t meetings of t h e heads of t h e i n v e s t i g a t i o n groups and t h e need f o r adequate exchange of in format ion a t such meet ings ,

These are t h e s o r t of matters which

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S p e c i a l problems of t h e p a r t i c u l a r f l i g h t p a r t i c u l a r l y concern t h o s e a s p e c t s of p o s s i b l e impairment of f l i g h t crew f i t n e s s and performance which are n o t demonstrable by autopsy. planned, whether unexpected c o n d i t i o n s deve lop , o r whether emergency s i t u a t i o n s arise. The cause of t h e s e e r r o r s and performance decrements may be found in:

E r r o r s and d e f i c i e n c y of performance may occur whether o p e r a t i o n s are a s

a ) E r r o r s of p e r c e p t i o n . These may be r e l a t e d t o a u d i t o r y , v i s u a l t a c t i l e o r p o s t u r a l s t i m u l i .

b) Errors of judgement and i n t e r p r e t a t i o n . Misjudgement of d i s t a n c e s , m i s - i n t e r p r e t a t i o n of i n s t rumen t s , confusion of i n s t r u c t i o n s , s enso ry i l l u - s i o n s , d i s o r i e n t a t i o n , l a p s e of memory, etc., f a l l i n t o t h i s category.

c ) E r r o r s of r e a c t i o n . These p a r t i c u l a r l y relate t o t iming and Co-ordination of neuromuscular performance and technique as r e l a t e d t o t h e movement of con t r o Is.

Cont r ibu t ing c a u s e s of e r r o r s and performance d e f i c i e n c y may l i e i n such areas a s :

d ) A t t i t u d e and mot iva t ion .

e ) Emotional e f f e c t .

f ) Perseverance.

A t h e s e f a c t o r s a r e l i k e l y t o be exaggerated by f a t i g u e which is a n u b i q u i JUS bu t e l u s i v e f a c t o r i n a v i a t i o n o p e r a t i o n s ; i t is i n t h e e v a l u a t i o n of t h e s e p o t e n t i a t i n g f a c t o r s t h a t the Human F a c t o r s Group may be of i n v a l u a b l e a s s i s t a n c e t o t h e Invest igator- in-Charge.

The Human F a c t o r s Group must d i s t i n g u i s h c a r e f u l l y between h y p o t h e s i s and genuine evidence; whenever p o s s i b l e , f a c t u a l evidence must be adduced b e f o r e a n a c c i d e n t can be a s c r i b e d t o apsycho-physiological factor. For example, i t may be suggested t h a t t h e p i l o t was p a r t i c u l a r l y i r r i t a b l e a t t h e t i m e of t h e f l i g h t ; bu t a r e p l a y of t h e r e c o r d i n g s of h i s i n - f l i g h t t r a n s m i s s i o n s may g i v e f a r b e t t e r evidence as t o whether o r n o t t h i s e f f e c t was o p e r a t i v e a t t h e t i m e of t h e a c c i d e n t .

9.10 summary

The composi t ion of t h e Human F a c t o r s Group must be chosen on t h e b a s i s of t h e type of a c c i d e n t and t h e evidence l i k e l y t o be a v a i l a b l e from hÙman sources . i n a v i a t i o n medicine w i l l be of g r e a t e s t v a l u e when t h e r e a r e many s u r v i v o r s but p a t h o l o g i c a l a s s i s t a n c e w i l l be r e q u i r e d whenever t h e r e are f a t a l i t i e s .

S p e c i a l i s t s

P a r t i c u l a r l y i n t h e even t of a wholly f a t a l a c c i d e n t , t h e p a t h o l o g i c a l evidence is an e s s e n t i a l p a r t of t h e t e c h n i c a l i n v e s t i g a t i o n and t h e Invest igator- in-Charge must ensu re t h a t important i n v e s t i g a t i v e in fo rma t ion is not s a c r i f i c e d t o meet s o c i o l o g i c a l and l e g a l d e s i r e s € o r r a p i d i d e n t i f i c a t i o n and d i s p o s a l of bodies . To t h i s end, h e should, i f p o s s i b l e , o b t a i n t h e s e r v i c e s of a p a t h o l o g i s t f a m i l i a r w i t h a i r c r a f t a c c i d e n t i n v e s t i g a - t i o n and who i s capab le of Co-ordinating t h e two inter-dependent f u n c t i o n s of i n v e s t i g a t i o n and i d e n t i f i c a t i o n .

The prime o b j e c t of t h e p a t h o l o g i s t should be t o o b t a i n ev idence as t o t h e cause, sequence and e f f e c t of t h e a c c i d e n t through a n examination of t h e o p e r a t i n g crew,

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t h e cab in a t t e n d a n t s and \ the passengers . as t o . i d e n t i f i c a t i o n and of medico-legal s i g n i f i c a n c e w i l l a u t o m a t i c a l l y emerge p a r t i c u l a r l y i f each examination is en anced by t h e Co-ordinated e f f o r t s of t h e p a t h o l o g i s t , p o l i c e ,

Co inc iden ta l ly wi th t h i s i n v e s t i g a t i o n , ev idence

odon to log i s t s , r a d i o l o g i s i s, etc.

The p a t h o l o g i c a l examination w i l l be g r e a t l y a s s i s t e d by adequate pre-planning - p a r t i c u l a r l y i n r e l a t i o n t o t h e recovery of bodies and t h e p r o v i s i o n of whole body r e f r i - ge ra t ion . I n t h e event t h a t p l a n s do not exis t , t h e Inves t iga tor - in-Charge must ensu re f a c i l i t i e s f o r t h e p a t h o l o g i s t t o c a r r y out t h e fo l lowing minimal requi rements based on i n v e s t i g a t i v e , medico-legal and s o c i o l o g i c a l needs:

a ) i d e n t i f i c a t i o n and complete examination of the o p e r a t i n g crew on t h e f l i g h t deck o r i n t h e cockp i t ;

b) a f u l l e x t e r n a l examination of a l l f a t a l c a s u a l t i e s ;

e ) i d e n t i f i c a t i o n of t h e cab in a t t e n d a n t s and comparison w i t h t h e pas senge r s ;

d ) minimal i n t e r n a l autopsy on a l l c a s u a l t i e s t o include:

i ) e s t ab l i shmen t of t he cause of dea th ;

i i ) d i scovery of major d i s e a s e l i k e l y t o i n f l u e n c e l i f e expectancy; and

i i i ) assessment of d e c e l e r a t i o n i n j u r y to :

- ca rd iovascu la r system, l iver and diaphragm

- head, sternum, s p i n e and p e l v i s ;

e ) s e l e c t i o n of blood specimens from a l l c a s u a l t i e s f o r carboxyhaemoglobin s tud ies ;

f ) c o l l e c t i o n of specimens of lung from a l l c a s u a l t i e s f o r e s t i m a t i o n of t h e mode of dea th .

A n experienced p a t h o l o g i s t w i l l i n t e r p r e t h i s f i n d i n g s with cau t ion . For t h e i r p a r t , t h e head of t h e Human Fac to r s Group and t h e Inves t iga tor - in-Charge must e n s u r e t h a t t h e p a t h o l o g i c a l f i n d i n g s are taken as bu t p a r t of t h e i n v e s t i g a t i o n a s a whole and are f u l l y c o r r e l a t e d wi th ev idence adduced w i t h i n t h e Group and by o t h e r Groups. h a s shown t h a t t h i s is- f a c i l i t a t e d and maximum advantage gained i f t h e p a t h o l o g i s t a t t e n d s t h e p e r i o d i c b r i e f i n g s by t h e Investigator-in-Charge.

Experience

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PART I I I

CHAPTER 10. - EVACUATION, SEARCH, RESCUE AND FIRE FIGHTING INVESTIGATION



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P a r t III.- The I n v e s t i g a t i o n I II- 10-1

CHAPTER 10

EVACUATION, SEARCH, RESCUE AND FIRE FIGHTING IM/ESTIGATIu\I

10.1 General

It is impor tan t t o c o n s i d e r t h e means provided and methods used d u r i n g t h e evacua t ion , s e a r c h , r e scue and f i r e - f i g h t i n g o p e r a t i o n s , a s w e l l as t h e time needed t o reach t h e s i t e of t h e a c c i d e n t and t o c a r r y out t h e proper o p e r a t i o n s . c i rcumstances of t h e a c c i d e n t , i t is necessa ry t o i n v e s t i g a t e t h e a c t i o n s t aken f o r t h e evacuat ion of t h e a i r c r a f t and those used f o r s ea rch ing f o r t h e a i r c r a f t and r e scu ing t h e su rv ivo r s .

Depending upon t h e

Such an i n v e s t i g a t i o n w i l l make it p o s s i b l e t o estimate t h e p o s i t i v e a n d f o r nega t ive f a c t o r s emerging d u r i n g t h e v a r i o u s o p e r a t i o n s mentioned a b w e and t o p repa re recommendations f o r improving t h e In t h i s connexion, t h e i n v e s t i g a t o r should be consc ious of t h e need t o examine o b j e c t i v e l y a l l e x i s t i n g s a f e t y , r e scue and f i r e f i g h t i n g methods and c a p a b i l i t i e s in t h e l i g h t of i n c r e a s i n g a i r c r a f t s i z e , f u e l q u a n t i t i e s c a r r i e d and passenger c a p a c i t y .

p rocedures and means i n use a t t h e t i m e of t h e a c c i d e n t .

Th i s p o r t i o n of t h e i n v e s t i g a t i o n should be conducted i n c l o s e co-operation with t h e i n v e s t i g a t o r s i n charge of t h e S t r u c t u r e , Human F a c t o r s and Opera t ions (wi tnes s s t a t emen t ) groups. .

The fo l lowing documents could be of a s s i s t a n c e t o t h e i n v e s t i g a t o r :

a) I C A 0 A i r p o r t S e r v i c e s Manual (Doc 9137-AN/898) , P a r t 1.

b) A i r c r a f t F i r e I n v e s t i g a t i o n Manual 1972 i s s u e d by t h e N a t i o n a l F i r e P r o t e c t i o n A s s o c i a t i o n ( I n t e r n a t i o n a l ) (NFPA No. 422M), 470 A t l a n t i c Avenue, Boston, Massachusetts 02210, USA.

10 .2 Evacuation Opera t ions

10.2.1 Genera 1

The importance of a i r c r a f t evacua t ion des ign , and of p rope r procedures p r i o r t o t h e a c c i d e n t when p r e d i c t a b l e , and a f t e r t h e a c c i d e n t , t o e n s u r e r e s p e c t i v e l y a g r e a t e r chance of s u r v i v a b i l i t y of t h e a i r c r a f t occupants and a s a f e evacua t ion of t h e a i r c r a f t by t h e s u r v i v o r s , cannot be o v e r s t r e s s e d . The main r o l e of t h e i n v e s t i g a t o r is t o de te rmine what a c t i o n s were taken and what means were used , and t o a n a l y s e both v e r y c r i t i c a l l y , Co-re la t ing t h e s e , where necessa ry , w i t h examination of t h e d e s i g n f e a t u r e s provided f o r evacuat ion i n t h e a i r c r a f t .

10.2.2 Pre-crash a c t i o n s

The i n v e s t i g a t o r shou ld , wherever p o s s i b l e , de te rmine and record t h e a c t i o n s taken on board b e f o r e t h e c r a s h t o b r i e f t h e pas senge r s on t h e n a t u r e of t h e emergency, t o i n s t r u c t them on what t hey should do and t o ensu re t h e bes t p o s s i b l e s u r v i v a b i l i t y of t h e a i r c r a f t occupants du r ing t h e c ra sh . would be t h e s u r v i v o r s ' s t a t e m e n t s and t h e r eco rd ing of t h e p u b l i c a d d r e s s system. p a r t i c u l a r , t h e i n v e s t i g a t o r should examine t h e fo l lowing p o i n t s :

The b e s t sou rces of i n fo rma t ion , when a v a i l a b l e ,

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g e n e r a l b r i e f inpi of passengers: g e n e r a l b r i e f i n g of t h e pas senge r s regard ing t h e v a r i o u s s a f e t y and rescue equipment a t t h e i r d i s p o s a l ( s e a t b e l t , oxygen supply, l i f e j a c k e t , e t c . ) , member(s) of t h e crew who gave t h e b r i e f i n g , t i m e of t h e b r i e f i n g , i ts i n t e l l i g i b i l i t y and a u d i b i l i t y t o a l l passengers;

p e r s o n a l p recau t iona ry measures: passengers r ega rd ing t h e removal of dangerous a r t ic les such as s p e c t a c l e s , t i e s , shoes; t h e t i g h t e n i n g of seat b e l t s ; t h e cushioning of each passenger wi th p i l l o w s , b l a n k e t s , c l o t h e s ; c l a r i t y and under- s t and ing of t h e s e i n s t r u c t i o n s ; s p e c i a l measures taken by each crew member t o p r o t e c t himself a g a i n s t pe r sona l i n j u r i e s d u r i n g t h e c r a s h ;

emergency e x i t s : s p e c i a l i n s t r u c t i o n s given t o passengers r ega rd ing t h e emergency e x i t s , p o s s i b l e a l l o c a t i o n of c e r t a i n e x i t s t o well- def ined groups of passengers, measures taken t o f r e e t h e a c c e s s t o a l l emergency e x i t s , and t o l o c a t e n e a r them crew a t t e n d a n t s o r passengers s p e c i a l l y b r i e fed on t h e i r f u n c t i o n i n g ;

emergency equipment: na tu re of t h e emergency equipment a v a i l a b l e ( p o r t a b l e f i r e e x t i n g u i s h e r s , axes , crow-bars, e l e c t r i c t o r c h e s , f i r s t - a i d k i t s , e t c . ) , measures taken by t h e crew i n o rde r t h a t it be qu ick ly a v a i l a b l e f o r u se a t t h e t i m e of t h e c r a s h ;

s p e c i a l i n s t r u c t i o n s given t o

aircraft: and t o move t h e c e n t r e of g r a v i t y as n e a r as p o s s i b l e t o i t s a f t l i m i t i f necessary ( f u e l j e t t i s o n i n g , dumping of m a t e r i a l , r e l o c a t i o n and proper s ecu r ing of t h e load i n t h e passengers ’ compartment, re-arrangement of t h e s e a t i n g p o s i t i o n of pas senge r s , e t c . ) ;

emerpency procedures: t r a i n i n g rece ived on knowledge and c o r r e c t imple- mentation of t h e s e procedures by t h e crew and e s p e c i a l l y by cab in a t t e n d a n t s , adequacy of t h e procedures l a i d down by t h e ope ra to r and of t h e a c t i o n s taken by t h e crew;

measures taken by t h e crew t o l i g h t e n t h e a i r c r a f t

h e l p from passenpers : l i s t any h e l p r eques t ed from, o f f e r e d o r g iven by passengers i n a r r ang ing f o r t h e necessary pre-crash a c t i o n s ( t a s k e n t r u s t e d t o each of t h e m and t h e way i t w a s c a r r i e d o u t ) , s t a t emen t on t h e behaviour and morale of t h e passengers p r i o r t o t h e c ra sh ;

I n case of d i t c h i n g t h e i n v e s t i g a t o r should a l s o examine t h e fo l lowing p o i n t s :

- l i f e j a c k e t s : s p e c i a l i n s t r u c t i o n s g iven t o t h e passengers r ega rd ing t h e l o c a t i o n of t h e l i f e jackets, how t o pu t them on and how t o use them, a c t i o n taken t o ensu re t h a t each passenger had h i s l i f e j a c k e t on, p rope r ly ad jus t ed and t o have e x t r a l i f e jackets r e a d i l y a v a i l a b l e n e a r emergency e x i t s ;

- l i f e - s a v i n g ra f t s : measures taken t o have t h e l i f e - s a v i n g r a f t s l o c a t e d n e a r emergency e x i t s w h e r e necessary ( i n d i c a t i o n of t h e i r s t o r a g e p o s i t i o n and r e - loca t ion on a plan of t h e a i r c r a f t would be an advantage) , s p e c i a l i n s t r u c t i o n s given t o the passengers r ega rd ing which, when and how t o board t h e r a f t s a f t e r t he d i t c h i n g .

16 /4 / 73 No. 3



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111-10-3 P a r t 111.- The I n v e s t i g a t i o n

10.2.3 Pos t -c rash a c t i o n s

The i n v e s t i g a t o r should , wherever p o s s i b l e , de te rmine t h e fo l lowing p o i n t s regard ing t h e evacua t ion of t h e a i r c r a f t a f te r t h e a c c i d e n t and c o n s i d e r , where a p p r o p r i a t e , t h e i r r e l a t i o n s h i p t o r e g u l a t o r y requi rements and t h e i r adequacy i n t h e l i g h t o.f expe r i ence :

emergency e x i t s : number, l o c a t i o n and des ign of emergency e x i t s , p re sence of p l a c a r d s nea r each of t h e s e c l e a r l y i n d i c a t i n g how t o open them, r e a d a b i l i t y of t h e s e p l a c a r d s (proper l o c a t i o n and l i g h t i n g ) , number and l o c a t i o n of e x i t s used ( i f some w e r e no t used , r easons f o r n o t be ing u s e d ) , number of persons which used each e x i t ( a p l a n of t h e a i r c r a f t i n d i c a t i n g t h e l o c a t i o n of each emergency e x i t , t h e l o c a t i o n of each crew member and passenger p r i o r t o t h e c r a s h and t h e exi t used by each person a f t e r t h e c r a s h would be of g r e a t a s s i s t a n c e ; a l s o , i f necessa ry , photographs of r e l e v a n t e x i t s ) ;

emergency equipment: e x t i n g u i s h e r s . axes, crow-bars, escape ropes and c h u t e s , e t c . ) , presence

n a t u r e of t h e emergency equipment used ( p o r t a b l e -

of a p p r o p r i a t e i n s t r u c t i o n s concerning t h e i r o p e r a t i o n , adequacy and f u n c t i o n i n g of t h e equipment, list of any a d d i t i o n a l equipment which would have been h e l p f u l ;

i n j u r i e s t o persons : i n j u r e d and of t h e i n j u r i e s s u s t a i n e d i n r e l a t i o n t o t h e i r l o c a t i o n ) , i n j u r i e s s u s t a i n e d du r ing t h e evacua t ion ( l i s t of pe r sons i n j u r e d and of t h e i n j u r i e s s u s t a i n e d i n r e l a t i o n t o t h e e x i t s and means used ) . Cross r e f e r e n c e t o t h e p l an mentioned i n a ) above should be made;

i n j u r i e s s u s t a i n e d du r ing t h e c r a s h ( l i s t of pe r sons

h e l p provided: h e l p provided t o t h e pas senge r s by t h e crew, o t h e r pas- s e n g e r s and t h i r d p a r t i e s (eyewi tness of t h e a c c i d e n t , r e s c u e t e a m , e t c . ) ;

evacua t ion t ime: t i m e a t which t h e evacua t ion s t a r t e d , t i m e necessa ry t o complete t h e evacua t ion ( d e t a i l e d by e x i t used i f r e l e v a n t ) ;

d i f f i c u l t i e s encountered du r ing t h e evacuat ion: f u r t h e r t o t h e p o i n t s mentioned under a ) o r b) above, l ist any d i f f i c u l t i e s encountered du r ing t h e evacua t ion such as language problems i n d i . r ec t ing passenge r s , p re sence of f i r e o r smoke i n t h e pas senge r s ' compartment, d e f i c i e n c i e s or f a i l u r e of t h e emergency l i g h t i n g system, abnormal p o s i t i o n of t h e a i r c r a f t , d i s t a n c e from t h e ground, evacua t ion of aged, i n f i r m o r i n f a n t pas senge r s as w e l l as passenge r s d i s a b l e d p r i o r t o t h e c r a s h o r i n j u r e d du r ing t h e c r a s h , s ta te of pan ic o f t h e pas senge r s , e t c . and s t a t emen t on how t h e s e d i f f i c u l t i e s a f f e c t e d t h e evacua t ion t ime.

I n c a s e of d i t c h i n g t h e i n v e s t i g a t o r should a l s o de te rmine t h e fo l lowing p o i n t s

a ) d i t c h i n g c o n d i t i o n s : s t a t emen t on t h e water c o n d i t i o n s a t t h e t i m e of d i t c h i n g ( roughness , t empera tu re , e t c . ) , and t h e l i g h t c o n d i t i o n s ( s u n l i g h t , moonl ight , t w i l i g h t , complete da rkness , e t c . ) ;



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b) l i f e j a c k e t s : type and number of l i f e jackets a v a i l a b l e compared t o t h e number of occupants aboard t h e a i r c r a f t , numbers of passengers who i n f l a t e d t h e i r l i f e j a c k e t before and a f t e r l eav ing t h e a i r c r a f t , e f f e c t i v e n e s s of t h e l i f e j a c k e t s i n t h e p r e v a i l i n g water c o n d i t i o n s , d i f f i c u l t i e s i n l o c a t i n g passengers i n t h e water due t o n o r - a v a i l a b i l i t y o r non-functioning o f l i g h t i n g dev ice (manual o r au tomat ic ) on l i f e j a c k e t s , any o t h e r d e f i c i e n c i e s of t h e l i f e j a c k e t used;

c ) l i f e - s a v i n g r a f t s : type used, l o c a t i o n i n t h e a i r c r a f t , t o t a l c a p a c i t y compared t o t h e number of occupants of t h e a i r c r a f t , d i f f i c u l t i e s , i f any, encountered i n launching, i n f l a t i n g , l o c a t i n g and boarding t h e r a f t s , number of occupants i n each r a f t compared t o i t s normal c a p a c i t y , avail- a b i l i t y aboard t h e l i f e - s a v i n g r a f t s of p rope r i n s t r u c t i o n s on how t o use them and t h e i r equipment, d e f i c i e n c i e s i n t h e l i f e r a f t s and t h e i r equipment (comfort , manual or au tomat ic l i g h t i n g , f l a r e s , r a d i o , e t c . ) , or i n t h e i r use .

10.3 Search Operations

The i n v e s t i g a t o r should determine how and when t h e sea rch ope ra t ions were i n i t i a t e d , what u n i t s o r agencies p a r t i c i p a t e d i n t h e sea rch as w e l l a s t h e means used aril!

methods adopted, t h e environmental cond i t ions a t t h e t i m e of t h e sea rch (weather, r e l i e f , ground or water cond i t ions ) and t h e t i m e a t which t h e a c c i d e n t s i t e w a s l oca t ed .

H e should determine whether t h e sea rch a c t i o n w a s adequate , and proper ; he should a l s o determine i f t h e r e l e v a n t procedures were followed and whether t h e s p e c i f i e d procedures were adequate and proper .

10.4 Rescue Operations

The i n v e s t i g a t o r should determine how and when t h e r e scue ope ra t ions were i n i t i a t e d , what u n i t s o r agencies p a r t i c i p a t e d i n t h e r e scue as w e l l a s t h e means and methods’used, t h e environmental cond i t ions a t t h e t i m e of r e scue and t h e t iming of t h e s e ope ra t ions . The v a r i o u s p o i n t s t o be examined w i l l obvious ly d i f f e r accord ing t o t h e l o c a t i o n of t h e acc iden t s i t e ( i n t h e v i c i n i t y of t h e take-off or l and ing aerodrome, e n rou te : land o r s e a ) . be examined, from which h e should choose those a p p l i c a b l e t o t h e a c c i d e n t he h a s t o i n v e s t i g a t e :

The i n v e s t i g a t o r w i l l f i n d hereunder a list of t h e main p o i n t s t o

a ) t i m e a t which t h e r e scue u n i t s were advised of t h e emergency o r of t h e acc iden t and by what means (alarm b e l l , t e l ephone , radio-telephony) ;

b) f i r s t i n s t r u c t i o n s given t o t h e s e u n i t s and how;

c ) number of v e h i c l e s by type (ambulances, h e l i c o p t e r s , a i r - cush ion v e h i c l e s , boats) on stand-by and i n r e s e r v e , t h e i r equipment ( t o o l s , e x t i n g u i s h e r s , oxygen supply , s t r e t c h e r , medical supply, e t c . ) and manpower;

d ) l o c a t i o n of t h e rescue u n i t s (stand-by and reserve);

e) a v a i l a b i l i t y of c r a s h p a n e l s and a c c e s s roads in t h e pe r ime te r of t h e aerodrome and of access roads a long t h e take-off or approach pa ths , cond i t ions of t h e c rash pane l s and of t h e access roads , if used;



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envi ronmenta l c o n d i t i o n s (weather , t e r r a i n r e l i e f , ground o r water cond i t i o n s ) ;

a v a i l a b i l i t y of radio- te lephony communications aboard the v a r i o u s v e h i c l e s t o d i r e c t and Co-ordinate t h e i r a c t i o n ;

t î m e a t which t h e f i r s t rescue u n i t s and t h e o t h e r r e s c u e u n i t s a r r i v e d a t t h e si te of t h e a c c i d e n t ;

d i f f i c u l t i e s encountered i n l o c a t i n g t h e s i te of t h e a c c i d e n t and t h e wreckage, reaching and breaking i n t h e wreckage, b r i n g i n g t h e i n j u r e d out of t h e wreckage;

f i r s t medica l a s s i s t a n c e provided t o t h e i n j u r e d a t t h e s i t e of t h e a c c i d e n t , adequacy of t h e means and personnel a v a i l a b l e ;

permanent or ad hoc arrangements made t o t r a n s p o r t t h e i n j u r e d t o t h e n e a r e s t h o s p i t a l ( s ) , adequacy of t hese a r rangements , of t h e means of t r a n s p o r t a t i o n and of t h e accommodation and medica l services a v a i l a b l e a t t h e h o s p i t a l ( s ) ;

t i m e a t which t h e r e scue ope ra t ions were completed.

10.5 F i r a F ight ing Opera t ions

The i n v e s t i g a t o r should de te rmine where and how t h e f i r e s t a r t e d , t h e pa th and spread of t h e f i r e , and i f p o s s i b l e , t h e combust ible materiais and smoke gene ra to r s . In t h i s con tex t he should a l s o cons ide r which e x i t s were a c t i v a t e d . H e should determine how and when t h e f i r e f i g h t i n g o p e r a t i o n s were i n i t i a t e ó , what u n i t s p a r t i c i p a t e d i n t h e s e ope ra t ions , reviewing s e p a r a t e l y t h e aerodrome f Ire f i g h r i n g s e r u T i c e s and e x t e r n a l f i r e f i g h t i n g s e r v i c e s a s w e l l as t h e means and methods used, t h e envi ronmenta l cond i t ions a t t h e time and t h e t iming of t h e f i r e f i g h t i n g . p o i n t s , g iv ing p a , r t i c u l a r emphasis t o t h e t i m e element when t h e a c c i d e n t occurs i n t h e conf ines o r immediate v i c i n i t y of t h e aerodrome:

The i n v e s t i g a t o r should examine t h e fo l lowing

t i m e a t which t h e v a r i o u s f i r e f i g h t i n g u n i t s were adv i sed of t h e evr - gency o r of t h e a c c i d e n t , and by what means (a la rm b e l l , t e lephone , rad io- t e le phony ) ;

f i r s t i n s t r u c t i o n s g iven t o t h e s e u n i t s and how;

number of v e h i c l e s by type ( f i r e t r u c k s , h e l i c o p t e r s . a i r - cush ion v e h i c l e s , b o a t s , e t c . ) on stand-by and i n reserve, t h e i r equipment ( ex t ingu i sh ing agen t s : t ype , q u a n t i t y , rate of d i scha rge ; s p e c i a l t o o l s , axes, crow-bars, powered t o o l s , etc.) and pe r sonne l a v a i l a b l e on each vehicle and their equip ment ( f i r e f i g h t i n g s u i t and he lmet , oxygen supp ly , e tc . ) ;

l o c a t i o n of t h e v a r i o u s f i r e f i g h t i n g u n i t s (stand-by and r e s e r v e ) which p a r t i c i p a t e d ;

a v a i l a b i l i t y of c r a s h p a n e l s and access roads i n t h e pe r ime te r of t h e aerodrome and of access roads a long t h e take-off o r approach p a t h s , c o n d i t i o n s of t h e c r a s h p a n e l s and access roads , i f used;



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I I I- 10- 6 Manual of A i r c r a f t Accident I n v e s t i g a t i o n

way t h e i n v e s t i g a t o r should determine :

environmental cond i t ions (weather, t e r r a i n r e l i e f , ground o r water cond i t i ons ) ;

prov i s ion of radio-telephony communications aboard t h e v a r i o u s v e h i c l e s t o d i r e c t and Co-ordinate t h e i r a c t i o n and, where ava , i l ab le , communication r eco rd ings ;

t i m e a t which t h e f i r s t f i r e f i g h t i n g v e h i c l e and t h e ot.her v e h i c l e s a r r i v e d a t t h e s i te of t he a c c i d e n t ;

d i f f i c u l t i e s encountered i n l o c a t i n g t h e s i t e of t h e a c c i d e n t and reach- ' i n g t h e wreckage, inc luding t h e l a c k of d e t a i l e d c h a r t s of t h e area f o r l o c a t i o n of and a c c e s s t o t h e s i te , p u t t i n g i n t o a c t i o n t h e f i r e f i g h t i n g equipment and c o n t r o l l i n g t h e f i r e ( l a c k of p rope r ly t r a i n e d pe r sonne l ) , i n t e n s i t y of t h e f i r e , wind d i r e c t i o n and s t r e n g t h , t empera ture , a v a i l - a b i l i t y of water supply nea r t h e s i t e of t h e a c c i d e n t ;

t i m e a t which t h e f i r e was under c o n t r o l and completely ex t ingu i shed ;

p recau t iona ry measures: measures taken t o prevent a sp read ing of t h e f i r e ( t r enches , c u t t i n g of trees, e t c . ) and a p o s s i b l e a c c i d e n t a l re-stnrt- ing of t h e f i r e , evacuat ion of a d j a c e n t houses o r b u i l d i n g s , e t c .

case of an emergency r e q u i r i n g t h e sp read ing of a foam c a r p e t on t h e run-

t i m e a t which t h e aerodrome f i r e f i g h t i n g u n i t s w e r e adv i sed of t h e e m e r - gency and by what means;

f i r s t i n s t r u c t i o n s given t o these u n i t s and how;

number of f i r e t r u c k s p a r t i c i p a t i n g i n t h e sp read ing , c a p a c i t y and rate of d i scha rge of each t ruck ;

a v a i l a b i l i t y of radio-telephony communications between t h e s e t r u c k s and t h e a i r t r a f f i c c o n t r o l tower, and, where a v a i l a b l e , communication record ing;

t i m e a t which t h e spreading on t h e runway w a s s t a r t e d and ended;

s i z e of t h e foam c a r p e t ( l eng th , w id th , t h i c k n e s s ) and l o c a t i o n on runway ( d i s t a n c e from t h e runway t h r e s h o l d , p o s i t i o n i n r e l a t i o n t o runway c e n t r e l i n e ) ;

d i f f i c u l t i e s encountered du r ing t h e sp read ing ( l a c k of t r a i n e d pe r sonne l , material, wind, e t c . ) ;

adequacy of t h e markings of t h e beginning and wid th of t h e foam c a r p e t accord ing t o t h e v i s i b i l i t y cond i t ions .



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PART I I I

CHAPTER 11. - INVESTIGATION OF EXPLOSIVES SABOTAGE

18/9 /78 No. 9



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P a r t III.- The I n v e s t i g a t i o n 111-11-1 -

CHAPTER 11

INVESTIGATION OF EXPLOSIVES SABOTAGE

11.1 General

So f a r as it i s known, l ook ing over t h e world p i c t u r e between 1946-1976, 4 1 a f r c r a f t have been damaged o r des t royed by t h e de tona t ion of an e x p l o s i v e dev ice w i t h h t h e a i r c r a f t . This f i g u r e does no t i nc lude known h i j a c k i n c i d e n t s o r t h e shoo t ing down of a i r c r a f t i n m i l i t a r y o r p a r a - m i l i t a r y a c t i v i t i e s . Ne i the r does it i n c l u d e unconfirmed c a s e s nor a i r c r a f t mi s s ing i n s u s p i c i o u s c i rcumstances . regarded a s conse rva t ive . Of t h e 4 1 a i r c r a f t des t royed o r damaged, 16 were p i s t o n engined and 25 were t u r b i n e engined t y p e s . I n a l l t h e s e i n s t a n c e s 2 1 a i r c r a f t were t o t a l l y des t royed and 785 passengers and crew l o s t t h e i r l i v e s . i n v a r i o u s p a r t s of t h e world cove r ing some 24 c o u n t r i e s and a f f e c t i n g 26 a i r l ines . Some 2 1 d i f f e r e n t t ypes of a i r c r a f t were involved .

The f i g u r e can be

The d i s a s t e r s occur red

Over t h e p a s t decade s c i e n t i s t s a t RARDE have c o l l a b o r a t e d wi th B r i t i s h and f o r e i g n a v i a t i o n i n v e s t i g a t i o n a u t h o r i t i e s t o de te rmine whether d e t o n a t i o n of an exp los ives charge occurred aboard a i r c r a f t which had crashed under mys te r ious circum- s t ances . and i n s c i e n t i f i c evidence deduced wi th t h e a i d of v a r i o u s a n a l y t i c a l t echn iques . The fo l lowing i s a review of t h e main t echn iques used. I n p a r t i c u l a r me ta l log raph ic and scanning e l e c t r o n microscopic ev idence is p resen ted on s e v e r a l f e a t u r e s a s s o c i a t e d w i t h exp los ive damage. w i t h r e s p e c t t o t h e s t r e n g t h of ev idence . Forens ic evidence is o u t l i n e d i n r e l a t i o n to the v a r i o u s non-metal l ic m a t e r i a l s l i k e l y t o be encountered and t h e methods of p h y s i c a l o r chemical examinat ion employed. Caut ion i s s t r e s s e d wi th r e s p e c t t o t h e i n t e r p r e t a t i o n of shredded f a b r i c s a s p o s s i b l y i n d i c a t i n g s i g n i f i c a n t ev idence of e x p l o s i v e e v e n t s i n a i r c r a f t i n f l i g h t by comparison w i t h o t h e r exp los ion expe r i ences . Leve l s of exp los ive d e t e c t i o n a r e i n d i c a t e d f o r t h e v a r i o u s chromatographic techniques a v a i l a b l e p r e s e n t l y t o t h e a n a l y s t . Major e v i d e n t i a l v a l u e t o be de r ived from radiography of bo th bod ies and baggage f o r embedded fragments of m e t a l i s h i g h l i g h t e d .

Cons iderable e x p e r t i s e h a s been accumulated i n t h e method of s e a r c h i n g d e b r i s

Although only desc r ibed i n b r i e f t h e s e v e r a l f e a t u r e s are d i scussed

11 .2 I n v e s t i g a t o r ' s Evidence

11 .2 .1 Material: ev idence a t t h e scene

The t e c h n i c a l i n v e s t i g a t i o n by s p e c i a l i s t s a t t h e s i t e of t h e a c c i d e n t is of t h e utmost importance. It is under t h e s e c i rcumstances t h a t t h e knowledge and exper ience of t h e i n v e s t i g a t o r is i n v a l u a b l e , p a r t i c u l a r l y i f e x p l o s i v e sabo tage is suspec ted , f o r it is a t t h i s s t a g e t h a t maximum material ev idence is t o b e i s o l a t e d and r e t a i n e d f o r subsequent l a b o r a t o r y examinat ion.

When faced w i t h more than 50 tonnes of d i s i n t e g r a t e d and p o s s i b l y bu rn t wreckage, probably spread over many m i l e s of d e s o l a t e coun t rys ide , o r sa lvaged piecemeal a s s m a l l amounts of f l o t sam, t h e ev idence w i l l be any th ing but c l e a r du r ing t h e e a r l y s t a g e s of i n v e s t i g a t i o n as t o t h e p robab le cause of t h e a c c i d e n t . The i n v e s t i g a t o r must proceed c a r e f u l l y , wi th an open mind, b e f o r e r each ing a conclus ion t h a t r e p o r t s of an ' exp los ion ' having been wi tnessed o r heard have no connec t ion wi th a major mulfunct ion of t h e a i r c r a f t systems or i ts power p l a n t s . speed t u r b i n e d i s c can produce a loud exp los ion - l ike noise .

For i n s t a n c e , t h e d i s i n t e g r a t i o n of a h igh

18/6 /78 No. 9 Copyright International Civil Aviation Organization


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111-11-2 Manual of Aircraft Accident I n v e s t i g a t i o n

Shrapnel-type p ieces of metal can sometimes p e n e t r a t e t h e wings o r f u s e l a g e , p o s s i b l y caus ing a f i r e t he r e s u l t of which i n t o t a l might be sugges t ive of an explos ion having occurred. d i f f e r e n c e s between t h i s type of damage and t h a t produced by t h e de tona t ion of an exp los ive substance.

To t h e experienced eye d e t a i l e d examinat ion w i l l show cons ide rab le

The s t r u c t u r a l break up of an a i r c r a f t in h igh speed f l i g h t caused by o v e r s t r e s s i n g o r f a t i g u e w i l l o f t e n be r epor t ed by witnesses as an ’explosion’ and t h e n o i s e , smoke o r f u e l vapour w i l l tend t o convince them.

A l i g h t n i n g s t r i k e can a l s o on r a r e occas ions create l o c a l exp los ive type damage, p a r t i c u l a r l y i f t h e a i r c r a f t ’ s s t r u c t u r a l e l e c t r i c a l bonding is f a u l t y . such l i g h t n i n g s t r i k e s w i l l no t cause ex tens ive o r c a t a s t r o p i c damage but f i r e and low p r e s s u r e explos ion of f u e l tanks is a p o s s i b i l i t y i f low f l a s h po in t f u e l i s i n u s e and vented nea r t h e wing t i p s , a f a v o u r i t e p l a c e f o r l i g h t n i n g s t r i k e s . o f e l e c t r i c a l d i scha rge , e n t r y o r e x i t , on t h e a i r c r a f t s t r u c t u r e should normally b e apparent a t t h e a i r c r a f t ex t r emi t i e s .

Normally

Support ing ev idence

I f t h e wreckage is a v a i l a b l e f o r i n spec t ion t h e m a t e r i a l evidence of a d e l i b e r a t e l y p l an ted and detonated explos ive dev ice w i l l r e v e a l d i s t i n c t i v e cha rac t e r - i s t i c s o r s i g n a t u r e s .

Detonat ion of a modern h igh explos ive can create p a r t i c l e v e l o c i t i e s i n excess , a t l e a s t i n i t i a l l y of 7 x 10 3 m sec-’ which g ive r ise , i f s u f f i c i e n t l y l a r g e , t o deep p e n e t r a t i o n s of s t r u c t u r a l components and even when ve ry s m a l l can deeply p e n e t r a t e s o f t m a t e r i a l s such as s e a t cushions and human bodies . N o f a i l u r e of any system o r power p l a n t i n t h e a i r c r a f t can a c c e l e r a t e small p a r t i c l e s t o such v e l o c i t i e s . Scorching, blackening, p i t t i n g , i .e. small c r a t e r s i n metal s u r f a c e s , or high v e l o c i t y c u t t i n g of s o f t m a t e r i a l s may a l l be presen t and a r e i n d i c a t i v e of ve ry unusual c i rcumstances.

The b l a s t i t s e l f , which may be i n an a r e a f r e e from any ope ra t ing mechanism or pres su r i zed system which could poss ib ly cause such a b l a s t , is obviously a p o i n t e r i n i t s e l f . T ra j ec to ry p l o t t i n g by rods , s t r i n g o r w i r e can sometimes assist i n t h e l o c a t i o n of t h e o r i g i n of de tona t ion . Quite o f t e n , by s u s t a i n e d and d i l i g e n t s ea rch f o r small d e t a i l s , p i eces of a de tona to r o r t iming device may be found jarmned i n t o a p i ece of s t r u c t u r e , fu rn i sh ing , s u i t c a s e , f r e i g h t o r a body. Such ev idence , however small, is v i t a l and may prove conclusive. Inspec t ion of bodies , c l o t h i n g and s u i t c a s e s is important and any f e a t u r e which sugges t s b l a s t , such as shredding , hea t o r melted p l a s t i c f i b r e s is important and should be r e t a i n e d f o r examinat ion.

Such evidence when subjec ted t o t h e l a t e s t t echniques i n t h e chemical l a b o r a t a r y may provide a c l u e t o t h e type of exp los ive used. Any m a t e r i a l , m e t a l l i c or otherwise , which appears unusual and u n i d e n t i f i e d wi th any p a r t of t h e a i r c r a f t should be preserved f o r f u r t h e r i n v e s t i g a t i o n , f o r t iming dev ices are a l s o i n f i n i t e i n des ign and appearance. Maximum s e c u r i t y of a l l specimens must be exe rc i zed a t a l l t i m e s .

11 .2 .2 F l i g h t d a t a recorder (FDR)

The ma jo r i ty of commercial pub l i c t r a n s p o r t ô i r c r a f t now c a r r y f l i g h t - d a t a and cockpi t vo ice recorders . is su rv ivab le even a g a i n s t s eve re impact, f i r e and l i q u i d s .

The d a t a r eco rde r is designed and i n s t a l l e d such t h a t i t



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111-11-3 P a r t III.- The I n v e s t i g a t i o n

The FDR w i l l reveal t o subsequent e x p e r t examinat ion the, immediate circum- s t a n c e s p r i o r t o t h e d i s a s t e r which may h e l p t o e l i m i n a t e a number of p o s s i b l e causes , i t w i l l n o t i n d i c a t e s p e c i f i c a l l y t h a t an exp los ion aboard t h e a i r c r a f t had occurred . For t h e informat ion s t o r e d i n t h e FDR t o be of v a l u e t h e c h i e f a c c i d e n t i n v e s t i g a t o r w i l l make recovery of t h e FDR one of h i s primary o b j e c t i v e s and f o r i t s taped d a t a t o be made a v a i l a b l e as soon as p o s s i b l e .

Reproduct ion of an a c u t a l FDR r eco rd wi th a l l its s imul taneous r ead ings is not p r a c t i c a b l e w i t h i n t h e c o n f i n e s of a s i n g l e page f o r a number of reasons . e x t r a c t s of t h e c r i t i c a l t r a c e s from t h e Cathay P a c i f i c Airways Convair 880 c r a s h of 15 June 1972 are reproduced i n F i g u r e 11-1 t o i l l u s t r a t e t h e s p i k e s recorded ( r i n g e d ) , and subsequent ly cons idered t o be i n d i c a t i v e of a d e t o n a t i o n on board t h i s a i r c r a f t , f o r t h e ' g ' and ' speed ' changes. The t r a c e s f o r heading , p i t c h and a l t i t u d e a l s o show s i m i l a r sudden changes of a t t i t u d e .

However,

The ab rup t c e s s a t i o n of t h e d a t e r e c o r d e r , sometimes accompanied by a s h o r t and wild d i v e r s i o n of t h e traces, is n e a r l y always due t o t h e c u t t i n g o f f of power by r u p t u r i n g of t h e e l e c t r i c a l supply cab le s . Such a r u p t u r e may be caused by a i r f r ame s t r u c t u r a l f a i l u r e or t h e d e t o n a t i o n of an exp los ive device . a c c e l e r a t i o n t r a c e , p o s i t i v e or n e g a t i v e t o t h e normal, has been observed a t t h e moment of cut-off on occas ions when an i n t e r n a l explos ion h a s been e s t a b l i s h e d . Th i s s p i k e is ve ry d i f f e r e n t i n c h a r a c t e r and t iming from t h a t a s s o c i a t e d wi th f l i g h t t u rbu lence and is probably caused by ve ry r a p i d v i b r a t i o n of t h e ' g ' t r ansduce r which is normally mounted on t h e a i r f r ame s t r u c t u r e c l o s e t o t h e c e n t r e of g r a v i t y of t h e a i r c r a f t (F igure 11-1). The p o s i t i o n of t h i s abnormal s p i k e a long t h e r eco rd ing f o i l or t ape w i l l g ive t h e p r e c i s e t i m e of t h e occurrence and, wi th o t h e r parameters such a s h e i g h t , speed, heading, p i t c h , e t c . w i l l be o f g r e a t a s s i s t a n c e t o t h e i n v e s t i g a t o r s i n t h e process of a s s e s s i n g o t h e r a s p e c t s .

A sha rp s p i k e on t h e ' g '

11.2.3 Cockpit vo ice r e c o r d e r (CVR)

On r a r e occas ions t h e CVR o p e r a t i n g from a number o f microphones on t h e f l i g h t deck, has g iven a c l u e t o t h e e v e n t s t h a t occur red immediately be fo re t h e i n c i d e n t , f o r example, remarks by t h e crew o r a mi l l i - second n o i s e swamping t h e r eco rd ing equipment a s a r e s u l t of t h e shock-wave f r c a d e t o n a t i o n of an e x p l o s i v e s device . Area microphones may a l s o p ick up f l i g h t deck a u r a l warnings such a s horns , b e l l s , e t c . which can be i d e n t i f i e d as a s s o c i a t e d wi th sudden l o s s of c a b i n p r e s s u r e , engine f i r e and o t h e r f a i l u r e s .

Smoke and t o x i c fumes from f i r e s can prove d i s a s t r o u s and recorded vo ices

When p re l imina ry i n v e s t i g a t i o n suppor t s t h e opin ion t h a t e 6 l o - of t h e crew on such occas ions can provide important c l u e s a s t o t h e u l t i m a t e cause of f i n a l l o s s of c o n t r o l . s i v e s sabotage was involved t h e read-out and a n a l y s i s of bo th d a t a an CVR r e c o r d e r s must always be undertaken by e x p e r t s , p r e f e r a b l y those exper ienced i n examining r eco rde r t r a c e s from previous c a s e s of e x p l o s i v e s sabotage i n a i r c r a f t .

11.2.4 Surface c h a r a c t e r i s t i c s of i n t e r e s t

F r a c t u r e s of meta l caused by an exp los ive event are normally d i f f e r e n t i n S h a t t e r i n g of metal c h a r a c t e r t o those caused by o v e r s t r e s s i n g o r c r a s h impact f o r c e s .

i n t o ve ry s m a l l and numerous fragments and minute deep p e n e t r a t i o n of a meta l s u r f a c e a r e no t c h a r a c t e r i s t i c s u s u a l l y found i n a i r c r a f t acc iden t wreckage. The s i z e and c h a r a c t e r i s t i c s of t h e s e p a r t i c l e s o f t e n accompanied by r o l l e d edges, s u r f a c e s p a l l i n g , p i t t i n g or evidence of h e a t is of importance whereas a f r a c t u r e d s u r f a c e may n o t i n i t s e l f p rovide conc lus ive ev idence of a n explos ion . A l l s u s p i c i o u s p a r t i c l e s should be preserved and i d e n t i f i e d f o r subsequent l a b o r a t o r y examinat ion.

18 / 6 / 78 No. 9



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I f a v i o l e n t explosion occurs wi th in an a i r c r a f t i n f l i g h t then t h e mode of break-up of t h e a i r c r a f t i t s e l f and i t s sequence of f a i l u r e w i l l u s u a l l y be very cornPl i c a t e d and q u i t e without l o g i c from a normal aerodynamic o v e r s t r e s s i n g s t andpo in t . f infore any thoughts of explos ive sabotage are propounded t h e s t r u c t u r e of t h e a i r c r a f t and i t s engines; must, of course, be e l imina ted as t h e p o s s i b l e caiise of any damage t o t h e s t r u c t u r a l p a r t s aiiti f a b r i c s .

11.7.5 &Ktp??-Y-_and c ?ii2g?2@!!c examinat i o n

Once the inves t iga to l , has obta ined m a t e r i a l evidefice i n support of an cxplosion having taken pI.ace every e f f o r t must be made immediately t o have as many of t h e dead and i n j u r e d as arc3 av -a i l ab le , X-rayed and submit ted f o r l i m i t e d pathology f o r z t ; ~ eictrnct'ion of any bur ied partic:I.es. y t h d o g i s t s and/or coroner n u s t be maintaincd Eroni t he s ta r t and t h e purpose f o r t h i s ~1 ose lii-iison explained. Tb,ic a l s o i!ften involves cu-operat ion wi t ! ? l e g a l and po l i ces a u t h o r i t i e s . Diplomacy and tact i s very necessary a t t h i s s t a g e . I L i s d e s i r a b l e , i f p a s s i b l e , f o r tlis p a t h o l o g i s t tii a s s i s t or lie p re sen t d u r i n g rad iographic examination ,;f. t!ie v i c t i m s . :'hotography, p r e f e r a b l y i n c o l o u r , i s a l so v e r y h e l p f u l t o l a t e r d e t a i l e d s tudy.

Close col . laborat ion wi th t h e medical team,

Pa thologica l examination f o r b l a s t e f f e c t un the eardrums, lung damage due t o overpressure , unusual o r gr^:;^ t raumat ic i n j u r i e s n o t normally a s s o c i a t e d w i t h an a i r c r a f t c r a s h impact, examination of s k i n t i s s u e f o r ho t p e n e t r a t i o n , f l a s h bu rns , 'peppering ' e t c . can be of g r e a t a s s i s t a n c e .

Any e x t r a c t e d p a r t i c l e s , however s m a l l , should be c a r e f u l l y preserved i n the unwashed c o n d i t i o n , f o r f u t u r e l a b o r a t o r y examination. It is perhaps n o t r e a d i l y apprec ia ted t h a t l i q u i d s used t o prevent p u t r i f i c a t i o n of m e t a l i t e m s e x t r a c t e d from bod ies , p a r t i c u l a r l y t h e formaldehyde based p r e s e r v a t i v e , can cause e x c e s s i v e s u r f a c e c o r r o s i o n during s t o r a g e and t r a n s p o r t a t i o n , wi th consequent l o s s of p o s s i b l y v a l u a b l e topographica l f e a t u r e s . S u r g i c a l s p i r i t would be a more a c c e p t a b l e medium f o r t h i s purpose. Care should a l s o be taken t o avoid undue handl ing of par t ic les wi th f o r c e p s and o t h e r hard materials which could a l s o o b l i t e r a t e sur£ace markings.

It may w e l l be t h a t no explos ive evidence is produced dur ing t h e au topsy examination due t o t h e l o c a t i o n of t h e explos ive device and t h e s h i e l d i n g e f f e c t of t h e a i r c r a f t s t r u c t u r e . However, the importance of X-ray and au topsy i n t h e e a r l y s t a g e s cannot be overemphasized when i n v e s t i g a t i n g a suspected e x p l o s i v e sabotage i n c i d e n t . The evidence obta ined from a body, however s m a l l , when s u b j e c t e d t o experienced f o r e n s i c l a b o r a t o r y , m e t a l l u r g i c a l and chemical a n a l y s i s , can be conclus ive .

11.2.6 I d e n t i f i c a t i o n of i t e m s

When c o l l e c t i n g i t e m s of p o t e n t i a l s c i e n t i f i c i n t e r e s t i t must be remembered t h a t s i m i l a r i t e m s found i n c l o s e proximity, but which do n o t e x h i b i t t h e s e c h a r a c t e r - i s t ics , should be included as c o n t r o l i t e m s f o r s c i e n t i f i c comparison. p a r t i c u l a r l y t o f a b r i c s , w i r e s , i t e m s of luggage and c l o t h i n g . f o r a f o r e n s i c s c i e n t i s t t o be a v a i l a b l e a t t h e scene t o h e l p i d e n t i f y those items of explos ive in te res t , o r t o t ake s o l v e n t swabbings of i n t e r e s t i n g s u r f a c e s f o r traces of undecomposed exp los ives , t h e i n v e s t i g a t i n g o f f i c e r should i n c l u d e c o n t r o l s of cotton-wool, s o l v e n t and a l l o t h e r i t e m s so used, proper ly l a b e l l e d and s e a l e d i n nylon bags.

This a p p l i e s Should i t be impossible

It may happen t h a t c r i m i n a l proceedings are l a t e r i n i t i a t e d , based on s c i e n t i f i c evidence of explos ives r e s u l t i n g from l a b o r a t o r y examinat ion, and t h a t evidence of c o n t i n u i t y must be e s t a b l i s h e d i n a Court of Law. s t a g e i n v e s t i g a t i n g o f f i c e r s should be most p a r t i c u l a r about r e c o r d s of o r i g i n , cus tody and handing over of items f o r f o r e n s i c examination and t o ensure t h a t adequate documen- t a t i o n and s i g n a t u r e s a r e obta ined a t a l l s t a g e s of t r a n s f e r .

To avoid d i f f i c u l t i e s a t a l a t e r



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11.3 M e t a l l u r g i c a l Evidence

11.3.1 General

Exp los ives f u n c t i o n by chemica l ly decomposing a t a rate much f a s t e r t han t h e speed of sound and are c h a r a c t e r i z e d by a r e a c t i o n f r o n t which proceeds gas a t a very h igh t empera tu re and p res su re . Th i s ex t remely h igh ra te p rocess , known as d e t o n a t i o n , l i b e r a t e s l a r g e amounts of energy a s s o c i a t e d wi th t h e r e a c t i o n f r o n t . A t y p i c a l detona- t i o n rate f o r m i l i t a r y h igh e x p l o s i v e s is 7 x 1 0 3 m sec-' and a p r e s s u r e of 3 x lo5 atmosphere both of which a r e l a r g e . a r i s e from a i r c r a f t a c c i d e n t s , f o r example a f u e l / a i r explos ion where t y p i c a l over- p re s su res are 2 x 101 atmosphere bu t e x c e p t i o n a l l y could be as h igh as 2 x l o 2 atmospheres, o r ground impact v e l o c i t i e s i n t h e range of 50-200 m sec-' w i th a p robab le supe r son ic maximum of about 500 m sec-1. p e r i p h e r a l v e l o c i t y of a t u r b i n e b l a d e , should i t break up under take-off l o a d , of about 450 m sec-l f o r a Boeing 747 j e t low p r e s s u r e f an . of high e x p l o s i v e s produces most v i o l e n t and r a p i d p rocesses which r e s u l t i n a number of s i g n a t u r e s imparted t o metals which can be p o s i t i v e l y i d e n t i f i e d by t h e a p p r o p r i a t e examination.

I n comparison t o o t h e r f a s t p r o c e s s e s which could

These v a l u e s must a l s o be compared wi th t h e maximum

Thus i t can be seen t h a t d e t o n a t i o n

When a d e t o n a t i o n occur s one or more of t h e fo l lowing f e a t u r e s may be observed,

a ) t h e c r e a t i o n of many s m a l l f ragments from t h e bomb cas ing .

b) deformat ion a t h igh rates of s t r a i n of m a t e r i a l s a d j a c e n t t o t h e d e t o n a t i o n source.

c ) t h e format ion of d i s t i n c t i v e s u r f a c e e f f e c t s such as p i t t i n g and/or gas washing, and

d ) t h2 format ion of c h a r a c t e r i s t i c f r a c t u r e p a t t e r n s .

l i . 3 . 2 Fragments

An e x p l o s i v e dev ice need no t be con ta ined wi th in a r i g i d m e t a l l i c c o n t a i n e r

I n g e n e r a l , i n o r d e r t o be e f f e c t i v e b u t , should t h i s be so then t h e expanding h o t gases r u p t u r e t h e rclsing p r o j e c t i n g t h e f ragments outwards a s i t were from a p o i n t source. t h e h igher t h e v e l o c i t y of d e t o n a t i o n t h e smaller w i l l be t h e f ragments formed. These fragments w i l l r e c e i v e l i t t l e f u r t h e r d i s t o r t i o n i f t hey a r e d e c e l e r a t e d r e l a t i v e l y s lowly, f o r example, by catchment i n s o f t cush ions , human bod ies o r s u i t c a s e s . i n p a s t i n v e s t i g a t i o n s a l l t h r e e s o u r c e s have proved t o be v a l u a b l e sou rces of in format ion (Bedford, 1976 and Clancey, 1968). caused by subsequent impact w i th wood o r p l a s t i c s laminated s u r f a c e s o r even metal.

Indeed,

T o t a l l o s s of d e t o n a t i o n c h a r a c t e r i s t i c is r a r e l y

The fragment, when found, is commonly l o c a t e d a t t h e bottom of a char red

The f ragments are o f t e n hot enough on impact t o m e l t t h e c a v i t y , p a r t i c u l a r l y w i t h polyure thane foam from cushion seats, and is an i n d i c a t i o n of t h e h igh v e l o c i t y of impact. sur rounding p l a s t i c s material as ev idenced i n F igu re 11-2 found d u r i n g t h e Comet inves- t i g a t i o n , (Clancey, 1968a, 1968b).

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11 .3 .3 Surface c h a r a c t e r i s t i c s of fragments

A v a r i e t y of f e a t u r e s have been observed on fragments from both l a b o r a t o r y c o n t r o l l e d explos ions and from i t e m s recovered from a i r c r a f t a c c i d e n t s . A very u s e f u l compi la t ion of s u r f a c e c h a r a c t e r i s t i c s is given i n a p u b l i c a t i o n (Tard i f f end S te r l i -ng , 1967) which i l l u s t r a t e s some of a number of va r ious s u r f a c e c h a r a c t e r i s t i c s which have been reproduced on mild s t ee l and aluminium i n c o n t a c t w i th n i t roglycer ine-based commercial b l a s t i n g explos ive , o r m i l i t a r y p l a s t i c (RDX) explos ive . Micro f e a t u r e s which have been observed are r o l l e d edges, gas-wash, s u r f a c e p i t t i n g and r o l l e d edges which are more commonly encountered.

11.3.4 Gas-wash

The e f f e c t is one of mel t ing and e r o s i o n of t h e m e t a l s u r f a c e by ho t de tona t ion gases , most f r equen t ly observed on t h e inne r s u r f a c e s of gun b a r r e l s a f t e r excess ive f i r i n g , hence i t is w e l l documented and understood. F igure 11-3 shows t h e su r face of a fragment from t h e Comet f lo t sam which e x h i b i t s t h i s f e a t u r e w h i l s t F igure 11-4 shows a s i m i l a r e f f e c t a f t e r de tona t ion of RDX conta ined i n an aluminium tube.

11.3.5 Surface p i t t i n g

This f e a t u r e , i l l u s t r a t e d i n F igure 11-5, can be observed on fragment s u r f a c e s c l o s e l y a s soc ia t ed with t h e po in t of de tona t ion , it has a l s o been observed on fragments from t h e Comet and from t h e Middle E a s t A i r l i n e s Boeing 720B acc iden t (Higgs and o the r s , 1976). In t h i s la t ter case RDX w a s confirmed a s p re sen t on some of t h e c o n t e n t s of t h e baggage hold. It i s thought t h a t t h e p i t s a r e caused by t h e impingement of high v e l o c i t y p a r t i c l e s of p a r t i a l l y combusted exp los ive and/or fused ex t raneous matter encountered between t h e explos ive charge and t h e 'w i tnes s ' material. A commercial n i t rog lycer ine-based b l a s t i n g explos ive and RDX r e s p e c t i v e l y were de tona ted i n aluminium tubes under con t ro l l ed cond i t ions and i t was observed t h a t on ly t h e fragments from t h e RDX showed p i t t i n g .

11.3.6 Rolled edges

This is a f r a c t u r e f e a t u r e a s s o c i a t e d wi th t h e formation of t h e fragment shown i n Figure 11-6 der ived from t h e Cubana DC8 acc iden t (Higgs ans o t h e r s , 1977) and should be compared with s i m i l a r f e a t u r e s produced exper imenta l ly as shown i n F igure 11-7 from the de tona t ion of a 2-oz charge of c o m e r c i a l b l a s t i n g exp los ive s t rapped t o a 1 . 5 v o l t zinc-cased dry c e l l . This f e a t u r e is known only t o r e s u l t from d e t o n a t i v e processes and is considered t o be t h e r e s u l t of t h e ven t ing of ho t gases p a r t i a l l y mel t ing and r o l l i n g over t h e sharp f r a c t u r e d edge i n a d i r e c t i o n away from the ven t ing gases . f i s s u r e s .

Such f e a t u r e s a r e completely smooth and devoid of f r a c t u r e marking o r o t h e r

It is d i f f i c u l t t o imagine how t h e s e fragments could be produced o t h e r than through t h e a c t i o n of explos ives . chemical d e p o s i t s , and high s t r a i n rate deformation. w i l l produce p a r t i c l e s of t he same gene ra l shape , t h e i r examination under t h e e l e c t r o n microscope r evea l s e n t i r e l y d ï f f e r e n t s u r f a c e c h a r a c t e r i s t i c s . of p a r a l l e l r i dges caused by t h e a c t i o n of t h e c u t t i n g t o o l , g iv ing an o v e r - a l l e f f ec t of a ploughed f i e l d . Laboratory experiments i n which smal l f ragments were produced by t h e a c t i o n of explos ives g ive e x c e l l e n t agreement wi th a c t u a l f o r e n s i c evidence.

The par t ic les e x h i b i t evidence o f i n t e n s e h e a t i n g , Although convent iona l machining

The deformation be ing



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P a r t III.- The I n v e s t i g a t i o n II 1-11-7

Thus i t c a n . b e seen t h a t s m a l l p a r t i c l e s of metal which e x h i b i t gas-wash, p i t t i n g and r o l l e d edges can o n l y be accounted f o r i n terms of an exp los ion and t h e r e is e x c e l l e n t agreement between a c t u a l f o r e n s i c ev idence and l a b o r a t o r y experiment.

11.4 - - ~ - S t r u c t u r e and Composition of Fragments

11 .4 .1 Twinning

A s w e l l a s t h e s u r f a c e e f f e c t s produced by e x p l o s i v e s t h e r e are deformation A t normal mechanisms, which are p e c u l i a r t o h i g h ra tes of s t r a i n a t normal t empera tu res .

r a t e s of s t r a i n metals deform by t h e usua l mechanisms a s s o c i a t e d w i t h d i s l o c a t i o n movement. t h e r e is i n s u f f i c i e n t t i m e f o r t h i s p rocess t o occur and i n some metals deformat ion t a k e s p l a c e by twinning as seen i n F igu re 11-8.

However because t h i s p rocess is thermal ly a c t i v a t e d a t h i g h rates of s t r a i n

I n copper and i r o n t h i s f e a t u r e is w e l l documented and is regarded as proof p o s i t i v e of an exp los ion . t h e 1967 Comet and t h e 1974 TWA Boeing 707 d i s a s t e r s .

Such f e a t u r e s were l o c a t e d i n f ragments recovered from

Occas iona l ly i t i s p o s s i b l e t o d e t e c t t h e s e f e a t u r e s i n were a d j a c e n t t o t h e c e n t r e of t h e exp los ion bu t n o t p a r t of t h e bomb However t h e d e t e c t i o n of twins by o p t i c a l microscopy i n t h i s i n s t a n c e p e r s i s t a n c e because of t h e i r i n f r e q u e n t occur rence .

1 1 . 4 . 2 R e c r y s t a l l i z a t i o n

Sometimes t h e deformat ion s u s t a i n e d by a fragment is so

components which c a s i n g (Cox, 1974). r e q u i r e s much

l a r g e t h a t t h e p a r t i c l e h e a t s s u f f i c i e n t l y f o r r e c r y s t a l l i z a t i o n of t h e worked s t r u c t u r e t o occur. F u r t h e r , as t h e p a r t i c l e s are g e n e r a l l y small and consequent lv c o o l i n g is f a s t t h e r e s u l t a n t g r a i n s i z e is abnormally s m a l l , t y p i c a l l y 1-3u, shown i n F igu re 11-9. Commer- r i d 1 m i l d s teels u s u a l l y have a g r a i n s i z e of abont 5 0 ~ dpwards. Very f i n e g r a i n s i z e s h a w been obse rvcd i n c o n t r o l l e d exper iments d r J a c t u a l i n v e s t i g a t i o n s (Higgs and o t h e r s , 1 9 7 6 ) . However, i t i s p o s s j h l e t o produce these g r a i n s i z e s by e i t h e r s p e c i a l thermo- rnzchúnical t r ea tmen t o r , more commonly, by g r a i n growth i n h i b i t o r s .

and not’ proof

11.4.3

For t h e s e r easons f i n e g r a i n size’s can on ly he r ega rded as a n i n d i c a t i o n p o s i t i v e of h e a t i n g as an outcome of e x p l o s i v e s involvement.

- Composition

The f i n d i n g of f ragments of material d i f f e r c n t LO t h a t i n u s e i n a i r c r a f t s L r u r t u r e i s f u r t h e r impor tan t ev idence o f t h e exp los ion of i n t r o d a c e d o b j e c t s i n t o t h e a i r c r a f t . Low a l l o y s t e e l f ragments have been d iscovered i n f o r e n s i c i n v e s t i g a t i o n s . Sometimes checking of a l l t h e m a t e r i a l i n use i n t h e a i r c r a f t is n e c e s s a r y t o confirm t h a t t h e e x p l o s i v e w a s i n a c o n t a i n e r whose inaterial w a s f o r e i g n t o any i n use i n t h a t p a r t i c u l a r a i r c r a f t .

11 .4 .4 Air-frame damage - Adiaba t i c shea r

Ad iaba t i c shea r o c c u r s when t h e h e a t genera ted by p l a s t i c deformat ion has i n s u f f i c i e n t t i m e t o d i s s i p a t e . Th i s r e s u l t s i n m i c r o s t r u c t u r a l m o d i f i c a t i o n s which have been observed i n s tee l , shown i n F igu re 11-10 (Bedford and o t h e r s , 1976) and i n t i t an ium, copper and aluminium a l l o y s . T’hc necessa ry c o n d i t i o n s f o r a d i a b a t i c s h e a r a r e t h a t t he deformation is r e s t r i c t e d t o a l o c a l i z e d r eg ion , t h a t large s t r a i n s occur and t h a t t h e deformat ion r a t e be high. Such c o n d i t i o n s are encountered i n p r o j e c t i l e l t a r g e t impact and exp los ive f r agmen ta t ion .

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Manual of A i r c r a f t Accident I n v e s t i g a t i o n _I_____.____- - -- 111-11-8

However i t has been shown (Wingrove, 1973) t h a t under favourable cond i t ions

Therefore a l though the d e t e c t i o n of a d i a b a t i c shea r zones is a most a d i a b a t i c shea r can occur a t v e l o c i t i e s of 160 m sec-' a l though no lower l i m i t h a s y e t been determined. u s e f u l i n d i c a t o r i t cannot be regarded a s proof p o s i t i v e .

11.4.5 Impact Craters

An e x c e l l e n t example of s u r f a c e p i t t i n g w a s found i n s t r u c t u r a l components connected wi th the c r a s h of t h e Cathay P a c i f i c Airways Convair 880 VR-HFZ on 15 June 1972 (Lidstone, 1972). which were t o t a l l y blackened sugges t ive of involvement i n a f i r e subsequent t o t h e fonnat ion of the craters.

F igu re 11-11 shows a t y p i c a l example of several such c r a t e r s each of

Impact w i th t h e a i r f r ame by s m a l l bomb case fragments can be of such v io l ence a s t o cause a s p l a t t e r c a v i t y as i l l u s t r a t e d i n F igure 11-12. t h a t t h e fragment must have been t r a v e l l i n g a t speeds i n excess of lo3 m sec-l f o r t h e p a r t i c l e t o have melted. The presence of t h i s f e a t u r e is t h e r e f o r e good evidence t h a t a de tona t ion took place.

It can be c a l c u l a t e d

11.5 Chemistry and Materials Assessment

11.5.1 Role of t h e f o r e n s i c s c i e n t i s t

The normal r o l e of a f o r e n s i c s c i e n t i s t , concerned wi th e v a l u a t i n g bomb d e b r i s , i s t o i s o l a t e from amongst a n overwhelming m a s s of g e n e r a l d e b r i s such i t e m s a s remain a f t e r the de tona t ion of a bomb o r home-made device. As such i n t e r e s t l i e s i n i d e n t i f y i n g fragments of b a t t e r y , t iming mechanism, w i r e s , t a p e s and t h e charge c o n t a i n e r . General ly t h e r e is o t h e r s u b s t a n t i a t i n g evidence t h a t an explos ion had occurred thus f o r e n s i c emphasis is placed on i d e n t i f i c a t i o n of t h e components of t h e device and on so lvent swabbings from s e l e c t e d i t e m s a s a pre l iminary t o chemical i d e n t i f i c a t i o n of t h e explos ive used.

A f u r t h e r a spec t of f o r e n s i c work on exp los ives dev ices i s t h a t Engl i sh Courts of Law do not demand d e t a i l e d proof o f exp los ive a s s o c i a t i o n of any items ra i sed a s e x h i b i t s a s is the case i n some fo re ign coun t r i e s . It is necessary only fo r t h e expe r t g iv ing evidence t o s t a t e t h a t i n h i s op in ion , based on long yea r s of expe r i ence , t h a t t he na tu re of t h e damage is c o n s i s t e n t with t h a t t o be found from c o n t r o l l e d explo- s ions involving s i m i l a r exp los ives and ma te r i a l s .

The problem f a c i n g t h e f o r e n s i c s c i e n t i s t d e a l i n g wi th a i r c r a f t wreckage i s q u i t e d i f f e r e n t i n b a s i c approach s i n c e he cannot assume that an exp los ion , t h a t is the de tona t ion of an exp los ive charge , had taken p l ace d e s p i t e hearsay evidence t o t h i s e f f e c t . The s c i e n t i s t i n t h e s e c a s e s has t o seek s i g n s which resemble known land-based explosion damage and t o use these as a s t a r t i n g po in t f o r h i s i n v e s t i g a t i o n , a t a l i t imes keeping a s t r i c t l y open mind a s t o a l t e r n a t i v e exp lana t ions which might account f o r t h e evidence being s tud ied . Comet G-ARCO acc iden t .

Such was the f o r e n s i c beginning of t h e enqui ry i n t o t h e

*

In a d d i t i o n t o t h e f e a t u r e s a l r eady descr ibed a s of m e t a l l u r g i c a l s i g n i f i - cance i n a s s o c i a t i o n with a d e t o n a t i v e event , i t i s p o s s i b l e t o g e n e r a l i z e and sugges t l i k e l y a r e a s of damage t o non-metal l ic ma te r i a l s . For example, a ) h i g h l y shredded and teased woven f a b r i c s , b ) p l a s t i c s pane ls wi th smal l p e n e t r a t i o n h o l e s , c ) unusual damage and d i s c o l o u r a t i o n of c u r t a i n s or s e a t i n g materials and d) s eve re ly damaged s u i t c a s e s , etc. i n c l o s e proximity t o many o t h e r s which appear r e l a t i v e l y undamaged. Each of the above f e a t u r e s may no t r e a d i l y i n d i c a t e t h e c h a r a c t e r i s t i c evidence of an explos ive event b u t , when viewed a t high magni f ica t ion much v a l u a b l e informat ion may ensue, examples of which are h igh l igh ted i n the fo l lowing paragraphs.

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P a r t III.- The I n v e s t i g a t i o n XII-11-9

11.5.2 ñadiophotography

Darkened s t r i a t i o n s accompanied by i r r e g u l a r tears, which seemed t o r a d i a t e fanwise from a p o i n t , on one of t h e seat swabs seen by t h e i n v e s t i g a t o r w a s recognized a s c l o s e l y resembl ing damage t o a s i m i l a r polyurethane seat cushion seen a t -E, Woolwich. used by c r i m i n a l s t o break open a s a f e and t h e cushion had been used a s n n i f f l h g t o deaden the sound of t h e explos ion .

Th i s l a t te r i t e m w a s p a r t of a case being s t u d i e d i n which e x p l o s i v e had been

The C o m e t s t o r y is s u f f i c i e n t l y w e l l known not t o need r ecoun t ing i n d e t a i l . A b r i e f b u t u s e f u l review of t h e s a l i e n t f e a t u r e s of t h i s i n v e s t i g a t i o n was publ ished i n The New S c i e n t i s t (Clancey, 1968b). The Comet i n v e s t i g a t i o n w a s t h e f i r s t major i n v e s t i g a t i o n of t h i s kind and was t y p i c a l of s e v e r a l s i n c e i n v e s t i g a t e d i n t h r e e important r e s p e c t s .

F i r s t l y , it h i g h l i g h t e d t h e va lue of X-ray photographic f a c i l i t i e s being app l i ed both to i t e m s and bodies f o r t h e l o c a t i o n of minute f ragments of bu r i ed m a t e r i a l , p a r t i c u l a r l y when t h e r e i s evidence of p e n e t r a t i o n of e i t h e r . d i l i g e n t s e a r c h t h a t a mass of in format ion can o f t e n b e de r ived from a minhum of d e b r i s and t h a t p l a s t i c s materials w e r e e q u a l l y e f f e c t i v e a s metals i n showing characteristic damage. ana lys ing fragment s.

Secondly, it revea led t o

T h i r d l y , u se of t h e scanning e l e c t r o n microscope was used f o r e x a m i a í n g and

11.5.3 F i b r e analysis

A fragment of z i n c e x t r a c t e d from t h e Comet seat squab w a s seen to be a s s o c i a t e d w i t h a t u f t of f i b r o u s m a t e r i a l which c o n s i s t s of 40 t o 80 f i b r e s of inax- diameter 0 .01 mm wound l o o s e l y i n a clockwise manner. hollow and possessed convolu t ions t y p i c a l of c o t t o n (Todd and o t h e r s , 1968). shows t h e s e f i b r e s marked a t A i n comparison wi th s i m i l a r wh i t e f i b r e s taken from one of t h e Comet seat cove r s . Chemical tests confirmed t h e f i b r e s t o be c o t t o n and po l i shed s e c t i o n s of f i b r e mounted i n epoxy r e s i n showed t h e t y p i c a l hol low kidney-shaped cross- s e c t i o n of c o t t o n .

The f i b r e s w e r e t a p e - l i k e a d F igure 11-13

11.5.4 X-ray d i f f r a c t i o n a n a l y s i s

An a i r c r a f t i n v e s t i g a t i o n which i l l u s t r a t e d t h e v a l u e of molecular s p e c i e s i d e n t i f i c a t i o n by use of X-ray d i f f r a c t i o n (XRD) a n a l y s i s w a s t h a t a s s o c i a t e d wi th d e b r i s from an A e r Lingus Viscount E1-AOM l o s t i n t h e I r i s h Sea on 24 March 1968 (Higgs, 1970). I n v e s t i g a t i o n of t h e o r i g i n a l f l o t s a m by Clancey showed no ev idence of exp los ives involvement. Some 18 months later two b l i n d s were dredged up and s e n t t o one of t h e au tho r s (DGH) € o r examinat ion. One of t h e s e b l i n d s shown i n F igure 11-14 had a l a r g e a r e a of b lackening which was thought t o be evidence of a f i r e having occurred aboard t h e a i r c r a f t b e f o r e i ts c r a s h i n t o t h e sea.

The cab in s i d e of t h e b l i n d w a s seen t o have a r e g u l a r r a i s e d p a t t e r n superimposed on a s i lvery-coloured s p e c u l a r subs tance g iv ing an o v e r - a l l l u s t r o u s appearance. Solvent removal of t h e outermost polymer l a y e r r e l e a s e d t h e under ly ing s p e c u l a r substance which was subsequent ly found by XRD a n a l y s i s t o be a form of b a s i c l e a d carbonate known a s PLüMBONACRITE. F u r t h e r , t h e darkened a r e a s w e r e a l s o seen t o have a lower con ten t of t h i s subs tance compared wi th t h e unblackened m a t e r i a l and a new XRD p a t t e r n f o r l e a d su lph ide .

Experiment showed t h a t immersion of t h e uncoloured b l i n d m a t e r i a l i n water con ta in ing hydrogen su lph ide gas s lowly converted t h e whi te b a s i c l e a d carbonate i n t o t h e darker l e a d su lph ide .

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Examination of t h e b l ind f o r o i l contamination w a s made d i f f i c u l t by t h e presence of an oil-modified lacquer a s i t s p r o j e c t i v e o u t e r l a y e r . s t a i n e d with unstained areas of b l i n d showed no d i f f e r e n c e t h a t could be a t t r i b u t e d t o t h e presence of o i l . Nevertheless , i t w a s considered t h a t t h e most probable mechanism by which t h e b l i n d w a s darkened w a s t h e entrapment of a q u a n t i t y of su lpha ted o r sulphonated o i l w i t h i n t h e f o l d s of the b l i n d , which w a s found i n t h e r o l l e d up p o s i t i o n , which had become b i o l o g i c a l l y degraded du r ing t h e long sea immersion and t h a t t h e e x c e s s o i l had long s i n c e been washed out .

11.5.5 Microscopic examination

Comparison of

Severa l e x c e l l e n t examples can be c i t e d (Refs. Higgs 1974, Hayes 1976, Higgs 1976 and Todd 1968) t o support t h e use of a s imple s tereomicroscope i n o r d e r t o h i g h l i g h t f e a t u r e s not r e a d i l y apparent t o t h e naked eye. r e s u l t s were derived from seemingly unfavourable circumstances connected with t h e f lo t sam from t h e TWA Boeing 707-331B, N8734 l o s t over t h e Ion ian Sea (Higgs 1974).

Perhaps t h e most s p e c t a c u l a r

Of p a r t i c u l a r i n t e r e s t amongst t h e l i m i t e d f l o t s a m recovered w a s a r e d Samsonite s u i t c a s e which appeared t o have s u f f e r e d on ly t r i v i a l damage. i n s p e c t i o n i t w a s observed t h a t s e v e r a l v e r y small p e n e t r a t i o n s and l a c e r a t i o n s of t h e o u t e r red p las t ics covering were present . Corresponding w i t h t h e s e w e r e blackened and once melted p e n e t r a t i o n s of t h e h i g h d e n s i t y po lye thy lene r ibbed i n n e r case s t r u c t u r e . Typical of t h i s f e a t u r e is t h a t shown i n F igu re 11-15. The damaged and blackened areas w e r e viewed under a low power s tereomicroscope and found t o p r e s e n t a mass of shredded, blackened and sof tened p l a s t i c s i n which w e r e e n t r a i n e d numerous coloured f i b r e s hav ing no obvious connection w i t h t h e case f a b r i c s . tweezers r evea led s e v e r a l minute fragments of metal a l l much smaller than a p i n ' s head. Eventual ly t h i s probing i s o l a t e d fragments of metal found subsequen t ly t o be aluminium, copper, b r a s s , z inc and i ron . f o r immediate s a f e examination. Subsequent scanning e l e c t r o n probe mic roana lys i s confirmed t h e elemental composition of t h e s e fragments as w e l l as r e v e a l i n g h i g h l y d i s t o r t e d s u r f a c e c h a r a c t e r i s t i c s . Manganese d i o x i d e traces were a l s o confirmed t o be p re sen t i n some of t h e blackened areas of t h i s c a s e , t h u s sugges t ing t h a t an e l e c t r i c c e l l had been i n very c l o s e proximity t o t h e d e t o n a t i v e source. Typical fragments are i l l u s t r a t e d i n F igu res 11-16 and 11-17.

On c l o s e

Care fu l probing w i t h s p e c i a l l y pointed

Each fragment w a s mounted on a g l a s s microscope s l i d e

11.5.6 Damage t o f a b r i c s

The Boeing 720B d e b r i s y i e l d e d evidence of damage t o f i b r o u s m a t e r i a l s not previously encountered. A green h a l f - s u i t c a s e w a s seen t o be not g r e a t l y damaged but which had a small a r e a of e x t e r n a l t e a r i n g n e a r t h e top edge. Close examination showed t h a t embedded i n t h e tear w a s a mass of p a r t l y fused red f i b r o u s m a t e r i a l . s u b s t r a t e t o t h i s green c a s e w a s a c o a r s e l y woven yel low r e i n f o r c i n g f a b r i c which remained undamaged a t t h e poin t o p p o s i t e t h e tear i n t h e green p l a s t i c s o u t e r covering. However, t h e impacted r e d mass had been fo rced between t h e warp and weft of t h e yellow f a b r i c and was s t r o n g l y adherent t o i t . Such damage could n o t p o s s i b l y r e s u l t from mechanical impact and must i n d i c a t e t h a t t h e red f i b r o u s mass w a s impacted on to t h e green suitcase w h i l s t s t i l l hot and wi th extremely h igh v e l o c i t y .

The

A white Clubmaster p o l y e s t e r s h i r t a l s o y i e lded evidence of bombardment by s i m i l a r fused red f i b r o u s material a t two l o c a t i o n s , namely, t h e c o l l a r a r e a and on the co rne r of t h e r i g h t hand s l e e v e but ton-hole . forced through t h e undamaged s h i r t m a t e r i a l t o r eappea r on t h e o p p o s i t e f a c e of t h e po lyes t e r weave. Bonding had taken p l a c e between t h e p o l y e s t e r and t h e red f i b r o u s mass such t h a t they could not be sepa ra t ed by s t r enuous tugging with t h e a i d of f o r c e p s

I n both i n s t a n c e s t h e red f i b r e s w e r e

18/61 78 No. 9 Copyright International Civil Aviation Organization


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P a r t 111.- The I n v e s t i g a t i o n 111-11-11

The f i n d i n g of RDX and n i t r o g l y c e r i n e t o g e t h e r w i t h t h e above f e a t u r e and many o t h e r s n o t recounted h e r e l e f t no doubt whatsoever t h a t an e x p l o s i v e cha rge had been de tona ted aboard t h i s a i r c r a f t i n c l o s e proximity t o a q u a n t i t y of c l o t h i n g and had given rise t o t h i s c h a r a c t e r i s t i c damage.

11.5.7 Shredded and t e a s e d f a b r i c s

D i s r u p t i o n of woven fabr ics i n c l o s e involvement wi th a n e x p l o s i o n are o f t e n seen t o be t e a s e d t o t h e e x t e n t t h a t l ong s t r eamers of warp and wef t t h r e a d s a r e exposed. once t h e weave i s s u f f i c i e n t l y weakened t o produce a tear. common s i g h t t o w i t n e s s o l d f l a g s , which are c o n s t a n t l y whipped by s t r o n g winds, showing such streamers a t t h e i r down wind extremities.

Two o t h e r aerial c i r cums tances , however, are known t o produce t h e same e f f e c t For example, it is a f a i r l y

S i m i l a r l y , i t w a s commonly found i n o l d e r a i r c r a f t which u t i l i z e d dope r e i n f o r c e d canvas c o v e r i n g s t h a t a tear s u s t a i n e d w h i l s t a i r b o r n e would shed i ts l acque r and become t e a s e d t o some c o n s i d e r a b l e e x t e n t whereas a tear d u r i n g impact would be c l e a n and devoid of t e a s i n g . C l e a r l y i n modern a i r c r a f t a f a b r i c so found a f t e r a c r a s h could mean t h a t a i r t u r b u l e n c e , f o l l o w i n g s t r u c t u r a l damage w h i l s t i n f l i g h t , could be r e s p o n s i b l e f o r t h e degree of damage observed. break-up of t h e a i r c r a f t is q u i t e immaterial i n t h i s ins tance . It c e r t a i n l y cannot be i n f e r r e d t h a t such damage, because i t resembles t h a t t o be found in a land-based exp los ion , n e c e s s a r i l y i n f e r s t h a t a n exp los ion o f high energy h a s t aken p l a c e d u r i n g f l i g h t .

The cause of t h e i n i t i a i s t r u c t u r a i

The most v a l u a b l e ev idence from damage f a b r i c s and woven materials can o f t e n on ly be s e e n when viewed under low power microscopy. Typ ica l examples of t h € s were encountered i n f a b r i c d e b r i s i s o l a t e d from f lo t sam connected w i t h t h e loss o f t h e Cubana DC8.CUT.1201 o f f Barbados on 6 October 1976 (Higgs and o t h e r s , 1977). Many minute and n o t so small fragments o f a gauze-l ike material were observed en t r apped i n s e v e r a l s u i t c a s e s which was later i d e n t i f i e d as a s p e c i a l weave of ny lon 6:6 bonded with a po ly i sobu ty lene polymer c o n t a i n i n g antimony oxide used a s t h e f i r e d e p r e s s a n t . It was a l s o d i scove red t h a t t h e polymer c o a t i n g d i s s o l v e d r e a d i l y i n k e r o s i n e , which e x p l a i n s why t h e c h a r a c t e r i s t i c green co lou red polymer c o a t i n g w a s absen t from t h e f l o t s a m fragments. come w e r e however fused and g l o b u l a r i z e d i n a manner, shown i n F i g u r e s 11-18, 11-19 and 11-20, which could no t be reproduced by t h e most t r a n s i e n t passage of t h e c l o t h through a buncen flame. which showed i n t e r n a l g a s e v o l u t i o n ( fo rma t ion of bubbles due t o decomposition w h i l s t molten) and /o r darkening t o produce v a r i o u s shades va ry ing from yel low t o brown. c o n t r a s t , experiments i n v o l v i n g d e t o n a t i o n of small charges of commercial b l a s t i n g exp los ive showed t h a t over an optimum range t h e c h a r a c t e r i s t i c s observed on t h e Cubana items could be reproduced, F i g u r e s 11-21 and 11-22 on a c o n t r o l sample o f t h e ny lon provided by t h e Canadian owners of t h i s a i r c r a f t .

Aïthough most of t h i s ny lon showed on ly mechanical ly t o r n ends t o t h e f i b r e s

For example, such h e a t i n g always produced severe g l o b u l a r i z e d ends

I n

11.5.8 Chemical i d e n t i f i c a t i o n s of e x p l o s i v e

N o ev idence o f e x p l o s i v e t r a c e s w e r e found on t h e Comet and Convair fragments o r , as p r e v i o u s l y s t a t e d , on t h e b l i n d s from t h e A e r Lingus Viscount . It i s considered t h a t t h e r e may have been come p o s s i b i l i t y of d e t e c t i o n had t h e s e n s i t i v e d e t e c t i o n methods now used been a v a i l a b l e a t t h a t t i m e . I n a l l t h r e e la tes t i n v e s t i g a t i o n s

Hayes 1976 and Higgs 1977) t h i n l a y e r chromatographic tests showed t h e

of RDX and NG on t h e Boeing 720B and of NG on t h e Cubana DC8 w e r e i n ample t r a c e s of e x p l o s i v e , t h a t f o r t h e TWA Boeing 707 being v e r y f a i n t w h i l s t

supply t o be confirmed beyond doubt by d i f f e r e n t procedures .

18/6/78 No. 9



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The DC8 s i t u a t i o n o f f e r s i n t e r e s t i n g p o s s i b i l i t i e s f o r f u t u r e occas ions i n t h a t d e s p i t e a t least 16 hours immersion i n sea wa te r , and a t l e a s t 2 t o 3 weeks d e l a y be fo re v a r i o u s i t e m s could be t e s t e d , s t r o n g r e a c t i o n s were ob ta ined f o r n i t r o g l y c e r i n e a f t e r so lven t swabbing of t h e su r faces of s e v e r a l p l a s t i c s covered s u i t c a s e s recovered amongst t h e f lo t sam.

All i tems s m e l t s t rong ly of k e r o s i n e when rece ived i n these l a b o r a t o r i e s . Kerosine is a l s o s t r o n g l y absorbed i n t o some p l a s t i c s , p a r t i c u l a r l y t h e form of polyvinyl c h l o r i d e (PVC) which formed t h e outer . cover ing of t h e s e cases. Th i s f a c t suggested t h a t t h e i n i t i a l f l a s h d e p o s i t s of exp los ive may have been washed i n t o t h e plastics by so lven t a c t i o n of t h e ke ros ine and thus preserved a g a i n s t s o l u t i o n i n sea water as would be expected i n t h e case of n i t r o g l y c e r i n e . PVC c u t from t h e case w e r e re f luxed i n so lven t . Unfor tuna te ly cho ice of so lven t is l i m i t e d if it is no t a l so t o d i s s o l v e t h e polymer and those m o s t s u i t a b l e f o r exp los ives r e s i d u e s a l s o e x t r a c t s ke ros ine and t h e p h t h a l a t e p l a s t i c i z e r s . Consequently subsequent clean-up procedure t o s e p a r a t e t h e exp los ive i n a form amenable t o chromatographic a n a l y s i s w a s ve ry t ed ious but i t d i d prove t h e po in t t h a t cons ide rab ly more exp los ive was conta ined w i t h i n t h e bulk of t h e polymer than appeared on t h e su r face .

Such w a s proved t o be s o when s e c t i o n s of

11.5.9 I n f r a r e d spectrophotometry

It is seldom t h a t s u f f i c i e n t exp los ive traces a r e l o c a t e d on d e b r i s t o enable a p o s i t i v e i n f r a r e d spec t romet r ic i d e n t i f i c a t i o n t o be made even a l lowing f o r t h e use of min ia tu re d i s c sample i n conjunct ion wi th a microbeam condenser . case, however, wi th d e b r i s from t h e Middle East A i r l i n e Boeing 720B OD-AFT i n v e s t i g a t i o n (Hayes and o t h e r s 1976) which crashed on t h e Saudi Arabian d e s e r t on 1 January 1976.

Such was t h e

One of t h e two ha l f s u i t c a s e s , a r ed t a r t a n case, w a s seen t o be l i b e r a l l y dus ted wi th a wh i t e powder; t h i s w a s e l imina ted from our e n q u i r i e s when i n f r a r e d a n a l y s i s showed t h e subs tance t o be an an ion ic sulphonated a l k y l d e t e r g e n t con ta in ing a condensed phosphate a d d i t i o n and was confirmed a s having been p a r t of t h e cargo mani fes t .

Solvent e x t r a c t i o n of t h e s u r f a c e s of t h i s r e d h a l f case y ie lded s u f f i c i e n t m a t e r i a l t oeg ive a good spectrum us ing t h e s tandard 13 mm potassium bromide d i s c technique . F igure 11-23 shows the s p e c t r a so obta ined i n comparison wi th t h a t of a pure sample of t h e m i l i t a r y exp los ive RDX (cyc lo t r imethylene t r i n i t r a m i n e , a l s o known as c y c l o n i t e and hexamine).

11.5.10 Detect ion procedures

Both th in- layer chromatography and gas - l iqu id chromatography a r e used, t h e la t ter i n conjunct ion wi th e l e c t r o n cap tu re d e t e c t o r s , t o y i e l d maximum s e n s i t i v i t y of d e t e c t i o n and minimum i n t e r f e r e n c e from non-electron cap tu r ing impur i t i e s .

Thin-layer chromatography us ing to luene as e l u a n t followed by sodium hydroxide hydro lys i s a t 105OC and v i s u a l i z e d wi th a modif ied Griess reagen t is p r e f e r r e d a s t h e b e s t s epa ra t ion system f o r a range of exp los ives ; i t does however not s e p a r a t e NG and PETN ( p e n t a e r y t h r i t o l t e t r a n i t r a t e ) . i n i1 mixture of e t h y l a c e t a t e and petroleum e t h e r a s e l u a n t which does not however s e p a r a t e RDX and HMX (cyc lo te t ramethylene t e t r a n i t r a m i n e ) . chloroform and methanol e f f e c t i v e l y s e p a r a t e s RDX and HMX but no t NG and PE". s e n s i b i l i t y f o r NG, RDX and PETN a r e r e s p e c t i v e l y 2 , 5 and 50 x lO-9g per spo t f o r a system opt imised f o r t he d e t e c t i o n of n i t r o g l y c e r i n e . Lower l e v e l s of d e t e c t i o n are a t t a i n a b l e f o r t h e o t h e r exp los ives under a p p r o p r i a t e cond i t ions .

A s e p a r a t i o n of t h e s e two exp los ives i s achieved

A t h i r d e l u a n t based on Levels of



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Part III.- The Inve'stigation , 111-11-13

Gas-liquid chromatography is employed mainly for nitroglycerine, mono and di-nitrobenzenes and the corresponding nitrotoluene isomers rather than for the long retention timed military explosives. The level of detection available for NG is 2 x 1012g.

18/6/78 No. 9



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111-11-14 Manual of Aircraft Accident Investigation

F i g u r e 11-1. A i r s p e e d and a c c e l e r a t i o n traces from the Convair 880 aircraft

18 /6 /78 No. 9

4 6

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P a r t III.- The I n v e s t i g a t i o n 111-11-1 5

X16

Figure 11-2. Comet seat fragment wi th occluded polyure thane foam

X250

Figure 11-3. Gas-wash e f f e c t on a fragment from t h e Comet

18/6/78 No. 9



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Manual of Aircraft Accident Investigation ____._..__ __- 111-11-16

x200

Figure 11-4. Gas-wash on aluminium from detonation of RDX

x250

Figure 11-5. Surface pitting on a fragment from the Comet aircraft

18/6/78 No. 9



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111-11-17 P a r t III.- The I n v e s t i g a t i o n ~ _ _ -

X700

F igure 11-6. Rol led edge on a fragment from t h e Comet a i r c r a f t

X7 O0

Figure 11-7. Con t ro l l ed de tona t ion of NG-based e x p l o s i v e

i n a s s o c i a t i o n w i t h a zinc-based 1 .5 v o l t d ry c e l l

e f f e c t



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X250

Figure 11-8. C r y s t a l twinning i n mild s t e e l

F igure 11-9. Example of r e c r y s t a l l i z a t i o n i n s t e e l a l l o y fragment

18/6/78 No. 9



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P a r t 111.- The I n v e s t i g a t i o n 111-11- 19

X500

Figure 11-10. Ad iaba t i c s h e a r i n mild s t e e l

x200

Figure 11.-11. P i t t i n g r e s u l t i n g from h i g h v e l o c i t y i.+ “’act

18/6/78 No. 9



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Manual of A i r c r a f t Accident I n v e s t i g a t i o n -- I II -11 -20

x375

F igure 11-12. P i t t i n g on aluminium wing metal from

Convair 880 VR-H FZ

X150

F igure 11-13. Comparison of Comet fragment f i b r e s ( a ) w i th seat f i b r e s (b)

18 /6 /78 No. 9



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Figure 11-15. T y p i c a l blackened p e n e t r a t i o n from Samsonite case

Figure 11-14. Damaged and blackened A e r Lingus Viscount b l i n d

. .., . ~. . . * _I i .̂ . . . . . .

18/6/78 No. 9



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111-11-22 Manual of A i r c r a f t Accident I n v e s t i n a t i o n

F igure f r

X130

Figure 11-16. Fragment of aluminium . from Boeing 707-331B.

Samsonite c a s e

X17 5

11-17. Fragment of copper 'om Boeing 707-331B

Samsonite case

18/6/78 No. 9



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111-11-23 P a r t 111.- The I n v e s t i g a t i o n _____

Figure 11- of

-19. En fused

. l a r g e ends

id

X250

view

X5 O

Figure 11-18. a i r c r a f t s h

Ny 1 on lowing

66 fuse

f l !d

com DCP ends

18/61 7% No. 9



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--

111-11-24

- -

Manual of A i r c r a f t Accident I n v e s t i g a t i o n

F igu re damage

11-21. Con t ro l l ed exF t o Canadian Nylon 66

X1500

F igure 11-20. Globular ized ends of f i b r e s showing

absence of b l acken ing and gas bubbles

X425

t losion sample

18/6/78 No. 9



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111-11-25 P a r t III.- The I n v e s t i g a t i o n ________

Figure 11-23. I n f r a r e d a b s o r p t i o n spectrum of RDX i s o l a t e d from

t h e red t a r t a n s u i t c a s e

X4 80

Figure P a

11-22. r t o f

Enlarged view of F igure 11-21

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18/6/78 No. 9



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PART IV. - REPORTING OF OCCURRENCES

P A R T

I V



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Part IV.- ReRortinq of ocaurenees IV-1-1

1.1 Reports

Annex 13 specifies i n Chapter 6.- Reporting, the various reports daIch iay be required f o r any one occurrence. Ricy are:

- ThePrelirpLnaryReport; - The ACddent/Incident Data Report; - ThepFnalReport; Rie smmlary of the Final Report. -

Details on each of these reprts are provided in the follobdng chaptctS.

1.2

The nAccident/Inddent Data Report" l s @led froa the 'Thal &Porta which must be completed first. However, the n A c d d e n t / I n c i d e n t Data Report" herr hen grouped dth the n p r e l l m i n a r y ~ e p o r t n because they are both rcquireä for the kcidant Data Reporting (MREP) systeia,

nie tu> reports are Ooquter ampatible and uhm~ received by ICA0 the information is first che&ed anci then stored in a -ter. information aonstitutes a wrldwide occurremce data bank which is used to provide Statem dtb the following f l i gh t safety infozmation services:

The cumlat ion of storcd

a ) ! ! _ m o n U i l l r _ l S - E ~ - k E t s : 9 a n t - €=- Y

infomation on occurrences which have been reported to ïCAû during the pricccding iionth. This w r l d d d e basis.

provides States with an up-to-date picture of significant acddenta on a

involved, phase of operation, etc., as w e l l as trends in accident rates, S a f e t y I M i m , etc. This digest pmvides States with warldwide accident statistics.

c l Re ,p&&es ,&,s ta tes@~es tc for &g.Eation, States wishing assistance i n detecting or defining specific fl ight safety problems, should forward to ICA0 a request f o r infomation outlining, as c lear ly as possible, the! safety problemunder study and mentioning how soon a reply is needed. Manual (ADREP Hanual - Doc 9156-AN/900) provides the format to be used by Sta t t8 f o r an "AUiEP information Request".

PART III of the ICA0 Acddent/Incident Reporting



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IV-1-2 üanual of Aircraft Accident investigation

Rcpïies to such requests w i l l be based on analysis of the mrldwide occurrence data received and stored by ICAO. The type of conmunication used by ICA0 fo r replying (telephone, cable o r letter) w i l l be determined according to the indication given by the State on the urgency of the reply. If the analysis made by ICA0 reveals that other States may be interested, such States w i l l be provided w i t h an information copy of the =Ply.

d ) A remrd for individual States, ICA0 may provide any State, upon its specific request, w i t h the compìete record of accidents and incidents reported by tha t State to ICAO, and thus function as an occurrence data bank for those States w h i c h wish to take advantage of th is service.

..............................

1.3 !Che Narrative Reports

Both the "Pinal Report" and the "S?mmiary of the Pinal Report" of the c o m n narrative type.

1.4 ReportingAccuracy

Compiete and accurate ampilation of any one of these reports is extremely inportant. The val idi ty of t h e safety infonuation provided to States by E A 0 depends not only on the care w i t h ihich occurrences haw been investigated but also on the care and accuracy dth iINch States to accurately report a l l accidents and incidents in accordance dth kinex 13, this Hanual and the ADREP wainial. only then can ïCAô provide valid information requîmd for acddant prevention.

reported. Therefore, it is in the interest of all



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PART IV.- Reporthg of m-2-1

State of Registry (or Occurrence) State of Uanufacture State providing information ICA0 (Attention AZG)

Same States as above hit not I W

2.1 available within the first three to four weeks of the investigation. Report provides a sfnipïe anä standard pethod fo r reporthg such prellmlnary informatîon. in accordance with Annex 13 the Preliminary Report is to be sent by the State aMdllctinQ the investigation:

Basic factual and circumstantial information on an a d d e n t is normally Tñe PrelinLnary

Ililti-engbed over 5 700 kg

nilti-engined between 5 700 kg and 2 250 kg

Wti-engined 2 250 kg or less anä single- engined (if aímrthiness or matters of interest inviolved)

. . . . . . . . . . . . . . . . . . . . . .

I

I - (Aircraft category)

Part i of the ADREP mai provides the form to be used for the Prellndnary Reprt as in11 as appropriate instructions f o r compiUng t ha t report. fonmrded t o a i l concerned within 30 days of the date of the acciäent.

aie Prellipinary Report shall be

10/9/76 .No. 6



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PART IV.- Reporting of OccUrrenCcS IV-3-1

- M

3.1

Annex 13 Ref.

- POR (Aircraft category)

Accident Data Report

When the investigation has been completed and the Final Iceport approved by the appmpriate authority of the Sta te conducting the investigation, the Accident Data Report is to be immediately prepared, provide a simple and standard method fo r reporting accurate and cornlete infomation on an accident. In accordance w i t h Annex 13 the Accident Data Reprt is to be sMt by the State conäucting the investigation:

The p rpose of the Acddent Data Report is to

Part X I of the AIIREP Manual provides the form to be used for the Accident Data Report as w e l l as appropriate instructions for coiiipiling that report. Lf the investigation reveals that some of the information previously given i n the Prelirninary Report requires revision it mist be corrected i n the A c c i d e n t Data Repor t . When ICA0 receives the Accident Dab Report, the Preliminary Report infomation w i l l then be upäated, Similarly, if a State re-opens an investigation, the information previously reported should be corrected by a new report.

Annex 13 does not inpose an obligation on States to conâuct an investigation into an incident. out an investigation, it is probable that safety matters are involveci and it is therefore important t ha t ICA0 receives the relevant information. incidents to multi-engined aircraft of a maximan weight of over 5 700 kg i n which the safety of the aircraft o r its occupants has been, or might have been, endangered. In accordance with Annex 13, no Preliminary Report is requested f o r incidents, aIt the incident Data Report is to be sent by the States conducting the investigation:

However, i f a State has found an incident significant enough to carry

This i s particularly important f o r



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IV-3-2 Manual of Aircraft k d d e n t investigation

FQR (Aircraft category) - m

ICA0 Hulti-engined over 5 700 kg i f ma t t e r s considered

- of interest to other States are involved.

Annex 13 Ref.

609

303 Constraints on incident Data Report

Considering the sensi t ivi ty i n many States regarding the dissemination of incident information, the followhg constraints are placed upon the use of incident data by I W :

- ICA0 will only use incident information for the purpose of accident prevention;

- ICAD w i l l not conäuct analyses based on aircraft incident information only, without identifying it as su&;

ICAI) w i l l de-identify incident reports before d i s t r i h t i o n , by deletion of nationality, registration, name of ouner/operator.

-



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PART IV.- Reporting of Occurrences IV-4-1

CHAPTER 4

'RIE FINAL REWRT

4.1 General

men it happens,an aircraft accident is a sk i r t l ing and shodting occurrence. There is intensive in te res t i n it f o r a brief time which then fades u n t i l l i t t l e remains other than the facts recorded i n the 'Final Report'. the "Pinaï Reporta i s complete anä accurate, not only fo r the sake of proper recordingskit also because prevention studies can only be of value i f they are based on complete and accurate information,

It is therefore most iaip0-t tha t

t

The V i n a l Reporta i s a synthesis of the report of the Invest igator in- Charge. should cover i n detail a l l aspects of the investigation. i n Umich the investigation i s conducted by a group organization, each group chairian should submit a report to the ïnvestigator-in-Charge together w i t h a l l relevant docuaaents and data covering the fac t s established by the group. to the Investigator-in-Ct?arge, he w i l l compile a consolidated report which w i l l include significant information derived f r o m the whole of the investigation and which dll k based to a large extent upon the reports of the various groups.

in the case of a small investigation, the report of the mvestigator-in-tAarge in the case of a major accident

When a l l groups have subiit ted their reports

These swrious reports are revieued, i n chmnological sequence of preparation, i n the following paragraphs.

402 Group Reports

in consultation with the group m s , the group chaiman is responsible fo r scrutinizing the evidence and preparing an 4 a r t i a l record of all the facts relevant to the group activity. evaluation of the significance of the evidence the group has establishcd, group report m l d be presented along the following lines:

A second reporting function of the group diairnran i s to prepare an Romally, a

- Introduction

This section gives brief identification de ta i l s of the accident, names, titles and affiliations of participating members should be l i s t ed and also such matters of organization as the forming of other groups to handle spedfic assignients. For example i n the case of the Operations Group other groups, such as a Witness Group, are s o œ t i w s foraied. The areas of investigation undertaken by the group and brief de ta i l s of period and locations of investigation ac t iv i ty are also matters which should be recordeä i n this section,

The



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IV-4-2 Manual of Aircraft Accident investiqation

- investiqation

Under this heading a l l the facts, conditions and circumstances established during the investigation are presented i n a narrative form under appropriate sub-headings describing the principle sections of the investigation area. For example, i n the case of the Operations Group sub-headings would include c r e w histories, f l igh t planning, dispatching, weight and balance, etc, Note that a l l the established fac ts relating t o the accident whether o r not considered significant to the causes of the accident mst be included, Copies of all relevant documents should be attached.

- mahation

The significance of the various facts to the circuistances of the accident should be discussed- shaild present a logical developaent of the findings in that investigation ama,

R r i s section of the gmup -port

4.3 Report of the investiqator-in-Charge

Even when an investigation has been conducted w i t h great care and integri ty and the InvestigatoFin-Qiarge has arrived a t an explanation of the accident &ich appears t o be satisfactory, his task is not finished unt i l a l l the facts tha t came to l igh t during the investigation and a l l the evidence which enabled him t o arrive a t a rational explanation of the accident are fu l ly recorded i n his report. in particular; originals, photostats o r cer t i f ied true copies of a l l documents obtained during the investigation mist be appended t o the report, F’urther, the investigator-in-Charge should bear i n mind that unless h i s report i s properly constructed and written i n clear, simple and concise language it may f a i l to explain why the accident happened.

in order t o provide a compmhensive and reliable record of the investigation of accidents a narrative presentation i s usually desirable, investigations many States find tha t accident report forms have some advantages. In these forms a great amount of detailed information is recorded by the investigator by completing the appropriate sections of the form. Narrative descriptions are rest r ic ted t o particular sections, e.g. where a sequence of events is being described. The forms are designed with a v i e w to reducing the time required to record the m r k of investigations, to incorporate some type of investigation check list i n t h e pmsentation and t o provide information i n a manner which will f ac i l i t a t e extraction for s t a t i s t i ca l progranimes, forms iw given a t Appendix 14. in a major investigation, however, the ïnvestigator-in- Charge SUperviSeS the collection of a l l group reports and is responsible for the composite report. T N s report should be a comprehensive factual report of the whole investigation and should fonn the basis f o r development a t a l a t e r stage of an analysis report which w i l l be ful ly supported by the factual information collected during the investigation and

However , f o r reporting small

Examples of some



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PART IV.- Reporting of Occurrences IV-4- 3

which w i l l lead ultimately to the establishment of the probable causes. contain three parts as follows:

It w i l l normally

- Introduction

mis part intraduces the reader to the accident and should include a brief suamiary including a short description of the nature of the accident and giving Iiumbers of casualt ies and the extent of damage t o the aircraft and to any other property. of the organization of the investigation, the names of the participating mernôers and a r e d of the progress of the investigation particularly where salvage and t ransfer of the wreckage have ken involved.

It should also give de ta i l s

- Investiqation

This part is descriptive i n character and should be a comprehensive factual report of the investigation. concerned i n the investigation, t h e report of the Investigator-in-Charge should comprise a consolidation of a l l the group reports received, properly balanced i n respect to each other i n the l igh t of the circumstances of the accident. Supporting documents, photographs, designs, etc. should be attached to the report and references made t o them where appropriate.

When a number of groups has been

- Evaluation

in thfs part, the investigator should present a logical developient of the significance of a l l the facts established i n the course of the investigation. There should be no necessity to repeat any description of evidence but the investigator should review the en t i r e accident and develop the various pattern conditions and events that may have existed. This should lead t o the formilation of a number of hypotheses which may then be discussed and tested against the background of evidence gathered during the investigation. The hypotheses which are not supported by the evidence should be eliminated, i n which case it i s important f o r the investigator to state why a particular hypothesis has been rejected. nie investigator-in-Charge should then jus t i fy his reasons for sustaining the val idi ty of the remaining hypothesis o r hypotheses.

4.4 Final R e p o r t

4.4.1 content and format

The Final Report of the investigation contains the findings together with

Annex 13 requires a sIi1pmary of the Final Report i n a defined foreat ( s e

the substantiating information derived f r o m the investigation and analysis processes.

Chapter 5 below). Although it is not obligatory f o r the Pinal Report of the investigation



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--

In juries Crew Passengers Ouiers

Fatal

Serious

IV-4-4

to be compiled i n t h i s manner, the advantages of so doing are overwhelming. I f the F i n a l Report is restr ic ted t o material s t r i c t l y relevant to the accident, it may preclude the need for preparing a separate sumnary with the inherent danger of d i s t o r t i n g the original meaning i n the interest of brevity.

Manual of Aircraft Accident investiqation

Minorhione J

The following detailed description of the manner i n which a report should be prepared is consistent w i t h the SuFmiary format. Each report should begin with a t i t l e giving the following information: name of the operator; type, model, nationality and registration marks of the aircraft; place and date of the accident; and a Synopsis describing briefly a l l relevant information regarding: Notification of the accident to national and foreign authorities; identification of the investigating authority and accredited representation; organization of the investigation; authority releasing the report and date of publication, and concluding w i t h a brief r e d of the circumstances leading to the accident.

J

The body of the report is divided in to f ive main sections which are reviewed hereunder i n detail.

1.1 History of the f l iqh t

Under t h i s sub-heading a description of the significant events which preceded th@ accident should be given, if possible i n chronological order. achieved by using the radio-telephony transcript as a basis for time and the f l i g h t recorder read-out for manoeuvres. Any relevant evidence can be added as long as it relates to established fact. Usually the f l i gh t number, the type of operation, the departure point and t i m e of departure, and the point of intended landing w i l l be given first followed by a description of the events leading t o the accident, including the c r e w briefing and flight planning, the departure, navigational details, significant comamications t ra f f ic , etc. It is important to give a description of the pertinent events as &Y ocairted and a t was known t o the f l i g h t crew.

The location of the accident s i t e (in la t i tude and longitude) and also the elevation should be included i n this section a s w e l l as the time of the accident i n GMT and **er it was day or night.

"WS may be

1.2 injuries to uersons

The following table should be completed in numbers:



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PART No- Reporting of Occurrences Iv-4-5

1.3 Damage to aircraft

Brief statement of the damage sustained by the aircraft i n the accident (destroyed, substantially damaged, s l igh t ly damaged, no damage).

1.4 Other damage

Brief description of damage sustained by objects o t b r than the subject aircraft such as buildings, ILS or approach l i gh t instal la t ions, etc.

1.5 Personnel informkion

Description of the f l i g h t c r e w qualifications, experience and history for each of the f l i gh t c r e w members (Pilot-in-comand, Co-pilot, Flight Engineer, etc.):

Names and ages;

Validity and typa of licences and ratings;

Flight experience, de ta i l s and types flour, haurs on the type, total hours, de ta i l s of recent training and mandatory and periodic chtcks; experience on mute or aerodrome involved i n the acdduit;

Duty and rest periods;

significant Imdical history and aaedical checks.

A brief statement of the qualifications and experience of cabin attendants, including evacuation d r i l l s , should also be given, as w e l l as pertinent inforiaation regarding other personnel such as air traffic services, maFntenance, etc., when relevant to the accident.

1.6 Aircraft information

Record infonnatîon on the aircraft h i s t o r y and maintenance including the following information:

Aircraft, type, serial mmber and date of construction;

Registration marks and name and address of osmer;

Certificate of Registration - validity;

Certificate of M r w r t h i n e s s - validity;

Maintenance log: date and tirne of issue and period of validity;



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IV-4-6 Manual of Aircraft Accident Investigation

Engine type and mdel, position on the aircraft and ser ia l number, engine overhaul period if an engine failure occurred and hours since overhaul for each engine. If relevant, same information fo r propellers;

Airframe history - t o t a l flying hours since manufacture, since overhaul and since l a s t periodic inspection;

Airframe mdification status;

Accessory history - i n respect of any component which had failed, give de ta i l s of operating l i f e and operating time since manufacture and since overhaul;

Defects - l ist and remark upon any technical defect i n airfram, engine o r accessories discovered during the investigation o r recorded i n the appropriate log and not cleared; (indicate whether f l i gh t was permissible w i t h any defect not cleared);

Aircraft load - gross weight of t h e aircraft, load distribution and its security i n relation t o the permissible l imits fo r the f l i gh t and a t the ti= of the accident. (Rie permissible l imits should be stated and a description given of the loading control system and h o w the detai ls of the aircraft load were established by the investigation.) specific gravity i f relevant.

State also the type of fuel used and

1.7 Heteoroloqical information

Describe the forecast weather conditions and also any relevant observations of actual weather conditions together w i t h an aftercast o r appreciation of the weather i n retrospect. Information along the following l ines should be included where appropriate:

Weather forecast - route ancì terminal forecasts available Lc> the p i lo t and details of any weather briefing pr ior t o departure o r received en-route ;

Weather observations a t the tirne and scene of the accident - ceiling, v i s ib i l i ty , RVR (runway visual range), wind speed and direction, temperature and dewpoint, etc.;

A c t u a l weather conditions over the route of the f l igh t ;

Synoptic weather situation;

Natural l ight conditions a t time of accident - day, twilight, night, moonlight, etc.



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PART IV.- Reporting of ûccurences IV-4-7

1.8 U d s to navigation

include relevant information on the avai labi l i ty of navigation f ac i l i t i e s , including PAR, ILS, VOR, DWE, etc., and on steps taken to establ ish the serviceabili ty of the f a c i l i t i e s a t the t i m e of the accident. Also l ist radio Doppler and i ne r t i a l naId.gatiOn equipment b a r d the aircraft and indicate diether an integrated fiight systcr, um8 installed. Serviceability of the equipment should be stated.

Details of maps, charts, approach plates, radar recordings, etc. appropriate to the f l i gh t should be attached to the report i n Section 5.

1.9 coeiunications

Describe the commanication facilities available to the aircraft and their effectiveness. dramstances of t h e accident should be included by reference to c o d c a t i o n logs o r transcripts of recordings; pertinent extracts should be attached to the report i n Section 9.

The Air Traffic Control and other operation conmunications relevant to the

1.10 Aerodrome information

When the accident has occurred during the take-off o r the landing phase provide relevant information concerning aerodrome instal la t ions, including run~ey length, slope, obstructions, runway conditions, etc. approach lighting, VASIS and runway lighting, etc. should also be given.

Description of aerodrome lighting, Including

. i f the aircraft was not'taking off from, or landing a t an aemärom, relevant information on the take-off or landing area should be given.

1.11 Flight recorders

Provide relevant information regarding t h e condition, location, serviceabili ty, functioning, capacity, parameter coverage, accuracy and sampling rates of the F l igh t Data Recorder and the Cockpit Voice Recorder. a short statement t o this effect wil l be made and the pertinent datq available therefrom w i l l be given, unless they were alreüdy given under 1.1 History of the fl ight. recorders d id not operate properly, the i r shortcomings should be described.

If the recorders operated properly,

if the

Normally f l i g h t recorder readouts axe not included here. They are generally attached t o the report i n Section 5.

1.12 Wredcaqe and impact information

Describe the dis t r ibut ion of the wreckage including the orientation of the

The impact heading, pitch and l a t e ra l a t t i tude and aircraft configuration path a t impact, the location of impact impressions on t h e ground, trees, buildings and other objects. on impact, and factors pertinent to the crashwrthiness of the aircraft should be given.



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Relevant charts and sketches should be referred t o and appended to the report. relatively uncomplicated accidents the whole of the examination of the wreckage may be described under th i s sub-heading. In major accident investigations, however, it wuld normally be necessary t o discuss the examination of the wreckage and technical invest lgatbns under appropriate sections, e.g. structures, powerplants, systemS, human factors, etc. The description i n each section should embrace the significant facts deteril ied by the group o r the special is t who was responsible fo r the detailed investigation and &ose compmhensive report will be contained i n the report of the Investigator-in-lharge.

In

In detail ing the technical features it is important t o include a l l material failures observed and t o indicate whether they occurred prior t o o r a t impact. essential that a l l failed o r malfunctioning components which are deemed t o be significant either t o the accident, or to aviation safety, be properly identified. sections should include details of spedal technical investigations and tests and the significance of the results t o the circumstances of the accident - see also 1.16.

It is

The various

1.13 W c a l and pathological information

Give a brief description of the investigation undertaken and data available therefrom which i s pertinent t o the technical investigation. t o f l igh t c r e w licences should be included under 1.5.

Medical information related

Human engineering factors pertinent to causal factors should be stated.

. a i rc raf t at t i tude a t impact; relationship of injur ies or pathological evidence t o seat )ledical evidence of significance t o the technical investigation such as deceleration forces,

design (attachments, seat bel ts) , breakup of the aircraft structure, smke inhalation, decompression; evidence of preparation f o r an emergency s i tuat ion (forced landing, ditching) o r unlawful interference should be discussed.

The resul ts of the autopsy and pathological examination concerning detection of disease and/or impaired efficiency (carbon monoxide, oxygen deficiency, alcohol, drugs, etc.) should be stated.

The presentation of the evidence relating to the examination of the human elements should be presented i n a m e r similar to that recomaended fo r examination of the aircraft elements.

if f i re occurred give information on the nature of occurrence and of the f i re fighting equipment used and i ts effectiveness.

1.15 Survival aspects

Give a brief description of search, evacuation and rescue, location of C r e w and passengers i n relation t o injur ies sustained. upon so far as i t s effectiveness is concerned. Rie effect of stress on seats and seat belts, and operating practices tha t have an effect on serviceabili ty should be stated.

Safety equipment should be reported



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1.16 Tes t s and research

Describe the nature of any tests o r research undertaken i n connexion w i t h the accident and s t a t e the results.

1.17 Additional information

Add any number of paragraphs that might be required to give the necessary facts, not already included i n 1.1 to 1.16, upon w h i c h appropriate cornnent may be made and f r o m which the necessary conclusions may be drawn so as to i l l u s t r a t e i n t rue perspective the causal factors i n the accident.

- Note: intended to comment i n the analysis section.

Ensure tha t each section contains a l l the technical data upon which it is

-1.18 N e w investíoation techniques

When n e w investigation techniques have been used during the investigation, br ie f ly indicate under th is subheading the reason for using the n e w techniques and refer here to the main features as w e l l as describing the resu l t s under the appropriate sub- headings 1.1 t o 1.17.

2.- ANALYSIS

The analysis should review and evaluate the evidence already presented under "Factual information* and develop the circumstances and events tha t may have existed. n i i s w i l l lead to the fornulation of possible hypotheses which may then be discussed and tested against the background of evidence gathered during the investigation. hypotheses which are not supported by the evidence should be eliminated: it is important to s ta te why a particular hypothesis has been rejected. The just i f icat ion for sustaining the val idi ty of the remaining hypothesis or hypotheses should be stated. There should follow a description of the pattern or series of conditions and events which have h e n detemined to have been causal factors i n the accident and reference should be made to the relevant evidence i n support of the argument as it is developed. When a conclusion is drawn which is an expression of opinion rather than an i r refutable conclusion this should be clearly indicated. There should be no hesitation i n s ta t ing a conclusion of %ause undetermined" should the evidence be insufficient to sustain a positive or probable cause.

these circumstances, however, an indication of the wst l ike ly explanation should be made i n the discussion,

Those

A t the end of t h i s section should be included a discussion of any matter tha t came to l i gh t during the investigation which , while indicating an unsatisfactory s t a t e of affairs, did not i n itself contribute direct ly to the cause of the accident.



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3.- C ~ S I m s

F'indinqs

These should indicate w h i c h aspects of the f l i g h t were contriaitory to the accident and which were not. example :

It i s usual to report on certain features i n every case, f o r

- The training and experience of the c r e w

- The documentation of the aircraft

- The airwxthiness of the aircraft

- The loading of the aircraft

- Whether o r not there was a pre-crash failure of the aircraft.

in addition the features which were contributory should be identified. Any issue of controversy should, i f possible, be resolved, for example:

- There w a s no malfunction of the elevator control;

- Pilot perfonuance was not affected by fatigue.

Areas of ambiguity should be identified and stated, fo r example:

- It cannot be established i f the pilot-in-command o r co-pilot w a s f lying the aircraft.

Causes

The expression of causes should be a concise statement of the reasons why

- the accident occurreà and not an abbreviated description of the circumstances of the accident.

4.- SAFETY R E C ~ T I O N S

Include here any safety recommendation made fo r the purpose of accident prevention and s ta te , i f appropriate, any resultant corrective action.

Irrespective of whether reconmendations are included as an integral par t of the report o r presented separately (dependent upon State procedures) it should be borne i n mind that the ultimate goal of a t ruly effective investigation i s to improve air safety. To t h i s end the recommendations should be made i n general o r specific terms i n regard t o matters arising from the investigation whether they be direct ly associated w i t h causal factors o r have been prompted by other factors i n the investigation.



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PART 3.- Reporting of Occurrences IV-4-11

5.- APPENDICES

Include, as appropriate, any other pertinent information considered necessary f o r the understanding of the report.

4.402 E'ublication and distribution

in accordance w i t h the specifications of Annex 13 - Chapter 6:

- The State conducting the investigation should consult the State of Registry and the State of Hanufacture, if these States had appointed accredited representatives to the investigation, before publishing the Final Report or any par t thereof;

- No State, not even the State which conducted the investigation under f u l l delegation, should circulate o r publish the Final Report or any part thereof without the cansent of the State which inst i tuted the investigation, unless the Report has already been published by the l a t t e r State.

- In addition t o the national distribution, the State conducting the investigation shal l send the "Final Report" with a rdnimum of delay t o :

a ) the State which inst i tuted the investigation ( i f it had delegated the whole of the investigation);

b) the State of Registry;

cl the State of Manufacture;

d ) any State w h i c h has provided information relevant to the accident.



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QupTER5

OF THE FINAL REPORT

5.1 Purpose of the Summary

The causes of aircraft accidents, especially those i n &ich large modern aircraft are involved, may be of concern to a l l States and particularly t o those using the same model o r type of aircraft. States of the findings of aircraft accident investigations is highly desirable and consti tutes a major contrialt ion t o aviation safety.

Therefore, a prompt dissenclnation to a l l Contracting

-The dissemination of the "Final Report" to a l l Contracting States is usually impractical because of the size of tha t document, especially when deta i l s w h i c h are not essent ia l f o r the understanding of the accident and its cause have been included. T h i s i s why a sumnary of the report containing the relevant information on the investigation is necessary fo r a l l Contracting States which are not d i rec t ly involved i n the investigation of the accident.

The pirpose of the " 3 a m a r y of the Pinal Report" is not t o replace the report, but to sumiiarize it i n a convenient and uniform format i n order tha t it can be readily included i n the ICA0 Aircraft Accident Digest, thus permitting its dissemination to a l l Contracting States.

5.2 of Accidents f o r which a Su p is Rewired

in accordance with the specifications of Annex 13 - Chapter 6 , the State which has conducted an investigation in to an aircraft accident, wherever it occurred, i s required t o submit a Sumnary of the Final Report to the International C i v i l Aviation Organization whenever tha t State considers that the international dissemination of the information contained i n the Final Report i s of exceptional value to the promotion of aviation safety, because of the successful employment of new investiqative teduiiqués or the disclosure of the need fo r s ignif icant preventive action.

5.3 Format

The Sunnoary of the Final Report is to be prepared i n the format set out' i n the Appendix t o Annex 13, which is reflected i n Chapter 4 above, one of the working languages of ICAO, using as far as possible the terminology contained i n the ICAO Lexicon (Doc 91101,

It mst be written i n

i0/9/76 No. 6



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5.4 Precautions t o be Taken when Preparing the Suinnary

in preparing a Summary of the Final Report ensure that:

a) a l l information relevant to an understanding of the factual information, analysis and conclusions is included under each appropriate heading;

b) where information i n respect of any of the items i n 1.- Factual infomation is not available, o r is irrelevant to the circumstances leading to the accident, a note t o this effect is included under the appropriate subheadings;

c) any other pertinent information from the Report, such as diagrams, photographs, charts, etc., considered essential f o r inclusion in the Summary is attached i n Section 5.- Appendices.

5.5 Mdressee of the si Y in accordance with the specifications of Annex 13, the Summary of the Final

Report i s to be sent i n t r ip l ica te to:

The Secretary General Attention AIG international C i v i l Aviation Organization P. O. Box 400, Succursale: P lace de l'Aviation internationale 1000 Sherbrooke Street West Wntreal, Quebec, Canada H U 2R2



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M A L OF AIRCRAFT ACCIDENT INVESTIGATION

PART V. - ACCIDENT PREVENTION

P A R T



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v-1-1 P a r t V.- Accident P r e v e n t i o n

CMPTER 1

GENERAL

A s a l r e a d y mentioned i n P a r t I , Chapter 1 of t h i s Manual, t h e fundamental purpose of an a i r c r a f t a c c i d e n t i n v e s t i g a t i o n is t o determine t h e f a c t s , c o n d i t i o n s and circumstances p e r t a i n i n g t o t h e a c c i d e n t , w i th a view t o e s t a b l i s h i n g t h e p robab le c a u s e ( s ) t h e r e o f , so t h a t a p p r o p r i a t e s t e p s may be t aken t o p reven t a r e c u r r e n c e of a s i m i l a r acc ident . Thus i t can be s a i d t h a t c a r e f u l a c c i d e n t i n v e s t i g a t i o n is t h e b a s i s of a c c i d e n t p reven t ion and, i n t h i s c o n t e x t , it should be c l e a r l y understood t h a t a c c i d e n t p reven t ion is not s o l e l y r e l a t e d t o t h e a c c i d e n t cause. During t h e course of t h e i n v e s t i g a t i o n t h e v a r i o u s a s p e c t s of t h e o p e r a t i o n of t h e a i r c r a f t , t h e maintenance of t h e a i r c r a f t , navi- g a t i o n a l f a c i l i t i e s , communications, a i r t r a f f i c c o n t r o l , c o c k p i t d e s i g n , a i r c r a f t crash- wor th iness , to - name a few, a r e examined. I n v a r i a b l y t h e i n v e s t i g a t o r , having r e g a r d t o t h e knowledge gained du r ing t h e i n v e s t i g a t i o n , w i l l form an o p i n i o n t h a t improvements could be e f f e c t e d which would raise t h e l e v e l of a i r s a f e t y , and i t is h i s r e s p o n s i b i l i t y t o make recommendations concerning t h e s e matters.

It is only by a w i d e and prompt d i s semina t ion of t h e r e s u l t s of t h e i n v e s t i g a t i o n , n o t only i n t h e States d i r e c t l y concerned, but a l s o on a worldwide b a s i s , t h a t proper a c c i d e n t p r e v e n t i o n can be achieved. I n t h i s connexion, a u t h o r i t i e s respon- s i b l e f o r a c c i d e n t i n v e s t i g a t i o n s should be f u l l y conscious of t h e importance of adhe r ing t o t h e s p e c i f i c a t i o n s o f Annex 13 and i n p a r t i c u l a r t o those r e g a r d i n g r e p o r t i n g . I

Another v e r y impor t an t f a c t o r i n a c c i d e n t p r e v e n t i o n is t h e c a r e f u l s tudy of i n c i d e n t s . An a c c i d e n t is seldom t h e r e s u l t of a s i n g l e cause ; i n most cases it is t h e r e s u l t of a more o r less complex c h a i n of c i rcumstances. It may be s a i d t h a t every i n c i d e n t is a p o t e n t i a l a c c i d e n t and h a s remained a n i n c i d e n t simply because one l i n k of t h e cha in w a s missing. T h e r e f o r e , every i n c i d e n t should be r e p o r t e d and when necessa ry inves- t i g a t e d with t h e same care as i f i t w e r e a n a c c i d e n t .

I f a t any t i m e du r ing t h e cour se of an i n v e s t i g a t i o n t h e n e c e s s i t y f o r u rgen t c o r r e c t i v e a c t i o n becomes appa ren t t h e a p p r o p r i a t e a u t h o r i t i e s should be informed without delay. Any such a c t i o n t aken should be mentioned i n t h e a c c i d e n t r e p o r t .

F i n a l l y , b e s i d e s a p rope r d i s semina t ion of ADREP in fo rma t ion and t h e ICA0 A i r c r a f t Accident D i g e s t , t h e importance of s a f e t y p u b l i c a t i o n s a t n a t i o n a l l e v e l is brought t o t h e a t t e n t i o n o f a u t h o r i t i e s r e s p o n s i b l e f o r a c c i d e n t i n v e s t i g a t i o n s and p reven t ion . i s by such p u b l i c a t i o n s t h a t a g e n c i e s , o r i n d i v i d u a l s , p r i m a r i l y concerned wi th a c c i d e n t p reven t ion (e .g . S t a t e a g e n c i e s , manufac tu re r s , f l i g h t crew, e t c . ) can p r o p e r l y be kep t informed of a c c i d e n t s and i n c i d e n t s r e l e v a n t t o a i r c r a f t and material used i n t h e i r own S t a t e , and of a p p r o p r i a t e t e c h n i c a l and o p e r a t i o n a l r e s e a r c h OK developments.

I It

301.5177 No. 7



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Part V.- Accident P reven t ion v-2-1

CHAPTER 2

STUDY OF INCIDENTS

S i g n i f i c a n t c o n t r i b u t i o n s t o a i r s a f e t y have r e s u l t e d from recommendations a r i s i n g from a c c i d e n t i n v e s t i g a t i o n s . Most Con t rac t ing S t a t e s i n adop t ing t h e s t anda rd d e f i n i t i o n of an a c c i d e n t have p l aced a S t a t u t o r y o b l i g a t i o n on t h e p i l o t , owner o r ope ra to r of an a i r c r a f t t o r e p o r t t o t h e i n v e s t i g a t i n g a u t h o r i t y any occurrence which f a l l s w i t h i n t h e terms of t h e d e f i n i t i o n . Informat ion of t h e occur rence t h u s forms t h e s t a r t i n g p o i n t from which an i n v e s t i g a t i o n a p p r o p r i a t e t o t h e c i r cums tances is commenced.

There are, however, many i n c i d e n t s occur r ing d a i l y where no i n j u r y o r damage is s u f f e r e d bu t i n which t h e s a f e t y of t h e a i r c r a f t may be p l aced i n jeopardy . The thorough i n v e s t i g a t i o n oi a l l such i n c i d e n t s f r e q u e n t l y p rov ides more b a s i c in fo rma t ion which can be used f o r t h e purpose of a c c i d e n t p r e v e n t i o n than may be provided by t h e e x h a u s t i v e i n v e s t i g a t i o n of a n aircraft d i s a s t e r . An i n c i d e n t can be envisaged as a n occurrence , o the r t han a n a c c i d e n t , which i s a s s o c i a t e d wi th t h e o p e r a t i o n of an a i r c r a f t when' t h e s a f e t y of t h e a i r c r a f t h a s been endangered, or i s a s i t u a t i o n which could endanger an air- c r a f t i f i t occur red a g a i n i n o t h e r c i rcumstances . A d e f i n i t i o n of an i n c i d e n t t h e r e f o r e can be phrased only i n g e n e r a l terms. The r e p o r t i n g of such occur rences can be achieved p r i m a r i l y by t h e encouragement of a i r s a f e t y programmes i n which t h e p o t e n t i a l b e n e f i t s t h a t w i l l f l ow from t h e i n v e s t i g a t i o n of i n c i d e n t s are so s t r e s s e d t h a t p i l o t s , o p e r a t o r s and o t h e r s i n t h e a v i a t i o n i n d u s t r y w i l l be w i l l i n g t o Co-operate wi thou t be ing embarrassed as a r e s u l t of i n fo rma t ion which is submi t t ed by them.

I n c i d e n t i n v e s t i g a t i o n should never be neg lec t ed bu t should be pursued wi th t h e same v igour as would be a p p l i e d t o a s e r i o u s acc iden t which by i t s n a t u r e becomes worldwide news.

Accident i n v e s t i g a t i o n has f r e q u e n t l y brought t o l i g h t p r e v i o u s i n c i d e n t s which were d ismissed as i n s i g n i f i c a n t a t t h e t i m e of t h e i r occu r rence . The knowledge acqui red i n r e t r o s p e c t from t h e a c c i d e n t i n v e s t i g a t i o n h a s demonst ra ted t h a t t h e s e i n c i - d e n t s , i f p r o p e r l y i n v e s t i g a t e d and i n t e r p r e t e d , could have s u p p l i e d t h e b a s i s of remedia l a c t i o n which would have p reven ted t h e occurrence of t h e a c c i d e n t under i n v e s t i g a t i o n . Therefore i t would be h i g h l y d e s i r a b l e t h a t i n c i d e n t s from which in fo rmaf ion l i k e l y t o c o n t r i b u t e t o a v i a t i o n s a f e t y can be ob ta ined , be g iven t h e same worldwide p u b l i c a t i o n as acc iden t s.



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P a r t V.- Accident P reven t ion V- 3- 1

CHAPTER 3

SAFETY WBL I CAT IONS

The I C A 0 A i r c r a f t Accident Diges t i s a worldwide s a f e t y p u b l i c a t i o n which i s of major i n t e r e s t t o a u t h o r i t i e s r e s p o n s i b l e f o r acc iden t i n v e s t i g a t i o n and prevent ion . However, i t cannot r e p l a c e s a f e t y p u b l i c a t i o n s a t r e g i o n a l and n a t i o n a l l e v e l f o r t h e f o l - lowing reasons :

- i t c o n t a i n s summaries of f a t a l o r major a c c i d e n t s t o a l l t ypes of commercial a i r c ra f t . Although l e s s o n s are l ea rned from eve ry a c c i d e n t , t hose i n which t h e a i r c r a f t t ype i s not i n o p e r a t i o n i n a p a r t i c u l a r S t a t e o r t h e opera- t i o n a l environment i s cons ide rab ly d i f f e r e n t , are o f t e n of less i n t e r e s t t o o p e r a t o r s and f l i g h t crew of t h a t S t a t e ;

- t h e p u b l i c a t i o n of a c c i d e n t s i nvo lv ing g e n e r a l a v i a t i o n i s l i m i t e d ; how- e v e r , i n some Sta tes , t h i s is a major a c t i v i t y o r may be of major concern;

- t h e p u b l i c a t i o n of i n c i d e n t s is l i m i t e d .

.kt r e g i o n a l l e v e l , o r g a n i z a t i o n s such as t h e European C i v i l Av ia t ion Con- f e rence (ECAC), may p u b l i s h s t a t i s t i c a l a n a l y s e s i n o r d e r t o p rov ide a more r e p r e s e n t a t i v e sample than might be p o s s i b l e a t n a t i o n a l l e v e l , p a r t i c u l a r l y i n c e r t a i n areas of t h e world. They also p r c v i d e an e x c e l l e n t media f o r exchange of a i r s a f e t y informat ion .

n a t i o n a l l e v e l , a s a f e t y p u b l i c a t i o n should c o n t a i n :

Summary of r e p o r t of s i g n i f i c a n t a c c i d e n t s and i n c i d e n t s which occurred t o a i r c r a f t r e g i s t e r e d i n t h e S t a t e

Summary of r e p o r t of a c c i d e n t s and i n c i d e n t s i n which impor tan t s a f e t y a s p e c t s were brought t o l i g h t by t h e i n v e s t i g a t i o n , e s p e c i a l l y when t h e a i r c r a f t involved w a s of a type i n o p e r a t i o n i n ' t h e S t a t e

a i r s a f e t y a r t ic les of a g e n e r a l n a t u r e o r g i v i n g in fo rma t ion on c e r t a i n t e c h n i c a l o r o p e r a t i o n a l c h a r a c t e r i s t i c s of a i r c r a f t and equipment i n o p e r a t i o n i n t h e S t a t e

a c c i d e n t s t a t i s t i c s ( p r e f e r a b l y wi th comment r e l a t i n g t o t r e n d s determined from t h e a n a l y s i s of t h e s e s t a t i s t i c s ) .

N a t i o n a l s a f e t y p u b l i c a t i o n s should be given a wide d i s t r i b u t i o n amongst a l l n a t i o n a l a g e n c i e s d i r e c t l y o r i n d i r e c t l y concerned wi th a v i a t i o n s a f e t y , i n c l u d i n g a i r l i n e s , manufac turers of a i r c r a f t and a i r c r a f t equipment, p i l o t s ' and a i r t r a f f i c c o n t r o l l e r s ' a s soc i a t ions.



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P a r t V.- Accident P reven t ion V-4-1

CHAPTER 4

ENGINEERING ASPECTS

4 . 1 General

It is d i f f i c u l t t o imagine any a c c i d e n t where, somewhere a l o n g t h e l i n e a human a c t o r omission does not p r o v i d e an impetus o r c a t a l y s t t o t h e c h a i n of events. One t a s k , o f t e n d i f f i c u l t , d u r i n g a n i n v e s t i g a t i o n i s t o i d e n t i f y t h e o r i g i n a l l i n k i n t h e c h a i n which makes the a c c i d e n t i n e v i t a b l e . T h i s is n o t done t o p o i n t t h e f i n g e r of blame, bu t t o h e l p t o p reven t a s i m i l a r occurrence.

A i r a c c i d e n t s have been s u b j e c t e d t o some form of c r i t i ca l s c r u t i n y e v e r s i n c e t h e mar r i age of t h e i n t e r n a l combustion eng ine t o t h e a i r f r ame . however, i n v e s t i g a t i o n s i n t o a c c i d e n t s have t aken i n t o s e r i o u s account t h e r e l a t i o n s h i p between man and h i s machine; t h i s i n c l u d e s pe r sonne l on t h e ground whether a t t h e f a c t o r y o r maintenance base as w e l l as a i r c rew. a i r b o r n e pe r sonne l c o n t r i b u t e d i r e c t l y t o an a c c i d e n t are few when compared w i t h aircrew; however, when mis t akes are made on t h e ground, be they on t h e drawing board o r i n t h e maintenance hangar , t h e e f f e c t s can be j u s t a s f i n a l as t h o s e which a r e brought about by an e r r o r of judgement o r a b r i e f mental a b e r r a t i o n o r an e r o s i o n of o p e r a t i n g s t a n d a r d s on t h e f l i g h t deck.

During r e c e n t y e a r s

The number of occas ions when non-

A l l who d e a l w i t h s a f e t y w i l l do w e l l t o remember t h a t t h e r e is no such t h i n g a s i n f a l l i b i l i t y , mi s t akes w i l l happen, f a i l u r e s w i l l occu r ; t h e " f a i l s a f e " concept i n a i r c r a f t d e s i g n can be s a i d t o be an admission o f t h i s s ta te of a f f a i r s .

The f i r s t and p robab ly t h e most important l e s s o n t o be a p p r e c i a t e d is t h a t N o d e s i g n e r , no eng inee r o r o p e r a t o r is a c c i d e n t s do n o t j u s t happen - t h e y are caused.

i n f a l l i b l e . board. E f f i c i e n t i n v e s t i g a t i o n o f each i n c i d e n t o r a c c i d e n t is t h e r e f o r e e s s e n t i a l so t h a t t h e l e s s o n l ea rned can be ploughed back, o r f r e e l y a d v e r t i s e d , i n o r d e r t h a t a c c i d e n t s from a s i m i l a r cause can be prevented i n t h e f u t u r e . There should be no s e c r e t s su r round ing t h e cause of a c i v i l a i r c r a f t a c c i d e n t .

' f u l l e s t i n fo rma t ion on t h e behaviour and mechanical r e l i a b i l i t y of a i r c r a f t , p a r t i c u l a r l y t r a n s p o r t a i r c r a f t i n service, c i v i l o r m i l i t a r y , be fed back t o t h e manufacturer and t h e a i r w o r t h i n e s s a u t h o r i t i e s so t h a t immediate r emed ia l a c t i o n s t u d i e s can be made. Th i s may a l s o , by r ead ing a c r o s s , l e a d t o improved r e l i a b i l i t y i n t h e n e x t g e n e r a t i o n of a i r c r a f t .

To err is human. The primary cause may start on t h e d e s i g n e r ' s drawing

It is extremely important t h a t t h e

Immediate remedial a c t i o n is v i t a l l y necessa ry where i n v e s t i g a t i o n h a s determined a t r u e and p o s i t i v e c a u s e , because i f such a c t i o n is not taken then ano the r a c c i d e n t from a similar cause can r e s u l t . obeyed. u n t i l remedial a c t i o n is taken.

Mandatory a i r w o r t h i n e s s d i r e c t i v e s must be If t h i s is not p o s s i b l e t h e n it i s safer t o "ground", i . e . n o t f l y t h e a i r c r a f t ,

4.2 -"Murphy' s Law"

I n a d d i t i o n t o t h e v a r i o u s l a w s of phys i c s which a r e observed i n aeronau-

" I f i t is mechanical ly p o s s i b l e t o assemble some p a r t i n c o r r e c t l y , someone, some t i ca l c i r c l e s t h e r e is y e t a n o t h e r l a w which, t o t h e u n i n i t i a t e d , goes something l i k e t h i s : day, w i l l assemble i t i n t h a t way". bad des igne r s ! p o s s i b i l i t i e s of mi s t akes which can occur i n assembly o r i n s p e c t i o n .

'Murphy' h a s been d e s c r i b e d as t h e p a t r o n s a i n t of It is v i t a l l y important i n t h e des ign s t a g e t h e r e f o r e t o e l i m i n a t e t h e

18/6/78 No. 9



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V-4-2 Manual of A i r c r a f t Accident I n v e s t i g a t i o n

4 . 3 &tal Fa t igue

Perhaps i n no o t h e r form of eng inee r ing h a s t h a t phenomenon 'metal f a t i g u e ' played such an i n s i d i o u s p a r t than i n a i r c r a f t engineer ing . reserve of s t r e n g t h i n i t s e a r l y l i f e may, i n t h e cour se of t i m e , f a i l s "in f a t igue" through repea ted a p p l i c a t i o n s of load. and l a r g e i n number. They may a l s o be t h e oppos i t e . aerodynamic o r s o n i c sources . n a u t i c a l des ign c r i t e r i a , means t h e per iod r e q u i r e d t o produce f a i l u r e under c e r t a i n cond i t ions . causes of f a t i g u e . and stress raisers and keep t h e normal working stress a t t h e lowes t p o s s i b l e l e v e l . I n a i r c r a f t s t r u c t u r e s where weight is impor tan t t h i s is n o t always a simple procedure, bu t poor f i t t i n g techniques , i n s u f f i c i e n t t o r q u e load ing , sha rp c o r n e r s , s c r a t c h e s and notches and co r ros ion i n v i t a l p a r t s a r e j u s t some of t h e obvious and t h e r e f o r e avo idab le c o n t r i b u t o r y f a c t o r s which may l ead t o f a t i g u e f a i l u r e . Every endeavour is made t o eng inee r o u t t h e f a t i g u e problem. compressive r o l l i n g , are j u s t some of t h e w e l l known methods used t o combat f a t i g u e . Corros ion must a l s o be guarded aga ins t i n h i g h l y s t r e s s e d p a r t s f o r , i f f a t i g u e does n o t c a t c h t h e des igne r o u t , i ts second cous in , stress c o r r o s i o n , w i l l , p a r t i c u l a r l y i n modern h igh s t r e n g t h l i g h t a l l o y s . Regular i n s p e c t i o n f o r c o r r o s i o n i s v i t a l . That f a m i l i a r express ion " sa fe and sound" is w e l l known and t h e r e i s no doubt t h a t t h e s t r u c t u r e of an a i r c r a f t must be sound t o remain sa fe ! I n v i t a l areas t h e philosophy of f a i l s a f e should be designed i n t o t h e s t r u c t u r e . Th i s concept is no t new: Leonardo D a Vinci , around the end of t h e f i f t e e n t h cen tu ry wrote: wings onc s h a l l make cord t o bear t h e s t r a i n and a looser one i n t h e same p o s i t i o n so t h a t if one breaks under t h e s t r a i n t h e o t h e r is i n p o s i t i o n t o s e r v e t h e same function! ' ' I n r ecen t yea r s t h e t r end i n a l l s t r u c t u r a l des ign is t o move away from t h e f a t igue - prone h igh s t r e n g t h a l l o y s towards less c r i t i c a l material . F u l l scale f a t i g u e t e s t i n g is, of course, s t i l l e s s e n t i a l and i t is a l s o e s s e n t i a l t h a t t h e s e t e s t s are w e l l ahead of t h e a i r c r a f t ' s d a t e of e n t r y i n t o senrice. h igh i n t e n s i t y n o i s e p a r t i c u l a r l y i n a r e a s a f t of modern j e t eng ines are a c u r r e n t problem. So t h e combination of f a i l s a f e concept, materials less prone t o f a t i g u e c racking , p r o t e c t i o n a g a i n s t co r ros ion and an advanced f a t i g u e t e s t i n g programme i n s imula ted working cond i t ions o f f e r s more confidence and promise f o r t h e f u t u r e .

A s t r u c t u r e wi th ample

These repea ted loads may be small i n amplitude

The term " f a t i g u e l i f e " , now a fami l ia r phrase i n aero- They may o r i g i n a t e from mechanical,

Much thought and work has however, e l i m i n a t e d some of t h e con t r ibu to ry The secret of combating f a t i g u e is t o e l i m i n a t e stress concen t r a t ions

Highly po l i shed and p ro tec t ed s u r f a c e s , shot peening,

"In cons t ruc t ing

Aerodynamic shock waves and cones of

4 . 4 In-Fl ight F i r e s

Accidents r e s u l t i n g from i n - f l i g h t f i r e s are nowadays comparatively rare; i n t h e m a j o r i t y of cases f i r e i n f l i g h t , c i v i l o r m i l i t a r y , h a s been due t o a major mechanical f a i l u r e of an engine, o r , i n one known i n s t a n c e , a h y d r a u l i c f l u i d f i r e which r e s u l t e d from t h e f a i l u r e of a component i n a t o t a l l y u n r e l a t e d system. The l e s s o n s learned from a g r e a t number of f i r e a c c i d e n t s i n v e s t i g a t e d dur ing t h e war y e a r s l e d t o a r e d r a f t i n g of des ign requirements cove r ing f i r e p reven t ion , d e t e c t i o n and e x t i n c t i o n i n both m i l i t a r y and c i v i l a i r c r a f t . t h e types of f i r e which have occurred.

It i s perhaps worth r ev iev ing some of

4.4 .1 Fuel f i r e s

The i g n i t i o n of free f u e l o r o i l fo l lowing a major mechanical f a i l u r e o r 'non conta ined ' f a i l u r e of a power p l an t was t h e predominating f e a t u r e i n nea r ly a l l f i r e acc iden t s .

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With t h e i n t r o d u c t i o n of t h e t u r b i n e eng ine , u s i n g a kerosene type of f u e l of h igh f l a s h p o i n t , d i d n o t n o t i c e a b l y a l t e r t h e p i c t u r e . Kerosene h a s u n f o r t u n a t e l y a low spontaneous i g n i t i o n tempera ture and can be a ve ry dangerous f u e l i f i t l e a k s onto h o t s u r f a c e such as a j e t p i p e o r c o l l e c t s benea th t h e h o t j e t p i p e o r t u r b i n e shroud. I n t h i s r e s p e c t kerosene is more dangerous than h igh o c t a n e p e t r o l . It is of t h e utmost importance t h e r e f o r e t h a t v e n t i l a t i o n , coo l ing , and d ra inage of engine compartments is adequate and e f f i c i e n t . i g n i t i o n of kerosene i n a n enc losed and u n v e n t i l a t e d space. Almost double t h i s tempe- r a t u r e would be necessa ry t o t h e spontaneous i g n i t i o n of p e t r o l i n t h e same c i rcumstances . F i r e i n t h e a i r at. a power p l a n t need no t be a s e r i o u s hazard p rov id ing t h e crew have an e a r l y and unmis takable warning of iFs outbreak and are provided w i t h , and are t r a i n e d t o use i n t h e c o r r e c t sequence, t h e means of e x t i n c t i o n , s h u t t i n g o f f promptly t h e f u e l at t h e low p r e s s u r e v a l v e w i l l i n m o s t cases e x t i n g u i s h t h e f i re .

A t empera ture as low as 215OC is s u f f i c i e n t t o cause spontaneous

4.4.2 Metal f i r e s

A s m a l l number of f i r e s have developed from t h e secondary i g n i t i o n of t i t an ium o r magnesium a l l o y i n eng ines . f r i c t i o n rubbing of t i t a n i u m b l a d e s has caused s e r i o u s f i r e s . and secondary i n cause , t h i s type of f i r e is mentioned because of t h e extreme tempera- t u r e s reached and t h e i n a b i l i t y of t h e a i r b o r n e e x t i n g u i s h e r system t o e x t i n g u i s h such f i r e s .

F a i l u r e s of t h e eng ine compressor caus ing Although few i n number

4.4 .3 Domestic f i r e s

Speaking of f i r e s i n f l i g h t , now we are i n t h e jumbo j e t age wi th v e r y l a r g e a i r c r a f t c a r r y i n g s e v e r a l hundred passengers i n cinema-like sur roundings , t h e domestic t y p e of f i r e i s now a rea l danger i n t h e passenger compartments. F i r e resistant or f i r e -p roof m a t e r i a l s f o r f u r n i s h i n g s and i n s u l a t i o n is e s s e n t i a l at t h e des ign and c o n s t r u c t i o n s t a g e . N o n f i r e -p roof p ipes c a r r y i n g oxygen and r o u t e d i n the s t r u c t u r e where t h e r e i s a f i r e r i s k must be eliminated. Electr ical looms and o i l systems should always be w e l l d ivorced from oxygen system. Seve ra l minor f i r e s have a ready occurred . Great r a r e is necessa ry p a r t i c u l a r l y from smokers. A s m a l l number of f i r e s i.n passenger compartments have occurred i n t h e l a tes t a i r l i n e s from c a r e l e s s d i s p o s a l of l i g h t e d c i g a r e t t e s , i n some i n s t a n c e s dropped i n t o waste paper towel boxes i n t o i l e t s . Passenger d i s c i p l i n e and c l e a r i n s t r u c t i o n s are a l s o necessary .

4.4.4 Hydraul ic f l u i d f i r e s

Now t h a t less flammable hydrau l i c f l u i d s have been developed t h i s t ype o r f i r e is a r a r i t y i n modern a i r c r a f t . However, such a f i r e once occurred i n a r e l a t i v e l y modern twin-engined j e t which culminated i n t o t a l d i s a s t e r s h o r t l y a f t e r take-off when t h e t a i l - p l a n e s t r u c t u r e w a s des t royed by a f i r e which r e s u l t e d from a cha in of e v e n t s s t a r t i n g wi th a d e f e c t i v e non-return v a l v e i n t h e a i r d e l i v e r y system from the A u x i l i a r y Power Uni t (APU). The NRV, which was a h inged f l a p va lve , remained open a s t h e r e s u l t of a su rge when main engine compressor v a l v e w a s s e l e c t e d a f t e r s t a r t - u p ; engine a i r p r e s s u r e r e a c t i n g a g a i n s t APU p r e s s u r e w i t h i n t h e APU i t s e l f c r e a t e d h igh tempera ture c o n d i t i o n s i n t h e APU plenum chamber which i g n i t e d t h e a c o u s t i c b l anke t . T h i s , i n t u r n burned through a l i g h t a l l o y bulkhead beyond which w a s t h e hydrau l i c compensator u n i t f o r t h e t a i l - p l a n e a c t u a t o r . The ensuing h i g h tempera ture degraded t h e f i r e r e t a r d a n t p r o p e r t i e s of t h e h y d r a u l i c f l u i d and an u n c o n t r o l l e d and undetec ted f i r e spread upwards through t h e f i n s t r u c t u r e which a c t e d as a chimney. A number of l e s s o n s w e r e l ea rned and t h e remedia l measures inc luded a modified NRV, f i r e - p r o o f bulkheaq, improved d r a i n a g e from t h e compensator chamber and t h e i n t r o d u c t i o n of s t a i n l e s s s tee l a c t u a t i n g rods f o r manual c o n t r o l of t h e e l e v a t o r s .

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4.5 x i n e e r i n g Prevent ion

4.5.1 F a i l s a f e des ign cri teria

T h i s must be embodied i n t h e d e s i g n i n a l l v i t a l c o n t r o l s , s t r u c t u r e , systems o r i n s t rumen t s , t h e i n - f l i g h t f - a i l u r e of which would l e a d t o d i s a s t e r . conjunct ion wi th t h i s cr i ter ia a l l b l i n d a s sembl i e s should be avoided and a l l v i t a l c o n t r o l s and s t r u c t u r a l p a r t s must be e a s i l y a v a i l a b l e f o r i n s p e c t i o n .

I n

4.5.2 Ambiguity

Ambiguity of meaning o r i n d i c a t i o n o r d i f f i c u l t y i n r ead ing qu ick ly v i t a l It i s q u i t e simple t o misread a mul t i -po in te r ins t ruments o r p l aca rds must be avoided.

altimeter by as much as 10 O00 f e e t . "Magicians have known f o r c e n t u r i e s t h a t people see but do n o t observe." S i m p l i c i t y of p r e s e n t a t i o n must be t h e a i m . Unnecessary compl ica t ion o r c l u t t e r i n t h e des ign o r p r e s e n t a t i o n of v i t a l f l y i n g ins t ruments can l e a d t o human e r r o r s i n r ead ing them. of occas ions wi th d i s a s t r o u s r e s u l t s .

Consequently t h i s has indeed happened on a number

From t h e hard l e s s o n s of p a s t mis takes a new gene ra t ion of ins t ruments h a s now emerged. P a r t i c u l a r a t t e n t i o n has been pa id t o t h e i r p r e s e n t a t i o n i n an endeavour t o "design out" e r r o r s i n reading. The a l t i m e t e r , i n p a r t i c u l a r , has been given s p e c i a l a t t e n t i o n not only t o i t s d i r e c t and unambiguous he igh t p r e s e n t a t i o n , but j u s t a s important , r a d i o l r a d a r a l t i m e t e r s coupled t o a Ground Proximi ty Warning System (GPWS) . Such systems are now f i t t e d t o t h e l a t e s t aircraft and a r e mandatory equipment i n some c o u n t r i e s .

4.5.3 I n c o r r e c t assembl ies

"Murply's Law" must be avoided by good des ign which w i l l ensure t h a t i t is mechanically impossible t o assemble v i t a l c o n t r o l s o r p a r t s i n c o r r e c t l y . Whilst t h i s requirement is now w r i t t e n i n t o t h e des ign requirements f o r a i r c r a f t , a c c i d e n t s from t h i s ve ry cause cont inue .

4.5.4 Maintenance, i n spec t ion and q u a l i t y c o n t r o l

I n a i r c r a f t , , perhaps more than any o t h e r t r a n s p o r t v e h i c l e , does t h e importance of t hese ground d i s c i p l i n e s f o r eng inee r s app ly ; i t is no use having a f a i l s a f e des ign i f t h e human inspec to r misses t h e i n i t i a l f a i l u r e . I t is no use t h e maintenance documents c a l l i n g f o r independent and d u p l i c a t e i n s p e c t i o n of v i t a l f l y i n g c o n t r o l s i f t h e second i n s p e c t o r f a i l s t o i n s p e c t and merely s i g n s t h e in spec t ion record because he has " i m p l i c i t f a i t h i n t h e work s t anda rd of Char l ie" . The hard l e s s o n of exper ience , o f t e n l e a r n t t oo l a t e , now ca l l s f o r t h e h i g h e s t s t anda rds of workmanship and consc ien t ious d i s c i p l i n e s from a l l ground maintenance personnel .

A i r c r a f t a c c i d e n t s due t o f a u l t y maintenance a r e rare; perhaps, because of t h i s b u i l d u p of confidence and t h e f a c t t h a t , g e n e r a l l y speak ing , t h e machine is now more r e l i a b l e than the human t h e r e i s nowadays a tendency f o r t h e frequency of i n s p e c t i o n s t o be lowered and t h e t i m e between overhauls t o be extended. I t is important t h a t where t h i s po l i cy i s approved t h a t i n spec t ions f o r metal f a t i g u e c rack ing and co r ros ion i n p a r t i c u l a r a r e given s p e c i f i c a t t e n t i o n . a i r c r a f t should be looked f o r more f r equen t ly a s t h e a i r c r a f t g e t s o l d e r , because normally both are a s s o c i a t e d wi th accumulated o p e r a t i o n a l t i m e . l a w which governs t h e l i f e and r e l i a b i l i t y of machines as w e l l as humans and t h e f a m i l i a r "bath tub" curve i l l u s t r a t e s t h i s adequate ly . another type of f a i l u r e w i l l predominate so t h a t over a Long per iod t h e f a i l u r e ( o r

Both these d e f e c t s which con t inue t o plague

There appears t o be a n a t u r a l

A s t i m e pas ses f i r s t one type and t h e

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a c c i d e n t ) r a t e p i c t u r e w i l l be i n t h e shape of a b a t h tub . a i r c r a f t o p e r a t o r and eng inee r is when t o retire h i s a i r c r a f t a f t e r i t s prime u s e f u l working l i f e b u t c e r t a i n l y towards t h e end of t h i s l i f e and when cl imbing t h e wear out p a r t of t h e cu rve i n s p e c t i o n s f o r c o r r o s i o n and f a t i g u e c r a c k i n g should be s tepped up and g r e a t care should be t aken not t o be l u l l e d i n t o a s e n s e of f a l s e s e c u r i t y because of a long and r e l i a b l e u s e f u l p a s t l i f e .

The problem f a c i n g t h e

4.5.5 F a t i g u e f a i l u r e s - S t r u c t u r e s

F a t i g u e f a i l u r e s of p a r t s of s t r u c t u r e s have been caused t o a l a r g e e x t e n t by e r r o r s of d e s i g n e r s and m a c h i n i s t s not g i v i n g s u f f i c i e n t c o n s i d e r a t i o n t o stress raisers, sudden changes of s e c t i o n , i n c o r r e c t geometry of form, s h a r p c o r n e r s , machine t o o l marks, rough s u r f a c e f i n i s h , g r i n d i n g burns a c c i d e n t l y caused d u r i n g manufactur ing p rocesses , and u n s u i t a b l e m a t e r i a l .

- Seldom is t h e r e any th ing new i n t h e cause of a component f a i l u r e . Fat igue, i n p a r t i c u l a r , which c o n t i n u e s t o plague a i r c r a f t and e n g i n e s , n e a r l y always o r i g i n a t e s from a s imple , known and t h e r e f o r e avo idab le d e f e c t o r imper fec t ion .

Sonic f a t i g u e , which is simply due t o h i g h i n t e n s i t y n o i s e , p a r t i c u l a r l y where cones of h i g h i n t e n s i t y n o i s e e x i s t behind j e t e n g i n e s is a c u r r e n t problem l a r g e l y being overcome by new s t r u c t u r a l des ign i n t h e s e areas.

4.5.6 F a t i g u e f a i l u r e s - B o l t s

F a t i g u e f a i l u r e of b o l t s under f l u c t u a t i n g t e n s i o n l o a d s h a s l e d t o s e r i o u s a c c i d e n t s . I n o r d e r t o prevent such f a i l u r e s i t i s e s s e n t i a l t h a t d e s i g n s tudy should always be made where such b o l t s a r e proposed i n c r i t i c a l s t r u c t u r e s wi th t h e o b j e c t of e l i m i n a t i n g b o l t s under f l u c t u a t i n g t e n s i o n stresses. J o i n t s w i t h b o l t s under shear l o a d i n g o f f e r g r e a t e r promise of freedom from f a i l u r e due t o f a t i g u e . Shear j o i n t s , t e s t e d i n a new des ign of a i r c r a f t have shown 150 p e r c e n t improvement over t ens ion j o i n t s . Bonded pane l s r a t h e r than r i v e t e d have a l s o improved f a t i g u e l i f e a s a r e s u l t of more e f f i c i e n t sp read ing of t h e l o a d , b u t c o r r o s i o n a t t h e s e bonded j o i n t s must be prevented a t a l l c o s t s . It i s v e r y seldom indeed t h a t a b o l t w i l l f a i l i n f a t i g u e w h i l s t under s h e a r l oad ing . B o l t s i n c r i t i c a l s t r u c t u r e s or j o i n t s should r e c e i v e s p e c i a l des ign a t t e n t i o n , f o r i n s t a n c e t h e shape of shank, f i n i s h , and c o r r e c t m a t e r i a l i s a l l - i m p o r t a n t . l i f e t o t h r e a d s c u t by a d i e . It is most impor t an t t h a t t h e b o l t i s a good f i t i n i t s hole , and t h a t i t s n u t i s c o r r e c t l y bedded and a l i g n e d t o t h e s t r u c t u r e .

Rol led t h r e a d s have been shown t o have a s u p e r i o r f a t i g u e

Mal-alignment w i l l i n t r o d u c e s e r i o u s e c c e n t r i c l o a d i n g and stress c o n d i t i o n s . reduce t h e f a t i g u e l i f e of t h e b o l t by 50 per c e n t . e s s e n t i a l . important. from g e n e r a l l y s t i f f e n i n g of t h e complete j o i n t , t h i s t echn ique r educes t h e range of t e n s i o n l o a d f l u c t u a t i o n s and v i b r a t i o n . c o r r e c t p re - t ens ion .

T e s t s have shown t h a t o n l y 2 or 3 d e g r e e s mal-alignment i s s u f f i c i e n t t o

Even d i s t r i b u t i o n o f l o a d i n g between each b o l t i n a m u l t i - b o l t assembly i s Pre - t ens ion ing of t h e b o l t du r ing assembly h a s proved advantageous. Apart

Cor rec t t o r q u e l o a d i n g i s of course

Care is of cour se n e c e s s a r y i n app ly ing t h e

4.5.7 Stress levels

I f stress levels are kept low f a t i g u e l i f e can be s u b s t a n t i a l l y increased . The s e r v i c e l i f e of a component can be i n c r e a s e d many t i m e s from a c l o s e and d e t a i l e d s t u d y and e l i m i n a t i o n of stress c o n c e n t r a t i o n , photo e l a s t i c c o a t i n g t echn iques t o determine stress d i s t r i b u t i o n and maximum stress a r e a s is one c u r r e n t method showing promise. I f t h e r e i s any doubt t hen a s a f e f a t i g u e l i f e sou ld be c l e a r l y s t a t e d f o r any v i t a l p a r t .

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4.5.8 Tes t ing

Inadequate t e s t i n g of components and s t r u c t u r e s and t h e r e l i a n c e upon des ign assumptions and c a l c u l a t e d s t r e n g t h have l ed t o u l t ima ted d i s a s t e r s . p a r t i c u l a r l y important where metal f a t i g u e is involved. of m a t e r i a l g ives only a rough guide t o i ts a b i l i t y t o resist f l u c t u a t i n g stresses. F u l l s c a l e , production f i n i s h e d , components and s t r u c t u r e s should be sub jec t ed t o f a t i g u e tests s imula t ing as near as poss ib l e t h e stress c o n d i t i o n s of s e r v i c e . should always be made f o r product ion v a r i a t i o n s , wear and tear i n s e r v i c e and co r ros ion .

This is Laboratory t e s t i n g of specimens

Due allowance

4 . 5 . 9 Correc t choice of m a t e r i a l

The c o r r e c t material f o r t h e purpose is e s s e n t i a l . This i s no t always an easy choice f o r t h e designer . t e n s i l e s t r e n g t h and l i g h t n e s s wi thout adequate i n v e s t i g a t i o n i n t o i ts f a t i g u e l i f e p r o p e r t i e s , o r even i t s a b i l i t y t o gene ra t e a s e r i o u s f i r e i n c e r t a i n c i rcumstances of f a i l u r e ( t i t a n i u m and magnesium a l l o y s ) . It is no advantage t o an a i r l i n e o p e r a t o r o r t h e occupants Q f t h e a i r c r a f t i f , a f t e r a number of a i r c r a f t have been b u i l t and d e l i v e r e d i n t o s e r v i c e , s e r i o u s f a i l u r e s due t o metal f a t i g u e occur. (DTD 683). A m a t e r i a l of g r e a t e r f a t i g u e r e s i s t a n c e , even i f t h i s meant a s l i g h t l y less payload o r performance, would obvious ly be advantageous as a long term po l i cy . Aluminium copper a l l o y s in s t ead of t h e h igh z inc a l l o y s a r e more r e l i a b l e from f a t i g u e and stress co r ros ion , although s l i g h t l y down i n t e n s i l e s t e n g t h . S t e e l has now rep laced l i g h t a l l o y s i n many a r e a s prone t o f a t i g u e o r stress co r ros ion . New non-metall ic and lamina ted m a t e r i a l s o f f e r much promise but l a b o r a t o r y and environment t e s t i n g over a long per iod w i l l be necessary f o r f u t u r e confidence.

Too o f t e n h a s a m a t e r i a l been chosen f o r i ts u l t i m a t e

To avoid e l e c t r o l y t i c c o r r o s i o n and p o s s i b l e u l t i m a t e f a i l u r e , c l o s e r a t t e n t i o n , than i n t h e p a s t , should be p a i d i n t h e f u t u r e t o t h e e l e c t r o l y t i c p o t e n t i a l s of d i f f e r e n t metals where mated o r a l loyed i n a i r c r a f t s t r u c t u r e s .

4.5.10 Corrosion, e l e c t r o l y t i c a c t i o n and f r e t t i n g

These are a l l enemies of an a i r c r a f t o r engine s t r u c t u r e and must be avoided by c a r e f u l design. Corrosion is of i n c r e a s i n g importance i n modern and expens ive a i r c r a f t d e s t i n e d f o r long s e r v i c e l i f e . Sur face c o a t i n g s have been developed t o combat co r ros ion and e ros ion of h igh ly s t r e s s e d p a r t s . Great c a r e must be exe rc i sed wi th a n t i - c o r r o s i v e coa t ings t o make s u r e t h a t , dur ing t h e p rocess , unfavourable i n t e r a c t i o n s w i t h t h e base metal does not develop which may l e a d t o premature and unexpected f a t i g u e f a i l u r e . P r o t e c t i v e t rea tment a t t h e assembly s t a g e i s e s s e n t i a l p a r t i c u l a r l y a t p i n j o i n t s , r i v e t s and ho le s . Epoxy p a i n t s , s t a i n l e s s s t e e l s , e t c . a r e now i n common use where co r ros ion i s a n t i c i p a t e d . Adequate d ra inage i n t h e lowest a r e a s of t h e f u s e l a g e is e s s e n t i a l . Carefu l i n spec t ion and maintenance i s e s s e n t i a l i f t h e a i r c r a f t is used i n a r o l e conductive t o gene ra l c o r r o s i o n , i .e. c rop sp ray ing or marine work. C a r e f u l choice o f mating m a t e r i a l s i s e s s e n t i a l and i t is no good having a good s u r f a c e p r o t e c t i o n if you then spo t weld some s t r i n g e r o r component on t o i t . This no t on ly d e s t r o y s t h e P r o t e c t i o n bu t sets up- a s t r e s s concen t r a t ion and provides an i d e a l co r ros ion nucleus. A s e r i o u s acc iden t occurred from t h i s v e r y cause. long l i f e and co r ros ion i s a major prohlcm wi th age. A s ~ i r c r a f t get o l d ? ! i n s p e c t i o n s f o r co r ros ion should be more frequent . form o f cor ros ion over l a t t e r yea r s has developed from microb io log ica l contamination o f f u e l tanks of t u rb ine engined a i r c r a f t . Proium r e s i n a e ) whose spores e x i s t i n a dormant s t a t e i n kcrosene. when i n con tac t wi th water i n f u e l exposed t o w a r m ambient t empera tures . and co r ros ion w i l l fo l low wi th t h e a t t e n d a n t r i s k s of blocked f u e l f i l t e r s and tank leakdge.

A i r c r a f t t e n d thcsp ddvc to have a

An i n t e r e s t i n g and troublesome, snd e x p m s i v e

This took t h e form of fungal growth ( c l ades - These w i l l develop

Condensation

Carefu l maintenance and chemical a d d i t i v e s w i l l combat t h i s menace.



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P a r t V.- Accident P reven t ion v-4 - 7

4.5.11 Recoverable f l i g h t r e c o r d e r s

Data o r aud io r e c o r d e r s a r e a v a l u a b l e t o o l in de te rmin ing t h e cause of many high speed a i r c r a f t a c c i d e n t s . h i g h degree of c r a s h p r o t e c t i o n a g a i n s t d e s t r u c t i o n through impact , f i r e of l i q u i d s , i f t hey a r e t o be of v a l u e t o t h e i n v e s t i g a t o r . of course , w r i t t e n i n t o t h e i r s p e c i f i c a t i o n . p re se rve a f t e r a n a c c i d e n t , a p r e c i s e , adequate and r e l i a b l e r e c o r d of what took p l a c e before t h e a i r c r a f t s t r u c k t h e ground, o r t h e sea. should be made f o r underwater s e p a r a t i o n and f l o t a t i o n wi th a homing beacon a l l au to - m a t i c a l l y ope ra t ed . It is, o f c o u r s e , e s s e n t i a l t h a t t h e wreckage b e ana lysed i n con jonc t ion w i t h t h e r e c o r d e r r eadou t so t h a t t h e i n d i c a t i o n s recorded can be p o s i t i v e l y confirmed o r den ied ; t h e r e c o r d e r ' s own t r a n s d u c e r s must, of c o u r s e , be checked f o r accuracy. Cockpit v o i c e r e c o r d e r s have a l s o proved t o be of v a l u e but care must be taken t o avo id m i s i n t e r p r e t i n g t h e in fo rma t ion con ta ined t h e r e i n .

These r e c o r d e r s however must be provided w i t h a

The r equ i r emen t s of t h i s p r o t e c t i o n is, For t h e purpose of such r e c o r d e r s is t o

I n t h e la t ter even t a p r o v i s i o n

4.5.12 O i l and ke rosene f i r e s

F i r e s have been caused by i g n i t i o n of f r e e o i l o r ke rosene f i n d i n g its way i n t o eng ine compartments by l e a k a g e , careless maintenance o r f a u l t y eng ine hand l ing . The p o s s i b i l i t y of f i r e must always be i n mind i n t h e ab initio d e s i g n s t a g e s of power p l a n t i n s t a l l a t i o n s and c a r e f u l d e s i g n s t u d y be made f o r adequa te and e f f i c i e n t f u e l d r a i n a g e and p r o t e c t i o n of v i t a l c o n t r o l s and systems. important where eng ine i n s t a l l a t i o n s are b u r i e d i n t h e s t r u c t u r e of t h e a i r c r a f t . There is a r i s k o f a non-contained p o r t i o n of t u r b i n e d i s c o r compressor wheel p e n e t r a t i n g f u e l tanks or c o n t r o l s . P r o t e c t i o n by steel p l a t e o r o t h e r adequa te measures i n t h e s e a r e a s should be considered. Adequate v e n t i l a t i o n and c o o l i n g of eng ine and j e t p i p e compartments below t h e spontaneous i g n i t i o n t empera tu re of ke rosene is essent ia l . High t empera tu res gene ra t ed by f r i c t i o n f o l l o w i n g mechanical f a i l u r e o r i n g e s t i o n can r e s u l t i n metal f i r e s i f t i t a n i u m o r magnesium is involved. Metal lurgy r e s e a r c h can e l i m i n a t e such f r i c t i o n f i r e s . Domestic t y p e of f i r e s can be prevented by f i r e -p roof des ign , i n s t r u c t i o n s and passenger d i s c i p l i n e .

P r o t e c t i o n is p a r t i c u l a r l y

4.5.13 Engine h e a l t h mon i to r ing

Major mechanical f a i l u r e of an eng ine is s t i l l t h e g r e a t e s t cause of f i r e s i n f l i g h t . Close monitor ing of t h e eng ines performance by manual o r au tomat i c means i s e s s e n t i a l t o p reven t c a t a s t r o p h i c c rack up of t h e engine wi th a l i k e l i h o o d of f i r e . V ib ra t ion monitor ing and f r e q u e n t a n a l y s i s of l u b r i c a t i n g o i l by s c i e n t i f i c means is t h e c u r r e n t mode of p reven t ion . m i l l i o n of i r o n i n t h e o i l of a jet eng ine and eng ines can be c o n s t a n t l y monitored i n f l i g h t by in s t rumen t s o f t h i s c a l i b r e . performance and o i l consumption l i m i t a t i o n s cannot be over emphasized.

It is now p o s s i b l e t o d e t e c t a s l i t t l e a s 5 p a r t s p e r

S t r i c t adherence by f l i g h t crews t o t h e engine

4.5.14 Cor rec t t o rque l o a d i n g

Cor rec t t o r q u e l o a d i n g of n u t s and b o l t s i n impor t an t j o i n t s and a s sembl i e s is e s s e n t i a l i f s e r i o u s f a i l u r e s i n s e r v i c e are t o be avoided. I t i s a l s o e s s e n t i a l t h a t t h e i n i t i a l t o rque l o a d i n g a p p l i e d d u r i n g c o n s t r u c t i o n is maintained throughout t h e l i f e of t h e j o i n t o r assembly. S e r i o u s a c c i d e n t s have occur red because v i t a l a s s e m b l i e s have embodied u n d e r s i r a b l e d e s i g n f e a t u r e s such a s t o r q u e l o a d i n g o n t o shims o r d i s t a n c e washers made from s o f t material such as aluminium o r copper. s e t t l i n g down o r co ld f low of t h e s o f t m a t e r i a l w i t h subsequent loss of s e c u r i t y and even tua l mechanical o r f a t i g u e f a i l u r e . Leakage of flammable f l u i d s due t o t h e same cause can, and h a s indeed caused s e r i o u s f i r e s i n f l i g h t .

Such a t echn ique leads t o

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Manual of A i r c r a f t Accident I n v e s t i g a t i o n _-- -_. . _-.- __- - V-4-8

4 .5 .15 Cables

F a i l u r e s of f l e x i b l e s t e e l c a b l e s a f t e r a s h o r t l i f e have occas iona l ly l ed t o d i s a s t e r . Such c a b l e s a r e o f t e n used i n v i t a l power c o n t r o l o r p r i m a r y f l y i n g c o n t r o l systems. routed over p u l l e y s much too s m a l l i n d iameter : The t o t a l a x i a l load i n t h e c a b l e should be as low a s p o s s i b l e , f o r example no t exceeding 10 per c e n t of t h e s t a t i c t e n s i l e breaking load of t h e cab le . has been noted t o be b e n e f i c i a l f o r long l i f e .

Fa t igue and excess ive w e a r of t h e s t r a n d s is caused by t h e c a b l e be ing

Lubr i ca t ion of t h e s t r a n d s du r ing manufacture of t h e c a b l e



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P a r t V.- Accident Prevent ion v-4-9

Many problems facing investigators.

A classical 'Murphy'. A vital non-return valve which, because of i t s design can be fitted the wrong way round.

The importance of more frequent and intensive inspections for corrosion and fatigue cracking as the aircraft gets older and commencing i t s wear out of part of the curve is emphasized by this irrefutable curve.

Light aircraft front spar. Overstressing type of failure in flight.

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V-4-10 Manual of Aircraft Accident Investigation

An example of noncontained mechanical failure (compressor-fatigue). Non-contained failures in engines mounted externally on the wing seldom hazard the aircraft, provided correct cockpit drills are carried out. However, it cannot be said with confidence that this statement would apply to engines installed inside the wings, ¡.e. RAF Vulcan and possibly Concorde. A genuine disc burst in a large turbine engine cannot be contained, and i s consequently, with engines installed internally, a serious hazard to the aircraft. Noncontained engine disruptions in the Vulcan has indeed led to disaster, on more than one occasion. In the twin spool type of engine, failure of the low pressure (LP) turbine shaft could lead, in a fraction of a second, t o an overspeed of the LP turbine beyond i t s design ultimate speed causing the disc to burst with the devastation of a bomb explosion. However, design improvements in the current civil Concorde engine suggests that the probability o f disc failure is remote, and the salutary lessons learned from the past, and read across from service experience, now include an automatic and instant fuel shut-off valve in the event of LP shaft failure to prevent catastrophic LP turbine overspeed, and steel shielding of vital services.

Combination of factors type of accident. Mechanical failure of engine - serious kerosene fire in flight. Human errors in cockpit fire drill - although successful forced landing, aircraft destroyed by in-effective fire fighting on ground.

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Part V.-

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A P P E N O ! C E S

MANUAL O F AIRCRAFT ACCIDENT INVESTIGATION

APPENDIX 1

DEFINITIONS AND SYMBOLS

Definitions of accepted aeronautical terms are given in the ICA0 Lexicon (Doc 9110).

This Appendix contains:

1) Definitions which are contained in Annex 13.

2) Significance of some symbols which a r e conmionly used in some States in connexion with aircraft accident investigations.

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I APPENDIX 1.- Definitions and Symbols 1-1

APPENDIX 1

DEFINITIONS AND SYMBOLS

1. Definitions

The following definitions are those included in Annex 13, Fourth Edition.

When the following terms are used in the Standards and Recommended Practices for Aircraft Accident Investigation they have the following meaning:

Accident. An occurrence associated with the operation of an aircraft w-hich takes place between the time any person boards the aircraft with the intention of flight until such time as all such persons have disembarked, in which:

a) a person is fatally or seriously injured as a result of being in or upon the aircraft.or by direct contact with the aircraft or anything attached thereto; or

Note. -Specifically excluded are: death f rom natural causes and fatal or senous injury to any person on board whether self-inflicted or inflicted by another person, or to ground support personnel before or after flight, or fatal or serious injury which is not a direct result of the operation of the aircraft, or which concerns stowaways. The definition of ‘serious injiiry ’ is provided hereunder in alphabetical order.

b) the aircraft incurs damage or structural failure which adversely affects the structure strength, performance or flight characteristics of the aircraft and which would normally require major repair or replacement of the affected component; or

Note. - Specifically excluded are: engine failure; damage limited to an engine or its accessories, or to propeller blades; bent fairings or cowlings; small dents or puncture holes in the skin; damage to wing tips, antennas, tires, or brakes.

c) the aircraft is missing or is completely inaccessible.

Note.--An aircraft is considered to be missing when the official search has been terminated and the wreckage has not been located.

Accredited Representative. A person designated by a State for the purpose of participating in an investigation conducted by another State.

Adviser. A person appointed by a State for the purpose of assisting its accredited representative at an investigation.

Aircraft. Any machine that can derive support in the atmosphere from the reactions of the air other than the reactions of the air against the earth’s surface.

Cause. Action(s), omission(s), event(@, condition(s), or a combination thereof, which led to the accident or incident,

Flight Recorder. Any type of recorder installed in the aircraft for the purpose of complementing accident/ incident investigation.

Note. -See Annex 6 , Part I, for specifications relating to flight recorders.

Incidenf. An occurrence, other than an accident, associated with the operation of an aircraft which affects or could affect the safety of operation.

Note.-The type of incidents which are of main interest t o the International Civil Aviotion Organization for accident prevention studies are listed in the I C A 0 Accident/ Incident Reporting Manual (Doc 9156-AN/900). Specifi cally excluded are:

Air Traffic Incidents, such as near collisions, and serious difficulty caused b y faulty procedures or lack of compliance with applicable procedures.

Investigation. A process conducted for the purpose of accident prevention which includes the gathering and analysis of information, the drawing of conclusions, including the determination of cause(s) and, when appropriate, the making of safety recommendations.

Investigator-inCharge. The person charged with the responsibility for the organization, conduct and control of an investigation.

Note.-Nothing in the above definition is intended to preclude the functions of an Investigator-in-Charge being assigned to a commission or other body.‘

Maximum Weight. Maximum certificated take-off weight.

Operator. A person, organization or enterprise engaged in or offering to engage in aircraft operation.

Preliminary Report. The communication used for the prompt dissemination of dlta obtained during the early stages of the investigation.

Safety Recommendation. A proposal of the Investi- gating Authority of the State conducting the investigation, based on information derived from the investigation, made with the intention of preventing accidents or incidents.

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1-2 Manual of.Aircraft Accident Investigation

Serinus Injury. An injury which is sustained by a person Stare o/' Manuficture. The Stateís) responsible for the in an accident and which: certification as to the airworthiness of the prototype.

a ) requires hospitalization for more than 48 hours. commencing within seven days from the date the injury was received; or

b) results in a fracture of any bone (except simple fractures of fingers, toes, or nose); or

c) involves lacerations which cause severe haemorrhage, nerve, muscle or tendon damage; or

d) involves injury to any internal organ; or

e) involves second or third degree bums, or any burns affecting more than 5 per cent of the body surface.

State of' Occurrence. The State in the territory of which an accident or incident occurs.

State of Registry. The State on whose register the aircraft is entered.

Note.--In the case of the registration of aircraft o f an international operating agency on other than a national basis, the States constituting the agency are jointly und severally bound to assume the obligations which. under the Chicago Convention. attach to a State of Registry. See, in this regard, the Council Resolution of 14 December 196 7 on Nationality and Registration of Aircraft Operated bv International Operating Agencies (Doc 8722-C/9 76).

Note regarding the "State of Occurrence": considered to be the State in which the aircraft wreckage, or major portion thereof, by volume, came to rest.

In accordance with general practice this is

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I APPENDIX 1.- D e f i n i t i o n s and Symbols 1-3

I 2 . Symbols

Airspeed Symbols

The "design manoeuvring speed" is a speed equa l t o Vs ( n l ) 112, where Vs is t h e s t a l l i n g speed w i t h wing f l a p s r e t r a c t e d , a t d e s i g n maximum weight , and n1 i s t h e des ign v a l u e of t h e manoeuvring l o a d f a c t o r s e l e c t e d .

The "design speed f o r maximum g u s t i n t e n s i t y " is a speed s u f f i c i e n t l y g r e a t e r t han Vs t o p rov ide adequa te p r o t e c t i o n a g a i n s t l o s s o f c o n t r o l i n t u r b u i e n t a i r , where Vs is t h e s t a l l i n g speed w i t h wing f l a p s and l a n d i n g g e a r r e t r a c t e d , a t d e s i g n maximum weight.

VA*

VB*

VC *

VD"

VF*

V f

. VFE

v~ E

'LOF

VMCA

vMC C,

The "design c r u i s i n g speed" is a speed s u f f i c i e n t l y g r e a t e r t han VB t o provide f o r i n a d v e r t e n t speed increases l i k e l y t o occur a s a r e s u l t o f severe atmospheric t u rbu lence .

The "design d i v i n g speed" is a speed s u f f i c i e n t l y g r e a t e r t han Vc t o p rov ide f o r s a f e recovery from i n a d v e r t e n t speed increases o c c u r r i n g a t VC.

The "design f l a p speed" is a speed s u f f i c i e n t l y g r e a t e r t han t h e minimum f l i g h t speed co r re spond ing t o t h e f l a p s e t t i n g and p a r t i c u l a r weight t o a l low proper c o n t r o l i n t h e even t o f f l a p r e t r a c t i o n and a l s o t o p r o v i d e an adequate margin o f s t r e n g t h f o r t h e a s s o c i a t e d placarded speed.

The " f l u t t e r speed" is a speed s u f f i c i e n t l y g r e a t e r t h a n VD, a t which t h e aero- p l a n e has been proven t o b e f r e e from f l u t t e r and d ive rgence ( u n s t a b l e s t r u c t u r a l d i s t o r t i o n due t o aerodynamic loading) .

The "maximum wing f l a p s extended speed" i s t h e maximum speed w i t h a u t h o r i z e d wing f l a p s i n a p r e s c r i b e d extended p o s i t i o n .

-The "maximum l a n d i n g g e a r extendeci speed" is maximum speed a u t h o r i z e d wi th the l a n d i n g gea r extended.

The " l i f t - o f f speed" is t h e speed a t which t h e a e r o p l a n e first becomes a i r b o r n e .

The "minimum c o n t r o l speed" i s t h e speed a t which, when t h e c r i t i c a l engine i s suddenly made i n o p e r a t i v e at t h a t speed, i t i s p o s s i b l e t o r ecove r c o n t r o l of t h e ae rop lane wi th t h e e n g i n e s t i l l i n o p e r a t i v e and t o ma in ta in i t i n a s t r a i g h t f l i g h t a t t h a t speed, e i t h e r w i t h zero yaw o r wi th an a n g l e of bank not i n e x c e s s o f 5O.

The "minimum c o n t r o l speed on t h e ground" i s t h e minimum speed a t which, t h e c r i t i c a l eng ine having been made suddenly i n o p e r a t i v e a t t h a t speed and having been recognized by t h e p i l o t , i t is p o s s i b l e t o m a i n t a i n c o n t r o l o f t h e aero- p l a n e w i t h t h e engine s t i l l i n o p e r a t i v e , u s ing pr imary aerodynamic c o n t r o l s a l o n e , and t h e r e a f t e r m a i n t a i n a s t r a i g h t pa th p a r a l l e l t o t h a t o r i g i n a l l y intended.

* The d e s i g n a i r s p e e d s are given i n terms of e q u i v a l e n t a i r s p e e d (EAS).

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1-4 Manual of A i r c r a f t Accident I n v e s t i g a t i o n

Airspeed Symbols

VMcLc The "minimum c o n t r o l speed on approach and l and ing f o r continued approach" is a speed, w i th one engine i n o p e r a t i v e , a t which i t is p o s s i b l e t o . f a i l t h e c r i t i ca l o p e r a t i n g engine and t o i n c r e a s e power on t h e remaining o p e r a t i n g eng ine ( s ) t o t h a t r equ i r ed t o cont inue a t an ang le of descen t of 30 without encounter ing dangerous f l i g h t c h a r a c t e r i s t i c s .

The "minimum c o n t r o l speed on approach and l and ing f o r d i scont inued approach" i s a speed wi th one engine i n o p e r a t i v e , and i n a d d i t i o n , f o r ae rop lanes wi th t h r e e o r more engines , w i th two engines i n o p e r a t i v e a t which it i s p o s s i b l e , wi thout re-trimming , t o :

VMCLD

a ) c l o s e t h e t h r o t t l e s of t h e o p e r a t i n g e n g i n e ( s ) f u l l y ,

b) i n c r e a s e t h e power of t h e o p e r a t i n g e n g i n e ( s ) u n t i l maximum take-off power cond i t ions are reached, wi thout encounter ing dangerous f l i g h t c h a r a c t e r i s t i c s .

The %aximum pe rmis s ib l e o p e r a t i n g speed" i s t h e maximum speed au tho r i zed , i n t h e en-route c o n f i g u r a t i o n , i n normal ope ra t ion .

The "minimum uns t i ck speed" is a speed, s e l e c t e d by t h e app l i can t* , a t and above which t h e aeroplane can be made t o l i f t o f f t h e ground and con t inue t h e take-off without d i s p l a y i n g any hazardous c h a r a c t e r i s t i c s ; by means of ground take-Offs a t t h a t speed.

Vm speed should be e s t a b l i s h e d

VR The " r o t a t i o n speed" i s t h e speed a t which t h e p i l o t i n i t i a t e s r o t a t i o n of t h e aeroplane t o cause r a i s i n g of t h e l and ing nose gea r .

"S The " s t a l l i n g speed" is t h e minimum speed i n f l i g h t a t which t h e aeroplane can develop a l i f t equa l t o t h e weight of t h e ae rop lane , t h e l i f t be ing t h e aerodynamic f o r c e perpendicular t o t h e f l i g h t pa th .

"m The "minimum demonstrated th re sho ld speed" i s a speed ob ta ined a t a he igh t o f 10.7 metres (35 f e e t ) above the l and ing s u r f a c e a t and above which it has been demonstrated t h a t t h e aeroplane can be made c o n s i s t e n t l y t o complete an approach, touchdown and landing wi thout d i s p l a y i n g any hazardous c h a r a c t e r i s t i c s when flown i n no apprec i ab le atmospheric t u rbu lence i n t h e fo l lowing manner:

a ) a s teady approach from a he igh t of 60 metres (200 f e e t ) above t h e l and ing s u r f a c e t o t h e 10.7 metres (35 f o o t ) h e i g h t p o i n t , a t a s u b s t a n t i a l l y s t a b i l i z e d ang le o f descent o f n o t less than 3O;

b)

c )

a rate of descent equal t o ze ro b e f o r e touchdown;

on ly those changes of c o n f i g u r a t i o n and/or power which would be made i n a normal l and ing should be made. No i n c r e a s e i n power should be made a f t e r pass ing t h e threshold.

VT min The "minimum th resho ld speed" is a speed, s e l e c t e d by t h e a p p l i c a n t , which i s n o t l e s s than t h e g r e a t e r o f :

a) V m + 5 kno t s ;

b) 1 . 2 Vs.

* "Applicant" whenever used i n t h e d e f i n i t i o n s of speeds is a pe r son apply ing f o r approva l

16 /4 /73 No. 3

of an aeroplane.



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I APPENDIX 1.- Def inFt ions a*rd Symbols 1-5

Airspeed Symbols

VT max The ximu mum t h r e s h o l d speed" is a speed, s e l e c t e d by t h e a p p l i c a n t , which is no t less t h a n a speed e q u a l t o VT min p l u s t h e lesser o f 0.2 Vs o r 20 knots .

V1 The "dec is ion speed" is t h e speed a t which sudden complete l o s s of power from t h e c r i t i ca l engine i s assumed t o be recognized by t h e p i l o t .

V2 min The "minimum take-off s a f e t y speed" i s a speed, s e l e c t e d by t h e a p p l i c a n t , which is g r e a t e r than a ) and b ) :

a ) as a p p l i c a b l e , a speed equal t o

"2

i ) 1.15 VS f o r two-engine and three-engine p r o p e l l e r - d r i v e n a e r o p l a n e s , and f o r a e r o p l a n e s without p r o p e l l e r s on which t h e a p p l i c a t i o n of power does n o t r e s u l t i n a s i g n i f i c a n t r e d u c t i o n i n t h e one-engine- inoperat ive power-on s t a l l i n g speed;

1 .10 V s f o r p r o p e l l e r - d r i v e n a e r o p l a n e s having f o u r engines , and f o r a e r o p l a n e s wi thout p r o p e l l e r s on which t h e a p p l i c a t i o n of power r e s u l t s i n a s i g n i f i c a n t r e d u c t i o n i n t h e one-engine- inoperat ive power-on s t a l l i n g speed;

i i )

b )

The " i n i t i a l climb-out speed" i s t h e speed , s e l e c t e d by t h e a p p l i c a n t , f o r climb a f te r a t t a i n i n g a h e i g h t o f 10.7 metres (35 f e e t ) above t h e take-off s u r f a c e d u r i n g a take-off w i t h one engine i n o p e r a t i v e .

a speed e q u a l t o 1 .10 VMCA.

3015177 No. 7



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APPENDIX 2

PHOTOGRAPHY



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APPENDIX 2.- Photography 2- 1

APPENDIX 2

PHOTOGRAPHY

1. I n t r o d u c t i o n

The va lue of photography i n a i r c r a f t acc iden t i n v e s t i g a t i o n cannot be over- s t a t e d . a r e an ex t remely impor tan t element of t h e i n v e s t i g a t i o n .

Good photographs f u r n i s h t h e b e s t p o s s i b l e r eco rd of a n i n v e s t i g a t i o n and they

I t is accepted t h a t most people have a t least a n e lementary knowledge of how t o use a camera and, acco rd ing ly , t h e r e should be no need t o d i s c u s s t h e b a s i c p r i n c i p l e s . This Appendix is t h e r e f o r e s p e c i f i c a l l y d i r e c t e d t o photography i n t h e f i e l d of a i r c r a f t acc ident i n v e s t i g a t i o n .

2. The Camera Equipment

The camera should be easy t o ope ra t e and r e l i a b l e and i t s c o n s t r u c t i o n should It should be compact and need few a c c e s s o r i e s and y e t i t must have a c a p a b i l i t y be robus t .

f o r producing n e g a t i v e s of good d e f i n i t i o n i n wide extremes of l i g h t i n g , s u b j e c t d i s t a n c e s and environment.

A very s u i t a b l e b a s i c camera f o r acc iden t i n v e s t i g a t i o n work is a good q u a l i t y 35 m i l l i m e t r e s i n g l e l e n s r e f l e x , p r e f e r a b l y au tomat ic o r semi-automatic, camera wi th t h e fo l lowing f e a t u r e s :

S h u t t e r speeds t o 1/1,000 second;

50 m i l l i m e t r e f 2 lens;

B u i l t - i n l i g h t meter;

Coupled range f i n d e r ;

E l e c t r o n i c f l a s h synchroniza t ion t o 11125 second;

Depth of f i e l d i n d i c a t i o n ;

P rov i s ion f o r close-up and wide ang le supplementary l e n s ;

A s o l i d l e a t h e r ever-ready c a r r y i n g case .

is sometimes advantageous f o r one member of t h e i n v e s t i g a t i o n team t o be equipped wi th an i n s t a n t type (Po la ro id ) camera, a l s o t h e c i rcumstances may be such t h a t t h e use of s t e r e o or movie photography might be d e s i r a b l e .

3. Film S u i t a b l e f i l m f o r a c c i d e n t i n v e s t i g a t i o n photography is a f i n e g r a i n pan-

chromatic f i l m 125 Weston = 23/10 DIN = 160 ASA. This is adequate € o r a good speed



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2- 2 Manual ~f A i r c r a f t Accident I n v e s t i g a t i o n

coverage and, if rSqL_*red, i t :an be eq larged t o ;isv reasonable s i z e and y e t r e t a i n h!gh q u a l i t y . a l l acc ident i n v e s t i g a t i o n phctography w i l l be i n b lack and white .

Occasional ly c c l o u r fiLm is d e s i r a S i € t 3 í i l u s t r a t e a s p e c i a l f e u t a r e , but almost

4 . Technique and Procedures

The i n v e s t i g a t o r should c a r e f u l l y p l an h i s photography and each p i c t u r e should be taken f o r a s p e c i f i c reason or purpose. While i t is b e t t e r t o t ake t o o many photographs than too few, random p i c t u r e t a k i n g i s to be avoided and a c a r e f u l s e l e c t i o n of t h e s u b j e c t s and t h o u g h t f u l composition w i l l enhance t h e photographic r eco rd .

P i c t u r e s of t h e g e n e r a l wreckage should be taken from a t least f o u r d i r e c t i o n s and t h e photographer should s t a n d a t t h e same d i s t a n c e away from t h e wreckage, so t h a t t h e wreckage i s kep t i n perspec t ive . impact a r e a s have been taken, t h e major components and p a r t i c u l a r l y any suspec t a r e a s of t h e wreckage should be photographed. f l i g h t pa th can la te r be superimposed a r e o f t e n of va lue f o r i n c l u s i o n i n t h e d o s s i e r . Oppor tuni t ies should be taken t o record photographica l ly t h e c o n t r o l p o s i t i o n s , t a b s e t t i n g s , e tc . where they may be s i g n i f i c a n t t o t h e i n v e s t i g a t i o n but c a r e should be taken t o i n c l u d e something i n t h e p i c t u r e s t o ensure t h a t inadver ten t r e v e r s e p r i n t i n g can be d e t e c t e d . I n some s i t u a t i o n s r e v e r s e p r i n t i n g w i l l g i v e f a l s e information.

Af t e r p i c t u r e s of t h e wreckage, t h e t e r r a i n and t h e

Photographs of t h e f l i g h t p a t h on which t h e e s t i m a t e d

When dec id ing on t h e composition of a p i c t u r e t h e i n v e s t i g a t o r should be clear i n h i s mind as t o why he h a s taken a p a r t i c u l a r s u b j e c t and h e should endeavour t o e l i m i n a t e

of t he - h o t o g r a p h ' f i l l s t h e e n t i r e p i c t u r e . Th i s i s a l s o d e s i r a b l e from t h e a s p e c t of enlargement as t h e 35 mm f i l m produces a r e l a t i v e l y s m a l l n e g a t i v e which must be e n l a r g e d many t i m e s t o be of v a l u e f o r s tudy and f o r i l l u s t r a t i o n p u r p o s e s . The process of e n l a r g i n g produces undes i rab le q u a l i t i e s i n any n e g a t i v e and t h e r e f o r e t h e nega t ive r e q u i r i n g t h e least amount of e n l a r g i n g produces t h e b e s t photograph. It n e c e s s a r i l y fol lows t h a t t h e more nega t ive occupied by t h e s u b j e c t matter, t h e less w i l l be t h e amount of e n l a r g i n g necessary when making a p r i n t .

. d i s t r a c t i n g o r i r r e l e v a n t i t e m s . Th i s can be achieved u s u a l l y by ensur ing t h a t t h e s u b j e c t

The i d e n t i f i c a t i o n of a s u b j e c t i s v i t a l and where i t is not e v i d e n t s u i t a b l e This can be done by marking on t h e s u b j e c t

When t h e s i z e

methods t o record t h e i d e n t i t y must be adopted. i t s e l f with a grease p e n c i l when t h e r e is a l a r g e enough s u r f a c e , o r by w r i t i n g a d e s c r i p t i v e c a p t i o n on a p i e c e of paper and p o s i t i o n i n g i t f o r i n c l u s i o n i n t h e p i c t u r e . of t he ob jec t being photographed i s not commonly kncwn, t h e i n t r o d u c t i o n i n t o t h e p i c t u r e of a scale o r r u l e r o r an o b j e c t of known dimensions, such as a match box o r a c i g a r e t t e packet w i l l provide a s u i t a b l e comparison f o r t h e viewer. When photographing f a i l e d components i t is h e l p f u l i n some circumstances t o have i n t h e p i c t u r e a n undamaged component f o r comparison purposes.

Close-up photography can be used t o produce p i c t u r e s showing breaks and damage which are o therwise d i f f i c u l t t o d e s c r i b e adequate ly by words alone. The use of t h e close-up l e n s should be p r a c t i s e d by t h e i n v e s t i g a t o r t o ensure t h a t a s a t i s f a c t o r y p i c t u r e can be obtained when r equ i r ed .

When photographing, a record of each exposure should be maintained f o r iden- t i f i c a t i o n purposes g iv ing d e t a i l s of t h e s u b j e c t and where necessary, t h e d i r e c t i o n i n which t h e photograph was taken.



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APPENDIX 2.- Photography 2- 3 -.

To ach ieve good photographs , p r a c t i c e and expe r i ence are necessa ry bu t t h e r e a r e a number of matters on which some guidance can be given.

The most common f a u l t s encountered i n photography are b l u r r e d images, which a r e usua l ly caused by i n c o r r e c t f o c u s s i n g o r camera movement a t t h e i n s t a n t t h e s h u t t e r is operated. I n t h e former case most modern s i n g l e l e n s r e f l e x cameras reduce t h i s p o s s i b i l i t y by i n c o r p o r a t i n g t h e f o c u s s i n g medium i n t h e viewing eye p iece . f a c i l i t y poor ly focussed n e g a t i v e s s t i l l occur and i n many i n s t a n c e s are due t o the photographer s h i f t i n g h i s p o s i t i o n w i t h o u t r e a l i z i n g i t , a f t e r c a r e f u l l y f o c u s s i n g t h e s u b j e c t and before o p e r a t i n g t h e s h u t t e r . The l a t t e r cause, camera movement, can be e l i m i n a t e d by a l i t t l e care i n ho ld ing t h e camera, p a r t i c u l a r l y when o p e r a t i n g t h e s h u t t e r and by t h e use of a s t eady ing agen t when u s i n g s lower s h u t t e r speeds. A t speeds s lower t h a n 1 /60 second i t is d i f f i c u l t t o e l i m i n a t e camera movement due t o hand shake and i n such cases i t i s recommended t h a t a t r i p o d and c a b l e release be employed. The t r i p o d o r s imi l a r s t e a d y i n g means is a l s o e s s e n t i a l when u s i n g supplementary l e n s , t h e e f f e c t of which g r e a t l y reduces t h e depth of f o c u s and makes a c c u r a t e focuss ing cri t ical . It w i l l be r e a d i l y understood t h a t once a camera is focussed a c c u r a t e l y under c o n d i t i o n s where t h e depth of focus is s m a l l , i t is d i f f i c u l t t o hand ho ld a camera and r e t a i n t h e o r i g i n a l focus .

However, d e s p i t e t h i s

W i t h a t t e n t i o n t o t h e fo rego ing p o i n t s , i t can r easonab ly be expec ted t h a t t h e n e g a t i v e w i l l be sha rp and i t on ly now remains t o o b t a i n good d e f i n i t i o n i n o r d e r t o produce a good q u a l i t y photograph. D e f i n i t i o n is l a r g e l y c o n t r o l l e d by exposure o r amount of l i g h t admi t t ed t o t h e camera. Under i d e a l c o n d i t i o n s exposure is no t c r i t i c a l w i t h i n f a i r l y broad l i m i t s but i n c o n d i t i o n s where lig!it i s no t uniform, or poor , i t is e s s e n t i a l t h a t c a r e f u l c o n s i d e r a t i o n be g iven t o t h i s f a c t o r i n o rde r t o r e c o r d t h e r e q u i r e d d e t a i l . The prime c o n s i d e r a t i o n when a s s e s s i n g l i g h t v a l u e s i s t h e amount of l i g h t a t t h e a c t u a l p o i n t where t h e camera w i l l be aimed. I f a l i g h t meter is used care shou ld be t a k e n t o measure t h e r e f l e c t e d l i g h t c l o s e t o t h e o b j e c t you wish t o photograph. Having e s t a b l i s h e d a l i g h t - v a l u e t h e nex t c o n s i d e r a t i o n must be t h e bes t s h u t t e r speed-aper ture combination which w i l l produce t h e optimum n e g a t i v e c o n t r a s t .

A s tudy of t h e f o l l o w i n g example w i l l show t h a t t h e r e is a wide cho ice of combinations which w i l l admit t h e same amount of l i g h t t o t h e camera.

Shu t t e r speed 1/1000 11500 11250 11 125 1 /60 1 / 3 0 1 / 1 5 seconds

Aperture f : 2 2. a 4 5.6 8 11 16

Which p a i r shou ld be s e l e c t e d ? very d i f f e r e n t c h a r a c t e r i s t i c s . The use of a l a r g e a p e r t u r e ( f 2 ) g i v e s a g r e a t l y reduced depth of f o c u s compared t o a s m a l l a p e r t u r e ( f16 ) . The a c t u a l d i s t a n c e s can be r e a d from t h e s c a l e i n c o r p o r a t e d on t h e camera. I n F igu re 2-1 t h e f r o n t i n s t rumen t h a s been high- l i g h t e d by t h e use of a l a r g e a p e r t u r e ( f 2 ) which h a s thrown t h e rear ins t rumen t ou t of focus due t o t h e sha l low depth of focus . I n F igure 2-2 us ing t h e same b a s i c f o c a l p o i n t both in s t rumen t s have been brought i n t o sha rp focus by t h e use of a small a p e r t u r e ( f16) and a cor responding s lower s h u t t e r speed . depth of focus which h a s embraced t h e whole s u b j e c t .

A t t h e extremes of t h e s c a l e t h e same l i g h t v a l u e s have

The l a t t e r combination h a s g iven a much g r e a t e r

I t i s not always p o s s i b l e t o u s e e x i s t i n g l i g h t i n g t o produce a s a t i s f a c t o r y nega t ive and i t t h e r e f o r e becomes necessa ry t o employ a r t i f i c i a l l i g h t i n g . I n t h e s t u d i o



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Manual of A i r c r a f t Accident I n v e s t i g a t i o n I

2-4

o r i n s i t u a t i o n s where i t is poss ib l e :u p l a c e t h e s i ibject i n a d e s i r e d p o s i t i o n some form of r l o o d l i g h t i n g can be used t o o b t a i n t h e necessary uni formi ty of l i g h t , but t h i s is seldom p o s s i b l e i n t h e f i e l d and the a l t e r n a t i v e i s a photographic f l a s h un i t . Formerly t h e m o s t s a t i s f a c t o r y and r e l i a b l e of t h e s e u n i t s w a s t h e f l a s h gun which employed expend- a b l e bulbs but unfor tuna te ly t h e supply and handl ing of b u l b s needed made t h e u n i t somewhat cumbersome. The a l t e r n a t i v e is t h e e l e c t r o n i c f l a s h u n i t which h a s been developed i n t o a robus t compact u n i t capable of making f i f t y o r more exposures without e x t e r n a l recharging. A c h a r a c t e r i s t i c of t he e l e c t r o n i c f l a s h u n i t is t h e s h o r t per iod of peak l i g h t compared wi th t h e f l a s h b u l b and when used wi th cameras i n c o r p o r a t i n g f o c a l p lane s h u t t e r s , which are predominant on modern cameras, i t is necessary t o observe t h e s h u t t e r speed synchroniza t ion l i m i t of t h e p a r t i c u l a r camera. In t h e p a s t t h i s c r e a t e d d i f f i c u l t i e s when us ing t h e e l e c t r o n i c f l a s h outdoors f o r f i l l - i n purposes bu t as t h e synchronized speeds have now been increased t o as h igh as 11125 second t h e problem now hard ly e x i s t s .

The use of f i l l - i n f l a s h i n outdoor c o n d i t i o n s is p o s s i b l y one of t h e b e s t u s e s t h a t can be made of an a r t i f i c i a l l i g h t . In many c a s e s t h e s u b j e c t t o be photugraphed i s p a r t l y shaded by trees or o t h e r o b s t r u c t i o n o r even by t h e s t r u c t u r e of t he a i r c r a f t i t s e l f . T t i s aliiiost impossible t o ob ta in good photographic r e s u l t s under such c o n d i t i o n s and t h e tise of a f l a s h t o f i l l i n and e l i m i n a t e u n d e s i r a b l e e f f e c t s of shadows i s e s s e n t i a l .

The a c t u a l camera s e t t i n g s employed when us ing f l a s h l i g h t out of doors i n d a y l i g h t w i l l vary cons iderably according t o t h e c o n d i t i o n s . However, wi th t h e s h u t t e r speed l i m i t e d by t h e e l e c t r o n i c f l a s h c h a r a c t e r i s t i c s s t i s f a c t o r y r e s u l t s a r e g e n e r n i . 1 ~ obta ined Dy averaging t h e a p e r t u r e s needed f o r a normal d a y l i g h t exposure and a pure f l a s h

r e q u i r e an a p e r t u r e of f16. However, from t h e same d i s t a n c e a t r u e f l a s h exposure nay requir:- ;in a p e r í d r z of f8 . A compromise of f l l under t h e s e c o n d i t i o n s would g ive a satis-- f a c t o r y r e s u l t .

.exposure. For example, wi th t h e s h u t t e r speed set o11 l i 1 2 5 second t h e day l igh t v a l u e may

5. Process ing

Processing of exposed f i l m and the making of enlargements a r e g e n e r a l l y regarded a s f u n c t i o n s f o r t echn ic i ans , but where f a c i l i t i e s a r e a v a i l a b i e t h e i n v e s t i g a t o r can u s u z l l y improve h i s s tandard of photography by tafii-g p a r t i n c?ie processing of h i s o m f i l n and observing negacive f a u l c s r e s u l t i n g f r o n i,-.! mishandlLig of tlir camera i n t n e f i e l d . i t i s p o s s i b l e f o r some c o r r e c t i o n of f a u l t s t o be m a & .

T h e same i a u l t s are not normnlly a p p x e n t on d:i enLargement a3 during t h e p r o c e s s

I n a d d i t i o n t o t h e opportunities f o r a n i n v e s t i g a t o r t o examine c r i t i c a l l y h i s photographic ~ e s ~ i l t s , which h i s caking art i n f t Lz proc2ssir;g may prov ide , t h e r e are C<rcumstances and s i t u a t i o n s where t h e a b i l i t y t a carr;d a u t l i m i t e d processing can be of real valae. Normally, some provis ion f o r ensur ing t h a t adequate photograplis a r e obta ined can be achieved by exposing more thar, one r o l l of f i l = w i t h t h e more important views d u p l i c a t e d on d i f f e r e n t r o l l s . f o r some o the r r e a s o n a r o l l of f i l m i s s p o i l t , t h e complete photographic record of t h e i n v e s t i g a t i o n i s not l o s t . However, i t rm!~o:e s i t e s where t h e i n v e s t i g a t i u n may cont inue f o r a p r o t r a c t e d pe r iod , provis ion can b e made f o r process ing of some f i l m on t h e s i t e . S m a l l compact d a y l i g h t developing t anks are a v a i l a b l e .iJf;lcn wi th t h e minimum of m a t e r i a l s w i l l provide t h e f a c i l i t y t o ensure t h a t before l e a v i n g t h e a c c i d e n t s i t e a set of s a t i s f a c t o r y n e g a t i v e s h a s been obtained.

This ensures t h a t i n t h e even t of a processing mishap o r i f



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APPENDIX 2.- Photography 2-5

#en t h e processing has been completed t h e r e remains t h e t a s k of s o r t i n g the photographs, annotat ing where necessary with appropriate descr ip t ions and s e l e c t i n g and mounting of s u i t a b l e p i c t u r e s f o r use i n i l l u s t r a t i n g the repor t . The r o l l of negat ives should be cut i n t o s t r i p s , placed i n t ransparent envelopes f o r pro tec t ion and easy i d e n t i f i c a t i o n and then, together with a set of t h e p i c t u r e s , placed i n the i n v e s t i g a t o r ' s doss ie r f o r f u t u r e reference. of a pas t inves t iga t ion i n search of some p a r t of t h e a i r c r a f t which a t t he t i m e , was of no p a r t i c u l a r i n t e r e s t . i t is very usefu l when the p a r t i n question can be c l e a r l y i d e n t i f i e d and the photographs may provide information which could not be obtained by any other means owing t o d isposa l of t h e wreckage on completion of the o r i g i n a l inves t iga t ion .

It may a t some t i m e be of value t o be able t o look through t h e negat ives

Fig. 2-1.- Large aperture íf2ì has given shaZlow depth of focus and rear instrument is out of focus.



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APPENûIX 3

FLIGHT RECORDERS: TYPES IN USE

(Flight Data and Voice Recorders)



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A P P E N D I X 3 . -"Fl ight Recorders: Types i n Use 3- 1

APPENDIX 3

FLIGHT RECORDERS: TYPES I N USE.

1. F l i g h t Data Recorders

The f o l l o w i n g paragraphs d e s c r i b e b r i e f l y v a r i o u s t y p e s of f l i g h t d a t a r eco rde r s .

A l l f l i g h t d a t a r e c o r d e r c o n t a i n e r s are e i t h e r b r i g h t orange o r b r i g h t yellow i n c o l o u r .

1.1 Lockheed A i r c r a f t S e r v i c e F l i g h t Recorder Models

The LAS Model 109C f l i g h t r eco rde r is manufactured by S p e c i a l Devices Div i s ion of Lockheed A i r c r a f t S e r v i c e Company, On ta r io , Ca l i f o r n i a .

The f l i g h t r e c o r d e r is cons t ruc t ed wi th a heavy c a s t aluminium base having a l l t h e necessa ry components mounted on i t t o provide o s c i l l o g r a p h i c traces i n s c r i b e d on t h e one-mil aluminium o r s t a i n l e s s s t ee l f o i l r eco rd ing media. The e n t i r e mechanism, with t h e excep t ion of t h e small t r a n s i s t o r i z e d a m p l i f i e r f o r t h e head ing u n i t , and t h e remote type acce le romete r s e r v o a m p l i f i e r u n i t , i s conta ined i n a spher ica l - shaped case with a square mounting f l a n g e a t i t s equator . The e n t i r e o u t e r s h e l l is manufactured in two s e c t i o n s of s t a i n l e s s s t ee l material which a l s o h a s i n n e r s t a i n l e s s s t e e l s h e l l s w i th a one-inch space between t h e s h e l l s f i l l e d with p e a r l i t e m a t e r i a l t o provide h e a t pro tec- t i o n t o m e e t minimum requi rements of l l O O o C f o r a t l e a s t 30 minu tes d u r a t i o n . Th i s model f l i g h t r e c o r d e r i n c o r p o r a t e s a s t a i n l e s s s t ee l clamp-type r e t a i n e r r i n g around i ts equa to r p o i n t . T h i s should p reven t t h e s e p a r a t i o n of t h e two s h e l l s e c t i o n s r e s u l t i n g from c rush ing l o a d s t h a t u s u a l l y occur i n major a c c i d e n t s .

The f l i g h t r eco rd is i n s c r i b e d on aluminium o r s t a i n l e s s s tee l f o i l 2& inches wide, one m i l t h i c k . i s placed on a s p i n d l e i n t h e cassette assembly. The aluminium f o i l is f e d from t h i s spool , over a f l a t t e f l o n covered p l a t e n , on t o a take-up s p o o l mounted on a n o t h e r s p i n d l e which is d r i v e n by t h e main d r i v e mechanism. The f l i g h t record c o n s i s t s of t h e fo l lowing parameters : a l t i t u d e , a i r s p e e d ( IAS) , v e r t i c a l a c c e l e r a t i o n s , magnetic heading and t i m e . The cast aluminium c a s s e t t e assembly which was o r i g i n a l l y u t i l i z e d i n t h e Model 109C f l i g h t r e c o r d e r h a s been r ep laced with a s t a i n l e s s s t ee l des ign which a l s o inco rpora t e s a t o p cover f o r b e t t e r record p r o t e c t i o n .

It is wound on a s t a i n l e s s s teel spoo l ; t h e s p o o l (supply)

I n t h e o r i g i n a l Model 109C f l i g h t r e c o r d e r s , t h e main d r i v e mechanism cons i s t ed of a s i n g l e phase motor d r i v i n g a gear t r a i n through a h e l i c a l s p r i n g and r a t c h e t . The g e a r t r a i n drove s imul taneous ly a c lock escapement v i a a to rque l i m i t i n g dev ice , t h e d r i v e pawl which drove t h e f o i l take-up spoo l s p i n d l e , and t h e t iming d i s c which ope ra t ed t h e t i m e s t y l u s . with a d i r e c t d r i v e motor (which e l i m i n a t e s t h e escapement and t o r q u e c o n t r o l a s sembl i e s i n t h e o r i g i n a l models) and they have a governing escapement i n t h e motor head t h a t c o r r e c t s 909 t i m e s a minute f o r c o n s t a n t ou tput s h a f t s p e e d . The d i r e c t d r i v e motor ope ra t e s on 2 8 v o l t s DC o r i15 vo!tc .IC 400 c y c l e s provided through a b r i d g e r e c t i f i e r and t r ans fo rmer . Th i s l a t t e r dri-ve s y s t e m may be r e t r o f i t t e d i n t h e ea r l i e r models.

I n t h e c u r r e n t models t h e f l i g h t r e c o r d e r s a r e equipped



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The f l i g h t recorder i n s t a l l a t i o n senses ambient s t a t i c a i r p re s su re from s t a t i c p re s su re p o r t verits loca ted on t h e s i d e of t h e f u s e l a g e o r a combined P i t o t - s t a t i c tube and the P i t o t p re s su re is sensed from e i t h e r t h e Co-p i lo t ' s P i t o t system o r a n independent P i t o t system: p i l o t ' s magnetic d i r e c t i o n a l gyro ins t rument and t h e v e r t i c a l a c c e l e r a t i o n d i r e c t l y from an acce lerometer u n i t conta ined wi th in t h e f l i g h t recorder . Later models are equipped wi th a remote type acce lerometer which u t i l i z e s a se rvo ampl i f i e r u n i t and may be r e t r o f i t t e d i n t h e earlier models.

heading information i s provided by s i g n a l s der ived from t h e co- f o r c e sensed

The LAS Model 109D f l i g h t r e c o r d e r ' s o p e r a t i n g f u n c t i o n s are e s s e n t i a l l y t h e same as those desc r ibed above f o r t h e Model 109C. The p r i n c i p a l d i f f e r e n c e s are: t h e mechanism as sembl i e s of t h e 109D are conta ined i n a rectangular-shaped case having dimen- s i o n s of 4.875 x 7.625 x 19.56 inches t o f a c i l i t a t e u n i v e r s a l l y l o c a t i n g it i n t h e a i r c r a f t ; and a rrmte type acce lerometer sensor i s used which enab le s t h e r eco rde r t o be l o c a t e d a t d i s t a n c e s away from t h e a i r c r a f t ' s c e n t r e of g r a v i t y .

1 . 2 F a i r c h i l d and United Cont ro l Corporat ion F l i g h t Recorder Models

The F a i r c h i l d Hode1 5424 series and t h e United Data Cont ro l Model F-542 series f l i g h t r eco rde r s provide a record of a l t i t u d e , i nd ica t ed a i r s p e e d , heading and v e r t i c a l a c c e l e r a t i o n , w i th r e spec t t o t i m e . The records are of t h e o s c i l l o g r a p h i c type and a r e made by engraving a l i n e i n t o a high-nickel-content s t a i n l e s s s t ee l s t r i p . I n a d d i t i o n t o t h e f o u r major parameters , a u x i l i a r y heading trace reco rds are made by means of a b inary coder and an a d d i t i o n a l b inary coder i s a v a i l a b l e f o r marking events o r f o r o the r purposes. A t h i r d encoder i s used f o r marking a b a s i c r e fe rence l i n e on t h e record- i ng mi-dl 'a. The record ing system i s composed of t h e r eco rde r , a magazine con ta in ing t h e record ing medium, and an acce lerometer u n i t which ir; remotely mounted a t or near t h e c e n t r e of g r a v i t y of t h e a i r c r a f t ,

The f Light r eco rde r assembly is i n a s tandard 113 ATR s i z e equipment case. An e l e c t r i c a l connector is loca ted a t t h e rear and t h e P i t o t and s t a t i c p re s su re connexions a re loca ted on t h e f r o n t pane l . The r eco rde r c o n s i s t s of two major sec t ions : a r eco rde r s e c t i o n comprising a11 t-he record ing elements and magaz m e f o r the a c t u a l record ing , and a secci-1: which c;ntairic a l l of the e l e c t r o n i c components. Th i s is e l e c t r i c a l l y connected t o t h c r eco rde r frame by means of t e r m i n a l boards. The main frame con ta ins t h e fol lowing f u n c t i o n a l components: Take-up Dr ive , Actua tor Drive, T i m e r , Heading Servo, Vert ical Acce lera t ion Servo, A l t i t u d e and Ind ica t ed 4 i r speed Sensors , Three Binary Uni t s , t h e T i m e Remaining I n d i c a t o r , and Elapsed T i m e I n d i c a t o r , Magazine Receiver Assembly, and a Front Panel Assembly. a 28 v o l t DC power supply, a time de lay r e l a y , and a s s o c i a t e d t e rmina l boards, components and wir ing.

The e l e c t r o n i c chass i s c o n t a i n s two se rvo a m p l i f i e r u n j t s , a power r e l a y ,

The magazine assembly inc ludes the r o l l e r s and suppor t mechanism t o guide the recording medium from a supply r e e l through t h e necessary speed c o n t r o l and l o c a t i n g r o l l e r s t o a take-up reel . The record ing medium is a s t a i n l e s s steel s t r i p , 4.92 inches wide and approximately one m i l t h i c k , which i s capable of s u s t a i n i n g t h e f u l l a c c i d e n t environment without thermal p ro tec t ion . n i t e immersion i n s a l t water without damage t o t h e record o r a reduct ion i n t h e accuracy of t h e engraved t r a c e s , The metal is a s p e c i a l a l l o y which i s capable of wi ths tanding h igh temperature and impact shocks without any degrada t ion in i t s mechanical p rope r ty . Sprocket h o l e s a re provided a t both edges of t h e medium t o guide t h e medium through t h e magazine and t o c o n t r o l i t s e l f . t h e medium moves uniformly and a t t h e rate of s i x inches pe r hour (30 sp rocke t h o l e s pe r hour ) .

The medium i s a l s o capab le of wi ths tanding indef i-

Within th: Lonstancy of t he a i r c r a f t power l i n e f requency ,



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APPENDIX 3 . - F l i g h t Recorders : Types i n Use 3-3

The acce le romete r u n i t is a s e a l e d component which t r a n s m i t s an e l e c t r i c a l s i g n a l p r o p o r t i o n a l t o t h e a c c e l e r a t i o n a long i t s v e r t i c a l a x i s . The u n i t i s c a l i b r a t e d t o provide s i g n a l s p r o p o r t i o n a l t o a c c e l e r a t i o n s from -3g t o +6g and is des igna ted t o be mounted a t o r c l o s e t o t h e c e n t r e of g r a v i t y of t h e a i r c r a f t .

Recording is accomplished by p e r i o d i c a l l y sampling t h e parameters which a r e being measured and engraving l i n e s by means of s c r i b e r s i n t o t h e r eco rd ing medium. s c r i b e r s t y l i are above t h e r eco rd ing medium as i t passes over a small d iame te r s c r i b i n g r o l l e r i n t h e magazine. S imul taneous ly , t h e s c r i b e r s t y l i f o r t h e f o u r f l i g h t parameters a r e mechanically pushed i n t o c o n t a c t w i th t h e r eco rd ing medium as it goes over. t h e s c r i b i n g r o l l e r . A f t e r each mark is made, t h e s t y l i a re r e l e a s e d from t h e i r c o n t a c t with the medium, and a r e then capable 'of assuming a new p o s i t i o n as determined by t h e sens ing e l emen t s . Although t h e s t y l i themselves a r e p ivo ted i n ex t remely low f r i c t i o n p i v o t s , t h e r eco rd t h a t is made is r e c t i l i n e a r r a t h e r t han c u r v i l i n e a r . Th i s is accom- p l i shed by u s i n g a k n i f e edge type of s c r i b e r and making t h e mark as t h e k n i f e edge is pressed i n t o c o n t a c t w i th t h e r eco rd ing medium as t h e medium p a s s e s over a r o l l e r which is pe rpend icu la r t o t h e d i r e c t i o n of medium t r a v e l . A l i n e a c r o s s t h e width of t h e medium r e p r e s e n t s t h e same i n s t a n t of t i m e when t h e s t y l i a r e p r o p e r l y a l i g n e d .

The

For a l t i t u d e , i n d i c a t e d a i r s p e e d , and heading pa rame te r s , t h e r eco rd ings are made a t t h e rate of o n e c o n t a c t p e r second. For v e r t i c a l a c c e l e r a t i o n , r eco rd ings are made con t inuous ly on F a i r c h i l d Recorders and a t t h e rate of t e n p e r second on t h e UDC Record. The b i n a r i e s are con t inuous ly i n e i t h e r t h e ON p o s i t i o n o r t h e OFF p o s i t i o n r e g a r d l e s s of t h e i r f u n c t i o n .

The p o s i t i o n i n g of t h e s c r i b e s t y l i f o r t h e f o u r parameters which are be ing measured are a s fo l lows :

a ) A l t i t u d e is measured and t h e s t y l u s is p o s i t i o n e d by an a l t i t u d e s e n s o r which is one-half of complete assembly which a l s o i n c o r p o r a t e s t h e i n d i c a t e d a i r s p e e d senso r . Th i s u n i t i s connected t o t h e a i r c r a f t s t a t i c p r e s s u r e system. S ince t h e s t a t i c p r e s s u r e i s a f u n c t i o n of t h e a l t i t u d e of t h e a i r c r a f t , when t h e a l t i t u d e changes , t h e s t a t i c p r e s s u r e w i t h i n t h e e n c l o s u r e of t h e a l t i t u d e senso r a l s o changes. A d e c r e a s e i n s t a t i c p r e s s u r e r e s u l t i n g from a g a i n i n a l t i t u d e makes t h e a n e r o i d expand and f o r c e s t h e p r e c i s i o n p i n through t h e c l o s e f i t t i n g bushing . The p i n moves t h e s t y l u s i n t h e same d i r e c t i o n i n which t h e p i n i s moving and overcomes t h e f o r c e of t h e f l e x u r e s u p p o r t i n g t h e s c r i b e arm. The amount of movement of t h e s c r i b e a r m is determined by t h e a l t i t u d e of t h e air- c r a f t , t h e c h a r a c t e r i s t i c of t h e f l e x u r e and t h e p o s i t i o n of t h e p r e c i s i o n p i n wi th r e s p e c t t o t h e f l e x u r e p o i n t of t h e s c r i b e arm. L a t e r F a i r c h i l d models i n c o r p o r a t e a l t i t u d e and a i r s p e e d se rvo a m p l i f i e r s which r e c e i v e s i g n a l s from t h e c e n t r a l a i r d a t a computer systems. This system i s t h e au tomat i c c o r r e c t i o n f o r any s t a t i c d e f e c t e r r o r i n t h e pneumatic i n s t a l l a t i o n .

b) The i n d i c a t e d a i r s p e e d senso r o p e r a t e s i n e s s e n t i a l l y t h e same way as t h e a l t i t u d e senso r . The diaphragm h a s i t s i n t e r i o r connected t o t h e P i t o t sys tem of t h e a i r c r a f t whi le t h e space around t h e diaphragm is connected t o t h e s t a t i c s y s t e m . going through a s imi l a r bushing and p r e s s i n g a g a i n s t a s imilar s c r i b e a r m h e l d i n p o s i t i o n by a s i m i l a r f r i c t i o n l e s s f l e x u r e . t h e d i f f e r e n t i a l p r e s s u r e between t h e P i t o t p r e s s u r e and t h e s t a t i c p r e s s u r e and p o s i t i o n s t h e s c r i b e arm i n acco rd ing ly .

The p r e c i s i o n p i n i s aga in mounted on t h e o u t s i d e of t h e diaphragm

The i n d i c a t e d a i r s p e e d senso r measures



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c ) The heading record ing system comprises e s s e n t i a l l y a p o s i t i o n s e r v o system which ope ra t e s d i r e c t l y from t h e gyroscopica l ly s t a b i l i z e d , magnet ica l ly s laved d i r e c t i o n a l gyro instrument i n t h e a i r c r a f t . mitter is u t i l i z e d i n t h e a i r c r a f t t o t r a n s m i t t h e heading s i g n a l t o t h e r e c o r d e r . The heading system i n t h e recorder is energ ized and operated from t h e MDI sys tem i n t h e a i r c r a f t and h a s no e l e c t r i c a l connexions t o anyth ing i n t h e r e c o r d e r .

A three-phase synchro t r a n s -

A b inary device is used t o determine which hemisphere is being recorded. With t h e b inary i n t h e "North" p o s i t i o n t h e record produced by t h e heading system i n d i c a t e s t hose bear ings l y i n g between 270 degrees (due West) through 360 d e g r e e s (due North) t o 90 degrees (due E a s t ) . A t 90 d e g r e e s , t h e b inary swi tches t o t h e "South" p o s i t i o n as t h e s c r i b e r t r a v e l s through 180 degrees (due South) back t o 2 7 0 deg rees . A t 270 deg rees , the b inary a g a i n swi tches t o t h e "North" r e g i o n between 270 degrees through 260 a g a i n t o 90 degrees . The c a l i b r a t i o n of t h i s heading system i s completely l i n e a r and no ambigui ty r e s u l t s from t h e use of t h e a u x i l i a r y binary device.

d ) The a c c e l e r a t i o n record ing system o p e r a t e s i n a manner s i m i l a r t o t h a t f o r t h e heading system. The a c c e l e r a t i o n record ing system u t i l i z e s an i n d u c t i o n potent iometer t o balance t h e e l e c t r i c a l s i g n a l produced i n t h e remote mounted accelerometer . The cam which i s opera ted from t h e s h a f t of t h e induc t ion poten- t iometer t o p o s i t i o n t h e s c r i b e r h a s been a c c u r a t e l y c a l i b r a t e d and machined s o a s t o provide a l i n e a r c a l i b r a t i o n over t h e f u l l range from -3g t o +6g. A major d i f f e r e n c e i n t h e UDC f l i g h t recorder between t h e record made f o r v e r t i c a l accel- e r a t i o n and t h a t made f o r t h e o t h e r t h r e e parameters i s t h a t t e n r e c o r d i n g s p e r second a r e made f o r the measurement f o r t h e v e r t i c a l a c c e l e r a t i o n . The c a m s h a f t which i s dr iven by t h e a c t u a t o r d r i v e svstem c o n t a i n s no t only t h e cams which ope ra t e t h e pressure bar f o r making oiìe record p e r second f o r t he o t h e r parameters , but a l s o mounts a s p e c i a l ten-lobe cam and o p e r a t e s a s p e c i a l p r e s s u r e b a r t o provide t e n impressions from the acce lerometer s c r i b e arm. The diamond used i n t h e accelerometer s c r i b e a r m i s n o t a k n i f e diamond as i n t h e o t h e r th ree record- i ng systems but i s a po in t diamond. I t i s t h e r e f o r e , p o s s i b l e by t h e use of t h e s e s c r i b e marks t o ana lyse t h e record a t e n t h of a second a t a t i m e . However, t h e F a i r c h i l d f l i g h t r eco rde r s c r i b e s a cont inuous a c c e l e r a t i o n trace. The accelerometer u n i t c o n s i s t s of a se i smic mass mounted on s p r i n g s i n s i d e a h e r m e t i c a l l y sea l ed enclosure. produced, whose phase and magnitude are p r o p o r t i o n a l t o t h e d i r e c t i o n of t h e a c c e l e r a t i o n f o r c e s and t h e i r e x t e n t . with z e r o v o l t s output e s t a b l i s h e d a t + lg . i s a c c u r a t e w i t h i n p l u s o r minus one pe r cent i n c l u d i n g a l l of t h e e f f e c t s of l i n e a r i t y , temperature , v a r i a t i o n , environment, h y s t e r e s i s and no i se .

The ou tpu t from t h e acce lerometer i s an AC v o l t a g e , i n d u c t i v e l y

The range of t h i s u n i t i s from -3g t o +6g The c a l i b r a t i o n of t he acce lerometer

1.3 Spec Too l Company F l i g h t Recorders

The Spec Tool Company Model Alpha Marathon Recorder au tomat ica l ly r e c o r d s a i r s p e e d , a l t i t u d e , heading, v e r t i c a l a c c e l e r a t i o n and e l a p s e d t i m e . r ecorder provides f o r vo ice recording upon demand, and p r o v i d e s f o u r ( 4 ) a d d i t i o n a l v o l t a g e c o n t r o l l e d d a t a channels sampled once each second.

In a d d i t i o n , t h e

The recorder system c o n s i s t s of two u n i t s , an STC 2.5000 recorder and a n STC 25020 accelerometer . powered from t h e r eco rde r .

The accelerometer i s a d i f f e r e n t i a l - t r a n s f ormer-type instrument



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APPENDIX 3.- F l i g h t Recorders: Types i n Use 3-5

The r e c o r d e r is eiicased i n a crash arid f i r e r e s i s t a n t housing. The sepa rab le dome is c o n s t r u c t e d of two (2 ) s tee l hemispheres sepa ra t ed by h igh - t empera tu re - r e s i s t an t i n s u l a t i n g material. The dome is connected t o t h e lower hous ing by f o u r ( 4 ) Camloc fag- t ene r s . The upper p o r t i o n of t h e lower housing a l s o forms a n i n s u l a t e d compartment.

Fastened t o t h e bottom of the lower housing is t h e base p l a t e assembly. The base p l a t e assembly inc ludes a l 1 t r ansduce r s except t h e acce le romete r , and a l l e l e c t r o n i c equipment.

The r e c o r d e r p rov ides e x c i t a t i o n t o d i f f e r e n t i a l - t r a n s f ormer-type t r ansduce r s , The DC s i g n a l s are d i r e c t e d and procures vary ing-vol tage DC s i g n a l s from t h e s e t r a n s d u c e r s .

i n t o pu l se rate modula tors which p rov ide a widely va ry ing p u l s e r e p e t i t i o n ra te over t h e requi red c a l i b r a t i o n range. second p u l s e ra te modulator is provided f o r time-shared (commutated) s i g n a l s . The commu- t a t o r i s i n t h e t a p e t r a n s p o r t assembly. In a l l , p r o v i s i o n s are inc luded f o r up t o e i g h t (8) time-shared i n p u t s , each sampled f o r O. 1 seconds each second.

One p u l s e ra te modulator is provided f o r a c c e l e r a t i o n and t h e

The p u l s e output is recorded on magnetic t ape . The t a p e moves a t about 4 inch p e r second. Four ( 4 ) r e c o r d i n g t r a c k s are provided by two ( 2 ) r e c o r d i n g heads , Two t r a c k s (1 and 3 ) are used i n t h e i n i t i a l d i r e c t i o n of t ape motion. A f t e r about s i x t y ( 6 0 ) hours of ope ra t ion (nea r t h e end of t h e t a p e ) t h e tape a u t o m a t i c a l l y reverses. Tracks 2 and 4 are then used t o r eco rd on t h e t a p e i n t h e oppos i t e d i r e c t i o n . Tape r e v e r s a l t i m e is essen- t i a l l y ze ro .

C a l i b r a t i o n of t h e r e c o r d e r i s accomplished a g a i n s t a d imens ion le s s r a t io r e l a t i n g . t h e p u l s e rate ou tpu t from a parameter a g a i n s t t h e p u l s e rate output from a v o l t a g e r e f e r e n c e . T h i s v o l t a g e r e f e r e n c e is achieved from a " re fe rence" t r a n s d u c e r which is i d e n t i c a l t o t h e o t h e r t r a n s d u c e r s except t h a t i t s c o r e i s f i x e d . The purpose of t h i s r e f e r e n c e s i g n a l i s t o c o r r e c t for minor v a r i a t i o n s i n c a l i b r a t i o n due t o t a p e s t r e t c h , t empera tu re , and t r a n s d u c e r e x c i t a t i o n c u r r e n t , etc.

The t a p e r i d e s a g a i n s t a guide r o l l e r , r o t a t i n g t h e roller. Th i s r o t a t i o n i s sensed and used t o s h o r t a 115V s i g n a l w i th a 100k source impedance. Th i s s i g n a l , when connected t o a neon (NE-51) bulb , o r i n t o a headse t , p rov ides p o s i t i o n ev idence t h a t :

a ) The power is on.

b ) The s i x t y (60) c y c l e conve r t e r is ope ra t ing .

c ) The t a p e t r a n s p o r t is plugged i n and ope ra t ing .

d ) Recording t a p e is a v a i l a b l e and advancing.

1 .4 SFIM Photographic F l i g h t Recorders

Min ia tu re SFIM photographic f l i g h t r e c o r d e r s are s u i t a b l e as "crash" r eco rde r s and are i n u s e i n a number of a i r c r a f t . A 2 1 and S e r i e s A 26, and a r e of t h e non-e jec tab le type . A 212 , A 2122 and A 213 (which has two t ape t r a n s p o r t speeds ) : r eco rde r s A 2620, A 2630 and A 2631, a l l of which have two t a p e t r a n s p o r t speeds. A 213, H . C . = 5 x L . S . : f o r S e r i e s A 26, H.S. = about 15 x L . C . )

These r e c o r d e r s are i n two c l a s s e s , namely Series Series A 21 comprises r e c o r d e r s

S e r i e s A 26 comprises (For



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3- 6 Manual of A i r c r a f t Accident I n v e s t i g a t i o n

A l l of t h e s e r eco rde r s are equipped wi th a time base marking t h e hour s , t e n s of minutes, and minutes t o g e t h e r wi th two s i g n a l e lements , one of which is a t t h e p i l o t ' s d i s p o s a l €o r marking s p e c i a l even t s , and t h e o t h e r is a v a i l a b l e f o r marking any parameter which t h e u s e r may wish t o record . v a r i a b l e t o s u i t t h e needs of t h e u s e r but they are a l l of t h e moving mi r ro r t ype , e i t h e r socket-mounted o r crossbar-mounted.

The o t h e r r eco rd ing elements used are

According t o t h e types of record ing e lements used , t h e A 21 series can be used t o record s imul taneous ly :

- e i t h e r 5 cont inuous parameters and 2 i n t e r m i t t e n t parameters ;

- o r 4 cont inuous parameters and 3 i n t e r m i t t e n t parameters .

Whereas t h e A 26 series is used t o record s imul taneous ly :

- 10 cont inuous parameters and 8 i n t e r m i t t e n t parameters .

I n S e r i e s A 26, t h e p i l o t can i n c r e a s e the- t a p e t r a n s p o r t speed t o ob ta in b e t t e r r eco rd ing d e f i n i t i o n a t take-off and on landing: t h i s a l s o a p p l i e s t o A 213 of t h e S e r i e s A 21.

Both series use photographic f i l m o r paper wound on spoo l s i n a magazine ( c a s s e t t e ) s epa ra t e from t h e d r i v i n g mechanism. S e r i e s A 26 u s e s a t a p e 90 mm wide, and S e r i e s A 2 1 u ses a t ape 60 mm wide. Both series are of t h e long d u r a t i o n type wi th record- i n g times ranging from 5 hours t o 50 hours (80 hours wi th u l t r a - t h i n paper) f o r t h e A 2 1 S e r i e s and up t o 250 hours (slow speed) or 120 hours ( r a p i d speed) f o r t he A 26 S e r i e s .

I n a l l cases d a t a process ing can he performed e i t h e r by a computer (punched card f o r each r eco rde r ) o r , i f need be, by hand ( g r i l l e c a l i b r a t e d t o s u i t each r e c o r d e r ) .

Recording elements i n normal use inc lude : galvanometers , r a t i o m e t e r s , f requency meters, barographs, manographs, o s c i l l o g r a p h s (moving armature , moving magnet) , acce le rometers ( a x i a l , t r a n s v e r s a l ) , thermographs, and pendular l e v e l recorders .

The record ing p r i n c i p l e used by both series is q u i t e simple. The t ape run- n ing from the supply spoo l t o t h e take-up s p o o l pas ses behind a c a l i b r a t e d s l i t which i s perpendicular t o t h e t r a n s p o r t d i r e c t i o n . The l i g h t sou rce is r e f l e c t e d pe rpend icu la r ly on t o t h e s l i t by the moving mi r ro r of t h e record ing element. The i n t e r s e c t i o n of t h i s r e f l e c t e d image and of t h e s l i t forms a spo t of l i g h t which marks t h e tape as i t p a s s e s by. t r a n s l a t e s the na tu re of t h e phenomenon under observa t ion . of a l a r g e number of parameters a c r o s s t h e whole width of t h e t a p e t h e s p o t s may c r o s s one another . s i n c e each spot is d i f f e r e n t by i t s na tu re and by i t s trace on t h e tape .

The r o t a t i o n of t he mi r ro r d i s p l a c e s t h e image of t h e f i l a m e n t a long t h e s l i t and s o During s imultaneous r eco rd ing

I n reading o u t , t h e r e i s no d i f f i c u l t y i n d i s t i n g u i s h i n g between t h e t r a c e s

When used as crash r eco rde r s , S e r i e s A 21 and A 26 are p laced i n s i d e one of two types of p r o t e c t i v e cas ing:

a > P r o t e c t i v e cas ing A 9852 con ta ins t h e r e s i s t o r s requi red f o r condi t ioning t h e l a m p c i r c u i t s and a r e l a y modifying b r i l l i a n c e of t h e i n d i c a t o r l i g h t s ( f o r A 213). It p r o t e c t s t h e r eco rde r a g a i n s t t h e e f f e c t s of a shock of 3 O00 m/s2 (more than 300 g) f o r 5 m s i n any d i r e c t i o n . T h i s cas ing i s intended p r imar i ly f o r shock p r o t e c t i o n .



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APPENDIX 3.- F l i g h t Recorders: Types i n Use 3- 7

b) P r o t e c t i v e c a s i n g AF 2100 c o n t a i n s t h e r e s i s t o r s r e q u i r e d f o r condi- t i o n i n g t h e lamp c i r c u i t s . i n conformi ty w i t h t h e FAA and SGAC r e g u l a t i o n s .

It p r o t e c t s t h e r e c o r d e r which i t c o n t a i n s

R e s i s t a n c e t o fire: l l O O ° C f o r 30 minutes w i t h f lames enveloping a t least 50 p e r cent of i t s o u t s i d e s u r f a c e .

1000 m / s 2 (more than 100 g ) f o r 5 rns i n any d i r e c t i o n .

\

R e s i s t a n c e t o shock:

Resistance t o 30 hours i n sea water o r i n t h e u s u a l f u e l s , w i t h immersion: a vacuum p r e s s u r e of 1 b a r (14.5 p s i ) main ta ined

i n s i d e t h e c a s i n g .

2 . - Cockpit Voice Recorders

The fo l lowing paragraphs d e s c r i b e b r i e f l y v a r i o u s t y p e s of c o c k p i t v o i c e r eco rde r s . yellow i n c o l o u r .

A l l c o c k p i t v o i c e r e c o r d e r c o n t a i n e r s are e i t h e r b r i g h t o range o r b r i g h t

. 2 . 1 TOLANA Voice Recorder

The TOLANA A 4210 v o i c e r e c o r d e r i s c o n s t r u c t e d i n accordance w i t h ARINC 557 recommendation (Airborne Voice Recorder) and American s p e c i f i c a t i o n TSO C 84 (Cockpit Voice Recorde r s ) .

T h i s r e c o r d e r p e r m i t s cont inuous r eco rd ing of f o u r d i f f e r e n t sou rces :

- t h e p i l o t ' s s t a t i o n box

- t h e C o - p i l o t ' s s t a t i o n box

- t h e f l i g h t e n g i n e e r ' s s t a t i o n box (B-707)

- o r t h e s t a t i o n box o f t h e p u b l i c a d r e s s system (V 724)

- t h e c o c k p i t area microphone(s ) .

The t a p e used is 6.3 mm wide and about 90 m long. It r u n s a t a speed of 4.75 cm/s. The f u l l c y c l e of t h e t a p e is completed i n 30 minutes .

The t a p e winds on t o a d e t a c h a b l e c a s s e t t e which a l s o carries t h e r eco rd ing head and t h e erasure system. The cassette is placed i n a crash-proof c o n t a i n e r .

The TOLANA A 4210 r e c o r d e r is a t p r e s e n t be ing f l i g h t t e s t e d on Boeing 707 and Viscount 7 2 4 , c a r r y i n g o u t commercial a i r t r a n s p o r t o p e r a t i o n s .

The r e c o r d e r is i n s t a l l e d behind t h e p r e s s u r e bulkhead i n b o t h cases. Its func t ion ing can be checked by means of a c o n t r o l u n i t placed i n t h e c o c k p i t ; t h i s u n i t a l s o c a r r i e s t h e e r a s u r e c o n t r o l which can be ope ra t ed by t h e crew o n l y when t h e unde rca r r i age i s down, t h e shock a b s o r b e r s compressed and one door open.



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The r eco rd ings are read o u t by means of s p e c i a l equipment a v a i l a b l e t o t h e o f f i c i a l s e r v i c e s a l o n e au tho r i zed t o r ead o u t t h e r eco rd ings .

2.2 C o l l i n s Radio Corpora t ion

F a i r c h i l d Camera and Instrument Corpora t ion Lockheed A i r S e r v i c e Microdot Inco rpora t ed United Cont ro l Corporation

The r eco rd ing medium i n each r e c o r d e r is one-quarter i n c h Mylar t a p e . The t a p e s r eco rd on f o u r channels s imul taneous ly from f o u r d i f f e r e n t i n p u t sou rces ( c o c k p i t "area" microphone and t h r e e crew member s t a t i o n microphones i n t h e c o c k p i t ) . I n f o u r t y p e s , a s i n g l e - r e e l type continuous loop is used; i n t h e f i f t h (United Con t ro l ) , t h e looped t a p e i s he ld i n a random s t o r a g e magazine. A l l r e c o r d e r s have a bulk-erase f e a t u r e which may be a c t u a t e d on ly when t h e r e i s weight on t h e l and ing gea r . Some a i r c r a f t i n s t a l l a t i o n s a l s o r e q u i r e a d d i t i o n a l c i rcumstances such as s e t t i n g of pa rk ing brake , u se of e x t e r n a l power source, o r one engine s h u t down and s h a f t braked, p r i o r t o bu lk e r a s u r e .



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M4NUAL OF AIRCRAFT ACCIDENT INVESTIGATION

APPENDIX 4

FLIGHT RECORDERS: EXAMPLES OF READ-OUT

( F l i g h t Data a n d Voice Recorders)



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APPENDIX 4 . - F l i g h t Recorders: Examples of Read--Out 4-1

APPENDIX 4

FLIGHT RECORDERS: EXAMPLES OF READ-OUT

1. F l i g h t Data Recorders

The read-out and a n a l y s i s of f l i g h t d a t a r e c o r d i n g s p rov ide t h e inves- t i g a t o r w i t h a means of r e c o n s t r u c t i n g t h e v a r i o u s elements of t h e f l i g h t p r i o r t o t h e acc ident . of the d a t a recorded and t h e f l i g h t d a t a graphs which w e r e d e r i v e d from t h e s e d a t a .

The fo l lowing are two examples of t h e p r e c a u t i o n s t a k e n t o e n s u r e t h e accuracy

1.1 Boeing 727

1.1.1 I n t r o d u c t i o n

Th i s r e p o r t p e r t a i n s t o t h e r eco rd ing medium from a F a i r c h i l d f l i g h t d a t a . recorder , i n s t a l l e d on a Boeing 727 a i r c r a f t . The a i r c r a f t w a s engaged i n a scheduled a i r

c a r r i e r o p e r a t i o n : t h e en - rou te s e c t o r of t h e f l i g h t w a s u n e v e n t f u l b u t d u r i n g t h e l a n d i n g r o l l t h e a i r c r a f t veered o f f t h e runway r e s u l t i n g i n s u b s t a n t i a l damage t o t h e a i r c r a f t . There were no r e p o r t e d i n j u r i e s t o t h e pas senge r s and crew.

Examination and r e s u l t s - 1 . 1 . 2

The f l i g h t r eco rd medium w a s minutely examined, from t h e l i f t - o f f a t t h e commencement of t h e f l i g h t through t h e touchdown and r o l l o u t f o r mechanical damage, parameter ma l func t ion , abnorma l i ty i n t h e t r a c e s , and s t y l i a l i gnmen t . The parameters w e r e func t ion ing throughout t h e f l i g h t and t h e r eco rd ing medium c o n t a i n i n g t h e p e r t i n e n t record was readable . A d a t a graph r e f l e c t i n g t h e t i m e pe r iod from t h r e e minutes b e f o r e toiichdown t o one minute a f t e r touchdown w a s p l o t t e d ( s e e F igu re 4-1).

The examinat ion f i n d i n g s a r e a s fo l lows:

all paramete r s w e r e f u n c t i o n i n g and r e c o r d i n g throughout. t h e r eadou t t i m e p e r i o d ;

r e f e r e n c e l i n e w a s observed t o be c o n s i s t e n t w i t h t h e c u r r e n t c a l i b r a t i o n r e c o r d ;

s t y l l i o p e r a t i o n was normal and good t i m e c o r r e l a t i o n w a s e s t a b l i s h e d between t h e parameters ;

r e c o r d i n g medium was observed t o b e c o n s i s t e n t and t h e t iming t o b e w i t h i n t o l e r a n c e ;

a l l parameters beyond t h e t i m e p o i n t of 20 seconds a f t e r touchdown became a b e r r a n t .

The a l t i t u d e d a t a i n t h i s r e p o r t are based on t h e QNH baromet r i c p r e s s u r e of 29.69 i n c h e s Hg, t o conve r t t h e p r c s s u r e a l t i t u d e read-out d a t a t o Mean Sea Level a l t i t u d e i n f e e t . e r r o r , and t h e r e f o r e a r e i n d i c a t e d v a l u e s .

Data for t h e o t h e r parameters are uncor rec t ed f o r i n s t rumen t and p o s i t i o n



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4- 2 Manual of Aircraft Accident Investigation

BOEING 727

Fig. 4-1



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APPENDIX 4.- F l i g h t Recorders: Examples of Read-Out 4- 3

1.2 Douplas DC-8

1.2.1 I n t r o d u c t i o n

T h i s r e p o r t p e r t a i n s t o t h e record ing medium from t h e f l i g h t d a t a r e c o r d e r , a Locùheed A i r c r a f t S e r v i c e ModellOg-C, S/N 318, i n s t a l l e d on a Douglas DC-8 a i r c r a f t . The a i r c r a f t was be ing opera ted on a l o c a l t r a i n i n g f l i g h t duri.ng which t h e f l i g h t r epor t ed on base l e g f o r l and ing . runway t h r e s h o l d i n a populated a r e a a d j a c e n t t o t h e a i r p o r t . I n a d d i t i o n t o t h e f i v e crew members and one i n s p e c t o r aboard t h e a i r c ra f t , 13 persons on the ground s u s t a i n e d f a t a ? i n j u r i e s .

The a i r c r a f t crashed about 2 100 f e e t s h o r t of t h e

The a i r c r a f t w a s des t royed , by impact and f i r e .

The f l i g h t r e c o r d e r i n i t s e n t i r e t y w a s recovered from t h e wreckage.

1 .2 .2 Examination and r e s u l t s

The f l i g h t r e c o r d e r s u s t a i n e d no impact and f i r e damage as a r e s u l t of t h e The record ing medium s u s t a i n e d cons iderable damage caused most ly by s t y l i and a c c i d e n t .

c a s s e t t e movement. This l a t t e r c o n d i t i o n was t h e r e s u l t of t h e knob on t h e hold-down s t u d coming off when t h e casse t te was s u b j e c t e d t o v e r t i c a l l o a d s d u r i n g t h e impact pe r iod . However, t h e record ing medium w a s s t r a i g h t e n e d without d i f f i c u l t y and t h e read-out of t h e f l i g h t record w a s not impaired.

The f l i g h t record medium w a s minutely examined, from t h e t i m e of l i f t - o f f on t h e t r a i n i n g f l i g h t t o t h e t e r m i n a t i o n of t h e t r a c e s , f o r mechanical damage, parameter malfunct ion, abnormal i ty i n t h e t r a c e s , and s t y l i a l ignment . T h i s examinat ion d i s c l o s e d t h a t t h e f l i g h t record medium w a s f u n c t i o n i n g i n a normal manner f rom t h e l i f t - o f f t i m e t o t h e i n i t i a l impact p o i n t where normal opera t ion t e rmina ted . A f l i g h t r e c o r d e r d a t a graph w a s p l o t t e d t o r e f l e c t a read-out of t h e e n t i r e f l i g h t , a t i m e p e r i o d of less than s i x minutes d u r a t i o n ( see F igure 4 - 2 ) .

The examinat ion f i n d i n g s are as fo l lows :

A l l parameters were f u n c t i o n i n g and record ing throughout t h e read-out t i m e p e r i o d .

S t y l i o p e r a t i o n was normal and good t i m e c o r r e l a t i o n was e s t a b l i s h e d between t h e parameters .

Reference l i n e w a s observed t o be c o n s i s t e n t wi th t h e c u r r e n t c a l i b r a t i o n per iod .

The a i r s p e e d and a l t i t u d e parameters beyond t h e t i m e p o i n t of 5 minutes 35 seconds are cons idered a b e r r a n t t r a c e s due t o abnormal a i r f l o w e f f e c t s on t h e p i t o t and s t a t i c p r e s s u r e s e n s o r s .

The heading and a c c e l e r a t i o n parameters beyond t h e t i m e p o i n t of 5 minutes 46 seconds a r e considered a b e r r a n t traces due t o impact f o r c e s .

The a l t i t u d e d a t a i n t h i s r e p o r t are based on t h e QNH barometr ic p r e s s u r e of 30.01 inches Hg , t o conver t t h e p r e s s u r e a l t i t u d e read-out d a t e t o Mean Sea Level a l t i t u d e i n f e e t . e r r o r s , and t h e r e f o r e are i n d i c a t e d v a l u e s .

The d a t a f o r t h e o t h e r parameters are uncorrected f o r ins t rument and p o s i t i o n



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4- 4 Manual of Aircraft Accident Invest igat ion

\

F i g . 4-2



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APPENDIX 4 . - F l i g h t Recorders: Examples of Read-Out 4- 5

2. Cockpit Voice Recorders

The fo l lowing is an example of how t h e read-out and a n a l y s i s of a cockp i t vo ice r eco rd ing can provide t h e i n v e s t i g a t o r w i th a weal th of i n fo rma t ion r e g a r d i n g v a r i o u s sounds recorded i n t h e cockp i t .

2 . 1 Convair 880

2 . 1 . 1 I n t r o d u c t i o n

Th i s r e p o r t p e r t a i n s t o t h e r eco rd ing medium from a cockp i t v o i c e r eco rde r i n s t a l l e d on a Convair 880, which c ra shed , wi th no s u r v i v o r s .

A government e l e c t r o n i c s l a b o r a t o r y performed a sound s p e c t r a l a n a l y s i s on a re - record ing of t h e a c c i d e n t a i r c r a f t CVR t a p e t o c o r r e l a t e recorded sounds in terns of approximate t o impact.

eng ine speeds a t s p e c i f i e d t i m e i n t e r v a l s a long t h e a i r c r a f t f l i g h t pa th p r i o r

2 . 1 . 2 Examination and r e s u l t s

A c a l i b r a t i o n t ape of sounds genera ted a t v a r i o u s engine speeds w a s made by ope ra t ing a s i m i l a r a i r c r a f t i n a f l i g h t p a t t e r n and c o n f i g u r a t i o n commensurate wi th t h e acc iden t a i r c r a f t . This r eco rd ing w a s a l s o examined by t h e sound s p e c t r a l a n a l y s i s technique i n o r d e r t o d e f i n e a comparative base l i n e c a l i b r a t i o n of eng ine genera ted sounds.

S e v e r a l prominent resonances were d e t e c t e d on t h e r e - r eco rd ing of t h e acc iden t CVR t a p e . These resonances c o n s i s t e d of a random d i s t r i b u t i o n of energy between 400 t o above 4000 Hertz (Hz) w i th t h e most prominent resonances c e n t r e d a t approximate f r e q u e n c i e s r ang ing from 2000 t o 2270 Hz. of t h e r e f e r e n c e r e - r eco rd ing y i e l d e d prominent resonances c e n t r e d a t approximate f requen- c i e s ranging from 1490 t o 2500 Hz. When p l o t t e d as a f u n c t i o n of announced engine speed, t hese f r e q u e n c i e s formed a s t r a i g h t l i n e f u n c t i o n .

A d d i t i o n a l l y , a sound s p e c t r a l s tudy examination

To d e f i n e and i d e n t i f y t h e s e prominent resonances and r e s u l t a n t f r e q u e n c i e s f u r t h e r i n terms of r o t a t i n g engine components, t h e Board i n a Co-ordinated e f f o r t w i th t h e A i r c r a f t Engine Group of General E l e c t r i c Company cont inued t h i s s tudy by examining both t h e o r i g i n a l CVR a c c i d e n t t a p e and r ep roduc t ions of t h i s t a p e .

These r o t a t i n g engine components were subsequent ly i d e n t i f i e d i n terms of sound p r e s s u r e (energy) l e v e l s and f r e q u e n c i e s . It w a s de te rmined t h a t t h e most prominent resonance noted corresponded t o t h e f i r s t s t a g e compressor b l a d e p a s s i n g fundamental frequency. Other less d i s c e r n i b l e fundamental pas s ing f r equenc ie s t h a t were i d e n t i f i e d included t h e second and t h i r d s t a g e compressor b l ades .

These f r e q u e n c i e s are a t a f i x e d cons t an t r e l a t i o n s h i p t o each o t h e r and are f u n c t i o n s of t h e number of compressor b l a d e s and t h e p h y s i c a l eng ine speed. These frequencies are i n c o n s t a n t r e l a t i o n s h i p wi th eng ine speed , t h u s a l l o w i n g i n t e r p r e t a t i o n on a continuous f l i g h t t i m e v e r s u s engine speed management b a s i s .



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A t o t a l f l i g h t p r o f i l e t i m e of e i g h t minutes p r i o r t o impact was s t u d i e d and Thei r i n t e r p r e t a t i o n i n t e r p r e t e d by General E l e c t r i c i n terms of engine speed management.

of engine speed management was made by independent ly de te rmining engine speed from t h e f i r s t and second stage compressor f r e q u e n c i e s and then averaging t h e s e va lues . Devia t ion of t hese averages w a s approximately 0.1 p e r c e n t . I n d i v i d u a l engine speeds were a l s o determined by t h i s method. spectrum, i t w a s determined t h a t t h e fo l lowing f l i g h t p r o f i l e ve r sus engine power management schedule was conducted by t h e f l i g h t crew.

Based on General E l e c t r i c i n t e r p r e t a t i o n of t he engine sound

S t a r t i n g a t t h e -8:OO minute t i m e p o i n t , two engines were a t f l i g h t i d l e and two eng ines a t approximately 7 8 per cen t , eng ine speed w a s cons t an t u n t i l -3:56 whereupon t h e two engines a t i d l e were boosted up t o n e a r t h e o t h e r eng ines , followed by a slow a c c e l e r a t i o n of a l l f o u r engines t o approximately 84.1 pe r cen t a t -3:38. Speed remained cons t an t u n t i l -2:57 whereupon a three-second a c c e l e r a t i o n t o approximately 86.1 pe r c e n t w a s completed a t -2:54. r educ t ion t o 85.0 p e r cen t . This engine speed cont inued u n t i l -0:15 a t which t i m e a t w o - second d e c e l e r a t i o n t o 82.5 per c e n t completed a t -0.13. This engine speed continued u n t i l approximately O. 8 seconds be fo re impact where a sudden i n c r e a s e i n power t e rmina ted i n t o t h e sound of impact.

Engine speed then remained cons t an t u n t i l -1:34 with a one-second

By u t i l i z i n g t h e above engine speed h i s t o r y i n conjunct ion wi th t h e a l t i t u d e and ind ica t ed a i r s p e e d d a t a recorded on t h e FDR, and t h e ambient cond i t ions a t t h e t i m e of t h e a c c i d e n t , an engine-generated n e t t h r u s t chronology was computed by General E l e c t r i c us ing t h e i r CJ-805-3A perf ormance computer deck.

F igure 4-3 d e p i c t s the computed f l i g h t envelope t o t a l n e t t h r u s t genera ted and t h e nominal percentage of phys i ca l r o t o r speed as a f u n c t i o n of f l i g h t t i m e p r i o r t o impact, based on t h e above f l i g h t p r o f i l e . Although i n d i v i d u a l engine speeds were d e t e r - mined, a nomina1 v a l u e of percentage of engine p h y s i c a l speed w a s used i n these computations. A l t i t u d e and ind ica t ed a i r speed d a t a ob ta ined from t h e FDR record were a l s o used. ûut- s i d e ambient temperature w e a t h e r obse rva t ion w a s used t o e s t a b l i s h tempera ture a l t i t u d e s lope , and w a s t r a n s l a t e d t o pas s through t h e s u r f a c e tempera ture . computed based on a 30 horsepower e x t r a c t i o n f o r accesso ry d r i v e l o s s and a f o u r pound/ second a i r bleed e x t r a c t i o n .

Engine performance w a s

These p o i n t s are p resen ted a s a t h r u s t band, s i n c e n e t t h r u s t accuracy is dependent p r imar i ly upon t h e speed /a i r f low r e l a t i o n s h i p and t h e compressor s t a t o r s chedu le to l e rance on t h r u s t , which could be g e n e r a l l y equ iva len t t o 2 2 per c e n t engine speed a t approach power s e t t i n g s .



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DIX

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4- 8 Manual of Aírcraf t Accident Investigation

1 ’ -4

I -3

Fig. 4-4.- Spectrogram of orfginal tape from Convair 880 (two channels Genera I E lec tr ic Research and Deve lopment Center.

4000

combined).



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APPENDIX 4 . - Fl igh t Recorders: Examples of Read-Out 4-2

I

-1 minute

3000

Fig. 4-5.- Spectrogram of original tape from Convair 880 ( two channe 2s combined). General Elec tr ic Research and Deve Zopment Center.



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APPENDIX 5

EXAMPLES OF FRACTURE ANALYSIS



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APPENDIX 5.- F r a c t u r e Ana lys i s 5- 1

APPENDIX 5

EXAMPLES OF FRACTURE ANALYSIS


A n impor tan t p a r t of t h e work of t h e Inves t iga tor - in-Charge is t o de te rmine t h e o r i g i n of a f r a c t u r e . which were conducted fo l lowing a c t u a l a c c i d e n t s .

Th i s appendix g i v e s some t y p i c a l examples of f r a c t u r e a n a l y s i s ,

2. F r a c t u r e Ana lys i s w i th t h e Aid of an E l e c t r o n Microscope

AArcraf t I d e n t i f i ca t ion : Convair 580

P a r t I d e n t i f i c a t i o n : Two mating p a r t s of t h e f r a c t u r e d to rque c y l i n d e r from No. 3 p r o p e l l e r hub socke t .

Meta l loRraphic examinat ion

The two f r a c t u r e s u r f a c e s w e r e examined a t 3 0 X under a bench microscope. The r eg ions marked A t o F i n F igu res 5-1 and 5-2 were r e p l i c a t e d w i t h c e l l u l o s e acetate. F igure 5-3 shows Region F a t a h i g h e r magn i f i ca t ion and r e p r e s e n t s t h e g e n e r a l c h a r a c t e r - i s t i c s of t h e macroscopic f r a c t u r e appearance. Arrows i n d i c a t e s e v e r a l s t e p s on t h e f r a c t u r e s u r f a c e a long t h e i n n e r edge of t h e p iece . These s t e p s d imin i sh i n h e i g h t as they extend i n t o t h e p i e c e , t e r m i n a t i n g t o form a f l a t s u r f a c e i n t h e middle of t h e p i ece . A t t h e t o p ( t h e o u t e r edge of t h e c y l i n d e r ) t h e r e i s an ob l ique , o r s l a n t e d , s u r f a c e .

The macroscopic appearance of t h e f r a c t u r e s u r f a c e is d i s t i n c t l y s i m i l a r t o many o t h e r s u r f a c e s formed under known f a t i g u e loading c o n d i t i o n s , w i t h non-coplanar mul- t i p l e c r a c k s i n i t i a t i n g a t t h e p o i n t s of h i g h e s t i n i t i a l s u r f a c e stress and t h e n growing toge the r t o form a cont inuous crack. Th i s c r a c k then advances u n t i l t h e stress i n c r e a s e i n t h e remaining material causes t h e whole p i e c e t o f r a c t u r e a l o n g . t h e p l a n e of h i g h e s t ~

shear stress, the reby forming a shea r l i p .

The c e l l u l o s e a c e t a t e r e p l i c a s of t h e s i x r e g i o n s were p rocessed t o form The p l a t inum-shadowed carbon r e p l i c a s which w e r e examined i n t h e e lec t ron microscope.

suspec ted i n i t i a t i o n s i tes (along t h e i n n e r s u r f a c e s ) were examined t o de te rmine t h e cause of i n i t i a t i o n . The f l a t f r a c t u r e r e g i o n w a s examined t o de te rmine t h e p ropaga t ion mechanisms. The s l a n t e d r e g i o n ( a t t h e top i n F igu re 5-3) w a s examined t o de t e rmine whether o r n o t i t w a s a shea r l i p .

It w a s qu ick ly determined t h a t t h e m a j o r i t y of t h e two o r i g i n a l f r a c t u r e sur - f a c e s was e i t h e r covered by d i s c o n t i n u o u s , u n i d e n t i f i e d , contaminat ion l a y e r s o r w a s damaged by ab ras ion . However, i s o l a t e d , randomly spaced pa tches of t h e o r i g i n a l s u r f a c e s (approximately 10 pe r c e n t ) were c l e a n enough t o be i d e n t i f i a b l e .

F igu re 5-4 shows t h e f r a c t u r e s u r f a c e about 30 microns away from t h e i n i t i a - t i o n s i t e i n Region E , and Figure 5-5 shows a p o r t i o n of Region B , a l s o about 30 microns from t h e i n n e r s u r f a c e . g e n e r a l l y f l a t pa t ches . but are absen t i n F igu re 5-5.

The arrows i n both F igu res 5-4 and 5-5 i n d i c a t e s t e p s between F a t i g u e s t r i a t i o n s are f a i n t l y v i s i b l e i n p o r t i o n s of F i g u r e 5-4



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The i d e n t i f i a b l e p o r t i o n s of t h e f r a c t u r e s u r f a c e s i n t h e f l a t r e g i o n s were c h a r a c t e r i z e d by t h e same f e a t u r e s as shown i n F igu res 5-4 and 5-5. An example, nea r t h e j u n c t i o n of t h e f l a t f r a c t u r e and t h e s l a n t f r a c t u r e i n Region D , is shown i n F igure 5 - 6 .

The i d e n t i f i a b l e p o r t i o n of the s l a n t f r a c t u r e c o n s i s t e d 'of shear dimples r e s u l t i n g from microvoid coalescence. An example is shown i n F igure 5-7 which w a s t a k e n from Region E.

Conclus ions

The presence of t h e d i scon t inuous f i l m of f o r e i g n matter on t h e whole of t h e two f r a c t u r e s u r f a c e s i n d i c a t e s t h a t t h e p i e c e s were corroded o r o therwise contaminated a f te r they were f r a c t u r e d and, t h e r e f o r e , t h a t t h e c rack d i d not n e c e s s a r i l y propagate under c o r r o s i v e cond i t ions . The absence of i n t e r g r a n u l a r f a c e t s and secondary c rack ing i n d i c a t e s t h a t t h e c rack d id not i n i t i a t e o r propagate e i t h e r by s t r e s s - c o r r o s i o n c rack ing or by hydrogen c rack ing (sometimes c a l l e d hydrogen embr i t t l ement ) . The absence of dimples and i n t e r g r a n u l a r f a c e t s nea r t h e i n i t i a t i o n s u r f a c e i n d i c a t e s t h a t t h e c rack d id n o t i n i t i a t e by simple mechanical overload.

The presence of s t r i a t i o n pa tches s e p a r a t e d by s t e p s nea r t h e inner s u r f a c e s of t h e two p ieces i n d i c a t e s t h a t t h e c rack i n i t i a t e d by f a t i g u e . pa t ches i n t h e f l a t f r a c t u r e ( i n p l a c e s where t h e o r i g i n a l s u r f a c e could be seen) shows t h a t t h e c rack propagated by f a t i g u e . The presence of dimples on t h e s l a n t e d f r a c t u r e s u r f a c e s shows t h a t t h e s e s u r f a c e s were formed by t e n s i l e over load and are shear l i p s . These microscopic obse rva t ions t h u s show t h a t t h e c rack i n i t i a t e d and was propagated by f a t i g u e and te rmina ted i n t e n s i l e f r a c t u r e of t h e remaining m e t a l .

The presence of f a t i g u e

The microscopic and macroscopic obse rva t ions show t h a t a f a t i g u e c rack grew The c y l i n d e r t h e n through t h e w a l l of t h e cy l inde r from t h e i n s i d e t o t h e mid-thickness.

f r a c t u r e d e i t h e r because t h e c rack w a s of c r i t i c a l s i z e f o r f r a c t u r e under t h e load ing con- d i t i o n s caus ing f a t i g u e , o r because a n anomalous over load suddenly f r a c t u r e d t h e c racked cy l inde r . It is not p o s s i b l e t o d i s t i n g u i s h between t h e s e two p o s s i b i l i t i e s us ing t h e s e l i m i t e d observa t ions .



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APPENDIX 5.- Fracture Analysis 5-3

L233 F i g 5-1.- One of the fractured p ieces , wi th arrows bounding the

fracture surface. ApprozimateZy 1X.

F i g 5-2.- The other fractured p iece . ApproximateZy IX.



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5-4 Manual of A i r c r a f t Accident Inves t iga t ion

F i g . 5 - 3 . - Region F a t a higher magnification. surface ( a t bottom) indicate steps. Approximately 1 O X .

Arrows along inner



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APPENDIX 5.- Fracture A n a l y s i s 5-5

F i g . 5-4.- Steps (bounded by the top and bottom arrows) separatinq a fat igue patch (bounded by the six arrows) from neighbowing patches.

Faint s t r ia t ions may be seen i n the fat igue patches. 9 ,OOOX.



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5- 6 Manual of A i r c r a f t Accident Inves t iga t ion

F i g . 5-5.- Steps (bounded by arrows) separating fat igue patches i n the i n i t i a t i o n area of region B. 9 , O O O X .



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APPENDIX 5.- F r a c t u r e Ana lys i s 5-7 ____

F i g . 5-6.- Str ia t ions i n fa t igue patches in the centre of region û. 15,OOOX.



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5- 8 Manual of A i r c r a f t Accident Inves t iga t ion

F i g . 5-7.- Shear dimples on the shear Z i p in region E. 45 ,OOOX.



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5- 9 - APPENDIX 5.- F r a c t u r e Analys is

3. Fa t igue F r a c t u r e O r i g i n a t i n g a t a Heat-Treat ing Crack

Aircraf t i d e n t i f i c a t i o n : Lockheed E l e c t r a

P a r t I d e n t i f i c a t i o n : P r o p e l l e r Blade, Part No. 6506549, S e r i a l No. B-6118, from P r o p e l l e r S e r i a l No. P-858. T o t a l t i m e on b lade - 1250 hours .

Summary

A m e t a l l u r g i c a l examinat ion of t h e f a i l e d b lade i n d i c a t e d t h a t a f a t i g u e f r a c t u r e had progressed from a p r i o r c r a c k which had been p r e s e n t d u r i n g manufactur ing opera t ion8 b e f o r e t h e f i n a l h e a t t r e a t m e n t was completed.

' V i s u a l examinat ion

A complete t r a n s v e r s e f r a c t u r e had occurred i n t h e r o o t s e c t i o n of t h e b l a d e a s shown i n F i g u r e 5-8. The f r a c t u r e o r i g i n a t e d a t t h e inboard r a d i u s of t h e c u f f r i n g i n t h e a r e a i n d i c a t e d by arrows "a", F i g u r e s 5-8 and 5-9. There w a s a s m a l l : area of f r a c t u r e a t t h e nuc leus (Arrows "ctl , F igure 5-10) t h a t had a rough, g r a n u l a r s u r f a c e and appeared t o be covered w i t h a b l a c k oxide scale. A f a t i g u e f r a c t u r e had s t a r t e d a t t h e edge of t h e g r a n u l a r a r e a and progressed through t h e p r o p e l l e r wall t o t h e p o i n t s i n d i c a t e d by arrows "b", F igure 5-9, b e f o r e t h e f i n a l f a i l u r e occurred.

Meta l lographic examinat i o n

The m i c r o s t r u c t u r e of t h e s t ee l w a s examined on a s e c t i o n through t h e nuc leus of t h e f r a c t u r e i n t h e area shown i n F igure 5-10. was covered wi th oxide scale , as shown i n F i g u r e s 5-11, 5-12 and 5-13. A small amount of d e c a r b u r i z a t i o n w a s found underneath t h e s c a l e , a s shown i n F i g u r e 15-13. No scale o r d e c a r b u r i z a t i o n w a s found on t h e f a t i g u e p o r t i o n of t h e f r a c t u r e . The appearance of a s e c t i o n through t h e f a t i g u e area i s shown t o t h e r i g h t of arrow "d" i n F igure 5-11.

The g r a n u l a r p o r t i o n of t h e f r a c t u r e

The presence of the. scale and d e c a r b u r i z a t i o n showed t h a t t h e g r a n u l a r por- t i o n of t h e f r a c t u r e s u r f a c e (arrows "c", F igure 5-10) had been exposed t o t h e a i r . w h i l e t h e s t e e l w a s a t a h igh tempera ture , such as would be encountered d u r i n g h e a t t rea tment . I t i n d i c a t e s t h a t a c r a c k about 0.6 inch long and 0.07 inch deep w a s p r e s e n t a t t h e cuff r i n g r a d i u s b e f o r e t h e f i n a l h igh tempera ture h e a t t rea tment w a s completed d u r i n g t h e manufacturing o p e r a t i o n s . mat e r ia1 . The examinat ion d i d no t r e v e a l any o t h e r ev idence of d e f e c t i v e

Hardness t e s t s

Rockwell hardness t es t s were >nade on the o u t s i d e s u r f a c e of t h e b lade near the cu f f r i n g a f t e r g r i n d i n g t o remove t h e p l a t i n g . s e c t i o n nea r t h e f r a c t u r e o r i g i n . th- Flickers numbers from 3 3 3 t o 3 4 2 . t o 35 Rc. of 30 t o 35 Rc a s r e q u i r e d by t h e manufactu-ing s p e c i f i c a t i o n s .

Vickers t e s t s were made on a p o l i s h e d The Rockwell v a l u e s obta ined ranged from 30 t o 31 Rc and

The a. 'erage Vickers hardness corresponded approximately Both tes ts i n d i c a t e d t h a t t h e bLtde had been h e a t t r e a t e d t o t h e hardness range



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5-10 Manual of Aircraft Accident Investigation

F i g . 5-8. - Piece of the faiZed p o p e ZZer b k d e , wi th t h e outboard end cut away. The fracture i s shorn on the r i g h t end of the piece. Arrow r'arr indicates

the location of t he fracture origin. Xi.



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Fig. 5-9.- Appwwaïic-e of t k e f iaa ture siirface. m e a ir ,d ic . s - :~c! h2 arro7~ ‘i~” ar2d progressed approximately to the points indicated

A jratigue crack originated i n the

“y L n - r o m ”birr bcfoye the finai! fai Zure occurred. 1 1 .



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F i g . 5-10.- Fracture surface i n the area indicated by arrow "arr, F i g . 5-9. Note the black, granuZar appearance o f the poption o f the fracture

indicated by arrows "e". X 5 .

F i g . 5-11.- Section through the fracture surface a t the junct ion of the fat igue fracture and the black, granular area shown i n F i g . 5 - I C . The

Light coloured fat igue fracture extends t o the r igh t from arrow "d". material t o the l e f t of arrow "d" i s oxide scale on the

fracture surface. 1% NitaZ etch. X l O O .



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APPENDIX 5.- F r a c t u r e Analysis 5- 13

Fig. 5-12.- Section thrdougk tke fracture area indicated by arrows F i g . 5-10, showing oxide scale on the fracture surface. The whitematerial

f%r',

is ,steel and the Light grey material i s scale. specirnent mount. ünetcked. X500.

Darker surface i s

F i g . 5-13.- Etched microstructure of the s t ee l adjacent t o the s c a k on the fracture, showing decarburization i n a th in layer under the

scale, 1% Nital etch. X100.



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4. Fa t igue F r a c t u r e O r i g i n a t i n g i n an Area Damaped During a Manufacturing Opera t ion

A i r c r a f t I d e n t i f i c a t i o n : Boeing 720 B

P a r t I d e n t i f i c a t i o n : Second s t a g e compressor d i s c , P a r t ' 110. 421602, from a P r a t t and Whitney JT-3D-1 engine , serial N O , P-643263 B

Summary

Three r a d i a l f r a c t u r e s had occur red about 120 degrees a p a r t i n t h e d i s c , s e p a r a t i n g i t i n t o t h r e e approximately e q u a l p i e c e s . duc ted on t h e two p i e c e s shown i n F igure 5-14 a t t h e Na t iona l Bureau of S tandards and on t h e t h i r d p i e c e a t t h e P r a t t and Whitney M a t e r i a l s Development Labora tory . c o n t a i n s informat ion ob ta ined from both of t h e s e l a b o r a t o r y s t u d i e s .

M e t a l l u r g i c a l examinat ions were con-

Th i s r e p o r t

M e t a l l u r g i c a l examination i n d i c a t e d t h a t t h e primary f a i l u r e i n t h e com- p r e s s o r d i s c w a s a f a t i g u e f r a c t u r e o r i g i n a t i n g i n a damaged area i n t h e s u r f a c e of a work- b o l t ho le .

The chemical composition and mechanical p r o p e r t i e s of t h e d i s c material com- p l i e d wi th t h e requi rements of a p p l i c a b l e s p e c i f i c a t i o n .

V i sua l examination

Examination of t h e f r a c t u r e s u r f a c e s i n d i c a t e d t h a t t h e primary f a i l u r e w a s a f a t i g u e f r a c t u r e through t h e work-bolt ho le (0.370-0.380 inch d i ame te r ) i n d i c a t e d by arrow "a" i n F igure 5-14. Numerous f a t i g u e o r i g i n s (Figure 5-17) were found on both s i d e s of t h e h o l e - i n t h e areas i n d i c a t e d by b r a c k e t s "c" and "d" i n F i g u r e s 5-15 and 5-16. No evidence of f a t i g u e w a s found i n e i t h e r of t h e o t h e r two r a d i a l f r a c t u r e s , bo th of which occurred through O. 5 inch diameter t i e - b e l t h o l e s .

The f a t i g u e f r a c t u r e had o r i g i n a t e d i n an area where t h e s u r f a c e of t h e h o l e had been seve re ly damaged, appa ren t ly by a r o t a t i n g t o o l . The v i s i b l e s u r f a c e damage con- s i s t e d mainly of c i r c u m f e r e n t i a l t o o l marks i n t h e area between ar rows "e" and "f", F igure 5-15. The appearance of t h e t o o l marks, some of which extended t o a depth of 0.004 inch below t h e undamaged s u r f a c e , are a l s o shown i n F i g u r e s 5-16 and 5-18.

A boroscope examination was made of t h e s u r f a c e of t h e o t h e r work b o l t h o l e s i n t h e p i e c e s shown i n F igure 5-14. The s u r f a c e s of t h e s e h o l e s con ta ined numerous sha l low s c r a t c h e s running i n both l o n g i t u d i n a l and s p i r a l d i r e c t i o n s (F igure 5-20), bu t no damage w a s found t h a t appeared t o be of t h e same type as t h a t found i n t h e h o l e where t h e f a t i g u e f r a c t u r e o r i g i n a t e d . The t i e - b o l t h o l e s a l s o appeared t o be f r e e from such damage.

Numerous c r a c k s (F igure 5-18) were found i n t h e damaged s u r f a c e of t h e work- b o l t h o l e c l o s e t o , and p a r a l l e l t o , t h e main f a t i g u e f r a c t u r e . These appeared t o be secondary f a t i g u e cracks. t h e h o l e , and d i s t i n c t l y d i f f e r e n t from t h e i r r e g u l a r ove r load s h e a r c r a c k s a s s o c i a t e d wi th t h e f r a c t u r e s through t h e t i e - b o l t h o l e s (Figure 5-19).

They were s t r a i g h t , appa ren t ly p e r p e n d i c u l a r t o t h e s u r f a c e of

A b lue d i s c o l o r a t i o n w a s found on t h e s u r f a c e of t h e f a t i g u e f r a c t u r e i n t h e o r i g i n a r e a of t h e p i e c e examined a t P r a t t and Whitney. maximum of 0.250 inch toward t h e . b o r e of t h e d i s c and 0.40 i nch toward t h e rin: from t h e

The d i s c o l o r a t i o n extended a



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APPENDIX 5.- F r a c t u r e Ana lys i s 5- 1 5

s u r f a c e of t h e work-bolt h o l e . l a b o r a t o r y by exposing a pre-cracked compressor b l ade made of t h e same type of m a t e r i a l as t h e f a i l e d d i s c t o r e a g e n t s s p e c i f i e d i n t h e JT-3D overhaul manual f o r removing g r a p h i t e v a r n i s h and baking f o r two hour s a t 300°F t o s imula t e r e - a p p l i c a t i o n of g r a p h i t e v a r n i s h .

The appearance of t h e d i s c o l o r a t i o n was reproduced i n t h e

Meta l iov raph ic examinat ion

The only abnormali ty found i n t h e m i c r o s t r u c t u r e of samples of m a t e r i a l from t h e f a i l e d compressor d i s c w a s a d j a c e n t t o t h e damaged s u r f a c e of t h e work-bolt h o l e where t h e f a t i g u e f r a c t u r e o r i g i n a t e d . s u r f a c e c r a c k s and l a p s were found as shown i n F igu res 5-21 and 5-22. i n Figure 5-22 t h e v i s i b l e e f f e c t s of t h e s u r f a c e damage extended t o a dep th of about 0.009 inch. macroetching i n d i c a t e d t h a t t h e e f f e c t of t h e damage extended t o a dep th of 0.014 inch below t h e most s e v e r e l y damaged s u r f a c e .

I n t h i s area a l a y e r of s e v e r e l y c o l d worked metal and I n t h e area shown

I n o t h e r areas t h e appearance of t h e m i c r o s t r u c t u r e , microhardness su rveys and

The m i c r o s t r u c t u r e of a s e c t i o n through t h e undamaged p o r t i o n of t h e work- b o l t h o l e is shown i n F igu re 5-23.

Examination w i t h a n e l e c t r o n microscope of r e p l i c a s t aken of t h e f r a c t u r e s u r f a c e s i n t h e o r i g i n area showed a f a t i g u e s t r i a t i o n p a t t e r n similar t o t h o s e found on low c y c l e f a t i g u e c r a c k s produced i n t h e P r a t t and Whitney Materials Development Laboratory.

Material composi t ion

The m a t e r i a l s p e c i f i e d f o r t h e f a i l e d d i s c was AMs4928 t i tanium-base a l l o y . The resu l t s of s p e c t r o g r a p h i c and chemical a n a l y s e s of t h e d i s c material and t h e chemical requirements of t h e s p e c i f i c a t i o n were as fol lows:

D i s c Material ( p e r c e n t )

Aluminium Vanadium I r o n Carbon Oxygen Nitrogen Hydrogen

5.98 3.89

less t h a n 0.30 0.09 O . 118 o. o19 O. 004

AMs 4928 ReQuirements ( p e r c e n t )

5.50 - 6.75 3.50 - 4.50 0.30 Max. 0.10 Max. 0.20 Max. 0.05 Max. 0.0125 Max.

The m a t e r i a l composi t ion complied w i t h t h e chemical r equ i r emen t s of t h e s p e c i f i c a t i o n .

Res idua l stress

An X-ray d i f f r a c t i o n a n a l y s i s i n d i c a t e d a r e s i d u a l t e n s i l e stress, p r i m a r i l y i n a c i r c u m f e r e n t i a l d i r e c t i o n , of 32 O00 p s i a t t h e damaged s u r f a c e of t h e work-bolt h o l e where t h e f a t i g u e f r a c t u r e o r i g i n a t e d .



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Mechanical p r o p e r t i e s

Samples from t h e f a i l e d d i s c complied w i t h t h e mechanical proper ty requi rements of t h e s p e c i f i c a t i o n s as shown by t h e r e s u l t s of room tempera ture t e n s i l e , hardness and notched-bar stress r u p t u r e tests g iven below. The t e n s i l e and stress n i p t u r e specimens were machined from tangent ia1 coupons c u t from t h e r i m of t h e d i s c .

D i s c D i s c S p e c i f i c a t i o n (Specimen i) (Specimen 2) Requirements

U l t i m a t e tensile s t r e n g t h , p s i 142 O00 150 O00 130 O00 Min. 0.2% y i e l d s t r e n g t h , p s i 130 600 142 O00 120 O00 Min. Elongat ion , p e r c e n t 15 20 10 Min.

25 Min. Hardness, Rockwell C 36 37 39 Max. Reduction in area, p e r c e n t 33 45

S t r e s s Rupture T e s t s

Specimen 1

Specimen 2

150 O00 160 O00 170 O00 180 O00 190 O00 150 O00 160 000 170 O00 180 O00 190 O00

T i m e (Hours) -

5 5 5.1 10.7

5 5 5.1

10.8 O. 2 (Ruptured)

5 Minimum

.O2 (Ruptured)

Spec i f i c a t ion Requirement 170 O00



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APPENDIX 5.- F r a c t u r e Analysis 5-17

F i g . 5-14.-. mo pieces of the fa i l ed compressor disc. Arrow rrarr indicates the work-bolt hole shown in Figure 5-15. X1/3.



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F i g . 5-1 5. - Appearance of t he fracture through the work-bo2t ho2e indicated by arrow rrarr, Pigure 5-14. Brackets r%rr and ”drr indicate t h e area where fa t igue

arrows “er f and f f f r r . cracks originated. Note too?, marks i n the surface o f the hole between

x 1-6.



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5- 1 9 --__- APPRNDTX 5. - Fracture Ana lys i s _I -_ .-

Fig. 5-16.- Fracture surface adjacent to the work-bolt hole, showing the area of fatigue origins (brackets "d" and "e") at slightly.

higher magnification than in Figure 5-15. X 3.



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Fig. 5-17.- The fatigue areas indicated by brackets in Figures 5-25 and 5-16, showing numerous fatigue origins (arrows). X 8.



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F i g 5-18.- Appearance of secondary cracks (arrows) and some of the deep too l marks i n the surface of the work-bolt hole. X 15.

F i g 5-19.: Appearance of one of the fractures through a t ie -bol t hole mid secondary m a c k in the swfafnce cf the hole. Compare w i t h f a t i g u e areas shown in Figures 5-26, 5-17, 5-18. X 4.



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5-22 Manual of A i r c r a f t Accident Inves t iga t ion __I______p

I f

J i $ 1 b

I

F i g . 5-20.- Surface of the work-bolt hole indicated by arrow ”b”, Figure 5-14, showing the type of sp i ra l scratches observed. X 3.

F i g . 5-21.- Microstructure of a sect ion cu t transverse t o the length of the work-bolt hole through one of the fat igue fractures f r i g h t edge of sec t ion ) . Arrows indicate secondary cracks i n the surface of the hole and the dashed l ine indicates the approximate depth of the cold worked

h! /er . Etched u i t h HF + I!iilOg i n H z O . X 200.



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APPENDIX 5.- Frac tu re Analysis 5-23

F i g . 5-22.- Microstructure of a section cu t paral le l t o the length of the work-bolt hole through the damaged surface (top) of the hole.

Etched same as Figure 5-21. X 100.

F i g . 5-23 . - Section through the undamaged portion of the surface of t he work-bolt hole. Etched same as Figure 5-21. X 100.



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5 . Fa t igue F r a c t u r e O r i g i n a t i n g i n an Area Damaged During a n Overhaul I n s p e c t i o n

A i r c r a f t I d e n t i f i c a t i o n : Douglas DC-7C

P a r t I d e n t i f i c a t i o n : P r o p e l l e r s h a f t ? P a r t No. 170207, fr3m Assemblv No. 429036, Engine No. 704500. T o t a l t i m e on t h e s h a f t : 10 111 h o u r s ; t i m e s i n c e overhaul : 850 hours; t o t a l eng ine time: 11 536 hours .

Summary

M e t a l l u r g i c a l examination of t h e p r o p e l l e r s h a f t showed t h a t a f a t i g u e c r a c k The s u r f a c e appearance, micro- had progressed from an e l e c t r i c a l arc burn i n an o i l h o l e .

s t r u c t u r e , and hardness of t h e s tee l a t t h e c rack o r i g i n and t h e s i z e of t h e burned area were s i m i l a r t o t h o s e i n an i n t e n t i o n a l burn made w i t h a Magnaflux machine.

The r e s u l t s of t h e examination i n d i c a t e d t h a t t h e s h a f t w a s made of t h e type of steel r equ i r ed by t h e a p p l i c a b l e s p e c i f i c a t i o n and t h a t i t had been h e a t - t r e a t e d t o t h e r equ i r ed s t r e n g t h level. been shot-peened as s p e c i f i e d .

The edges of t h e h o l e s had been rounded and t h e s u r f a c e s had

Background in fo rma t ion

During t h e i n v e s t i g a t i o n of a n a c c i d e n t t o a DC-7CY a t t e n t i o n was called t o t h e i n c i d e n t i d e n t i f i e d above which had involved ano the r a i r c r a f t some two months earlier. The i n c i d e n t c o n s i s t e d of a minor p r o p e l l e r overspeed. Subsequent i n v e s t i g a t i o n l e d t o t h e discovery of a s p i r a l c r ack about 6 i nches long i n t h e p r o p e l l e r s h a f t .

A m e t a l l u r g i c a l l a b o r a t o r y examination of t h e cracked s h a f t w a s s t a r t e d a t t h e Wright Aeronau t i ca l D i v i s i o n of C u r t i s s Wright and l a t e r a similar examination w a s made a t t h e Na t iona l Bureau of Standards. Information f o r t h i s r e p o r t w a s supp l i ed by both l a b o r a t o r i e s .


The c r a c k w a s opened f o r examination by making t h e s a w c u t s i n d i c a t e d i n F r a c t u r e s u r f a c e markings showed t h a t a f a t i g u e c r a c k had s t a r t e d i n an o i l F igu re 5-24.

h o l e a t t h e p o i n t i n d i c a t e d by arrow "a" i n F igu res 5-24 and 5-25, and p rogres sed toward t h e rear end of the s h a f t . Subsequent ly , a second f a t i g u e c rack formed on t h e oppos i t e s i d e of t h e h o l e and progressed toward t h e forward end of the s h a f t . The two c r a c k s followed a s p i r a l path a t a n ang le of approximately 450 t o t h e a x i s of t h e s h a f t , i n d i c a t i n g t h a t t hey w e r e formed under predominantly t o r s i o n a l loads . They e v e n t u a l l y grew t o a combined l e n g t h of about 8 inches .

The l o c a t i o n of t h e nucleus of t h e i n i t i a l crack and t h e f r a c t u r e markings i n d i c a t e d t h a t abnormal stress concen t r a t ion had c o n t r i b u t e d t o t h e i n i t i a t i o n of t h e c rack . Examination of t h e s u r f a c e of t h e o i l ho le a t t h e nuc leus r e v e a l e d a small, c i r c u l a r d i s - coloured a r e a c o n t a i n i n g i n d i c a t i o n s of f u s e d metal . e l e c t r i c a l arc b u m by me ta l log raph ic examination and by comparing i t w i t h a n a r c burn made i n t e n t i o n a l l y i n t h e l a b o r a t o r y .

This s p o t was l a t e r i d e n t i f i e d as a n



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APPENDIX 5.- F r a c t u r e Analys is 5-25

Three a r c b u m s s i m i l a r t o t h e one a t t h e f r a c t u r e o r i g i n were found i n o t h e r o i l h o l e s , two i n t h e h o l e i n d i c a t e d by arrow %", Figure 5-24, and one i n t h e h o l e i n d i c a t e d by arrow "c". The appearance of one of t h e s e b u m s is shown i n F igu re 5-26.

The s u r f a c e of t h e h o l e s i n d i c a t e d t h a t t hey had been shot-peened and t h e edges of t h e h o l e s w e r e w e l l rounded.

Mannaflux Arc Bum

The arc b u m a t t h e c r a c k o r i g i n as w e l l as those found i n t h e o t h e r o i l ho le s appeared t o be similar t o burns found i n t h e o i l h o l e s of a n o t h e r p r o p e l l e r s h a f t p rev ious ly examined a t t h e Wright Aeronau t i ca l D iv i s ion Labora tory . had occurred d u r i n g a rod magnaflux i n s p e c t i o n made t o d e t e c t c r a c k s a t t h e o i l ho le s . such an i n s p e c t i o n a rod, u s u a l l y b r a s s o r copper , is p laced through a p a i r of o i l h o l e s and an e l e c t r i c a l c u r r e n t is passed through t h e rod t o induce a magnet ic f i e l d around t h e ho le s . if one end of t h e rod does n o t make good c o n t a c t w i th t h e c o n t a c t p l a t e s of t h e Magnaflux machine.

These p rev ious b u m s In

Arcing between t h e s h a f t and t h e rod can occur i f t h e . s h a f t is grounded, p a r t i c u l a r l y

A burn , similar t o t h e one shown i n F igure 5-26, w a s produced i n h o l e "c", . Figure 5-24, i n t h e Wright Aeronau t i ca l l a b o r a t o r y wi th a Type AMQ-483 Magnaflux machine

o p e r a t i n g a t 6 v o l t s and 2000 amps. t h e ho le and between t h e c o n t a c t p l a t e s of t h e machine. of t h e rod w a s i nc reased by , p l a c i n g a p i e c e of paper between t h e rod and t h e c o n t a c t p l a t e .

A b r a s s rod 5 / 1 6 inch i n d i ame te r was p laced through The c o n t a c t r e s i s t a n c e a t one end

Meta l lon raph ic examinat ion

S e c t i o n s f o r examinat ion were c u t as i n d i c a t e d by t h e dashed l i n e i n Figure 5-25 and through t h e i n t e n t i o n a l arc b u m i n h o l e "c", F igu re 5-24. The micro- s t r u c t u r e of t h e steel i n t h e v i c i n i t y of t h e f r a c t u r e o r i g i n is shown i n F igu re 5-27. The s t r u c t u r e i n t h e semi -c i r cu la r area a t t h e co rne r i n d i c a t e d by arrow "a" is t y p i c a l of a small e l e c t r i c a l arc b u m i n quenched and tempered steel. I n t h i s p a r t i c u l a r b u m t h e e l e c t r i c a l h e a t i n g and subsequent r ap id coo l ing i n t h e small volume of a f f e c t e d meta l had produced numerous i n t e r g r a n u l a r c r a c k s as shown i n F igures 5-27 and 5-28. of t h e f r a c t u r e below arrow "a", F igu re 5-27 , i n d i c a t e d t h a t an i n t e r g r a n u l a r c r a c k ex tending from t h e s u r f a c e s of t h e ho le approximate ly t o t h e edge of t h e s e m i - c i r c u l a r a r e a had served a s a nuc leus f o r t h e f a t i g u e c rack .

The con tour

Outs ide of t h e burned a r e a t h e steel had a tempered m a r t e n s i t i c s t r u c t u r e , t y p i c a l of a p r o p e r l y h e a t - t r e a t e d steel.

h e m i c r o s t r u c t u r e of t h e s e c t i o n through t h e i n t e n t i o n a l a r c b u m is shown i n Figure 5-29. The s i z e of t h e zone a f f e c t e d by t h e a r c and t h e m i c r o s t r u c t u r e of t h e s t e e l i n t h e burned a r e a were similar t o those found i n t h e b u m a t t h e nuc leus of t h e f r a c t u r e . No c r a c k s were d e t e c t e d i n t h e i n t e n t i o n a l burn.

Hardness tests

Tests made a t Wright Aeronau t i ca l and t h e Bureau of S tandards i n d i c a t e d t h a t t h e hardness of t h e s t e e l i n t h e p r o p e l l e r s h a f t o u t s i d e of t h e a r e a a f f e c t e d by t h e a r c burns was 305 B r i n e l l (3,000 kg) . This is w i t h i n t h e range of 285 t o 321 B r i n e l l r equ i r ed by t h e a p p l i c a b l e m a t e r i a l s p e c i f i c a t i o n .



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5-26 Manual of A i r c r a f t Accident Invec t iga t ion

Knoop microhardness surveys were made a t t h e Bureau of Standards t o compare t h e hardness i n t h e v i c i n i t y of t h e c rack o r i g i n wi th t h a t i n the i n t e n t i o n a l a r c burn. The r e s u l t s were as foì lowe:

Knoop Hardness (200 Eram load)

Crack o r i g i n I n t e n t i o n a l burn

I n burned a r e a 5 74 555 Outside burned a r e a 3 4 3 333

These r e s u l t s i n d i c a t e a r a t h e r c l o s e s i m i l a r i t y between t h e burn a t t h e c rack origin and t h e i n t e n t i o n a l burn.

Chemical composition

The m a t e r i a l s p e c i f i c a t i o n r e q u i r e s t h e use of AMs 6412 steel i n t h e pro- p e l l e r s h a f t . Following a r e the r e s u l t s of a spec t rochemica l a n a l y s i s of the s h a f t ' material and t h e s p e c i f i c a t i o n requirements f o r t h e e lements determined:

Sha f t S p e c i f i c a t i o n material (per c e n t ) requirement (per c e n t )

Manganese Nickel Chromium Mo ly b denum S i l i c o n

o. 79 1.95

.81

. 2 3

.29

0.65 - 0.85 1.65 - 2.00 .70 - .90 .20 - - 3 0 . 2 0 - .35

The s h a f t m a t e r i a l complied wi th t h e chemical requi rements of the s p e c i f i c a - No de te rmina t ions were made f o r carbon, phosphorus, and t i o n f o r t he ' e l emen t s determined.

sulphur s i n c e t h e hardness and mic ros t ruc tu re of t h e s tee l were s a t i s f a c t o r y .



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5-27 A P P E N D I X 5.- Fracture Analysis .- _ _ ~ ~

%*ea _L/ &+ ~

F i g . 5-24.- Section of the shaf t a f t e r saw cuts were made t o open up the crack. Arrow rrarr indicates the nucleus of the

crack a t one of the o i l holes. X i.



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Manual of Aircraft Accident Invest i g a c i o n I_ -I__ -I_

5-28

F i g . 5-26.- One o f t w o arc burns (arrow "d") found i n the oiZ indicated by arrow "b", F i g . 5-24. X 15.



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APPENDIX 5.- Frac tu re Analysis 5-29 -_

F i g . 5-28.- A portion of the section shown i n Figure 5-27, showing the intergranular nature of the cracks i n the burned area.

I % Nital etch. X 500.

Fig. 5-29.- Section through an intent ional arc burn made i n the surface of the o i l hole indicated by arrow rrcrr, Figure 5-24. 1 % f l i t a l etch. X 100 .



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5-30 Manual of A i r c r a f t Accident I n v e s t i g a t i o n _ .

6. Fa t igue F r a c t u r e O r i g i n a t i n g i n an Area of Corros ion DamaFe

A i r c r a f t I d e n t i f i c a t i o n : Boeing 727

Part I d e n t i f i c a t i o n : Outer h a l f of No. 4 main l and ing gea r wheel; B.F. Goodrich Part No. 10-944, S e r i a l No. 196R.

Summary

The f r a c t u r e i n t h e f a i l e d wheel progressed from f a t i g u e c r a c k s which s t a r t e d a t small areas of c o r r o s i o n damage on the i n s i d e s u r f a c e of the wheel. and spec t rochemica l a n a l y s i s i n d i c a t e d t h a t t h e aluminium a l l o y material used i n t h e wheel w a s h e a t t r e a t e d t o t h e s p e c i f i e d c o n d i t i o n and complied w i t h t h e chemica l requi rements of t h e a p p l i c a b l e s p e c i f i c a t i o n .

Hardness measurements


A f a t i g u e f a i l u r e had occurred i n t h e o u t e r h a l f of t h e No. 4 main l and ing gear wheel. f r a c t u r e i s shown i n F igu re 5-30.

The appearance of t h e f a i l e d p a r t and t h e s u r f a c e of t h e complete c i r c u m f e r e n t i a

The f r a c t u r e had two d e f i n i t e f a t i g u e o r i g i n s i n areas of c o r r o s i o n damage on t h e i n s i d e s u r f a c e of t h e wheel. a r rows "a" and "b", F igu re 5-30. s e c t i o n is shown i n F igure 5-31.

The l o c a t i o n s of t h e f a t i g u e o r i g i n s are i n d i c a t e d by The l o c a t i o n of t h e s e p o i n t s on a s k e t c h of t h e wheel

Numerous s c a t t e r e d s p o t s of c o r r o s i o n damage (F igu re 5-32) were found on t h e i n s i d e s u r f a c e of t h e wheel. Two of t hese s p o t s were found a t t h e h i g h l y l o c a l i z e d f a t i g u e o r i g i n s (arrows "a" and "b", F igu re 5-32), i n d i c a t i n g t h a t t h e y had se rved as n u c l e ï f o r f a t i g u e cracks.

Meta l lographic examination

Meta l lographic examination of a s e c t i o n through t h e p o i n t i n d i c a t e d by arrow "b", F igu re 5-32, r evea led evidence of i n t e r g r a n u l a r c o r r o s i o n , as shown i n F i g u r e s 5-33 and 5-34.

Hardness tests

, Hardness measurements made on a s e c t i o n of t h e wheel gave a B r i n e l l (500 kg load ) Hardness Value of 133. T h i s is w i t h i n t h e normal range f o r t h e s p e c i f i e d material, aluminium a l l o y 2014-T6.

Material composition

. A spec t rochemica l a n a l y s i s of t h e material used i n t h e wheel 'showed t h a t t h e chemical composition of t h e sample complied wi th t h e requi rements of Fede ra l Spec i f i ca - t i o n QQ-A-367 f o r 2014-T6 a l l o y . The r e s u l t s of t h e a n a l y s i s were as fo l lows :



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S i l i con I ron Copper Manganese Magnesium Chromium Nickel Zinc Titanium Aluminium

Wheel Sample (per cent )

O. 81 O. 4 1 4.6 O. 84 O . 6 2 O . 6 2 0.03 0.09

less than 0.05 remainder

QQ- A-3 6 7 Requirement

(per cent )

1 .0 max. 0.5 - 1.2

3.9 - 5.0 0.4 - 1.2 0.2 - 0.8 0.1 max.

0.25 max. 0.15 max. rema i n der

Fig . 5-30.- Appearance of the f a i l e d wheel and surface of the fracture. Fatigue cracks originated i n the areas indicated by arrows rra11 and “b”. X 1/3.



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5-32 Manual of Aircraft Accident Invest igat ion

I- - - - F i g . 5-31.- Sketch of haZf wheeZ sec t ion ,

showing the Zocation of t he f a t i g u e or ig ins .



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5 - 3 3 .___ APPENDIX 5.- F r a c t u r e Analysis -- ~_.____

F i g . 5-32.- Appearance of the fa t igue areas of the fracture. Arrows "arr and "brr

indicate some o f the numerous other corroded spots on the inside surface of the wheel. X 1-2.

indicate spots of corrosion damage a t the fat igue origins. The smaller arrows



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Manual of A i r c r a f t Accident Invest igat ior i -I_ - -- 5-34

F i g . 5-33.- Metallographic sect ion through the fatigue or ig in indicated by amo23 rrbrr, Pigwe 5-32. The fa t igue fracture extends downuard from the

corroded area indicated by arrow r'orr. Areas rrorr and "c" are shown a t higher magnification i n Figure 5-34. Unetched. X 200.



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APPENDIX 5.- F rac tu re Analysis 5-35

F i g . 5-34 . - Intergranular corrosion i n the areas indicated by arrows frorr and Ifeff, Figure 5-33. Keller 's etch. X 500.



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7. S t r e s s Corrosion F a i l u r e of Aluminium Alloy R i v e t s

A i r c r a f t I d e n t i f i c a t i o n : Cessna 210

P a r t I d e n t i f i c a t i o n : Le f t a i l e r o n

Vi sua l Examination

V i s u a l examination showed t h a t cons ide rab le c o r r o s i o n had occurred on t h e i n s i d e s u r f a c e s of t h e a i l e r o n , mainly on t h e bottom s k i n and c l o s i n g r i b , and i n t h e r i v e t e d j o i n t a t t h e bottom l e a d i n g edge where a l ead counterweight had been a t t a c h e d t o t h e r i b . The only s e r i o u s damage appeared t o be i n t h e r i v e t e d j o i n t where 23 of t h e 2 4 r i v e t s used t o hold t h e counterweight i n p l a c e had f a i l e d . The manufactured heads of a l l of t h e f a i l e d r i v e t s had broken o f f a t t h e bottom sk in . No r i v e t s had f a i l e d excep t t h e ones t h a t were i n c o n t a c t w i th t h e counterweight.

The bottom s i d e of t h e outboard s e c t i o n of t h e a i l e r o n is shown i n The l o c a t i o n of t h e f a i l e d r i v e t s is shown between arrows "a" and "b" and F igure 5-35.

t h e u n f a i l e d r i v e t i n t h i s area i s i n d i c a t e d by arrow "c". F igu re 5-36 shows how t h e counterweight w a s a t t a c h e d , wi th long r i v e t s (arrow "d") ex tend ing from t h e bottom s k i n through t h e l ead bar t o an aluminium angle a t t a c h e d t o t h e r i b . There w a s a build-up of c o r r o s i o n p roduc t s i n t h e r i v e t e d j o i n t where t h e counterweight w a s a t t a c h e d , p a r t i c u l a r l y between t h e f ay ing s u r f a c e s of t h e bottom s k i n , r i b f l a n g e , and l ead ba r . These f ay ing s u r f a c e s had n o t been pa in t ed be fo re assembly. The only p a i n t found i n t h e j o i n t s was on t h e s u r f a c e s under t h e "V" crimps i n t h e bottom s k i n (arrow "g", F igure 5 - 3 7 ) . These s u r f a c e s probably were coa ted u n i n t e n t i o n a l l y when t h e o u t s i d e s u r f a c e s of t h e assembly were pa in t ed .

Meta l lographic Examination

S e c t i o n s through t h e two s h o r t r i v e t s i n d i c a t e d by arrow "f", F igu re 5-36, through a long f a i l e d r ive t and through t h e u n f a i l e d long r i v e t (arrow "c", F igu re 5-35) were examined. The s e c t i o n through one of t h e s h o r t r i v e t s i s shown i n F igure 5-38. Both s h o r t r i v e t s were f r e e from c r a c k s and showed no s i g n i f i c a n t i n d i c a t i o n s of corrosion ' .

I d e n t i f i c a t i o n of Material

The materials used i n t h e a i l e r o n assembly were i d e n t i f i e d by spec t ro- chemical examination, as follows:

Top and bottom s k i n Alc lad 2024 Aluminium Alloy Closing r i b Alc lad 2024 Aluminium Alloy Angle (count e rwe igh t a t tachment ) Alclad 2 0 2 4 Aluminium Alloy Shor t r i v e t (Arrow "f", F igu re 5 - 3 6 ) 2117 Aluminium Alloy Long r i v e t (Arrow "d", F igure 5-36) 5056 Aluminium Alloy Counterweight Lead

Both of t h e long r i v e t s examined were seve re ly corroded a long t h e shanks (F igure 5-39) where they were i n con tac t w i th t h e l ead coucterweight . i n t e r g r a n u l a r type of c o r r o s i o n found on t h e r i v e t shanks i s shown i n F igure 5-43.

An example of t h e



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APPENDIX 5.- F r a c t u r e Analysis 5-37

Stress c o r r o s i o n c rack ing had occurred a t t h e j u n c t i o n of t h e manufactured head and shank of both of t h e long r ive ts examined and a t t h e d r i v e n head of t h e r i v e t t h a t had not f a i l e d completely. head of t h e f a i l e d r i v e t . F igu re 5-35, is shown i n F igu re 5-40. o r i g i n are shown i n F igu re 5-41 and t h e i n t e r g r a n u l a r n a t u r e of t h e main c r a c k i s shown i n F igu re 5-42.

Such c r a c k i n g had r e s u l t e d i n a complete f r a c t u r e under t h e The l a r g e stress c o r r o s i o n c r a c k under t h e head of r i v e t "c",

Evidence of c o r r o s i o n and m u l t i p l e c r a c k s a t t h e

The m i c r o s t r u c t u r e of both of t h e long r i v e t s examined showed a g r a i n .boundary network (F igu res 5-42 and 5-43) t h a t appeared t o be a p r e c i p i t a t e formed by long-

t i m e ageing a t t h e ambient t empera tu res encountered i n service. t h a t t h e r i v e t material w a s s u s c e p t i b l e t o i n t e r g r a n u l a r c o r r o s i o n and stress c o r r o s i o n cracking.

Such a network i n d i c a t e s



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F i g . 5-35.- Outboard section of aileron (bottom surface). AZZ leading edge r i v e t s between arrows liarr and %'l had fa i l ed except the one indicated by

arrow rrcrr. Arrows rrarr and "b" indicate, approximately, the ends of the counterweight. X ï / 6 .



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F i g . 5-36.- A portion of the forward edge of the ai leron showing two o f the f a i l e d r i v e t s (arrows "d"), the lead counterweight ( e ) ,

and two of the short r i v e t s í f ) . X î$.



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5-40 Manual of Aircraft Accident Inves t iga t ion

Fig . 5-37.- Detail view of a portion of the fa i lure area, showing four f a i l e d r i v e t s and corrosion products i n the jo in t . Arrows rrgrr indicate painted areas

which were not seriously corroded. X 1.

F i g . 5-38.- Section through one of the short r i v e t s indicated by arrows " f " , F i g . 5-36. KeZZer's etch. X 50.



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F i g . .5-39.- Section through the Zong r i v e t indicated by arrow "c", F i g . 5-35. Arrow %hl indicates severely corroded area on the shank. Encircled area

i s shown i n F i g . 5-40. X 5.

F i g . 5-40.- EncircZed area i n F i g . 5-39 a t higher magnification, showing the crack under

i n F i g . 5-41. XeZZer's etch. X 50. the head. The area around the mouth o f the crack i s showz a t higher magnification



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F i g . 5-41.- Area around the mouth of the crack shown i n F i g . 5-40, showing numerous secondarg cracks and indications o f corrosion. ünetched. X 200.

F i g . 5-42.- A portion of the crack shown i n F i g . 5-40. Note the secondary cracks and the intergranular nature o f the sepupution. KeZZer?s etch. X 500.



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F i g . 5-43.- Severe in tergranukr corrosion i n the r i v e t i n the area indicated by arrow r'hr', F i g . 5-39. Kel ler ' s etch. X 500.



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8 . Overload High P r e s s u r e F r a c t u r e Caused by Se rv ice Damage

A i r c r a f t I d e n t i f i c a t i o n : Boeing 707-3218

P a r t I d e n t i f i c a t i o n : Two p i e c e s of t h i r d s t a g e t u r b i n e d i s c , P r a t t and Whitney A i r c r a f t , P a r t No. 438903, from t h e Number 4 engine.

Summary

Examination of p i e c e s of t h e f a i l e d d i s c showed t h a t a c i r c u m f e r e n t i a l f r a c - t u r e occurred through a deep groove i n t h e f r o n t face . Evidence of s e v e r e a b r a s i o n and h igh tempera tures were found i n t h e groove and surrounding metal. t h e a b r a s i o n had been s u f f i c i e n t t o reduce t h e s t r e n g t h and ha rdness of t h e metal a d j a c e n t t o t h e groove. It had a l s o r e s u l t e d i n i n t e r g r a n u l a r c r ack ing and t h e format ion of a h igh tempera ture ox ide scale on s u r f a c e s exposed t o t h e atmosphere.

The h e a t a s s o c i a t e d wi th

Vi sua l examinat ion

Two p i e c e s of a f a i l e d t h i r d s t a g e t u r b i n e d i s c , shown I n F igu res 5-44 and 5-45, had r a d i a l f r a c t u r e s a t each end and a c i r c u m f e r e n t i a l f r a c t u r e approximately two inches from t h e bottoms of t h e b l ade r e t e n t i o n s l o t s . The c i r c u m f e r e n t i a l f r a c t u r e had occurred through a deep groove ( i n d i c a t e d by arrows i n F igu res 5-44 and 5-45) appa ren t ly caused by t h e f r o n t f a c e of t h e d i s c rubbing a g a i n s t t h e t h i r d s t a g e inne r a i r seal.

Meta l lographic examinat ion

The l abora to ry examinat ion was l a r g e l y conf ined t o the small p i e c e shown i n F igure 5-44 as i t w a s much b e t t e r preserved than t h e l a r g e r p i e c e submi t ted . The worn groove w a s approximately 0.025 inch ,deep and showed evidence o f s e v e r e a b r a s i o n w i t h a s s o c i a t e d h igh temperature . There were numerous c racks i n t h e groove, as shown i n F igu re 5-46, t h a t appeared t o be t y p i c a l of b r i t t l e , i n t e r g r a n u l a r c r a c k s t h a t had occur red wh i l e t h e metal w a s a t a h igh tempera ture . The s u r f a c e s of t h e groove and a p o r t i o n (about 0.1 inch) of t h e c i rcumferent ia l . f r a c t u r e (F igure 5 - 4 7 ) ad jacen t t o t h e groove were coa ted wi th a b lack , h igh tempera ture oxide s c a l e . D i s t i n c t temper c o l o u r s on t h e c i r c u m f e r e n t i a l f r a c t u r e s t a r t e d a t t h e edge of t h e b lack scale and extended t o t h e back f ace . Temper c o l o u r s on t h e r a d i a l f r a c t u r e s extended about 0 .6 t o 0.9 inch from t h e c i r c u m f e r e n t i a l f r a c t u r e . These temper co lou r s i n d i c a t e d t h a t an abnormal tempera ture g rad ien t w a s p r e s e n t i n t h e meta l a t t h e t i m e t h e f r a c t u r e s occurred . The maximum tempera ture was a t t h e groove and t h e g rad ien t extended through t h e d i s c t o t h e back f a c e and t o about 1 inch from t h e groove i n a r a d i a l d i r e c t i o n .

The c i r c u m f e r e n t i a l f r a c t u r e nea r t h e groove appeared t o be a b r i t t l e , i n t e r - g ranu la r type of s e p a r a t i o n whi le ad jacent t o t h e back f a c e of t h e d i s c t h e f r a c t u r e was t y p i c a l of a t e n s i l e shear f a i l u r e .

Examination of t h e mic ros t ruc tu re of t h e metal on a s e c t i o n through t h e worn groove and c i r c u m f e r e n t i a l f r a c t u r e revea led a h e a t a f f e c t e d zone i n Che metal a d j a c e n t t o t h e groove. c h a r a c t e r i s t i c s and reduce t h e hardness of t h e metal, as shown i n F igu re 5-48. seve re ly hea t a f f e c t e d area, w i t h i n about 0 . 1 inch of t h e groove, t h e ha rdness ranged from 165 t o 208 Knoop o r about 80 t o 90 Rockwell B. These hardness va lues are about t h e same

The tempera ture i n t h i s zone had been h igh enough t o change t h e e t c h i n g I n t h e most



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as would be obtained on the material i n the f u l l y annealed or so lu t ion t r ea t ed condition. rhey ind ica t e t h a t t he metal had been heated t o a temperature of 17000F o r higher. ever, t he evidence of in te rgranular separa t ion found on the f r ac tu re and i n t h e metallographic sec t ion (Figure 5-49) i nd ica t e s t h a t t he temperature may have been considerably higher than 17000F.

How-

Hardness tests

Hardness tests on t h e d i s c material remote from the heat-affected zone gave values ranging from 36 t o 40 Rockwell C. This corresponds approximately t o a range of 336 t o 362 Br ine l l , which i s wi th in t h e range of 302 t o 388 Br ine l l required by t h e appl icable P r a t t and Whitney Ai rc ra f t Spec i f ica t ion , PWA 1003-B.

F i g . 5-44.- Piece of the faiZed th i rd stage turbine disk. worn groove i n the fpont face a&acent t o the circwnferentiaZ fracture.

Arrows indicate the X 2.



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5-4 6 Manual of A i rc ra f t Accident Inves t iga t ion

F i g . 5-45 . - Front face of a second piece of third stage turbine disk, showing the worn groove (arrows) along the cìrcwnferentìui? fracture. x 4".



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57-47 APPENDIX 5.- Fracture Analysis ._.I

i

Fi?. 5-46.- Views of the f ron t face of the disk a t two p h c e s aGacent t o the czrcwnferentiai! fracture, showing the network of cracks i n the worn groove

and the uni fom, appearance of the wear pattern. X 10.



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F i g . 5-47.- Appearance o f the surface of the circwnferentiaz fracture. The dark area indicated by arrows is adjacent

t o the worn groove. X 2.



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F i g . 5-48.- Section through the worn groove írran t o '55") and circumferential fracture í"b" t o "d"), showing the r e s u l t s of microhardness t e s t s . The numbers shown are the Knoop hardness values obtained from the indentations innnediately t o the r igh t of the numbers. The white area a t the upper r igh t extending from the groove t o arrow "e"

The dark appearance along the l e f t edge of the i s a severely heat a f fec ted zone. section í a r r m "d") i s due t o uneven illumination when the photograph

m s made. Marble's etch. X 15.



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5-.50 Manual of Aircraft - Accident Investigation

F i g . 5-49.- Section through the worn groove (Irari t o “b”), showing intergranular separation i n the ad;lacent metal. Marble’s etch. X 50.



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APPENDIX 6

EXAMPLES OF SEQUENCE OF FA1 LURE INVESTIGATION



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APPENDIX 6.- Examples of Sequence of F a i l u r e I n v e s t i g a t i o n 6- 1

APPENDIX 6

EXAMPLES OF SEQUENCE OF FAILURE INVESTIGATION


When f a i l u r e occur s i n f l i g h t i t becomes impor t an t t o d e t e r m i n e ' t h e sequence T h i s appendix g i v e s some examples demons t r a t ing how a m e t a l l u r g i c s tudy of f a i l u r e .

conducted i n a l a b o r a t o r y can be used as a b a s i s f o r e s t a b l i s h i n g a sequence of f a i l u r e (see a l s o Appendix 10) .

2. Wing S p a r F a i l u r e

A i r c r a f t I d e n t i f i c a t ion : Beechcraf t D-185

Part I d e n t i f i c a t i o n : P i e c e s of t h e f r o n t s p a r assembly from t h e l e f t wing a d j a c e n t t o t h e o u t e r p a n e l a t t a c h p o i n t .

sumnia ry

The f r o n t s p a r of t h e l e f t wing had f a i l e d on t h e outboard s i d e of t h e o u t e r panel a t t a c h p o i n t . Primary f r a c t u r e s had occurred i n t h e two a t t achmen t f i t t i n g s a t t h e l o c a t i o n s i n d i c a t e d by arrows "a" and "b" i n F igu re 6-1.

Laboratory examinat ion

Each of t h e at tachment f i t t i n g s had been f a b r i c a t e d from two steel f o r g i n g s with h o l e s a t one end designed t o a c c e p t t h e wing h inge b o l t . The two f o r g i n g s were welded t o g e t h e r around t h e h inge b o l t h o l e s and t h e remaining p o r t i o n of t h e f o r g i n g s then formed two arms t h a t were welded i n t o t h e e l l i p t i c a l s p a r cap tube as shown i n F igu re 6-2.

Both of t h e f i t t i n g s had f a i l e d i n t h e arms abou t li t o 2 i nches outboard of t h e c e n t r e of t h e hinge b o l t h o l e s . The f r a c t u r e s u r f a c e s ( F i g u r e s 6-3 and 6 - 4 ) showed no evidence of f a t i g u e c rack ing p r i o r t o f a i l u r e . overload f a i l u r e s r e s u l t i n g from e x c e s s i v e bending loads . forward arm had f a i l e d e n t i r e l y i n t e n s i o n and t h e a f t a r m had f a i l e d i n t e n s i o n on t h e forward s i d e w i t h a compression ' h i n g e " on t h e a f t s i d e (F igu re 6-3.) Th i s p a t t e r n is c o n s i s t e n t w i t h f a i l u r e r e s u l t i n g from a rearward bending load on t h e o u t e r p a n e l of t h e wing. There were d e f i n i t e i n d i c a t i o n s of a r e v e r s a l of l o a d i n g on t h e t o p f i t t i n g . Both arms had f a i l e d i n t e n s i o n and t h e r e were a l s o secondary t e n s i o n c r a c k s on both t h e forward and a f t s i d e of t h e f i t t i n g . t o f a i l u r e i n t e n s i o n and t h e forward arm showed evidence of t h e f r a c t u r e s u r f a c e s recon- t a c t i n g under heavy p r e s s u r e a f t e r t h e f r a c t u r e i n t h e forward a r m occurred. of f a i l u r e appeared t o i n d i c a t e t h a t a rearward bending load broke t h e forward arm i n t e n s i o n and bent t h e rear arm s l i g h t l y . A forward bending l o a d t h e n fo rced t h e f r a c t u r e surf a c e s t o g e t h e r and broke t h e r e a r arm i n t e n s i o n .

The f r a c t u r e s appeared t o be t y p i c a l I n t h e bottom f i t t i n g t h e

The a f t a r m showed some i n d i c a t i o n of rearward bending p r i o r

T h i s p a t t e r n



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The broken end of t h e top a t tachment f i t t i n g had been r o t a t e d upward. The cond i t ion of t h e f i t t i n g and a s s o c i a t e d p a r t s i n d i c a t e d t h a t t h e r o t a t i o n occurred b e f o r e t h e top f i t t i n g f a i l e d completely. Th i s i n d i c a t e d t h a t t h e bottom f i t t i n g f a i l e d and t h e wing fo lded upward before t h e f i n a l s e p a r a t i o n occurred i n t h e top f i t t i n g .

Hardness tests

Rociwell hardness tests were made on s e c t i o n s of t h e f a i l e d f i t t i n g s and t h e s p a r cap tubing. The r e s u l t s were as fo l lows:

Bottom f i t t i n g Bottom cap tube Top f i t t i n g Top cap tube

Average Rockwell C Hardness

38 4 1 39 39

Ind ica t ed T e n s i l e s t r e n g t h

( p s i >

171,000 188,000 177,000 177,000

The manufac turer ' s s p e c i f i c a t i o n s r equ i r ed t h a t t h e f i t t i n g s be h e a t - t r e a t e d t o a t e n s i l e s t r e n g t h range of 165,000 t o 210,000 p s i and t h a t ' t h e s p a r cap tub ing be hea t - t r e a t e d t o 165,000 t o 195,000 p s i . The r e s u l t s of t h e ha rdness t es t s ind ica t ed t h a t bo th of the f i t t i n g s and t h e tub ing complied wi th t h e t e n s i l e s t r e n g t h requirement of t h e

- spec i f icat i on.



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APPENDIX 6.- Examples of Sequence of Fa i lu re Inves t iga t ion 6- 3

F i g . 6-1.- A porf ion of the fa i l ed l e f t f rong wing spar. Arrows rrarr and "brr indicate the locations of the fractures

i n the wing panel attachment f i t t i n g . X 6 .

F i g . 6-2.- ûutboard portion of the faiZed bottom spar attachment f i t t i n g . The forward arm (arrow rrcrr) and the a f t a r m (arrow "drr)

are welded iwto the spar cap tube. X i 6 .



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6-4 Manual of A i rc ra f t Accident I n v e s t i g a t i o n

F i g . 6-3.- Mating surfaces of the fracture i n the bottom attachment f i t t i n g . Arrows rrerf indicate compression areas on the a f t side of

the fracture i n the a f t arm of the f i t t i n g . X 1 2.

F i g . 6-4.- Mating surfaces of the fracture i n the top attachment f i t t i n g . Arrow f f f f f indicate mating areas of compression Zoading on the forward

side of the fracture i n the forward a r m of the f i t t i n g . X 1 i.



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APPENDIX 6.- Examples of Sequence of F a i l u r e I n v e s t i g a t i o n 6-5

3. Break Up of Airframe i n t h e A i r

A i r c r a f t I d e n t i f i c a t i o n : Convair 580

P a r t I d e n t i f i c a t i o n : The fo l lowing components from t h e r . ight p r o p e l l e r assembly, A l l i s o n Aeroproducts Model A644ìFN-606, S e r i a l Number P-984, w e r e examined:

a ) Torque P i s t o n , P a r t Number 6523111, S e r i a l Number H5-5492, from P r o p e l l e r Socket P o s i t i o n 3.

b) Torque Cy l inde r Heads ( P a r t Number 6525482), Torque Unit Shims ( P a r t Number 6516975), and I n t e r n a l Snap Rings ( P a r t Number 6516971), from P r o p e l l e r Socket P o s i t i o n s I and 3.

c ) Torque Cy l inde r , P a r t Number 6851622, S e r i a l Number BL485, from P r o p e l l e r Socket P o s i t i o n 3.

d ) P r o p e l l e r Blades, P a r t Number 6508894

a. Serial Number B-8087 from Socket P o s i t i o n 1.

b. Ser ia l Number B-9208 from Socket P o s i t i o n 2.

c. S e r i a l Number B-8957 from Socket P o s i t i o n 3.

d. Ser ia l Number B-8758 from Socket P o s i t i o n 4.

summary

a ) The i n t e r n a l s p l i n e s of t h e to rque p i s t o n w e r e a lmost completely worn away and t h e e x t e r n a l s p l i n e s w e r e s e v e r e l y damaged. c a t i o n r equ i r emen t s f o r t h e to rque p i s t o n were noted. The s p l i n e s had n o t been n i t r i d e d and t h e i n s i d e s u r f a c e had not been s h o t peened.

Two d e v i a t i o n s from s p e c i f i -

b) V i s u a l examinat ion of t h e to rque c y l i n d e r head , t o r q u e u n i t shims and i n t e r n a l snap r i n g from Socket P o s i t i o n 3 r evea led ev idence of h i g h p r e s s u r e c o n t a c t between t h e c y l i n d e r head and t h e f a c e of t h e to rque p i s t o n .

c ) A complete t r a n s v e r s e f a t i g u e f r a c t u r e had occur red i n t h e to rque c y l i n d e r a d j a c e n t t o a n i n t e r n a l shoulder . a f i l l e t on t h e i n s i d e s u r f a c e had merged t o form a l a r g e , con t inuous c i r c u m f e r e n t i a l f a t i g u e c r a c k b e f o r e t h e c y l i n d e r f a i l e d . p l e t e l y through t h e c y l i n d e r w a l l be fo re t h e f i n a l f a i l u r e occur red .

Numerous f a t i g u e c r a c k s o r i g i n a t i n g i n

The f a t i g u e c r a c k d i d n o t p e n e t r a t e com-

d ) Overload t e n s i o n f a i l u r e s had occurred i n t h e r o o t s e c t i o n s of a l l f o u r of t h e p r o p e l l e r b lades . Examination of t h e f r a c t u r e s d i d n o t r e v e a l any evidence of p r i o r f a t i g u e c rack ing . requirements .

No ev idence w a s found of any d e v i a t i o n s from s p e c i f i c a t i o n



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I n i t i a l l a b o r a t o m examination

The i n i t i a l l abo ra to ry examination of t h e p a r t s l i s t e d above w a s conducted i n t h e Materials Labora to r i e s of t h e A l l i s o n Div is ion of t h e Genera l Motors Corporation. Subsequently, p o r t i o n s of t h e torque p i s t o n and torque c y l i n d e r and samples from each of t h e f o u r p r o p e l l e r b l ades were taken t o a government m e t a l l u r g i c a l l abo ra to ry f o r independent s tudy. A number of photographs taken du r ing t h e i n i t i a l phase of t h e l abora to ry i n v e s t i g a t i o n and some of t h e d a t a used i n t h i s r e p o r t were supp l i ed by t h e A l l i s o n Mater i a 1s Laboratory .

R e s u l t s of t h e examination

Torque P i s t o n

Photographs i l l u s t r a t i n g t h e cond i t ion of t h e to rque p i s t o n are shown i n F igures 6-5 t o 6-10. The i n t e r n a l s p l i n e s w e r e almost completely worn away, as shown i n F igu res 6-6, 6-7 and 6-9. sma l l p o r t i o n s of t h e roo t . ' A l a r g e s t e p had been worn i n one s i d e of a l l of t h e e x t e r n a l s p l i n e s , as shown i n F igu res 6-8 and 6-9. Th i s wear had removed approximately 50 p e r c e n t of t h e c r o s s s e c t i o n a l area of each e x t e r n a l s p l i n e (F igure 6-9).

The only t r a c e s of t hese s p l i n e s remaining on t h e p i s t o n were

Aeroproducts manufacturing s p e c i f i c a t i o n s f o r t h e to rque p i s t o n r equ i r ed n i t r i d i n g of t h e i n t e r n a l and e x t e r n a l s p l i n e s . A minimum s u r f a c e ha rdness of 88 on t h e Rockwell 15 N s c a l e and a core hardness of 28 t o 34 Rockwell C were s p e c i f i e d . Hardness measurements on a s u r f a c e t h a t should have been n i t r i d e d gave a n average va lue of 15 N-74, i n d i c a t i n g t h a t t h e s p l i n e s had no t been n i t r i d e d . The average c o r e hardness obta ined on two s e c t i o n s cu t from t h e sp l ined end of t h e p i s t o n was 27 Rockwell C.

The l a c k of n i t r i d i n g w a s confirmed by t h e examination of meta l lographic s e c t i o n s through t h e i n t e r n a l and e x t e r n a l s p l i n e s . None of t h e areas examined where t h e o r i g i n a l s u r f a c e s remained i n t a c t showed any evidence of n i t r i d i n g , as i l l u s t r a t e d i n F igures 6-9 and 6-10.

Manufacturing s p e c i f i c a t i o n s a l s o requi red t h a t t h e i n s i d e s u r f a c e s of t h e torque p i s t o n be sho t peened. peening on t h e s e su r f a c e s .

A v i s u a l examination d i d no t r e v e a l any evidence of s h o t

Chemical and spec t rochemica l a n a l y s e s made a t t h e Na t iona l Bureau of S tanda rds gave t h e fo l lowing r e s u l t s :

a ) Chemical a n a l y s i s

Torque p i s t o n

Re a gent

Ph os ph o rus Carbon Sulphur

o. 4 3 o. 012 o. 012

Carbon w a s determined g r a v i m e t r i c a l l y a s carbon d iox ide a f t e r combustion. Sulphur was determined by ioda te t i t r a t i o n of su lphur d iox ide produced by combustion. Phosphorus was determined phot ome t r i c a 11 y by t h e molybdenum- b l u e method .



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APPENDIX 6 , - Examples of Sequence of F a i l u r e I n v e s t i g a t i o n 6- 7

Note: A dash -

b ) Spect rochemica 1 ana l y s i s P e r c e n t

36347 P i s t o n 0.56 0.28 - - 1.80

S p e c i f i c a t i o n s : AMC 6470, Maximum l i m i t o r range of

0.50 0.20 - - 1.40 t o t o t o

0.70 0.40 1.80

' 0.33 1.18

metall ic element.

0.30 0.95 t o . t o

0.40 1.30

i n d i c a t e s t h a t t h e e l e m e n t ' s c o n c e n t r a t i o n was n o t determined.

These a n a l y s e s r e v e a l e d t h a t t h e samples d i d comply wi th s p e c i f i c a t i o n s .

Torque u n i t c y l i n d e r head , shims and i n t e r n a l snap r i n g

Cons ide rab le ev idence of h igh p r e s s u r e c o n t a c t between t h e f a c e of t h e to rque p i s t o n and t h e c y l i n d e r head w a s found i n - t h e p a r t s from t h e No. 3 p r o p e l l e r socke t (F igures 6-11 t o 6-16. A comparison of t h e c o n d i t i o n of t h e t o rque c y l i n d e r from t h e No. 3 and No. 1 p r o p e l l e r s o c k e t s is shown i n F i g u r e s 6-11, 6-12 and 6-13. The No. 1 head showed normal ev idence of l i g h t c o n t a c t whi le t h e No. 3 head showed c o n s i d e r a b l e s u r f a c e damage, a p p a r e n t l y due t o t h e f a c e of t h e to rque p i s t o n s t r i k i n g t h e head r e p e a t e d l y wi th cons ide rab le f o r c e . A d d i t i o n a l ev idence of such abnormal o p e r a t i o n of t h e No. 3 to rque u n i t w a s found i n t h e . c o n d i t i o n of t h e t r a v e l a d j u s t i n g shims (F igu re 6-14), some of which w e r e hammered t h i n and fragmented. The i n t e r n a l snap r i n g (F igu re 6-16) a l s o showed an abnormal damage p a t t e r n . A photograph of t h e shims and snap r i n g from t h e No. 1 t o rque u n i t is shown i n F igu re 6-15 f o r comparison.

Torque Cy l inde r

A complete c i r c u m f e r e n t i a l f r a c t u r e a t t h e l o c a t i o n i n d i c a t e d by t h e arrow i n F igu re 6-17 had s e p a r a t e d t h e t o r q u e c y l i n d e r i n t o two p i e c e s (F igu re 6-18). f r a c t u r e occurred through a n i n t e r n a l f i l l e t a d j a c e n t t o a s h o u l d e r between t h e smooth bore p o r t i o n of t h e c y l i n d e r and t h e i n t e r n a l s p l i n e s . The appearance of t h e f r a c t u r e s u r f a c e is shown i n F i g u r e 6-19 and 6-20.

The

Two p i e c e s of t h e c y l i n d e r w e r e submi t ted t o t h e P h y s i c a l Meta l lurgy Branch of t h e Naval Research Labora tory (NRL) f o r an a n a l y s i s of t h e f r a c t u r e . T h i s a n a l y s i s revea led t h a t t h e f r a c t u r e w a s i n i t i a t e d and propagated by f a t i g u e u n t i l f i n a l f a i l u r e occurred in t e n s i l e s h e a r .

Numerous s t e p s l i k e t h o s e shown a l o n g t h e bottom edge of t h e f r a c t u r e in * Figure 6-20 were found a l o n g t h e i n n e r s u r f a c e of t h e c y l i n d e r w a l l .

t h a t numerous f a t i g u e c r a c k s w e r e i n i t i a t e d i n t h e i n t e r n a l f i l l e t . The f a t i g u e c racks merged as they propagated i n t o t h e c y l i n d e r w a l l u n t i l a 360° c i r c u m f e r e n t i a l c r a c k was formed. T h i s c r a c k p e n e t r a t e d through from 50 t o 90 per c e n t of t h e w a l l t h i c k n e s s be fo re t h e f i n a l ove r load p o r t i o n of t h e f r a c t u r e occurred . f r a c t u r e a long t h e o u t s i d e s u r f a c e comple te ly around t h e p e r i p h e r y of t h e c y l i n d e r , indi- c a t i n g t h a t t h e f a t i g u e c r a c k d i d n o t p e n e t r a t e comple te ly through t h e w a l l b e f o r e t h e f i n a l f a i l u r e occurred .

These s t e p s i n d i c a t e

A s h e a r l i p w a s observed on t h e



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Sec t ions through t h e f r a c t u r e are shown i n F igu res 6-21 and 6-22. The f i l l e t where Lhe f a t i g u e c racks o r ig ina t ed w a s i n a small undercut a d j a c e n t t o t h e shoulder shown t o t h e l e f t of t he f r a c t u r e i n F igure 6-21 and on t h e r i g h t i n F igure 6-22 The undercut was 0.004 inch , which i s wi th in t h e b l u e p r i n t t o l e r a n c e of 0.000 t o 0.005 inch. The w a l l t h i ckness was 0.1620 inch , a l s o wi th in t h e r equ i r ed range of 0.1575 t o 0.18325 inch.

The i n s i d e su r face of t he c y l i n d e r was n i t r i d e d a s s p e c i f i e d on t h e manuFac- t u r i n g drawing . , The hardness of t h e case was Rockwell 15N-93 and t h e average va lue obtained on t h e co re w a s Rockwell C30. These va lues complied with t h e b luepr in t r equ i r e - ments of 15N-88 minimum f o r t he case and R c 30 t o 36 f o r t h e co re .

A s shown i n F igure 6-22, t h e f i l l e t where the f a t i g u e c racks o r i g i n a t e d w a s The a c t u a l c r ack o r i g i n s c lose t o t h e edge of t h e n i t r i d e d po r t ion of t h e c y l i n d e r w a l l .

were approximately 0.015 inch from the edge of t h e n i t r i d e d su r face . Thus, t h e r e i s a p o s s i b i l i t y t h a t r e s i d u a l t e n s i l e stresses r e s u l t i n g from t h e n i t r i d i n g , as w e l l a s t h e normal stress concen t r a t ion a t t h e f i l l e t , may have con t r ibu ted t o t h e i n i t i a t i o n of t h e f a t i g u e cracks.

Chemical and spec t rochemica l a n a l y s e s of a sample of t h e torque c y l i n d e r material, made by t h e Na t iona l Bureau of S tandards A n a l y t i c a l Chemistry Div i s ion , gave t h e fo l lowing r e s u l t s :

a ) Chemical ana lys i s

Reagent

Carbon Sulphur Phosphorus

Torque c y l i n d e r O. 18 0.009 0.013

b) Spectrochemical a n a l y s i s Pe r cent

A l Mo - C r - N i - S i - Number Label * - Cu - 36348 Cylinder 0.54 0.39 0.05 0.30 5.0 0.45 - S p e c i f i c a t i o n : AIS1 501 s t a i n l e s s steel , m a x i m u m l i m i t o r range of

li metal l ic element.

- - 0.35 0.5 Cu + N i 4 . O t o o. 75 t o

0.70 t o t a l 6.0 -

Note: A dash i n d i c a t e s t h a t t h e e l emen t ' s concen t r a t ion was n o t determined. - These ana lyses revea led t h a t t h e samples d i d comply wi th t h e spec i f i c a t i o n s .

P r o p e l l e r Blades

A l l f o u r of t h e p r o p e l l e r b lades had f a i l e d a t o r nea r t h e cuff r i n g , as shown i n Figure 6-23. predominantly s l a n t f r a c t u r e s u r f a c e and ev idence of necking i n t h e f a i l e d area. v i s u a l examination d i d not r e v e a l any evidence of f a t i g u e c rack ing o r o t h e r type of progres- s i v e damage p r i o r t o t h e a p p l i c a t i o n o f . the overload t h a t produced t h e f r a c t u r e s . appearance of the f r a c t u r e s i s shown i n F igures 6-23 t o 6-27 and s e c t i o n s through t h e f r a c t u r e s u r f a c e s a r e shown i n F igure 6 - 2 8 .

The f r a c t u r e s were a l l t y p i c a l of t e n s i o n overload f a i l u r e s , w i t h The

The



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E l e c t r o n f ractography s t u d i e s made i n t h e A l l i s o n Materials L a b o r a t o r i e s revealed a t e n s i l e s h e a r t ype of f r a c t u r e with no evidence of f a t i g u e i n Blade B-9208.

Evidence of r e d u c t i o n i n w a l l t h i c k n e s s (necking) a s s o c i a t e d wi th t h e

The r e s u l t s were as fo l lows : f r a c t u r e s w a s obtained i n w a l l t h i c k n e s s measurements on s e c t i o n s l i k e t h o s e shown i n F igu re 6-28.

Wall Thickness

C l o s e t o 4 t o 12 i nches F r a c t u r e From F r a c t u r e ’ ( inch ) ( inch)

Blade B-8087 O. 1739 Blade B-9208 O. 1763 Blade B-8957 O. 1563 Blade B-8758 O. 1944

o. 2021 o; 1998 O. 1930 O. 2254

The w a l l t h i c k n e s s v a l u e s ob ta ined away from t h e f r a c t u r e may be less than t h e o r i g i n a l w a l l t h i c k n e s s i n t h e cuff as t h e r e d u c t i o n i n t h i c k n e s s r e s u l t i n g from t h e overload may have extended through t h e area where t h e measurements were taken. However, t h e v a l u e s ob ta ined i n d i c a t e d t h a t p r i o r t o f a i l u r e t h e b l a d e s complied wi th t h e b l u e p r i n t requirements of 0.169 inch minlmm and 0.197 inch average w a l l t h i c k n e s s i n t h e cuf f r i n g a rea .

.

Hardness measurements made on s e c t i o n s n e a r t h e f r a c t u r e s gave t h e f o l l o w i n g v a l u e s :

Average Hardness (Rockwell c)

Blade B-8087 Blade B-9208 Blade B-8957 Blade B-8758

32 33 32 33

The v a l u e s ob ta ined were a l l w i t h i n t h e s p e c i f i e d range of Rockwell C 30 t o 34.

Meta l log raph ic examina t ions were made on sect i o n s through t h e f r a c t u r e s of t h e f o u r b lades . examined had a s a t i s f a c t o r y m i c r o s t r u c t u r e similar t o t h a t shown i n F igu re 6-29.

f o u r b l ades w e r e made i n t h e A l l i s o n Materials Labora to r i e s . The r e s u l t s showed t h a t t h e b l ade materials complied wi th t h e chemical requirements of t h e a p p l i c a b l e material spec i - f icat ions.

No evidence of d e f e c t i v e material w a s observed. A l l f o u r samples

Spec t rog raph ic a n a l y s e s of samples of m a t e r i a l from t h e r o o t s e c t i o n s of t h e



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Conclusions reached

From t h e r e s u l t s of t h e l a b o r a t o r y s t u d i e s t h e fo l lowing sequences of f a i l u r e w e r e determined :

a ) Excessive wear of t he torque p i s t o n s p l i n e s (due t o l a c k of n i t r i d i n g ) decreased t h e normal r e s t r a i n t on t h e movement of t h e p i s t o n t o such an e x t e n t t h a t t h e p i s t o n w a s r e p e a t e d l y forced a g a i n s t t he c y l i n d e r cap dur ing opera t ion of t h e p i t c h c o n t r o l system.

The pounding of t h e p i s t o n a g a i n s t t h e c y l i n d e r cap increased t h e f l u c t u a t i n g loads i n t h e c y l i n d e r and caused a f a t i g u e c r a c k t o develop i n t h e c y l i n d e r wa l l . The f a t i g u e c r a c k d i d n o t propagate completely through t h e th i ckness of t h e c y l i n d e r w a l l s o t h a t t h e normal h y d r a u l i c pressure of t h e system w a s maintained u n t i l t h e c y l i n d e r f a i l e d completely.

The c y l i n d e r f a i l e d s o suddenly t h a t t h e p r o p e l l e r p i t c h lock was over- loaded and a l s o f a i l e d .

A s a r e s u l t of t h e p i t c h l o c k f a i l u r e t h e p r o p e l l e r b l ades were fo rced toward low p i t c h and t h e p r o p e l l e r speed increased u n t i l a l l of t h e b l ades f a i l e d i n t ens ion due t o e x c e s s i v e c e n t r i f u g a l loads.

One of t h e blades w a s thrown through t h e f u s e l a g e . This destroyed t h e s t r u c t u r a l i n t e g r i t y of t h e f u s e l a g e t o such an e x t e n t t h a t i t broke up i n t h e a i r and t h e a i r c r a f t c r a shed .



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APPENDIX 6.- Examples of Sequence of F a i l u r e I n v e s t i g a t i o n 6- 11

F i g . 6-5.- Appearance of the torque p is ton a f t e r removal from Propeller Socket Posit ion 3. A l l i son photograph (Neg. Ni, . 8-20467). Xl.



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6-12 Manual of A i r c r a f t Accident Inves t iga t ion -

- _I B ~ .._.”_*- .” -

F i g . 6-6.- Appearance of the torque pis ton a f t e r sectioning, showing the inside surface and the damaged internai! splines. AZZison

photograph (Neg. No. 5-120714). XI.

F i g . 6-7.- A c2oser view o? the damaged internui! splines shown i n F i g . 6-6. X 5.



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APPENDIX 6.- Examples of Sequence of Fa i lure Inves t iga t ion 6-13 - ~ _ _ _ ~.__________. _______ ~ ____ -. .

F i p . 6-8.- Damaged wterna2. splines of the torque piston.

edges o f one spl ine end t o ou t l ine i t s contour.

¡Vote step worn

X 5 . i n the l e f t side of each spl ine. A white l ine has been drawn along the

F i g . 6-9.- Section through the torque p is ton spl ines , showing the contour of the damaged external splines ( t o p ) and the extent of the wear on the internal

lack of evidence of ni t r id ing a t points, such as those indicated by arrows rrarr 1% Nital etch. X 5.

splines (bottom), which have only the roots (arrows irarr) remaining. Note

and '%", where origina1 surfaces remained in tac t .



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6-14 Manual of Aircraft Accídent Investigation " ----- I

F i g . 6-10.- Microstructure o f a sect ion through the root of one of the internal, splines of the torque pis ton, showing no evidence o f ni tr iding.

1% Nital etch. X 200.



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APPENDIX 6 . - Examples of Sequence of Fa i lu re Investigation 6-15

F i g . 6-11.- Torque cylinder, heads from propeller socket pos-itions 3 ( l e f t ) and 1, showing the dif ference between the two heads i n the evidence of contact with the

face of the torque pis ton. AZlison photograph. (Neg. No. 8-20472). X I .



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6-16 Manual of A i rc ra f t Accident ïnvcs t i .ga t ior i

Fig , 6-12.- A portion of the surface shown i n F i g . 6-11 of the torque cylinder head from the No. 3 propeZZer socket. AZZison photograph (Neg. No. 8-20459) . X 4 .

F i g . 6-13.- A portion of the surface shown i n F i g . 6-13 of the torque Cylinder head from the No. 1 propeller socket. A l l i son photograph (Neg. No. 8-20460). X4.



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APPENDIX 6.- ExarnDles of Sequence of F a i l u r e Inves t iga t ion 6- 17

Fig. 6-14.- Torque u n i t skims and snap r ing from the No. 3 propelZer socket, showing the damaged condition of some of the shims. Al l i son photograph INeg. No. 8-20468). XI.



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6-18 Manuai of Aircraft Accident Investigation

F i g . 6-15.- Torque u n i t shims and snap ring from the No. 1 propel ler socket. Shown for comparison with F i g . 6-14. Al l ison photograph (Neg. NO. 8-20469). Xi.



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APPENDIX 6 . - Examples of Sequence of F a i l u r e I n v e s t i g a t i o n ___ 6-19 - - - - .. ~ ...-... ~~

F i g . 6-16.- A portion of the snap r+.g from the No. 3 propeller socket, showing shaZZm grooves found in the surface. A l l i son photograph (Neg. No. 8-20455). X6.



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6-20 Manual of A i r c r a f t Accident Invest igat ion

F i g . 6-17.- Failed torque cylinder from the No. 3 propeller socket with the fracture f i t t e d together. Arrow indicates the Zocation of the

fracture. A l l i son photograph (Neg. No. 8 -20476) . X 7 / 8 .



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APPENDIX 6.- Examples of Sequence of Failure Investigation 6-21

Fig. 6-18.- Failed torque cylinder, showing the Zocation of t h s shouZder between the smooth bore portion of the qZinder

AZLison photograph The fracture is a t the top in both piecss.

the fracture adjacent t o and the internal splines. (Neg. No. 8-20470) . X 7 / 8 .



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Fig. 6-19.- Mating surfaces of t he torque cyZinder fracture. The features of the fracture show more clear2y on the piece a t 'the r z g h t . The fat igue portion extends

f rom the inside surface through approximately 50% of t he wall thickness a t the bottom and through about 90% of the wall thickness a t the upper r i g h t .

A l l i son photograph (Neg. No. 8-20471) . X 7 / 8 .



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APPENDIX 6 . - Examples of Sequence of Failure Inves t iga t ion 6-23 __

F i g . 6-L’lI.- A p o r t i o n OS the fracture surface or1 the piece of the cylinder shown a t t h e r i g h t i n F i g . 6- 19. The small steps along the bottom edge of the

fracture are iiidications of mu l t i p l e fat igue origins. X5.

F i g . 6-21.- Section through the fracture i n the cylinder w i t h the mating surfaces of the fracture $-itted together. Arrow indicates the location of the fat igue

origins i n the f i l l e t between the s l i g h t l y undercut inside surface and the in t e r ior shoulder. The fat igue portion of the fracture extends from

2c2 t o ”a”. X l O .



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6-24 Manual of A i r c r a f t Accident Invest igat ion

F i g . 6-22.- Polished and etched section through the fracture i n the cylinder with the mating fracture surfaces (lower r igh t ) f i t t e d together. !&e dark area t o the

This sect ion i s a mirror image of the one shown i n F i g . 6-21. A l l i son l e f t of the arrm is the ni tr ided k y e r on the inside surface of the cylinder.

photograph (Neg. No. 5-120950). Etchant: Ni tal and Picral. X50.



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APPENDIX 6 . - Examples of Sequence of Failure Investigation 6-25

.. I

.B-8087 B-8758 B-9208 B-8957 F i g 6-23.- Root sec t ions of the four propeZZer b h d e s , shmivg the Zocation of the

fmc tu res . Allison photograph (Neg. No. 5-120932). X 1/3.



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F i g . 6-24.- Surface of the fracture i n Blade B-8087. Al l ison photograph (Neg. No. 5-120933). X l .



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F i g . 6-25.- Surface of the fracture in Blade B-9208. A l l ikon photograph (Neg. No. 5-120934). X1.



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F i g . 6-26.- Surface of the fracture in Blade B-8957. Allison photograph (Neg. No. 5-1 20935). X I .



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APPENDIX 6. - Exainp1.e~ of Sequence of Fa i lure Inves t i na t ion 6-29

F i g . 6-27.- Surface of the fracture in Blade B-8758. A l l i son photograph (Ney. No. 5-220936). Xl.



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l

i *

. ^ " ^

B-8087

B-8957 F i g . 6-28. - Sections through

B-9208

B- 87 58

the fractures (top edge o f each I - . , sect ion) of the four propeller blades.' XS;



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APPENDIX 6. - Examples of Sequence of Fa i lu re Inves t iga t ion 6-3 1

F i g . 6-29. - Tempered martensit ic microstructure t yp ica l of that found i n sections from the v i c i n i t y of t he fractures i n a l l o f

the four propeller bZades. 1% Nital etch. X500.



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APPENDIX 7

EXAMPLES OF ELECTRICAL SYSTEMS INVESTIGATION



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APPENDIX 7.- Examination of E l e c t r i c a l Systems 7-1 . .. -.

APPENDIX 7

EXAMPLES OF ELECTRICAL SYSTEMS INVESTIGATION .


The main purpose of examining e l e c t r i c a l systems is t o de te rmine t h e i r wo~rking c o n d i t i o n a t t h e t i m e of t h e acc iden t . of conclus ions reached du r ing a c t u a l a c c i d e n t i n v e s t i g a t i o n s .

Th i s appendix g i v e s some t y p i c a l examples

2 . Lockheed Electra, VHF Naviga t ion Receiver Bulbs

During t h e c o u r s e of t h e examination of t h e systems i n v e s t i g a t i o n of a Lockheed E l e c t r a which c ra shed i n water a c e r t a i n p e c u l a r i t y w a s observed , S p e c i f i c a l l y , a l l t h e tubes of t h e VHF Naviga t ion Rece iver e x h i b i t e d a milky-white appearance and h a i r - l i n e cracks. c e r t a i n tests were conducted.

I n view of t h e s i m i l a r i t y and unusual c h a r a c t e r of t h e a forement ioned c r a c k s ,

The purpose of t h e s e tes ts was t o de te rmine i f t h e c r a c k s were caused by a sudden immersion i n w a t e r of a tube a t o p e r a t i n g temperature.

The a p p a r a t u s used i n t h i s test c o n s i s t e d of t h e fo l lowing: a communications r e c e i v e r ( c o n t a i n i n g i d e n t i c a l t u b e t y p e s ) o p e r a t i n g a t normal power a p p l i c a t i o n and a beaker of water a t a t empera tu re of 550 Fahrenhe i t .

- The t u b e s i n t h e r e c e i v e r were brought t o o p e r a t i n g t empera tu re by a l lowing t h e r e c e i v e r t o o p e r a t e f o r 30 minutes. I n t h e f i r s t p a r t of t h i s tes t , t u b e s were removed from t h e rec.eiver and immediately immersed i n t h e water. I n t h e second p a r t of t h i s t e s t t h e tubes were allowed t o c o o l f o r 5 seconds be fo re be ing immersed i n water.

The r e s u l t s of t h i s test showed t h a t t ubes immediately immersed i n t h e water developed a h a i r - l i n e c r a c k v e r y s i m i l a r t o t h e t u b e s recovered from t h e wrecked a i r c r a f t . Tubes t h a t had been a l lowed t o c o o l f o r f i v e seconds developed no b r e a k s o r cracks.

3 . Convair 3 4 0 , Electr ical Wiring

Th i s a i r c r a f t c r a shed fo l lowing i n - f l i g h t f a i l u r e of t h e r i g h t eng ine p r o p e l l e r . One p r o p e l l e r b lade e n t e r e d t h e f u s e l a g e on t h e lower r i g h t s i d e , s e v e r i n g , i n t e r a l ia , two e lec t r ic w i r i n g bundles benea th t h e f l o o r l i n e .

One w i r i n g bundle con ta ined wi r ing f o r t h e cockp i t v o i c e r e c o r d e r and t h e f l i g h t d a t a r eco rde r . The o t h e r , a n aluminium condu i t , conta ined t h r e e power f e e d c a b l e s t o t h e ESS DC BUS.

The fo l lowing t w o photographs d e p i c t t h e b e s t examples of e lectr ic power presence a t t h e t i m e t hey were c u t by t h e p r o p e l l e r blade. One shows t h e 115 VAC power w i r e t o t h e v o i c e r e c o r d e r and t h e o t h e r shows one of t h e DC power f e e d c a b l e s . . These f i n d i n g s i n d i c a t e t h e p re sence of normal AC and DC power a s w e l l as i n t a c t d i s t r i b u t i o n systems a t t h e t i m e of t h e p r o p e l l e r f a i l u r e .



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Manual of Aircraft Accident Inves t iga t ion -- 7- 2

Figq. recorder,, cut by propeller blade while e l e c t r i c power was present. welding of strands and melting of single strands.

7-1.- Power Lead (115 VAC, 16 gauge stranded .wire) t o cockpit voice riote

Also, note f la t tened and scraped appearance of strands i n the foreground.



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APPENDIX 7 . - Examination of E l e c t r i c a l Systems 7-3

Fig. 7-2.- Power feed cable ( 2 8 VDC, No. 20 wire) t o Essential DC Bus, cut by propeZZer blade when e t ec t r i c power> was present. Note smoothly rounded strands in backpound resu l t ing f r o m melting. Also, note f la t tened and

scraped appearance of strands in the foreground.



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7-G Manual of A i r c r a f t Accident I n v e s t i g a t i o n ~

4. MC 1-11, Light Bulb F i laments

Three photographs - two f o r t h e STALL IDENT FAIL warning system and one f o r t h e NO. 1 A I R SYSTEM FAIL warning system.

The two bu lbs f o r t h e s t a l l i n d e n t i f i c a t i o n f a i l u r e system were compared wi th t h e STALL IDENT warning l i g h t s mounted a d j a c e n t l y on t h e same pane l s . d i s c l o s e d t h a t bo th FAIL bu lbs were i l l umina ted o r 'at least t h e f i l a m e n t s were hea ted a t t h e t i m e of be ing s u b j e c t e d t o p h y s i c a l shock, whi le t h e IDENT bu lbs were obvious ly co ld . T h i s i n d i c a t e d t h a t DC e lec t r ic power was p r e s e n t a t t h e t i m e t h e a i r c r a f t s t r u c k t h e ground. t r a n s f o r m e r / r e c t i f i e r s were supply ing DC power. i n t a c t e l e c t r i c power d i s t r i b u t i o n system and an i n t a c t warning system.

The comparison

This i n d i c a t e d f u r t h e r t h a t t h e AC g e n e r a t o r s were supp ly ing power and t h e F u r t h e r , t h e s e f i n d i n g s po in ted t o an

The c o n d i t i o n of t h e a i r system f a i l u r e warning bulb f i l a m e n t co r robora t ed t h e s e f i n d i n g s .



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APPENDIX 7.- Examination of Electrical Systems 7-5

F i g . 7-3.- Warning l i gh t bulb, envelope in tac t , severe stretching of the filament. Indicates bulb was illuminated a t the time of

receiving physical shock during accident.



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!:.

> , - .. I. _.". . ..

F i g . 7-4.- Warning Zight bulb, envelope in tac t , severe stretching o f the f i lament. Indicates bulb was illuminated a t time of receiving

physical shock during accident.



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APPENDIX 7.- Examination .of .E lec t r i ca l ( Systems 7-7

F i g . 7-5.- Warning Zigl i t bulb, envelope in tac t , severe stretching o:’ the fiLament. Indicates bulb was illuminated a t the time of

receiving physica 2 shock during accident.



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5. Boeing 377, Genera tor Bus Bar

T h i s aluminium bus bar w a s recovered i n t h e c o n d i t i o n as shown i n t h e f o u r Later, i t was determined t h a t t h e e l e c t r i c a l d i s t r e s s no ted on t h e ba r was photographs.

c o i n c i d e n t a l t o t h e a c c i d e n t and d i d not relate t o t h e c a u s a l area. However, c e r t a i n informat ion w a s de r ived from a m e t a l l u r g i c a l s tudy which he lped t o determine t h e r eason f o r t h e damage sus t a ined .

The s tudy d i s c l o s e d t h a t d i s s i m i l a r metals were used i n f a b r i c a t i n g t h e bus b a r assembly. These c o n s i s t e d of t h e aluminium bus b a r , s t ee l t e r m i n a l s t u d s and b r a s s nuts . Improper to rqu ing of t h e t e rmina l nu t w i l l c ause undue p r e s s u r e on t h e aluminium under t h e t e r m i n a l base and t h e aluminium w i l l "cold flow". Th i s c o n d i t i o n r e s u l t s i n loosening of t h e to rque and inc reased e lectr ical r e s i s t a n c e which f u r t h e r r e s u l t s i n gene ra t ion of hea t and f u r t h e r increased r e s i s t a n c e . aluminium away from t h e t e r m i n a l s t u d base wi th f u r t h e r loosening of t h e torque.

The a t t e n d a n t h e a t can t h e n m e l t t h e

Maintenance personnel were i n t h e h a b i t of u s i n g a vo l tme te r t o check v o l t a g e drops a c r o s s t h e t e rmina l s . When t h e v o l t a g e drop w a s g r e a t e r t han a predetermined m i l l i - v o l t v a l u e , t h e t e r m i n a l w a s t i g h t e n e d , a p p a r e n t l y wi thou t r e g a r d f o r t h e s p e c i f i e d inch- pounds, u n t i l t h e v o l t a g e drop w a s aga in w i t h i n t o l e r a n c e s . T h i s r e s u l t e d i n over - torquing t h e t e r m i n a l and t h e whole p rocess of "cold flow", i n c r e a s e d e l e c t r i c a l r e s i s t a n c e and inc reased tempera tures began anew. Therefore , t h i s c o n d i t i o n became se l f -p ropaga t ing up t o t h e p o i n t where t h e aluminium bus bar melted o r burned away from a r c i n g and t h e t e r m i n a l s t u d w a s allowed t o d rop o u t .

Thus, i t appea r s obvious t h a t t h i s damage occur red over a cons ide rab le pe r iod of t i m e and should have been d e t e c t e d much earlier by t h e normal p rocess of maintenance in spec t ions .

The photograph d e p i c t i n g a c ros s - sec t ion of one damaged t e rmina l s t u d p r e s e n t s a good example of t h e damage caused by h e a t , a r c i n g , and t h e i n t e r a c t i o n between d i s s i m i l a r metals.



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APPENDIX 7.- Examination of Electrical

Systems 7-9


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APPENDIX 7.- Examination of

Ele

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al Systems

7-11 _

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7-13 APPENDIX 7.- Examination -- of E l e c t r i c a l _. Systems

6. BAC 1-11, Auxiliary Power Unit Generator Terminal Block

This terminal block is located on t h e APU f i r e w a l l i n t he t a i l sec t ion of the a i r c r a f t . inspection. resu l ted i n damage by arcing and at tendant high temperatures. block around the terminal base.

The condi t ion depicted i n these two photographs w a s detected during an This condi t ion i s a good example of a poor e l e c t r i c a l connexion which has

Note melting of t h e p l a s t i c

F i g . 7-10.- Auxiliary power u n i t generator terminal block. Example of poor connexion with resuZting damage by arcing and heat? Note melting of p las t ic around the stud base.



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APPENDIX 7.- Examination of E l e c t r i c a l Systems 7-15

7. Boeing 707, Engine F i r e Ex t ingu i she r Line

Th i s a i r c r a f t s u s t a i n e d a t u r b i n e f a i l u r e i n t h e No. 4 engine w i t h an ensuing f i r e i n t h e r i g h t wing o u t e r pane l .

The two photographs d e p i c t t h e No. 4 engine f i r e e x t i n g u i s h e r l i n e removed from t h e r i g h t wing l e a d i n g edge compartment a t t h e inboard s e a l i n g r i b , No. 4 eng ine pylon a t t a c h i n g a rea .

T h i s l i n e w a s found t o be chafed through on i ts bottom s i d e , as i n s t a l l e d , from c o n t a c t w i th wing s t r u c t u r e over a cons ide rab le t i m e pe r iod , d i scha rges were made t o t h i s eng ine ; however, i t is obvious t h a t much of t h e e x t i n g u i s h i n g agent must have been expended over-board through t h i s h o l e , which measured 1 i$ i n c h e s i n l eng th . Note a l s o , i n t h e close-up view, t h a t a c rack ex tends ou t on one end of t h e h o l e and measured 1 f i nches i n l eqg th .

Two f i r e e x t i n g u i s h a n t

An e x i s t i n g c o n d i t i o n of t h i s type would g r e a t l y reduce t h e e f f e c t i v e n e s s of t h e engine f i r e e x t i n g u i s h i n g system.



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7-16 M

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APPENDIX 8

AIRCRAFT WEIGHT AND BALANCE



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APPENDIX 8.- A i r c r a f t Weight and Balance 8- 1

1.

f o l d

APPENDIX 8

AIRCRAFT WEIGHT AND BALANCE

I n t r o d u c t i o n

The i n v e s t i g a t o r h a s t o s tudy t h e a i r c r a f t weight and ba lance from t h e th ree - s t a n d p o i n t of s a f e t y , b e s t p o s s i b l e performance and f l y i n g q u a l i t i e s . .

The i n v e s t i g a t i o n may, i n f a c t , relate not only t o t h e dangers of exceeding t o any a p p r e c i a b l e deg ree t h e maximum weights o r t h e c e n t r e of g r a v i t y l i m i t s , but a l s o t o t h e d e t e r i o r a t i o n i n .performance and f l y i n g q u a l i t i e s which r e s u l t s merely from f a i l u r e t o comply w%th t h e r equ i r emen t s i n t h i s r e s p e c t .

The o b j e c t of t h i s appendix i s on t h e one hand t o g i v e 2 b r i e f r e c a p i t u l a t i o n of t h e b a s i c d a t a e s s e n t i a l f o r unde r s t and ing weight and ba lance s h e e t s and on t h e o t h e r hand t o p rov ide some c o n c r e t e examples ( g l i d e r , l i g h t p r i v a t e a i r c r a f t , h e l i c o p t e r , l a r g e t r a n s p o r t a i r c r a f t ) of t h e problems l i k e l y t o be encountered i n t h i s p a r t of t h e i n v e s t i g a t i o n .

2. Brief R e c a p i t u a l t i o n of Some Basic Data

2 . 1 F a c t o r s Governing t h e Weight

Empty weight :

Weight of a n a i r c r a f t a s d e l i v e r e d by t h e manufacturer w i thou t t h e o p e r a t o r ' s own i n s t a l l a t i o n s .

Equipped empty weight:

Empty weight p l u s t h e s t a n d a r d a i r b o r n e equipment whatever t h e type of ope ra t ion ( n a v i g a t i o n i n s t r u m e n t s , a i r c r a f t documents, w a t e r € o r t o i l e t s , e t c . ) .

Basic weight ( o r weight i n o p e r a t i n g o r d e r ) :

Equipped empty weight p l u s t h e weight of non-permanent equipment va ry ing according t o t h e r o u t e t o be flown (seats according t o t h e v e r s i o n s e l e c t e d , l i f e - r a f t s , commissariat , etc.).

It should be no ted t h a t a c e r t a i n number of equipment v e r s i o n s may be de f ined f o r a given a i r c r a f t ; t h e b a s i c weight corresponding t o a g i v e n v e r s i o n and a given crew must t h e r e f o r e be c o r r e c t e d whenever t h e r e is a change i n t h e number of crew members and/or i n s t a l l a t i o n s ( s e a t s , e t c . ) .

Opera t ing weight :

Bas i c weight p l u s f u e l on take-off and any c o r r e c t i o n s t o a l low f o r d i f - f e r ences between planned and a c t u a l v e r s i o n s .



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8-2 Manual of A l r c r a f t . Accident . Inves t i g a t i0.n

Take-off weight:

Operat ing weight p l u s t h e payload ( t o t a l t r a f f i c load) (passengers and t h e i r baggage (s tandard assessment i n accordance wi th c u r r e n t r e g u l a t i o n s of a c t u a l w e i g h t ) ) , ( f r e i g h t i n t r a n s i t , m a i l s ) .

It should be r e c a l l e d t h a t t h e r e are two main c a t e g o r i e s of ope ra t ing l i m i t a t i o n s :

a) t h e a i r w o r t h i n e s s l i m i t a t i o n s which a r e e n t e r e d i n p a r t on t h e c e r t i f i c a t e of a i r w o r t h i n e s s and which r e s u l t from t h e a p p l i c a t i o n of a i r w o r t h i n e s s requirements. cumstances of t h e f l i g h t .

t h e ope ra t ing l i m i t a t i o n s which are con ta ined i n t h e F l i g h t Manual (prepared by t h e manufacturer and approved by t h e o f f i c i a l s e r v i c e s ) , and i n t h e Operat ions Manual ( p e c u l i a r t o each o p e r a t o r and l i k e w i s e submit ted f o r approva l t o t h e o f f i c i a l s e r v i c e s ) , and which r e s u l t from t h e a p p l i c a t i o n of o p e r a t i n g requirements. These l i m i t a t i o n s depend on t h e p a r t i c u l a r c i rcumstances of t h e f l i g h t .

These l i m i t a t i o n s must be complied wi th whatever t h e cir-

b)

The a p p l i c a t i o n of t h e requirements i n q u e s t i o n g e n e r z l l y e n t a i l s t h e d e f i n i - t i o n of f o u r s t r u c t u r a l weight l i m i t a t i o n s :

maximum weight on t a x i i n g o r s t a r t i n g t h e eng ines (maximum t a x i i n g we igh t ) ;

maximm landing weight;

maximum z e r o f u e l weight;

and ope ra t ing weight l i m i t a t i o n s , f o r example:

maximum au thor i zed take-of€ weight (maximum o p e r a t i o n a l take-off we igh t ) .

Allowed t r a f f i c load:

D i f f e rence between t h e maximum au thor i zed take-off weight (allowing f o r v a r i o u s l i m i t a t i o n s ) and t h e ope ra t ing weight.

It should be noted t h a t t h e maximum allowed t r a f f i c l oad is t h e never-exceed load , i.e. t h e d i f f e r e n c e between t h e maximum zero f u e l weight and t h e c o r r e c t e d b a s i c weight.

T o t a l t r i p f u e l :

Estimated f u e l consumption from take-off t o aerodrome of d e s t i n a t i o n (over a r r i v a l beacon).

It should be noted t h a t t h e method of computation may vary from one o p e r a t i n g S t a t e t o another.



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APPENDIX 8.- A i r c r a f t Weight and Balance 8- 3 - __

Reserves :

C o n s i s t i n g of t h e a d d i t i o n a l f u e l r e q u i r e d by t h e r e g u l a t i o n s o r f i x e d (en- r o u t e r e s e r v e , a l t e r n a t e aerodrome r e s e r v e , ho ld ing reserve, procedure r e s e r v e , engine s t a r t i n g , e n g i n e t e s t i n g on t h e ground, t a x i i n g , a c c e l e r a t i o n and i n i t i a l climb on take- o f f ) and t h e f u e l n o t a v a i l a b l e f o r t h e f l i g h t (unusable f u e l a t t h e bottom of t h e t anks , hea t ing ) - a l s o a f i x e d va lue .

It should be noted t h a t f o r v a r i o u s r easons t h e q u a n t i t y of f u e l t o be t a k e n

Moreover, t h e methods on board, t h e sum of t h e t o t a l t r i p f u e l and t h e r e s e r v e s f o r a g iven f l i g h t , . m a y be sup- pleuiented t o t h e maximum p o s s i b l e w i t h i n t h e o p e r a t i n g l i m i t a t i o n s . of computing t h e v a r i o u s r e s e r v e s may va ry from one o p e r a t i n g S t a t e t o another .

Payload message:

T h i s supplements t h e weight and ba lance s h e e t by i n d i c a t i n g f o r each s t a g e t h e n a t u r e of t h e payload c a r r i e d and i t s d i s t r i b u t i o n i n t h e a i r c r a f t .

In fo rma t ion con ta ined i n t h e message is as fo l lows :

n a t u r e , number and d i s t r i b u t i o n of pas senge r s by classes;

n a t u r e of t h e f r e i g h t and d i s t r i b u t i o n by ho lds .

T h i s message, which is in tended t o show t h e t r a f f i c c a r r i e d , may prove ve ry va luab le t o t h e i n v e s t i g a t o r .

2.2 F a c t o r s Governing t h e P o s i t i o n of t h e ' C e n t r e of G r a v i t y

Reference p o i n t o r l i n e :

O r i g i n (de f ined by t h e manufac turer ) from which t h e d i s t a n c e measurements r e q u i r e d f o r t h e centre of g r a v i t y c a l c u l a t i o n s must be made.

Arm:

H o r i z o n t a l d i s t a n c e between an a i r c r a f t component and t h e r e f e r e n c e p o i n t or l i n e ; t h e a l g e b r a i c s i g n s of - o r + are as s igned t o t h i s d i s t a n c e , depending on whether t h e component i n q u e s t i o n i s forward o r a f t of t h e r e f e r e n c e p o i n t o r l i n e . .

Moment :

Product of t h e weight of a g iven component and i t s a r m q u a l i f i e d by t h e a l g e b r a i c s i g n .

Cen t re of g r a v i t y envelope:

The range of pe rmi t t ed movement between t h e extreme forward and extreme a f t c e n t r e of g r a v i t y p o s i t i o n s of t h e loaded a i r c r a f t . Such l i m i t s a r e determined i n accordance w i t h t he a i r w o r t h i n e s s requi rements f o r each a i r c r a f t t ype . They are shown i n t h e F l i g h t Yanual, and may be expressed e i t h e r as a percentage of t h e mean wing chord or as a d i s t a n c e i n r e l a t i o n t o t h e r e f e r e n c e p o i n t o r l i n e .



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A W (kg)

120 000-

100 OOO-

80 000-

60 000'

40 000-

20 000-

2.3 E f f e c t of t h e P o s i t i o n of t h e Centre of Grav i ty

An a i r c r a f t with a forward c e n t r e of g r a v i t y p o s i t i o n t ends towards t h e manoeuvrabi l i ty l i m i t with an i n c r e a s e i n t h e s t i ck f o r c e s , while an a i r c r a f t w i th a rear c e n t r e of g r a v i t y p o s i t i o n tends towards t h e s t a b i l i t y l i m i t w i th a decrease i n s t i c k forces.

It should be r e c a l l e d t h a t t h e c a l c u l a t i o n of t h e p o s i t i o n of t h e c e n t r e of g r a v i t y e n t a i l s t h e de te rmina t ion of t h a t p o s i t i o n as t h e p o i n t of a p p l i c a t i o n of i t s t o t a l loaded weight. The c e n t r e of g r a v i t y p o s i t i o n would be c o r r e c t * i f t h e p o s i t i o n cor responding t o a given load is s i t u a t e d w i t h i n t h e c e n t r e of g r a v i t y envelope.

I n o rde r t o make t h i s c a l c u l a t i o n , t h e a l g e b r a i c sum of t h e p a r t i a l moments of each of t h e components involved must be determined and t h i s sum g i v e s t h e moment of t h e t o t a l weight ; hence t h e p o s i t i o n of t h e c e n t r e of g r a v i t y i n r e l a t i o n t o t h e r e f e r e n c e

sum of moments. sum of weights p o i n t o r l i n e is

These ope ra t ions , which a r e s imple f o r g l i d e r s or l i g h t a i rc raf t , ve ry soon become unwieldy f o r heavy a i r c r a f t ; they a r e s i m p l i f i e d by us ing a system of a l g e b r a i c i n d i c e s (def ined i n t h e a i r c r a f t ope ra t ions manual) p r o p o r t i o n a t e t o each v a l u e of t h e

b a s i c moments. The express ion then becomes

s h i p which is always c h a r a c t e r i s t i c of t h e c e n t r e of g r a v i t y p o s i t i o n . I n o rde r t o avo id t h e n e c e s s i t y of c a l c u l a t i n g t h i s r e l a t i o n s h i p , g raphs a r e i n s e r t e d i n t h e o p e r a t i o n s manual.; rhe f i n a l index I (sum of p a r t i a l i n d i c e s ) is p l o t t e d on t h e h o r i z o n t a l ax is and t h e t o t a l weight W (sum of p a r t i a l weights ) is p l o t t e d on t h e v e r t i c a l a x i s ; p o i n t s corresponding t o a p a r t i c u l a r r e l a t i o n s h i p w i l l form a s t r a i g h t l i n e (ho -c .g . l i n e ) t h e s l o p e of which w i l l be p ropor t iona l t o t h e c e n t r e of g r a v i t y p o s i t i o n ; t h e c.g. p o s i t i o n can be r ead o f f p r a c t i c a l l y immediately on such graphs ( see F igu re 8-1).

sum of i n d i c e s a relation- sum of moments sum of weights K sum of weights '

rr

I 1 L I I

1 I I c

0 10 20 30 40 50 60 70 80 I (Index)

Fig. 8-1

* The i n v e s t i g a t i n g o f f i c e r may a l s o have r eason t o examine a l a t e r a l c e n t r e of g r a v i t y p o s i t i o n (use of wing t anks or wing t i p t anks , f o r example).



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APPENDIX 8.- A i r c r a f t Weight and Balance 8- 5

It should be noted t h a t major a i r l i n e s a r e now t e n d i n g t o d e a l w i th t h e c a l c u l a t i o n of t h e c.g. p o s i t i o n by means of computers. method is used , it i s h i g h l y d e s i r a b l e t o have a record of t h e c a l c u l a t i o n s .

It should be noted t h a t , whatever

3. Examples of Typ ica l Cases

3.1 Example of a G l ide r

Claiming t h a t i t would improve t h e performance and ease of p i l o t a g e of a g l i d e r , 'a p i l o t i n s t a l l e d a 2.3 kg weight , w i t h i n reach of h i s hand, on t h e f l o o r forward of t he c o n t r o l column which could be s l i d over a d i s t a n c e of 25 cm e i t h e r forwards o r backwards, a s r e q u i r e d .

I n o r d e r t o assess t h e e f f e c t of t h i s m o d i f i c a t i o n on t h e c e n t r e of g r a v i t y cond i t ions of t h e a i r c r a f t , t h e i n v e s t i g a t o r had t o c a r r y out t h e fo l lowing ope ra t ions :

3.1.1 Weight computation

b a l l a s t weight + a t tachment and s l i d i n g assembly:

last weight of g l i d e r : 166 kg (empty).

3 kg.

maximum weight au tho r i zed : 265 kg.

Maximum p o s s i b l e weight f o r t h e p i l o t equipped w i t h parachute :

265 kg - (166 kg + 3 ) 5 96 kg.

T h i s weight w a s ç y e a t e r t h a n t h e weight of t h e p i l o t and h i s equipment a c t u a l l y i n t h e g l i d e r , bu t t h e i n v e s t i g a t o r r e t a i n e d it i n o rde r t o make t h e c a l c u l a t i o n f o r t h e most unfavourable case .

3.1.2 Assessment of t h e d i s t a n c e i n r e l a t i o n t o t h e r e f e r e n c e p o i n t

The most unfavourable p o s i t i o n of t h e s l i d i n g weight w a s obvious ly t h a t i n which t h e weight was a s f a r away as p o s s i b l e from t h e r e f e r e n c e p o i n t , a d i s t a n c e which cannot be g r e a t e r than t h e d i s t a n c e measured on t h e b l u e p r i n t between t h e r e f e r e n c e p o i n t and t h e a i r c r a f t nose: i .e. 1 metre. A s a f i r s t approximation, t h e i n v e s t i g a t i n g o f f i c e r r e t a i n e d t h i s d i s t a n c e ( i n p o i n t of f a c t no t much g r e a t e r t h a n t h e a c t u a l d i s t a n c e ) .

3.1.3 Cent re of Grav i ty P o s i t i o n

A f t e r c o n s u l t i n g t h e manufac turer ' s i n s t r u c t i o n s , t h e fo l lowing c a l c u l a t i o n could be made:

A i r c r a f t empty

P i l o t + parachu te

Weight + a t tachment

Moments (kg x m) A r m (m) Weights (kg)

166 +O. 553 +91.8

96 -0.33 -31.68

- 3 -1.00 - 3.00

265 .__t +0.21 f-- +57.12



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3.1.4 ComLlusion

The c e n t r e of g r a v i t y l i m i t s f o r t h i s t ype of g l i d e r was :

forward c e n t r e of g r a v i t y l i m i t : + O. 19

aft c e n t r e of g r a v i t y l i m i t : + 0.34

The imes t i&ptw t h e r e f a r e e s t a b l i s h e d t h a t t h e arm which w a s found a t + 0.21 w a s nea r t h e forward c e n t r e of g r a v i t y l i m i t , bu t w i t h i n t h e p e r m i s s i b l e l i m i t s . d e l i b e r a t e s e l e c t i o n of unfavourable approximations enabledhim t o e s t a b l i s h t h a t t h e modifica- t i o n considered had n o t l e d t o any d e p a r t u r e from t h e r e g u l a t i o n envelope.

The

3.2 Example of a L i d t A i r c r a f t

A fou r - sea t e r single-engined a i r c r a f t broke up i n f l i g h t w h i l s t manoeuvring. I n order t o examine t h e p o s s i b l e hypotheses f o r t h i s d i s i n t e g r a t i o n , t h e i n v e s t i g a t o r endeavoured t o r e c o n s t r u c t both t h e t o t a l weight: of t h e a i r c r a f t and t h e p o s i t i o n of i ts c e n t r e of g r a v i t y a t t h e t i m e of t h e a c c i d e n t .

Although it w a s r e l a t i v e l y easy t o o b t a i n in fo rma t ion about t h e weight of t h e occupants and t h e i r baggage, t h e f u e l on board and i n p a r t i c u l a r i ts d i s t r i b u t i o n r a i s e d a s l i g h t l y more complicated problem. forward and rear tanks. w e Lecommended by t h e manufacturer, brit it w a s imposs ib l e to a f f i r m t h a t t h i s procedure was followed by t h e p i l o t . acc iden t and t h e t o t a l f l y i n g t i m e w a s n o t more than 55 minutes.

T h i s a i r c r a f t t ype w a s i n f a c t equipped w i t h When t h e four s e a t s w e r e occupied i n i t i a l use of t h e r e a r t a n k

I n a d d i t i o n , t h e t a n k s were f i l l e d on t h e very morning of t h e

The i n v e s t i g a t o r had t h e r e f o r e t o determine t h e p robab le f u e l consumption and e s t a b l i s h two p o s s i b l e l i m i t s f o r t h e p o s i t i o n of t h e centre of g r a v i t y (one based on t h e assumption t h a t t h e f l i g h t w a s made on t h e rear tank only , t h e o t h e r based on t h e assump- t i o n t h a t t h e f l i g h t w a s made on t h e forward tanks only) .

3.2.1 Use of rear t ank only

Weight (kg) A r m (m)* Moment (kg x m)

Equipped empty weight ( i n c l u d i n g l u b r i c a n t ) last weighing

Occupants ( a c t u a l f i g u r e s )

Forward seats R e a r seats

Baggage (weighed a f t e r t h e a c c i d e n t )

505

141 155

40

+ 0.287

+ 0.42 + 1.16

+ 1.90

+ 144.9

+ 59.2 + 179.8

+ 76.0

* A l l p o s i t i v e , as t h e r e f e r e n c e l i n e is ve ry f a r forward, a t t h e l e v e l of t h e l ead ing edge of t h e r e c t a n g u l a r p a r t of t h e wing.



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APPENDIX 8.- Aircraft Weight and Balance 8-7

(Contd) Weight (kg) Arm (m)* 'Moment (kg x m)

Fuel

Forward tanks ' (80 i) not used

Rear tanks (70 1) a f t e r estimated consumption for 55 minutes of f l i gh t

56 + 0.10 + 5.6

+ 28.2

922 __3 + 0.535 - + 493.7 + 1.13 _I_

25 -

The reference wing chord being 1 . 7 1 m, the position of the centre of gravity can also be expressed as 31.3 p e r cent of Che reference wing chord.

3.2.2 Ü s e of forward tanks only

Weight (kg) Arm (m) Moment (kg x as)

Equipped empty weight (including lubricant) las t weighing

Occupants (actual figures)

Forward seats Rear sea ts

Baggage ( r ea l figures)

505 + 0.287 + 144.9

141 + 0.42 + . 59.2 155 + 1.16 + 179.8

40 + 1.90 + 76.0

Fuel

Forward tanks (80 1) a f t e r estimated consumption for 55 minutes of f l i gh t 32 + 0.10 + 3.2

+ 55.4 - 49 + 1.13 - Rear tank (70 i)

922 - + 0.562 4-- + 518.5

The reference wing chord being 1 .71 m, the position of t he centre of gravity can also be expressed a s 32.9 per cent of the reference wing chord.

3.2.3 Conclusion

The l i m i t s for t h i s type of a i rc raf t w e r e :

maximum take-off weight: 960 kg

centre of gravity forward l i m i t : + 0.290 m or 1 7 p e r cent

centre of gravity a f t l i m i t : + 0.565 m or 33 per cent

* A l l positive, as t h e reference l i n e is very f a r forward, a t the leve l of the leading edge of the rectangular par t of the wing.



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A t t h e t i m e of d i s i n t e g r a t i o n , t h e a i r c r a f t weight (922 kg) was near t o t h e maximum take-off weight and t h e c e n t r e of g r a v i t y , which w a s ve ry near t o t h e rear l i m i t i n both cases, was p r a c t i c a l l y a t t h e l i m i t i f t h e forward t a n k s only w e r e used. Although t h e s e cond i t ions were wi th in pe rmis s ib l e l i m i t s , t h e dec rease i n e l e v a t o r s t i c k f o r c e p e r g due t o t h e extreme a f t c e n t r e of g r a v i t y p o s i t i o n and t h e f a c t t h a t t h e weight was c l o s e t o t h e maximum weight made i t easy t o exceed t h e pe rmis s ib l e load f a c t o r and could e x p l a i n t h e i n - f l i g h t f a i l u r e .

3.3 Example f o r a ,Hel icopter

A t h ree - sea t e r h e l i c o p t e r c rashed i n a f i e l d when one of t h e passengers l e f t t h e hel ic iopter i n f l i g h t by means of a rope l adde r .

With an a i r c r a f t which a l r e a d y h a s an a f t c e n t r e of g r a v i t y p o s i t i o n , such an ope ra t ion may prove dangerous and t h e p i l o t must always know where t h e c e n t r e of g r a v i t y w i l l be a f t e r t h e drop i n weight . The i n v e s t i g a t o r , t h e r e f o r e , had t o r e - e s t a b l i s h t h e weight and p o s i t i o n of t h e c e n t r e of g r a v i t y of t h e a i r c r a f t f i r s t w i th t h r e e occupants , and the= wi th two occupants on ly .

3.3.1 Weight and Balance wi th Three Occupants

Weight (Kg)

Equipped empty weight ( b a t t e r i e s i n rear po si t i on) 6 04

P i l o t + t w o passengers 228

O i l 7

79

918 Fuel (110 1) -

3.3.2 Weight and Balance wi th Two Occupants

Weight (Kg)

Equipped empty weight ( b a t t e r i e s i n r e a r p o s i t i o n ) 6 04

P i l o t + one passenger 152

O i l 7

Fuel (110 1) 79

842 -

A m (m)

+ 0.23

- 0.75

+ 0.12

+ 0.60

Arm (m)

+ 0.23

- 0.75

+ 0.12

+ 0.60

Moments (Kg x m)

+ 138.92

- 171.00

+ 0.84

+ 47.40

+ 16.16

Moments (Kg x m)

+ 138.92

- 114.00

+ 0.84

+ 47.40

+ 73.16



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APPENDIX 8.- A i r c r a f t Weight and Balance

3.3.3 The c e n t r e of g r a v i t y l i m i t s were:

8- 9

- 0.050 m (forward l i m i t )

+ 0.073 m ( a f t l i m i t ) .

With t h r e e occupants (3.3.1) t h e p o s i t i o n of t h e c e n t r e of g r a v i t y w a s :

'6.'' = + 0.018 m 918 +

i .e. w e l l w i t h i n l i m i t s .

With two occupants (3.3.2) t h e p o s i t i o n of t h e c e n t r e of g r a v i t y w a s :

+A= 73 + 0.087 m; 842

hence t h e a f t l i m i t f o r t h e c e n t r e of g r a v i t y w a s exceeded and t h i s gave rise t o t h e a c c i d e n t .

3.4 Examples f o r a Large Transpor t A i r c r a f t

A four-engined j e t a i r c r a f t took o f f on a t r a n s - A t l a n t i c f l i g h t and f a i l e d t o respond t o t h e movement of t h e c o n t r o l column a t t h e a n t i c i p a t e d moment of r o t a t i o n .

The pilot-in-command succeeded i n t ak ing o f f by a d j u s t i n g t h e e l e v a t o r t r i m c o n t r o l s e v e r a l deg rees upwards a l though i t had been c o r r e c t l y pre-set i n accordance w i t h t h e d a t a shown on t h e weight and ba lance s h e e t .

The i n v e s t i g a t i o n i n t o t h i s i n c i d e n t , which might have had s e r i o u e consequences, e n t a i l e d checking t h e weight and ba lance s h e e t which w a s e s t a b l i s h e d f o r t h e f l i g h t .

The o r i g i n a l weight and ba lance s h e e t used by t h e crew and t h e weight and balance s h e e t as computed by t h e i n v e s t i g a t o r are reproduced a t F i g u r e s 8-2 and 8-3 r e s p e c t i v e l y . Comparison of t h e s e two documents shows t h a t t h e o r i g i n a l weight and ba lance shee t (F igu re 8-2) gave t h e p o s i t i o n of t h e c e n t r e of g r a v i t y a t take-of f as 22.2% MAC, although i t w a s computed t o be 29.5% MAC by t h e i n v e s t i g a t o r (F igu re 8-3). This r e s u l t e d from an e r r o r i n s i g n of t h e f u e l i ndex (F igure 8-4) on t h e o r i g i n a l weight and ba lance s h e e t . As a consequence t h e crew p re - se l ec t ed t h e e l e v a t o r t r i m t o an improper se t t ing .



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s 10 Manual of Aircraft Accident Investigation

RIGIT Na ............................. DA- : ................................. AIR-* .............................. m m SEC-. ................... ParpAReD B y I ........................

C. CW G. AT T'AKECSF

Check that the point indicating C d C. poslticm fœ the weight d I n d a of the riruait withmt hei f o b within the authœized zone,

F i g . 8 . 2 . - Copy of the Weight and Balance Sheet used by the crew (See on f igure 8 . 4 the proper f u e l index and note here error i n sign)



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APPENDIX 8.- A i r c r a f t Weight and Balance 8-11

FLIGHT No: ...........................

DATE : .................................

AIRCRAFT .............................

FLIGHT SEC MENT ....................

PREPARED By: ........................

c. OF G. AT TAKE-OFF

Check that t h e ;>c>ir:t inJicxtinK C .

cf C position :or tl:e t.,el;iit .irid

<:pr 1-e. -I---



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5-707.328 & 328.8- FUEL INDEX

FUEL IN TANKS No. 1, 2, 3, 4

(I A . P A M

FUEL I 5

10 11 12 13 14 15 16 17 18 19

20 21 22 23 24 25 2) 27 28 29

30 31 32 33 34 35 36 37 38

TANKS ~1,2,3,4 FULL

INDEX

+ 0.1

+ 0.3

+ 0.3 + 0.4 + 0.4 + 0.5 t 0.6 + 0.7 + 0.8 t 0.9 t 1.0 .) 1.1

t 1.2 t 1.4 + 1.5 t 1.7 t 1.9 + 2.1 t 2.4 + 2.6 t 2.5

+ 2.4

t 2.2 t 2.1 t 1.9 t 1.8 .I- 1.6 -t 1.5 + 1.3 t 1

+ I

Y)

REMARKS

qual quantiq I fuel in tank lo. 1, 2, 3, '

INDEX INCREASES

ffect of Na ! and3tanhs

INDEX DECREASES

Check that fuel density

does not impìy the

use of tanks I A and 4A

DO not interpolate 0 between these 2 tables 9

2 WING TANKS No. i, 2, 3, 4 FULL & FUEL IN TANKS No. IA & 4A

t 3.6 INDEX

WING TANKS FULL PLUS FUEL IN TANK No. 5 I

FUEL 1

42 43 4 4 45 46 47 48 49

50 51 5 2 5 3 54 5 5 56 57 58 59

Q 63 64

ull comple- nent with ank No. 5

4 cells

65 66 67 68 69

70 71 7 2

Full !om lement

No. 5 I ceiis

wig tank

INDEX 4 Cell. f 3.4 + 3.1 + 2.0 t 2.4 t 2.1 + 1.8 t 1.5 t 1.1

t 0.7

t 0.4 t 0.1 - 0.2 - 0.6 - 1.0 - 1.3 - 1.6 - 2 - 2.3

- 2.8

- 3.1 - 3.5 - 4 - 4.4

- 4.8

7 Cell. + 3.3 t 2.9 t 2.6 t 2.2 t 1.8 t 1.4 + 1 t 0.6

+ 0.2

- 0.2 - 0.7 - 1.1 - 1.5 - 1.9 - 2.3 - 2.7 - 3.2 - 3.6

Q - 5.2 - 5.7

- 6.2 - 6.6 - 7 - 7.5 - 8 - 8.5 - 9 - 9.6

- 9.7

REMARKS

Effect of No. 5 tank

INDEX DECREASES

All densities

A l l densities

Fig. 8.4. - Fuel Indbz Table



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APPENDIX 9

IDENTIFICATION OF VICTIMS

The INTERPOL form f o r t h e i d e n t i f i c a t i o n of v i c t ims of major ca t a s t rophes i s included i n t h i s Appendix f o r t h e information of States



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APPENDIX 9.- I d e n t i f i c a t i o n of V i c t i m s 9- 1

APPENDIX 9

IDENTIFICATION OF VICTIMS

Documentation and Summary of Methods


The purpose of t h i s Appendix is t o d i s c u s s two methods of documentation, and t o summarize t h e methods of i d e n t i f i c a t i o n .

I t i s d i f r i c u l t : if no t impossible t o des ign t h e perfect : form t o document something so v a r i a b l e a s t h e f i n d i n g s a r i s i n g from t h e examinat ion of a body from an air- c r a f t accident-. I t i s necessary t o record d e t a i l s about a body r e l a t i n g t o i t s i d e n t i f i c a - t i o n , the cause , rind the c i r cums tances of i t s dea th . S ince e v e r i n c r e a s i n g numbers of persons may be killed i n a given a c c i d e n t i t i s expedient t o reduce t h e number of forms f o r each body as f a r a s p o s s i b l e , t o minimize t h e i r complexity and t o p rov ide forms t h a t can b e used and handled wi th ease . a p p r o p r i a t e whether 3 holly be s u b s t s n t i a l l y i n t a c t and f u l l y c l o r h e d , o r nakeà and p a r t i a l l y d i s i n t e g r a t e d . Thus any form t o be of v a l u e i n t h e con tex t of an a i r c r a f t a c c i d e n t must b e a compromise between a many paged document , comprehensively l i s t i n g every f e a t u r e t h a t might need t o be recorded wi th aïnple space f o r t h e i r d e s c r i p t i o n s and , a t t h e o t h e r end o f t h e s c a l e an e s s e n t i a l l y p l a i n p i e c e of paper w i th minimum headings , p l a c i n g upon t h e examiner t h e burden of rememhering every d e t a i l t o which he should g ive a t t e n t i o n and about which he should r eco rd h i s f i n d i n g s .

They should be a t once simple y e t comprehensive; they must b e

Work is i n p r o g r e s s t o p repa re forms which can be adopted by ICAO, which w i l l meet both t h e needs of t h e t e c h n i c a l a i r c r a f t a c c i d e n t i n v e s t i g a t i o n and i d e n t i f i c a t i o n , and which w i l l i n c o r p o r a t e a nomenclature p e r m i t t i n g computer p rocess ing . wi th t h i s p r o j e c t work is i n p r o g r e s s towards a s t anda rd ized nomenclature f o r f o r e n s i c odontology which can be adopted by ICAO.

I n con junc t ion

I n t h e meantime t h e expe r i ence of one Con t rac t ing S t a t e i s reproduced i n t h i s Appendix as a gu ide and f o r c o n s i d e r a t i o n by o t h e r S t a t e s . C o n s t r u c t i v e c r i t i c i s m of t h e s e forms, o r a d v i c e of o t h e r forms i n u s e , would assist ICAO i n deve lop ing a form f o r i n t e r n a - t i o n a l accep tance i n a i r c r a f t a c c i d e n t i n v e s t i g a t i o n .

2. Documentat i o n

2 . 1 The INTERPOL Disaster V i c t i m I d e n t i f i c a t i o n Form

T h i s form, a copy of which i s inc luded i n t h i s Appendix (pages 9-5 t o 9-10), has been c a r e f u l l y des igned by e x p e r t s from t h e wor ld ' s p o l i c e f o r c e s and is o r i e n t e d towards i d e n t i f i c a t i o n , n o t towards a i r c r a f t a c c i d e n t i n v e s t i g a t i o n . It has been found t o be i d e a l f o r t h e i d e n t i f i c a t i o n of a s i n g l e body but less than i d e a l f o r u se i n a major a i r c r a f t a c c i d e n t f o r t h e fo l lowing reasons :

2 4 / 2 / 7 2 No. 2



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9- 2 Manual of Aircraf t Accident I n v e s t i g a t i o n

A s i n g l e type of form does s e r v i c e f o r a male o r female body and f o r u s e e i t h e r as a form f o r record ing d e t a i l s of a c o r p s e o r f o r d e t a i l s of a miss ing person. I f t h e r e f o r e t h e r e i s an a c c i d e n t w i th 200 dead, one w i l l have 400 i d e n t i c a l forms, va ry ing only i n t h e s e c t i o n s completed, 200 of which w i l l have t o be compared w i t h t h e o t h e r 200. some i n v e s t i g a t o r s i n d i c a t e s t h a t t h e t a s k of comparison is much easier i f forms r e l a t i n g t o bodies and forms r e l a t i n g t o miss ing persons a r e much more r e a d i l y d i s t ingu i shed .

It i s a fo lded form wi th 4 pages ( a f t e r t h e removal of t he i n s t r u c t i o n s ) . Experience h a s shown t h a t a form which i s a s i n g l e s h e e t of paper i s b e t t e r than a folded one when l a r g e numbers have t o be handled: s i n g l e s h e e t forms a r e used and are kept each i n a t r anspa ren t envelope o r f i l e cover a f t e r completion, r e f e r e n c e is p o s s i b l e wi thout removal from t h e f i l e .

Experience of

i f

The form inco rpora t e s a n odon to log ica l record c h a r t based upon t h e r e c e n t l y recommended i n t e r n a t i o n a l two-digit system of too th nomenclature. This nomenclature is an e x c e l l e n t one and i s l i k e l y t o r e c e i v e wide acceptance. (see Note). It h a s been found t h a t t h i s h a s two d isadvantages i n p r a c t i c e :

However, the c h a r t i s designed a s a p i c t o r i a l c h a r t on ly

i) When t h e form i s used as a record of a miss ing person t h e d e n t a l information is l i k e l y t o be provided e i t h e r by te lephone , t e l eg ram o r t e l e x , and, no t be ing i n p i c t o r i a l form, t r a n s l a t i o n t o a p i c to - r i a l c h a r t may be e i t h e r imposs ib le o r mis leading . A l t e r n a t i v e l y t h e missing person’s o r i g i n a l r eco rds inc lud ing a p i c t o r i a l c h a r t may be provided by a d e n t i s t i n which case t h e r e is no need f o r t h e p i c t o r i a l c h a r t t o be l a b o r i o u s l y copied .

ii) When t h e form i s used t o record f i n d i n g s i n a cadaver i t w i l l o f t e n be apparent t h a t e i t h e r t he body i s going t o be e a s i l y i d e n t i f i e d by many types of evidence o r , a l t e r n a t i v e l y t h a t d e n t a l evidence i s l i k e l y t o be of prime importance. When t h e l a t t e r s i t u a t i o n a p p l i e s i t may be e s p e c i a l l y impor tan t f o r t h e odon to log ica l c h a r t t o be completed very c a r e f u l l y by t h e d e n t i s t himself wi th t h e shape and p r e c i s e p o s i t i o n of each r e s t o r a t i o n shown, Where t h e former s i t u a - t i o n a p p l i e s a record of r e s t o r a t i o n by t o o t h and s u r f a c e i s su f - f i c i e n t and much t i m e can be saved by t h e d e n t i s t d i c t a t i n g t o a n a s s i s t a n t h i s f i n d i n g s as he works.

Note.- I t i s considered it would be an advantage f o r whichever purpose t h e f o r m be used, f o r t he odontoZogica2 char t t o be supplemented by space f o r nota t ional records about each too th .

The form does no t provide space except i n a misce l laneous s e c t i o n (V) f o r autopsy f ind ings . I n a n a i r c r a f t a c c i d e n t t h e examinat ion of a body both f o r acc iden t i n v e s t i g a t i o n and i d e n t i f i c a t i o n purposes should n o t be d ivorced , and i n a bu rn t body, i n t e r n a l au topsy f i n d i n g s wi th r e f e r e n c e , f o r example, t o pos t - su rg ica l s t a t e s can be s p e c i a l l y r e l e v a n t t o i d e n t i - f i c a t i o n i n p a r t i c u l a r .

241 21 7 2 No. 2



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APPENDIX 9.- I d e n t i f i c a t i o n of Vic t ims 9-3

2 . 2 The United Kingdom Forms

The forms reproduced a t pages 9-11 t o 9-20 of t h i s Appendix are s l i g h t l y modified v e r s i o n s of some in iise i n t h e United Kingdom. F ive d i f f e r e n t forms are used. This might b e cons idered a d i sadvan tage bu t t hose who use them c o n s i d e r t h a t t h e i r advan- t a g e s outweigh t h e i r d i sadvan tages . They comprise two forms (M.l. b l u e , M . 2 . orange) f o r male bodies , and two forms ( F . l . p ink and F.2. yellow) f o r female bodies . Bodies, t h e sex of which is n o t immediately de t e rminab le are no t a f r e q u e n t problem and have n o t ' j u s t i f i e d an a d d i t i o n a l form; i t h a s been found s u f f i c i e n t t o use "male" forms and mark them wi th a l a r g e X or I i n t h e top right-hand co rne r . The f i f t h form is w h i t e and is t h e in fo rma t ion sheer f o r a mis s ing known person. i nches which is t h e same as t h e page s i z e of t h e INTERPOL form.

Each form measures 13 4 x 8

The forms are used i n t h e fo l lowing manner. As t h e j o i n t examinat ion f o r a male body p roceeds , t h e p a t h o l o g i s t and h i s c l e r i c a l a s s i s t a n t complete form M . 1 . and t h e p o l i c e and d e n t i s t s i n t u r n fill i n t h e form M.2. Each form is i n s e r t e d on completion i n t o a t r a n s p a r e n t envelope o r f i l e cove r and the two are s t a p l e d t o g e t h e r . I t i s then simple t o u s e and hand le t h e r e c o r d s and they a r e s a f e from s o i l i n g . A t h i r d t r a n s p a r e n t envelope con ta in ing a ca rd wi th samples of material, laundry marks etc., c o l l e c t e d by t h e p o l i c e from t h e c l o t h i n g , can u s e f u l l y be c l i p p e d t o t h e f i r s t two, p o l i c e f o r c e s and t h e p r e s e r v a t i o n of such samples reduces t h e need f o r , c e r t a i n l y t h e length o f , d e s c r i p t i v e r eco rds .

Such c a r d s are used by many

This procedure e l i m i n a t e s t h e p o s s i b i l i t y of confus ing t h e in fo rma t ion form8

When a match h a s been ob ta ined , t h e f i l e s w i th t h e body r e c o r d s when t h e t i m e comes f o r comparison of t h e two; t h e former are p r i n t e d on whi te paper and are r e a d i l y d i s t i n g u i s h a b l e . of t h e miss ing known pe r son are s t a p l e d t o t h e f i l e s r e l a t i n g t o t h e body and t h e whole can be t r a n s f e r r e d t o t h e " i d e n t i f i e d t r ay" ; bu t t h e c o n t e n t s of t h e v a r i o u s p a r t s of t h e ' 'dossier" are r e a d i l y r ecove rab le f o r easy r e f e r e n c e should t h i s be necessa ry .

For example, by t a k i n g t h e envelopes c o n t a i n i n g b l u e and orange forms r e l a t i n g t o male bodies : i f t h e orange form i n t h e f i r s t envelope r e c o r d s t h a t documents i n c l o t h i n g on body 134 belonged t o John Smith, t h e envelope c o n t a i n i n g t h e w h i t e form having a l l t h e d e t a i l s about John Smith, and perhaps o t h e r t h i n g s l i k e d e n t a l X-rays, would be s e l e c t e d from the p i l e of w h i t e forms (a r ranged f o r convenience i n a l p h a b e t i c a l o r d e r i n two sets, male and f ema le ) . wi th the con ' t en t s of John Smi th ' s i n fo rma t ion f o l d e r it w i l l p robably be p o s s i b l e t o f i n d quick ly s e v e r a l p i e c e s of conf i rmatory ev idence of a s p e c i f i c n a t u r e r a t h e r t han circum- s t a n t i a l n a t u r e ( a s i s p r o p e r t y ) . S c a r s desc r ibed as having been p r e s e n t on John Smith may correspond w i t h s c a r s no ted on body 134 and numerous p o i n t s of s i m i l a r i t y may be found i n t h e d e n t a l r eco rd of t h e body and t h e d e n t a l r eco rds of John Smith. Thus w i t h conf i rmatory evidence p e r m i t t i n g a f i r m conc lus ion t h a t body 134 is t h a t of John Smith, a l l r e c o r d s of body 134 and John Smith can be a t t a c h e d t o each o t h e r t o form a s i n g l e " f i l e " , of t h e com- p l e t e d i d e n t i f i c a t i o n .

From comparison of t h e r e c o r d s on t h e orange and b l u e forms of body 134

The b l u e and p ink forms have on t h e i r f a c e a small s k e l e t a l diagram. This is of g r e a t v a l u e i n c a s e s of m u t i l a t i o n w i t h va ry ing degrees of t r a u m a t i c amputation. s t a g e i n t h e examination fragmented p a r t s have t o be examined and as f a r as p o s s i b l e major fragments need t o be matched wi th t h e bod ies from which they o r i g i n a t e d . important i f t h e f ragments themselves b e a r c l u e s t o t h e i r i d e n t i t y (e.g. r i n g s o r a t a t t o o ) f o r t hese c l u e s may be t h e only ones t o t h e i d e n t i t y of t he body from which they came. Thus when i t becomes necessa ry t o match a forearm amputated j u s t above t h e elbow w i t h a body, t h e s e a r c h f o r t h e bodies t o b e re-examined f o r d e t a i l e d ana tomica l comparison can

A t some

This is e s p e c i a l l y

2 4 / 2 / 72 No. 2



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most speed i ly be seen i f r e f e r e n c e is made t o t h e s k e l e t a l diagrams where a missing p a r t can be ind ica t ed by an e n c i r c l i n g l i n e and t h e l e v e l of amputation by a s i n g l e s t r o k e of t h e pen. To g lance a t 200 diagrams through t r a n s p a r e n t f i l e c o v e r s t a k e s much less t i m e than reading 200, even b r i e f , d e s c r i p t i v e n o t e s , e s p e c i a l l y i f t h e s e are i n s i d e fo lded r e p o r t forms.

3. Summary of I d e n t i f i c a t i o n Methods

I d e n t i f i c a t i o n by r e l a t i v e s , f r i e n d s o r o t h e r persons t o whom deceased w a s known i n l i f e .

I d e n t i f i c a t i o n by p o l i c e and a n c i l l a r i e s .

I d e n t i f i c a t i o n by s p e c i a l i s t s who examine remains.

V i sua l Evidence (1) V i s u a l r e c o g n i t i o n of body

( r a r e l y p o s s i b l e i n modern a i r c r a f t d i s a s t e r )

( 2 ) Visua l r e c o g n i t i o n of p r o p e r t y (may be a t tempted i f o t h e r methods below f a i l o r are inconc l u s i v e )

Circums t a n t ia 1 Evidence (3) Loca t ion of t h e body

( 4 ) Clo th ing materials

(5) Contents of pockets

(6) J ewe l l e ry

S p e c i f i c Evidence Ordinary, body (7) I n d i c a t i o n s of s ex f e a t u r e s

(8) I n d i c a t i o n s of age

(9) S i z e

(10) Hair

Denta l ev idence (11) R e s t o r a t i o n s , E x t r a c t i o n s , P r o s t h e s e s , etc.

Unusual body f e a t u r e s (12) Scars, moles, s k i n d i s e a s e , etc.

(13) Occupat iona l marks

(14) T a t t o o marks

(15) F inge r p r i n t s

Spec ia l s i g n s tes ts (16) Presence of known pathology o r examinations

(17) Radiology

(18) Serology

2 4 / 2 / 7 2 No. 2



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APPENDIX 9.- I d e n t i f i c a t i o n of V i c t i m s 9-5

O1 SURNAME Op FIRST NAMES

I N T E R N A T I O N A L CRIMINAL POLICE O R G A N I Z A T I O N - I N T E R P O L 20, NO Armongaud. 02 - SAINT-CLOUD.. Franco

o3 S M M F o r I

IDENTIFICATION DATE OF THE DISASTER : PLACE :

I OB REUGION

I 07 ADDRESS

O9 EVER FINGERPRINTED? WHERE AND WHEN?

i o NAME, ADDRESS AND TELEPHONE NUMBER OF GRSON WHO CAN IDENTIFY

11. - (For completion only when Disaster Victim Identification Form Is used to detail dercriptlon of d.wU.d vlctim of dlsutor).

M REFERENCE No. 104 PROBABLE AGE I OB TIME AND DATE OF DISCOVERY I o3 SEX

I I O5 LOCATION OF BODY AT DISASTER

O6 CONDITION OF THE BODY (Intact, dirloc.1.d limbs, disfigured).

07 NAME, ADDRESSAND OCCUPATION OF THE PERSON WHO FOUND THE BODY

111. - (For completion always whon Disaster Victim Identification Form is used to detail description of m lu lng porson

PHYSICAL: or docoasd v l d m of d1out.r).

02 HEIGHT o3 WEIGHT O4 BUILD 05 COMPLEXION 07 SPECTACLES I l I I O1 COLOUR

I I I I I I O8 COLOUR OF HAIR AND PECULIARITIES (Dyed, long, short. straight, curly, receding from forehead, bald):

09 NOSE (Size, shape, pscullaritlor):

10 EARS (Size, shape, type of l o h ) :

11 MOUTH AND LIPS (Size, shop.):

12 SCARS AND PECULIARITIES ON FACE:

2 4 / 2 / 7 2 No. 2 Copyright International Civil Aviation Organization


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13 T E U H (Good, bad, clun, dircolourod, unovrn, largo, omall. wldoly rpoced, protruding, artiflcial):

14 NAME. ADDRESS AND TELEPHONE NUMBER OF DENTIST WHO PERFORMED DENTAL WORK (for dosing persons):

15 ARE DENTAL CHARTS AND DENTAL X-RAYS AND/OR DENTAL PLATE IDENTIFICATION NUMBERS (for miering p.nono) A V A I U W

10 PARTICULAR MARKS AND SCARS ON BODY (Ddormltkr, opamtion ran, tatoo marka, moles, vaccination marka, perforation of oar l o h . birîhmarka):

17 EXTREMITIES (Amputdionr, callour fomutionr, nail deformith):

18 BLOOD GROUP:

19 NAME. ADDRESS AND TELEPHONE NUMBER OF FAMILY DOCTOR:

Note: s.cobn 111 may bo comphîed by any diagrams or X-Raya which might be of orsirtance in identification.

ODONTOGRAM UPPER

16 15 14 13 12 11 21 22 23 24 26 26 27 20

40 47 46 46 44 43 42 41 31 32 33 34 36 36 37 30 LOWER

Tho odontognm rhould bo HIIod In by a dontiit ; any nocorsary technical erplanatlonr may be,glven below.

NAME:

ADDRESS:

24/2/ 72 No. 2



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APPENDIX 9.- Identification of Victims 9- 7

IV. - (For completion rlwrya whon Dlrarîor V l d m idontitleation Form Ir u r d to dotall dorcriptlon of mining p.m or doc& v l d m of diaador).

O1 CLOTHING:

02 UNDERCLOTHING:

09 ACCESSORIES:

04 DRY CLEANING AND LAUNDRY MARKS OR OTHER IDENTIFIABLE MARKS ON CLOTHING:

O5 JEWELLERY:

8 DOCUMENTS:

07 MONEY:

08 MISCELLANEOUS:

rom Inrtructlon rh-1 on how to complota tho form

09 FINGERPRINTS

10 PHOTOGRAPHS

11 DENTAL OR OTHER X-RAYS:

24/2/72 No. 2



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~~ ~

v. - ADDITIONAL INFORMATION (For compktlon dmp whon Dluatu Vldlm Idonîlflcrtion Form is uaed to detall description of midng pomon or doco...d victlm of dludw) .

VI. - IDENTIFICATION

(For completion only when Disaster Victim Identification Form is used to detail description of doca..d victim of diruter).

DECEASED VICTIM OF DISASTER IDENTIFIED AS: I O1 REFERENCE No:

O2 SURNAME:

03 FIRST NAMES:

04 ADDRESS: 05 CAUSE OF DEATH:

I OB METHOD OF IDENTIFICATION:

07 OUALIFIED DOCTOR OR AUTHORITIES MAKING THE IDENTIFICATION:

LIAME (Print):

DESIGNATION:

ADDRESS:-

DATE AND SIGNATURE:

24/2/72 No. 2



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APPENDIX 9.- Identification of Victims 9- 9

DISASTER VICTIM IDENTIFICATION FORM INSTRUCTIONS ON HOW TO FILL OUT THE FORM

PURPOSE OF COW:

l h e p r ron t form is msant to bo usad ifbr dlrut .n in order to: - Rocord informition about an unidonüflod body. --Rocard information about a misring m o n .

One form ahouid be compktod tos weh vlcîim found at the scene of ihm dlruter (Sections II. 111, IV, V, VI). Wherewr possibk, the arrirtance of an InsiRute of Forenslc Medlclne, Odontology or Pathology, a police pathology k b or, faillng thir, a horpltai physlclan or other practltioner should be sought.

Another’copy of the form should be completed for u c h mluln pmon bellevad to bo a victlm of the dirastar (Soctionr i, Ili. IV, V). Dotaiid doscrlptlono must be obtalned from re?ativer, friends, doctors and dentlsh in order to compieta the form accurritriy and fully.

The victlms can then be identidad by correlating the two copbs of the form.

GENERAL RULES TO BE OBSmVED FOR EACH VICT1Y

Removo inlumd and gim thwn A n t aid.

Do not move any of the bodlea until ail Inquiries and examinationa whlch can be made on, the rpot have b r n

Determine and record the posltian of onch body.

Do not touch any wreckage, human remaina or property until ail evidence that mi ht aseist In the identification har been photographed or recorded, and even when the examlnation and idontifkation of t k victims is finished, do not touch any wreckage untli the compstrnt authoritier have completad their invertigatlona.

Collect all perronal porreeolons that may belong to the decearrsci and keep there with the remains to which they belong while they are being removed to the morgue. (if there is any doubt about whether a partlcuiar Item belongs to a certain body, it rhould be so indicated : an Incorrectly assigned Item could cause an error In Identlficatlon.)

Attach Immediateiy a tag carrying an identification number marked in Indelible ink to each corpse : the tag rhould be attached to the body itreif and not to a stretcher or to a blanket In which the remains have been wrapped.

compktad.

HOW TO COMPLETE THE FORM

The form conrista of SIX sectlons marked I, il, 111, IV, V. VI. For a missing person, sections I, I l i , IV, V, should be completed; for an unidentified body, sections II, ill, IV, V, Vi.

The form should be filled In accurately and carefully; an appurently minor detall may In fact prove to be vitally important.

Begln with victims who are easlly Identified.

I. - 03 Indicate the sex by marklng M F or I (indotwmlnite).

II. - O1 Reforonce number: Entr identiflcatlon number glvon on tag attached to corpse.

03 ber: If the genital organs ate burnt or otherwise unruognirable and examination of the pelvls glver no results,

O4 Apparent age: Valuable ciueo mlght be obtained from the brain, aorta, Internai viscera or - in the case of children -

ûtl Cordltbn of iba body: State whether it Is Intact, dlrfigured, whefher the limbs hare been dislocated or whether

other clues to the vlctlm’o oex rhould be sought.

oorlficntlon centras; an anthropometric examination mlght airo be of aome help.

It conslrtr of human remalns. 2 4 / 2 / 7 2 No. 2



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111. - O2 Height: An examination of the rholeton and the size and length of boner may provide useful information

08 Eyes: Indicate, if possible, colour, opaclty and any abnormalltles.

07 Spectaclor: Describe type, shape, etc., and mention if contad lenses were worn.

0s Hair: Describe hairstylo, colour and length of halr (.tato whether recently cut, whether curly, wav

abnut height. Further information rhould bo g i m on build, rt.ts of nutritlon and murck~r.

straight, dyed : indicate degree of baldnesr and whether worn combed back from the forehead). Note characteristics orhair on different parts of the body. Put spûclmenr In enveloper marked with body's identification number.

09 Mou: Shape, rlze and pocullarltks.

10 Lur: Shapo, a h and typa of labor.

11 Youth and Ilp.: Size, psculiarltler, shape of chin.

13 Tooth: Toath should be count4 (upper right, up r left. lower right, lower left) and thoro misrlng, as well as an cavities or fillings (and material used) noted. State whetcr In good or bad condition, lar e or omall, clwn or dlscolourek uneven, widely spaced. artlficlal, protrudlng, etc. Remove any dentureo and mark with tRe numbor of the corpse. In the case of children, the development of the tooth rhould bo ..tibllrhd.

16 Muks and run on "y: Deformltler. oporatlon rcarr. tittoon (dercrlk cardully and photograph If possible), moles, vaccination marho, pierced ur., birthmarks, etc. Dercrlbe any pocullarltlea: type, appearance, alze and locatlon.

17 Irb.mitier: Amputationr, old fncturn, bone deformltler. nalls (bitten?), callous formatlon on hrndr or feet, corns, cccupîional deformitlar.

16 Blood group: In addition to traditional methods, fragments may be identified by establirhlng their blood groups. Sufflclentl preserved red corpuscles and blood samples am often recovered in blood vesrelr of the deep muscle layers ot tirsue gagmanto.

body) which reveal peculiarities !cible to be of assistance in identification.

- Note: The present form may be com lasd by any dlagramr or X-rays (head or body of corpse, profile, front or back views of

IV. - O1 Clothlng: The colour, cloth, shape and make of clothing should be noted. All available information about the items listed below should be given (in the same order): head ear, overcoat, suit or drerr, Jacket or knitwear, trousers or skirt, shirt or blouse, tie or fur plece, socks or stockingr. All ftems In this rection should be described accurately (and photographed if necessary). It is very im ortant to keep the Item8 In separate envelopes specially desi nod for this purpose and to mark the envelopes with the numgor of the corpse to which they belong. Samples of materia! should be stuck on paper or cardboard and marked with the corpse number. In cases where victims have been burnt, pieces of clothin might

e found under armpits. in the cruîch or other places whlch have been lesa exposed to fire. Even on badly-burnt %odies, a belt may have protected laundry marks on clothing from the full effect of the fire.

O2 Undorclothlng: vest or sweat-ihirt, petticoat, underpants. etc.

O3 Accerrories: shoes, ocad, glover, handbag, bracer, bolta, garters.

O4 Laundry and dry cleaning muka 8nd other IdontMaMo mark. on clothlng: Plwse note names. monograms, laundry marks, size tags and manufacturers' labels.

05 Jewollery, rlngr, watches, keya: Describe in great detail ; if the body has been badly burnt, look for these articles in the vicinity. Only assign them to the corpu when there Is no doubt wh8troevei that they belong.

00 Documents: Draw up a complete list of the contento of pockets, handbag and wallet.

07 Money: Draw up a complete list (coins, cheques).

08 Mi~collaneour: Various items such as luggage, cameras, tape recordera, badges, decorations, etc., should be included here.

O9 Fingerprint.: If ossible, the fingerprints of each corpse should be taken and recorded on a fingerprint card. i h e fingers of each hand slould be numbered as follows: thumb = 1 ; index finger i. 2; third fingsr - 3 ; ring finger = 4 ; little finger - 5. Mark corpse number on card.

10 Photographs: Photographs should be taken full-face ; In addition, photographr taken from other angles and a fuil- length photograph of the body may be included. All photographe should be marked with the corpse number.

11 Dental or other X-ray. may be attached hera.

V. - Any peculiarities not provided for in the form rhould be mentioned in this sectlon. Any instructions from nextof-kin concerning disposal of the body and of the victlm's possessions should also be mentioned here.

Each airline should designate a firm of undertakers to be summon3d in the event of an accident. - Note: The coffin must bear the corpre identification number.

VI. - Presents no difficulties.

2 4 / 2 / 7 2 Na. 2



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APPENDIX 9.- I d e n t i f i c a t i o n of Vict ims 9-11

Any obvious visual characteristics

FATAL AIRCRAFT ACCIDENT VICTIM IDENTIFICATION AND AUTOPSY FORM

Extent of burning

M.1.

Aircraft Reg. No: Body No:

Date of Examination: Pathologist: Sex: MALE

identified as:

Means of identification: Primary: Confirmatory :

EXTERNAL EXAM I NATION

Visual

Dental Estimated age:

if measured Weight: I Height: Body build: I

Degree of obesity: Moustache

1 1- Hair: Colmii of skin:

Nails i Caiocir I

External scars, skin niarks/tumours, etc.

Circumcised: Yes/No/Uncertain

Surgical Testes: Present/Single/ /Traumatically missing Removal

Scalp Vault of Skull

Face I Chest

l Abdomen

~

L. Arm

L.. Lec

FOR USE IN CASES OF MUTILATION

Summary:

Humeral Heads: L Femoral Heads: L Hands:

I

L L L



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Brain and Meninges

Base of skull .

Sternum

Ribs

Body No: INTERNAL EXAM INATION

Clavicles

L t R t

Appendix

Kidneys

Spine

Present/Surgical removal/

Lt R t

Gall Bladder: Present/Surgical removal/ Traumatically missing Traumatically missing

Pelvis

Pleural space

Oesophagus

Lungs

Pericardium and heart

Aorta

Diaphragm

Stomach

Peritoneum and mesentery

I Intestines

Liver

Spleen

Other Organs

SPECIMENS TAKEN:

Histology Yes/No

Toxicology Yes/No

24/2/72 No. 2

CAUSE OF DEATH AND REMARKS:



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.APPENDIX 9.- Identification of Victims 9-13

FATAL AIRCRAFT ACCIDENT VICTIM IDENTIFICATION AND AUTOPSY FORM M.2.

Date of Examination: Body No:

Examiner: Sex : MALE

CLOTHING

Outer Garments:

Under Garments:

JEWELLERY

__- __

OTHER EFFECTS (Wallets, documents, etc)

2 4 / 2 / 7 2 No. 2



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9- 1 4 Planual of A i r c r a f t Acc.ident I n v e s t i g a t i o n

DENTAL EXAMINATION

Body No: -- Date of Examination: Examiner:

-

II 11 n 7 n 22

-

n 2b -T

2 5 2 6

-

n

1 Prostheses, Orthodontics, etc.

b3 b? 1 Malformations, Oral Abnormalities, etc.

Dental Estimates of Age, Sex, Race, etc.

2 4 / 2 / 7 2 No. 2



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APPENDIX 9.- I d e n t i f í c a t i o n of V i c t i m s 9-15

Estimated age: Dental

---_--l_l--. .

FATAL AIRCRAFT ACCIDENT VICTIM IDENTIFICATION AND AUTOPSY FORM F.1.

Weight: Height:

Aircraft Fìeg. No: Body NO:

Length Hair: 7 Colour

Colour of skin:

Ears: Pierced I Not pierced

Date of Examination:

Lipstick:

Nail varnish:

~

Pathologist: Sex: FEMALE

Identified as:

Means of identification: Primary: Confirmatory:

EXTERNAL EXAMINATION

Body build:

Degree of obesity:

External scars, skin markshmours. etc.

~~ ~

Any obvious visual characteristics

~~

Extent of burning I I

Breasts

I Scalp 1 Vault of Skull

Face

Chest

Abdomen

Back

L. Arm

R. Arm

L. Leg

R . Leg

I

FOR USE IN CASES OF MUTILATION

Summary:

Humeral Heads: L Femoral Heads: L Hands: L

L t

24_/2/72 No. 2



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#

PresentBurgical removal/ Traumatically missing

Present/Total

Traumatically missing

hysterectomy/ Sub-total

9-16 Manual of Aircraf t Accident Inves t iga t ion

Gall Bladder: Present/Surgical removal/ Traumatically missing

Ovaries: Present/Single/Surgical removal/ Traumatically missing

. . .*

Brain and Meninges

Base of skull

Sternum

~

Ribs

Spine

Pelvis

Pleural space

Oesophagus

Lungs

Pericardium and heart

Aorta

Diaphragm

Stomach

Peritoneum and mesentery

Intestines

Liver

Spleen

Appendix

Uterus

Kidneys

Other Organs

INTERNAL EXAMINATION Body No:

Clavicles

Lt R t

SPECIMENS TAKEN:

Histology Yes/No

Toxicology Yes/No

24/2/72 No. 2

CAUSE OF DEATH AND REMARKS:



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9-1 7 - - - ____. . . _. -. - APPENDIX 9.- I d e n t i f i c a t i o n of Victims

FATALAIRSRIF T ACCIDENT VICTIM IDENTIFICATION AND AUSOP?Y_FOHY F.2.

Body No:

Exdmi i ier : Sex: FEMALE ..-----..-_I-. _I_.__

CLOTHING

Oii!er Cimnerits:

t

LEW E L LE R Y

- OTHER EFFECTS (Handbag, documents, etc.)

2 4 / 2 / 7 2 Na. 2



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9-18 Phiilia 1 of A i r c r a f t Ace iderit 1 i i~vc.sL igii t ion

DENTAL EXAMINATION

Bodv No: . - . . .. ... .. .. Date of Examination: Examiner: -_____ - ~ -

.I7 II I I

__

21 23 I

22

__._ . . -

!

25 m 21 28

55 5( Y 52 51

I S e4 W 67 81 R I G H T

61 hP

L E T T 7 1 n 73 14 li

48 41

Prostheses, Orthodontics. etc

45 32

Ma If o r m a t ions, Oi a I A brior m a I it ¡es, etc ,

Dental Estimates of Age, Sex, Race, etc.

2 4 / 2 / 7 2 No. 2



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APPENDIX 9.- Identification of Victims 9-19 ..,

FATAL AIRCRAFT ACCIDENT VICTIM IDENTIFICATION AND AUTOPSY FORM

Accident t o Aircraft Reg. No: Surname: Body No:

Mr/Mrs/M iss/l nf

REGISTRATION PARTICULARS

1. 2. 3. 4.

9. 1 o. 11.

Forenames Date of Birth Place of Birth Usual Residence

Father's Name Mother's Name Husband's Name

5. Religion 6. Profession 7. Nationality 8. MarriedlSingle

Profession

Profession Place of Birth

Nationality Nationality Nationality

12. AVAILABLE NEXTOF KIN

Name in full:

Address:

Relationship:

Telephone:

13. OTHER CONTACTS

a) Solicitors b) Dentist c) Doctor d) Others

requested Dental chart obtained

sent to Field Team

~

IDENTIFICATION PARTICULARS

14. Build: Height: Weight:

15. Race: 16. Colour of eyes:

17. Colour and peculiarities of hair:

19. Nails peculiarities. varnished or bitten:

18. Moustache - YeJIYo Beard - Yes/No

20. Ears pierced - Yes/No

21. Scars or missing parts:

22. Tattoos: 23. Circumcision - Yes/No

24. Moles or other identifying marks:

Obesity:

25. Medical history (e.g. operations, non-surgical illnesses, broken bones, etc.)

2 4 / 2 / 7 2 No. 2



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26. LIKELY CLOTHING a) Outer Garments:

26

36

b) Under Garments:

27

37

27. LIKELY JEWELLERY

28. LIKELY CONTENTS OF POCKETS

29. DENTAL INFORMATION (when telephoned or telexed). Not used if original records available.

Right 18 - - 48

16 - - 46

15 55

85 45

- -

-

14 54

84 44

- -

-

30. DISPOSAL: Cremation Local/Repatriation

Burial Local/Repatriation

Country for repatriation:

12 52

82 42

- - Left

2 4 / 2 / 7 2 No. 2



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MNUAL OF AIRCRAFT ACCIDENT INVESTIGATION

APPENDIX 10

IN-FLIGHT BREAKUP



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APPENDIX 10.- I n - f l i g h t Breakup 10-1

APPENDIX 10

IN-FLIGHT BREAKUP

1. General

I n - f l i g h t s e p a r a t i o n s are u s u a l l y t h e r e s u l t of metal f a t i g u e , improper des ign , or aerodynamic loading.

I n determining t h e sequence of e v e n t s of t h e b reak ing , t h e b reaks or separa- t i o n s must be s p e c i f i e d as t o which i s primary, secondary, t e r t i a r y , etc. cons ide r a s i n g l e r o t o r h e l i c o p t e r i n which a p i t c h l i n k broke on one b l a d e - t h e primary s e p a r a t i o n . r o t o r t hen f e l l t o t h e ground, and a b l a d e broke i n a n area where a f a t i g u e c rack w a s p r e s e n t - t h e t e r t i a r y break i n t h e sequence. be thoroughly i n v e s t i g a t e d , i t must be p l aced i n i t s proper p e r s p e c t i v e r e l a t i v e t o t h e e n t i r e breakup p a t t e r n .

For example,

T h e - r o t o r b l ade then c u t t h e t a i l boom o f f - a secondary s e p a r a t i o n . The t a i l

Although t h e cause of t h e f a t i g u e zone must

An a i r c r a f t i n - f l i g h t breakup is a n e v e n t u a l i n c o m p a t i b i l i t y between t h e a p p l i e d aerodynamic load and t h e l o a d s u s t a i n i n g c a p a b i l i t i e s of . t h e s t r u c t u r e . p rope r ly i n - f l i g h t s t r u c t u r a l s e p a r a t i o n s , a working knowledge of aerodynamics and s t r u c t u r a l eng inee r ing is d e s i r a b l e f o r t h e a i r c r a f t a c c i d e n t i n v e s t i g a t o r .

To a n a l y s e

I n t h e s u b j e c t of aerodynamics t h e r e should be f a m i l i a r i t y w i t h t h e g u s t and manoeuvring load equa t ions , s t a b i l i t y and c o n t r o l , a i r f o i l p i t c h i n g moments, and centre of p r e s s u r e v e r s u s ang le of a t t a c k . a u t o p i l o t i n p u t s , c o n t r o l s u r f a c e b a l a n c e , boundary f e n c e s , v o r t e x g e n e r a t o r s , l e a d i n g and t r a i l i n g edge s l o t s and f l a p s , and s e r v o and a n t i s e r v o t a b s .

There should be a knowledge of f l i g h t c o n t r o l des ign ,

On t h e s u b j e c t o f s t r u c t u r e s t h e r e should be an i n t i m a t e f a m i l i a r i t y w i t h c o n s t r u c t i o n t echn iques a s w e l l a s a n unde r s t and ing from a p r a c t i c a l a s p e c t t h e meaning of moment of i n e r t i a , s e c t i o n modulus, and e las t ic a x i s . t h e e q u a t i o n s of stress d e a l i n g w i t h t e n s i o n , compression, bending, s h e a r , and t o r s i o n .

There should. be a f a m i l i a r i t y w i t h

2. Analysis .

To be a b l e t o a n a l y s e a n i n - f l i g h t breakup, it f i r s t must be c l e a r l y understood how an a i r c r a f t is aerodynamical ly loaded i n i t s normal c o n f i g u r a t i o n . Reference is made t o F igu re 10-1. It must be remembered t h a t an a i r c r a f t r o t a t e s around t h e c e n t r e of g r a v i t y , and t h e c e n t r e of g r a v i t y is l o c a t e d i n c l o s e proximity t o t h e q u a r t e r chord p o i n t of t h e mean aerodynamic chord. The c e n t r e of g r a v i t y i n t h i s i l l u s t r a t i o n may be assumed t o be i n t h e c e n t r e of t h e a i r c r a f t and i n t h e area of t h e s p a r o u t l i n e . The arrow under t h e engine r e p r e s e n t s t h e weight of a l l i t e m s ahead of t h e C.G. ( c e n t r e of g r a v i t y ) , and t h e arrow under t h e a f t f u s e l a g e r e p r e s e n t s t h e weight of a l l i t e m s a f t of t h e C.G.. The sum of t h e moments of t h e s e two f o r c e s around t h e C.G., i n a d d i t i o n t o t h e wing p i t c h i n g moment, i f i t is a cambered a i r f o i l , w i l l r e s u l t i n a nosedown p i t c h . T h i s r e s u l t a n t nosedown p i t c h i s prevented by a download on t h e t a i l . Th i s download then b r i n g s t h e p i t c h i n g moment t o z e r o , and may be cons ide red a s t h a t b a l a n c i n g f o r c e which places t h e a i r c r a f t i n a s ta te of e q u i l i b r i u m a s f a r a s p i t c h i n g moments are concerned. The summation of v e r t i c a l f o r c e s , a s w e l l a s h o r i z o n t a l f o r c e s , must e q u a l z e r o i f a s t a t e of e q u i l i b r i u m is t o e x i s t . I n cons ide r ing t h e v e r t i c a l l o a d s , t h e t w o l a r g e arrows under t h e a i r c r a f t r e p r e s e n t t h e t o t a l



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weight of t h e a i r c r a f t m u l t i p l i e d by t h e e x i s t i n g load f a c t o r , p l u s the download on t h e h o r i z o n t a l t a i l , r e p r e s e n t t h e t o t a l down foi-ce, and t h i s i n t u r n m u s t be brought t o ze ro by an e q u a l up f o r c e , which i s t h e l i f t of t h e wiLig.

These ct»T.:nward f o r c e s ,

I t must be remembered a t t h i s t i m e t h a t i f t h e t o t a l weight exceeds th.. l i f t , o r t he t o t a l l i f t exceeds t h e weight, t h e r e w i l l be an a c c e l e r a t i o n i n t h e d i r e c t i o n of t h e g r e a t e r fo rce . f o r c e s , p a r t i c u l a r l y t h r u s t and drag, i n t h i s i l l u s t r a t i o n . a f t fo rces . The l a t e r a l o r l e f t and r i g h t f o r c e s can be of major importance i n i n - f l i g h t breakup i f a yaw c o n d i t i o n e x i s t s . t h e d i f f e r e n t i a l i n wing drag.

This i s an important f a c t o r when c o n s i d e r i n g t h e summation of h o r i z o n t a l These would be t h e f o r e and

Severe yaw i s p r e s e n t a f t e r t h e l o s s of a wing, due t o

Assuming t h a t there is no yaw i n t h i s case, t h e v e r t i c a l f o r c e s , l i f t and weight, and t h e h o r i z o n t a l f o r c e s , t h r u s t and drag, must be analysed.

I f , f o r example, a p i l o t l o s e s c o n t r o l of a n a i r c r a f t i n weather , and t h e a i r c r a f t e n t e r s a s p i r a l , t h e t h r u s t w i l l exceed t h e drag. This w i l l be t r u e whether t h e powerplant i s a t f u l l t h r o t t l e or a t i d l e , f o r t h e weight of the a i r c r a f t , depending upon t h e nosedown a t t i t u d e , can f a r outweigh t h e t h r u s t of t h e powerplant. This w i l l be t r u e u n t i l t h e a i r c r a f t a t t a i n s a v e l o c i t y such t h a t t h e drag e q u a l s t h e t h r u s t . Th i s w i l l be t e r m i n a l v e l o c i t y f o r t h a t p a r t i c u l a r nosedown p i t c h a t t i t u d e . v e l o c i t y of an a i r c r a f t , means t h e maximum v e l o c i t y a t t a i n e d i n a nosedown a t t i t u d e such t h a t t h e f l i g h t p a t h is toward t h e c e n t r e of t h e e a r t h .

The s p e c i f i c term, terminal

The modern c i v i l a i r c r a f t is so c l e a n aerodynamical ly t h a t t o test i t f o r a t e r m i n a l v e l o c i t y would r e s u l t i n d e s t r u c t i v e a i r s p e e d s . This v e l o c i t y h a s no p r a c t i c a l v a l u e and i s not a des ign requirement. Unfor tuna te ly , however, t h e a i r s a f e t y i n v e s t i g a t o r w i l l become involved i n a i r c r a f t a c c i d e n t s where t h e a i r c r a f t h a s been subjec ted t o air- speeds f a r i n e x c e s s of t hose f o r which i t w a s designed. This h igh speed f l i g h t regime is g e n e r a l l y encountered i n a c c i d e n t s involv ing l o s s of c o n t r o l d u r i n g f l i g h t by r e f e r e n c e t o i n s t r umen t s.

I n s tudying Figure 10-1, under a h igh v e l o c i t y f l i g h t regime, i f back e l e v a t o r p r e s s u r e is a p p l i e d , t h e "g" f o r c e s i n c r e a s e as w e l l a s t h e h o r i z o n t a l t a i l download.

I f t h e a i r c r a f t h a s a cambered a i r f o i l (no t symmetr ical) , t h e nosedown p i t c h - i ng moment i n c r e a s e s as t h e square of t h e v e l o c i t y . download on t h e t a i l . a l s o reacts t o t h e square of t h e v e l o c i t y . s t a r t t o p i t c h up f o r s t a b i l i t y reasons. I f t h e a i r c r a f t is i n a s p i r a l , t h i s p i tchup a b i l i t y of t h e h o r i z o n t a l t a i l t h e n merely t e n d s t o t i g h t e n t h e s p i r a l .

Th i s f a c t a l s o r e q u i r e s a l a r g e r Th i s download c a p a b i l i t y of t h e t a i l is e a s i l y acqu i r ed , s i n c e i t

It i s designed t h i s way t o cause t h e nose t o

The stresses must now be s t u d i e d . The t o p s k i n of t h e h o r i z o n t a l t a i l ( s t a b i l i z e r o r s t a b i l a t o r ) i s under a t e n s i l e stress wi th t h e corresponding compressive stress on t h e bottom. h o r i z o n t a l t a i l download is d e f l e c t e d upward, and t h e r e is t e n s i l e stress on t h e bottom s k i n s u r f a c e s and compressive stresses on t h e t o p s k i n s u r f a c e s .

The wing i n suppor t ing t h e h igh "g" l o a d s as w e l l a s t h e l a r g e

S ince t h e f u s e l a g e i s supported i n t h e area of t h e C . G . , t h e r e is a maximum bending moment a t t h e C.G. in a tensi le stress, and t h e r e f o r e t h e bottom of t h e f u s e l a g e i s under a compressive stress.

Th i s p l a c e s t h e top of t h e f u s e l a g e (above t h e n e u t r a l a x i s )



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APPENDIX 10.- I n - f l i g h t Breakup 10- 3

The q u e s t i o n now is, "What can break?" The f u s e l a g e could break anywhere a long i t s l e n g t h , f o r i t must be v i s u a l i z e d as a bending beam suppor t ed only a t t h e wing. Fuselage b reak ing i s r a t h e r uncommon i n t h e medium-to-small s i z e g e n e r a l a v i a t i o n a i r c r a f t . However, i t h a s occur red , and can a g a i n occur , i n l a r g e t r a n s p o r t and bomber type a i r c r a f t .

There are two o t h e r areas where t h e s t r u c t u r e w i l l normal ly s e p a r a t e o r break. These are t h e wing and t h e h o r i z o n t a l t a i l .

The f i r s t c o n s i d e r a t i o n is t h a t of t h e wing s e p a r a t i n g f i r s t , as shown i n A s t h e wing b reaks , t h e a i r c r a f t i s i n s t a n t a n e o u s l y changed from a s ta te of F igure 10-2.

e q u i l i b r i u m t o one of disequi l ibr ium,part icular ly as far as moments of r o l l are concerned. The r i g h t wing wi th i t s high l i f t v a l u e s w i l l v i o l e n t l y r o l l t h e a i r c r a f t t o t h e l e f t , whi le t h e l e f t wing, which a l s o posses sed t h i s l a r g e p o s i t i v e l i f t , w i l l r o l l t o t h e r i g h t over t h e fuse l age .

In s tudy ing F igu re 10-3, i t is q u i t e common t o f i n d a t t h e a c c i d e n t s i te t h a t t h e sepa ra t ed wing h a s damaged o r comple te ly severed t h e t a i l of t h e a i r c r a f t .

A s tudy of t h e wing pr imary s t r u c t u r a l b reaks , and a n e lementary mock-up a t t h e s i t e , w i l l conf i rm t h i s t ype of breakup. Bear i n mind t h a t t h e remainder of t h e air- c r a f t may be demolished o r burned t h e r e b y i n c r e a s i n g t h e deg ree of d i f f i c u l t y i n o b t a i n i n g t h e evidence.

There are two impor tan t f a c t s t h a t t h e i n v e s t i g a t o r must r e a l i z e f o r t h i s type of breakup. F i r s t , t h e h o r i z o n t a l t a i l must have been on t h e a i r c r a f t i n o r d e r t o gene ra t e t h e h igh "g" l o a d s n e c e s s a r y t o cause a p o s i t i v e wing s e p a r a t i o n , and second, h i g h speed f l i g h t w a s involved . (Some a i r s p e e d w e l l over V., o r manoeuvring speed.)

I n t h e nex t common t y p e of i n - f l i g h t s e p a r a t i o n , r e f e r e n c e is made t o F igu res 10-1 and 10-4. The a i r c r a f t is loaded normally as i n F i g u r e 10-1 and e i t h e r t h e wing w i l l b reak upwards o r t h e t a i l w i l l b reak , normally downwards. The manner i n which t h e h o r i z o n t a l t a i l s e p a r a t e s is a matter of p i l o t t echnique o r c o n t r o l i npu t . There have been p o s i t i v e s t a b i l i z e r s e p a r a t i o n s , bu t t h e s e are r a t h e r rare. These are of t h e s t a b i l i z e r - e l e v a t o r combination h o r i z o n t a l t a i l i n which t h e p i l o t a p p l i e s such a v i o l e n t download t o t h e e l e v a t o r h inge l i n e ( e x c e s s i v e c o n t r o l back p r e s s u r e ) t h a t i t i n t u r n t w i s t s t h e l e a d i n g edge of t h e s t a b i l i z e r up around t h e e l a s t i c a x i s of t h e s t a b i l i z e r . The t o r s i o n a l d e f l e c t i o n i s maximum a t t h e s t a b i l i z e r t i p s , and z e r o where t h e s t a b i l i z e r a t t a c h e s t o t h e f u s e l a g e .

Rega rd le s s of how t h e h o r i z o n t a l t a i l is s e p a r a t e d , t h e a i r c r a f t w i l l respond I t w i l l p i t c h v i o l e n t l y nose down as shown by t h e curved ar rows , as shown i n F igu re 10-4.

t h e wing w i l l encounter a h igh n e g a t i v e a n g l e of a t t a c k as shown by t h e loading arrows under t h e wing, and t h e i n e r t i a of t h e a i r c r a f t w i l l be i n t h e d i r e c t i o n as shown by t h e l a r g e s t arrow.

The r e s u l t a n t s e p a r a t i o n is shown i n F igu re 10-5, i n which t h e wing i n c u r s a nega t ive s e p a r a t i o n . The i n v e s t i g a t o r need not be s u r p r i s e d t o f i n d permanent set i n t h e wings from p o s i t i v e load ing , o r c o n t r a r y t o t h e d i r e c t i o n i n which t h e wing sepa ra t ed . It must be remembered t h a t be fo re t h e h o r i z o n t a l t a i l s e p a r a t e d i t w a s s u b j e c t i n g t h e wing t o h igh p o s i t i v e t 'g 'st i i n an e f f o r t t o b reak t h e wing upward. When t h e t a i l s e p a r a t e d , t h e wing w a s i n s t a n t l y loaded i n t h e r e v e r s e d i r e c t i o n , and t h i s l oad ing does not remove a l l of t h e p o s i t i v e loading permanent set .



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The i n v e s t i g a t o r must v i s u a l i z e the wing, t a i l and f u s e l a g e combination as a wouiid c lock sp r ing . The f a s t e r t h e a i r c r a f t i s flown, t h e t i -gh te r t h e s p r i n g i s wound, and when some s t r u c t u r a l member of t h i s combination breaks i t is equ iva len t t o suddenly r e l e a s i n g the sp r ing . It is a l s o analogous t o a bomb exploding , f o r t h e s t r u c t u r e pos- s e s s e s a h i g h degree of p o t e n t i a l energy, and when i t s e p a r a t e s t h e r e is a g r e a t d e a l of no i se genera ted as t h e r e s u l t of energy r e l e a s e . Th i s is t h e r eason a wi tnes s t o an in- f l i g h t s e p a r a t i o n w i l l r e p o r t t h a t t h e a i r c r a f t exploded. He h e a r s t h e n o i s e a s an explo- s i o n , and h i s imagina t ion w i l l then add f i r e and smoke, a l though t h e wreckage is f r e e from soot and burning evidence a t t h e acc iden t s i t e .

It must be borne i n mind t h a t an i n - f l i g h t s e p a r a t i o n of t h e primary s t r u c t u r e is always a shor t - t ime- in t e rva l even t , a matter of seconds, o r f r a c t i o n s of seconds.

There must be no guessing o r assuming i n t h e s tudy of an i n - f l i g h t breakup. Keep i n mind t h a t t h e a i r c r a f t obeys t h e l a w s of phys i c s j u s t a s p r e c i s e l y dur ing breakup as i t does dur ing normal f l i g h t . There should be no mystery about i t , y e t on t h e o t h e r hand, de te rmina t ion of t h e breakup sequence i s no t accomplished i n two minutes a t t h e acc iden t site: i t may r e q u i r e many hours of i n v e s t i g a t i o n and a n a l y s i s of t h e evidence.



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APPENDIX 10.-

In-flig

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Breakup

10-5


ivil Aviation O

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AO

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APPENDIX 10.- In

-fligh

t Breakup

10-7


ivil Aviation O

rganization P

rovided by IHS


AO

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APPENDIX 10.- In-flight

Breakup

10-9


ivil Aviation O

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w w x OF AIRCRAFT ACCIDENT INVESTIGATION

APPENDIX 11

MID-AIR CCLLISICF4 ANALYSIS



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APPENDIX 11.- Mid-air C o l l i s i o n Ana lys i s 11-1

APPENDIX 11

MID-AIR COLLISION ANALYSIS

1. General

When two a i r c r a f t c o l l i d e , s i g n i f i c a n t marks are u s u a l l y l e f t on each a i r - c r a f t . An examinat ion of t hese marks w i l l r e v e a l many f a c t s t o t h e i n v e s t i g a t o r , and àn i n t e r p r e t a t i o n of t h e s e f a c t s w i l l e n a b l e a more comprehensive a n a l y s i s .

C e r t a i n f a c t s are normal ly l ea rned by a n i n v e s t i g a t o r about t h e a c t i o n s of a t least one, and q u i t e o f t e n bo th , a i r c r a f t p r i o r t o c o l l i s i o n , Such in fo rma t ion i n c l u d e s p o s i t i o n s , times over known f i x e s , f l i g h t p l a n , t r u e a i r s p e e d s , and ground speeds , w i t n e s s obse rva t ions , e t c . I t i s important t o c o r r e l a t e t h i s in format ion wi th t h a t ob ta ined from t h e examinat ion of t h e wreckage.

I n many c o l l i s i o n a c c i d e n t s , c e r t a i n f a c t s may be a v a i l a b l e on one a i r c r a f t but no t on t h e o t h e r . The e v a l u a t i o n of t h e s c r a t c h marks i s t h e only way t o de te rmine these unknown f a c t s . For example, i f t h e speed of one a i r c r a f t is known, the speed of t h e o t h e r can be determined. Examination of t h e d i r e c t i o n of t h e s c r a t c h marks a i d s i n d e t e r - mining whether t h e a i r c r a f t were l e v e l , c l imbing , descending, head-on, e tc .

The fo l lowing pages t rea t one f a c e t of t h e mid-air c o l l i s i o n problem mathe- ma t i ca l ly and g r a p h i c a l l y i n o r d e r t o provide t h e i n v e s t i g a t o r w i th y e t a n o t h e r t o o l i n t h e never-ending sea rch f o r t h e of t en t imes e l u s i v e probable cause , thereby f u r t h e r promoting a v i a t i o n sa€ e t y through a c c i d e n t p reven t ion .

2. Poss ib l e Pa ths of C o l l i d i n g A i r c r a f t

Both a i r c r a f t i n level f l i g h t .

Both a i r c r a f t c l imbing .

Both a i r c r a f t l e t t i n g down.

One a i r c r a f t l e v e l , one a i r c r a f t c l imbing.

One a i r c r a f t l e v e l , one a i r c r a f t l e t t i n g down.

One a i r c r a f t c l imb ing , one a i r c r a f t l e t t i n g down.

I n a l l of t h e fo rego ing c a s e s , t he a i r c r a f t may o r may n o t be a t t h e same speed.

I n a l l of t h e above c a s e s , t h e f l i g h t pa ths of t h e a i r c r a f t may be d i r e c t l y head-on, a t an obtuse a n g l e , a r i g h t a n g l e , an a c u t e a n g l e , o r d i r e c t l y ove r t ak ing . (Note: I n a d i r e c t l y ove r tqk ing a n g l e , obvious ly t h e a i r c r a f t could no t be a t t h e same speed i f both a re l e v e l , n e i t h e r could a s lower a i r c r a f t over take a f a s t e r one . )



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R e : x l t of a mid-air co l l i s ion between a Stamp SV-4 and a Caravelle SE 270.

,^ . .:ce A i ~ c r ~ $ . : j ' t iiecidént L l iges t ivo. 1 2 - 3~immnr.y Yo. 35. i



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APPENDIX 11.- Mid-air Col l i s ion Analysis 11-3

Close-up of the t a i l and Zeft side of the Carmeiiiie showing scores.



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11-4 Manual of A i rc ra f t Accident I n v e s t i g a t i o n

It is r e a d i l y appa ren t t h a t t h e p o s s i b l e p a t h s of c o l l i s i o n a r e l i m i t l e s s . I n f a c t , i n a l l p r o b a b i l i t y , t h e a i r c r a f t w i l l approach each o t h e r from d i f f e r e n t d i rec- t i o n s and d i f f e r e n t a l t i t u d e s s imul taneous ly . S i g n i f i c a n t s c r a t c h marks w i l l i n many cases be found on both t h e h o r i z o n t a l and v e r t i c a l s u r f a c e s of each a i r c r a f t . S ince d i r e c t i o n and speed a re involved , proper t rea tment of t h e s c r a t c h marks w i l l enable the i n v e s t i g a t o r t o r e s o l v e h i s f i n d i n g s i n t o f o r c e v e c t o r s and t o s o l v e t h e problems t r i g o - n ome t r ica l l y . 3. Rules of Thumb

A ) Although t h e r u l e s which apply t o s c r a t c h marks are t h e same whether they a r e found on t h e h o r i z o n t a l o r v e r t i c a l s u r f a c e s , o r a combinat ion thereof , they have been p laced i n a one-plane s u r f a c e f o r c l a r i t y .

RULE 1. There are only t h r e e p o s s i b l e p l a n e s i n which two o r more a i r c r a f t may ope ra t e . (1) The same p lane as t h e h o r i z o n t a l s u r f a c e s wherein no r e l a t i v e h o r i z o n t a l movement t a k e s p l a c e . ( 2 ) The same p lane a s t h e ver - t i c a l s u r f a c e s wherein no r e l a t i v e h o r i z o n t a l movement t a k e s p lace . (3) A t h i r d r e s u l t a n t plane wherein both r e l a t i v e h o r i z o n t a l and r e l a t i v e v e r t ica 1 movement t ake p lace s imu It an eou s l y ,

RULE 2. I f t h e s c r a t c h marks on each a i r c r a f t s l o p e i n oppos i t e d i r e c t i o n s wi th r e spec t t o t h e i r l o n g i t u d i n a l a x i s , t hen t h e smaller ang le between t h e l o n g i t u d i n a l a x i s and t h e s c r a t c h mark is t h e one t o be measured on each a i r c r a f t (F igure 11-1).

B ) Note t h a t Rules 2 t o 4 a r e based on t h e f a c t t h a t when two l i n e s i n t e r - s e c t , two a n g l e s a re formed. I n t h e s e c a s e s , t h e two l i n e s involved are t h e s c r a t c h mark and t h e l o n g i t u d i n a l a x i s . Rules 2 t o 4 w i l l show which a n g l e s t o measure and how t o recognize v a r i o u s types of c o l l i s i o n s .

RULE 3 . I f t h e s c r a t c h marks on each a i r c r a f t s l o p e i n oppos i t e d i r e c t i o n s , a s i n F igu re 11-1, then each s c r a t c h mark w a s made i n a d i r e c t i o n proceeding from f r o n t t o rear.

RULE 4 . I f t h e s c r a t c h marks a re s loped i n t h e same d i r e c t i o n , then one a i r c r a f t over took t h e o the r , and t h e l a r g e r a n g l e between t h e l o n g i t u d i n a l a x i s and t h e s c r a t c h mark i s measured on t h e s lower a i r c r a f t . The smaller a n g l e i s measured on t h e f a s t e r a i r c r a f t . (See F igure 11-2.)

I f t h e s c r a t c h marks are s loped i n t h e same d i r e c t i o n , one of t h e s c r a t c h marks had t o be made i n a d i r e c t i o n proceeding from r e a r t o f r o n t . The a i r c r a f t on which t h i s mark appea r s i s t h e s lower a i r c r a f t . (See F igu re 11-2. )

RULE 5 . I f t h e sum of the s c r a t c h a n g l e s i s less than 90°, the c o l l i s i o n ang le is obtuse ( g r e a t e r than 90 ' ) . (See F igu re 11-3.)

RULE 6 . I f t h e sum of the s c r a t c h a n g l e s i s e q u a l t o 90°, then the c o l l i s i o n ang le is 90°. (Figure 11-4.)

RULE 7 . I f t h e sum of t h e s c r a t c h a n g l e s i s g r e a t e r than 90°, t he c o l l i s i o n ang le is a c u t e ( l e s s than g o o ) . (F igure 11-5.)



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RULE 8. If t h e s c r a t c h a n g l e on one a i r c r a f t is t h e same as t h e s c r a t c h a n g l e on t h e o t h e r , t hen t h e speeds of t h e two a i r c r a f t are t h e same. (F igure 11-6. )

RULE 9.

C ) The fo l lowing r u l e s d e a l w i th s c r a t c h marks found on t h e v e r t i c a l sur-

The l a r g e r s c r a t c h a n g l e w i l l always appear on t h e s lower a i r c r a f t .

f a c e s of each a i r c r a f t :

RULE 10. I f t h e s c r a t c h marks on each a i rc raf t s l o p e i n oppos i t e d i r e c t i o n s wi th r e s p e c t t o t h e i r l o n g i t u d i n a l a x i s , t hen t h e smaller a n g l e between t h e l o n g i t u d i n a l a x i s and t h e s c r a t c h marks is t h e one measured on each a i r c r a f t . (See F i g u r e s 11-7 and 11-8.)

RULE 11. The s c r a t c h marks i n Rule 10 w i l l always proceed i n a f ron t - to - r ea r d i r e c t i on on each a i r c r a f t .

RULE 1 2 . I f t h e s c r a t c h marks i n Rule 1 0 a l s o proceed i n a g e n e r a l l y bottom- to- top d i r e c t i o n , t h e a i r c r a f t c o l l i d e d i n a r e l a t i v e l y noseup a t t i t u d e wi th r e s p e c t t o each o the r . (See F igu re 11-7.) Conversely, i f t h e s c r a t c h marks i n Rule 10 a l s o proceed i n a g e n e r a l l y top-to-bottom d i r e c t i o n , t h e a i r c r a f t c o l l i d e d i n a r e l a t i v e l y nosedown a t t i t u d e wi th r e s p e c t t o each o the r . (See F igu re 11-8.)

RULE 13. I f t h e s c r a t c h marks s l o p e i n t h e same d i r e c t i o n , t hen one a i r c r a f t over took t h e o t h e r , and t h e l a r g e r a n g l e between t h e l o n g i t u d i n a l a x i s and t h e s c r a t c h mark is measured on t h e s lower a i r c r a f t . The smaller ang le is measured on t h e f a s t e r a i r c r a f t . (See F i g u r e s 11-9 and 11-10.)

RULE 14 . I n a l l cases under Rule 13, t h e s lower a i r c r a f t is t h e one having t h e s c r a t c h mark which w a s made i n a r ea r - to - f ron t d i r e c t i o n . Conversely, t h e fas ter a i r c r a f t w i l l have t h e s c r a t c h mark made i n a f ron t - to - r ea r d i r e c t i o n . (See F i g u r e s 11-9 and 11-10.)

RULE 15. I f t h e s c r a t c h marks on t h e s lower a i r c r a f t a l s o proceed from bottom t o t o p , t hen t h a t a i r c r a f t w a s above t h e o t h e r . Conversely, i f t h e s c r a t c h marks on t h e s lower a i r c r a f t proceed from t o p t o bottom, then t h a t a i r c r a f t w a s benea th t h e o t h e r . (See F i g u r e s 11-9 and 11-10.)

RULE 16. I f t h e sum of t h e s c r a t c h a n g l e s is less than goo, t h e c o l l i s i o n a n g l e i s ob tuse . (See F igu re 11-11.)

RULE 1 7 . s i o n a n g l e is 90°.

I f t h e sum of t h e s c r a t c h a n g l e s is e q u a l t o goo,, t hen t h e c o l l i - (See F igu re 11-12.)

RULE 18. If t h e sum of t h e s c r a t c h a n g l e s i s g r e a t e r t han 90°, t h e c o l l i s i o n a n g l e i s a c u t e . (See F i g u r e 11-13.)

RULE 19. I f t h e s c r a t c h a n g l e on one a i r c r a f t is t h e same as t h e s c r a t c h a n g l e on t h e o t h e r , t hen t h e speeds of t h e two a i r c ra f t a r e t h e same. F igu re 11-14. )

(See



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11-6 Manual of A i r c r a f t Accident I n v e s t i g a t ion

MEASURE THIS

LONG ITU D I NAL



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APPENDIX 11.- Mid-air Collision Analysis 11-7

1 " m A * t B

I \ \

B

FASTER AIRCRAFT APPROACHING FROM RIGHT

t .B

I .'A

B

FASTER AIRCRAFT APPROACHING FROM LEFT

F i g . 11-2



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--- A - - - _

IF ANGLE 1 PLUS ANGLE 2 = LESS THAN 90° THEN ANGLE 3 = MORE THAN 90°

Fig. 11-3

n B

2,’ /

Ø /

Ø /

0

ANGLE 1 PLUS 2 = 90° ANGLE 3 = 900

I THEN

Fig. 11-4



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C

IF ANGLE 1 PLUS ANGLE 2 GREATER THAN 900 , THEN ANGLE 3 IS LESS THAN 900

IF ANGLE 1 = ANGLE 2, THEN AC = BC

Fig. 11-6



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C

A 4 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 0 1, 0

Fig. 11-7

i i-: 4

C

Fig. 11-8



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APPENDIX 11.- Mid-air C o l l i s i o n Analys is 11-11

t B te A

F i g . 11-10



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I IF ANGLE 1 PLUS ANGLE 2 IS LESS THAN 90' , THEN ANGLE 3 IS GREATER THAN 900

B

I

F i g . 11-11

C

IF ANGLE 1 PLUS ANGLE 2 = 90' , THEN ANGLE 3 = 900

IF ANGLE 1 PLUS ANGLE 2 i s IS GREATER THAN 900 , THEN ANGLE 3 IS LESS THAN 900

I I

B v ~

\

F i g . 11-13

I .- -:= THEN AC = K ANGLE 2,

B A --- -----_--_

Fig. 11-14



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APPENDIX 11.- M i d - a i r C o l l i s i o n A n a l y s i s

4 . Tr iang le R e l a t i o n s h i p s

11-13

C

F i g . 11-15

1 ) I n any g iven t r i a n g l e such as ABC above, c e r t a i n formulas have been taken from t r igonometry i n o r d e r t o s o l v e t h e mathemat ica l p o r t i o n s of s c r a t c h mark inves t iga t ions- . The f i r s t of t h e s e fo rmulas is t h e l a w of s i n e s :

BC - - AC Sin of a n g l e 3 S i n of a n g l e 2 Sin of a n g l e 1

- - AB

2 ) The second formula i s t h e l a w cos ines :

2 2 a ) (AB)’ = (BC) + (AC) - Z ( B C ) (AC) cos a n g l e 3

b) (BC) = (AB) + (AC)’ - (AB) (AC) cos a n g l e 1

c l (AC) = (AB) + (BC)’ - Z ( A B ) (BC) cos a n g l e 2

2 2

2 2

3 ) Another r u l e from t r igonometry is used i n t h e problems invo lv ing s c r a t c h marks i n t h e s i t u a t i o n where an o v e r t a k i n g a i r c r a f t approaches a t a n a n g l e from t h e rear. Th i s causes a s c r a t c h mark on t h e s lower a i r c r a f t i n such a d i r e c t i o n t h a t t h e obtuse a n g l e must be measured ( see Rule 4 ) . Since t r i g o n o m e t r i c t a b l e s d o n o t show a s i n f o r a n g l e g r e a t e r than 90°, a r e l a t i o n s h i p must be shown i n o r d e r t o o b t a i n t h e s i n . as fo l lows:

The r u l e is

S i n X = Sin(1800 - X )

I n o t h e r words, t h e s i n of 125’ is t h e same as t h e s i n of 55’ (180-125).

5. Sample Problems

A) Consider a s i t u a t i o n where in t h e s c r a t c h marks on each a i r c r a f t are p a r a l l e l t o t h e i r r e s p e c t i v e l o n g i t u d i n a l a x i s . This is t h e s i m p l e s t t o compute. I f no th ing is known about t h e f l i g h t p l a n o r w i t n e s s s t a t emen t s a s t o whether t h e a i r c r a f t were approaching head-on o r o v e r t a k i n g , i t is necessa ry t o examine c a r e f u l l y t h e s c r a t c h marks t o see i f t h e d i r e c t i o n i n which t h e s c r a t c h marks were made can be determined from t h e wreckage. Q u i t e o f t e n , p i e c e s from one w i l l be found i n t h e o t h e r , which w i l l t e l l t h e d i r e c t i o n . Also , t h e d i r e c t i o n i n which t h e metal i s t o r n i s i n d i c a t i v e . I f t h e a i r c r a f t c o l l i d e d head-on, t h e c l o s u r e speed is simply t h e sum of t h e i r a i r s p e e d s . I f one a i r c r a f t over took t h e o t h e r , t h e c l o s u r e speed i s the d i f f e r e n c e between t h e i r a i r - speeds,



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Bj Consider t h e fo l lowing s i t u a t i o n :

a ) We know the fol lowing:

A i r c r a f t A w a s t r a v e l l i n g a t 100 knots .

The s c r a t c h mark on A was i n a f ron t - to - r ea r d i r e c t i o n and measured 45' from t h e l o n g i t u d i n a l a x i s .

The s c r a t c h mark on a i r c r a f t B w a s i n a f ront - to- rear d i r e c t i o n and measured 3 2 O .

The d i r e c t i o n of t he s c r a t c h marks t e l l s us t h a t t h e smaller a n g l e s are those measured (Rule 2.)

Both a i r c r a f t were a t the same a l t i t u d e .

b; BV examination w e can deduce the fo l lowing:

Since t h e sum of t h e s c r a t c h marks addsup t o less than 90°, t h e a i r c r a f t c o l l i d e d a t an obtuse ang le (Rule 5. )

Since a i r c r a f t A had t h e l a r g e r s c r a t c h ang le of t h e two a i r c r a f t , i t was s lower (Rule 9.)

c) So lu t ion t o f ind :

i ) The a i r speed of a i r c r a f t B.

2 ) The c o l l i s i o n angle 3 .

3 ) The c losu re speed of t h e two a i r c r a f t .

Step 1. Using t h e law of c i n e s , f i n d t h e speed of a i r c r a f t ß:

BC -~ - AC Sin ang le 2 S in ang le 1

BC - AC Sin 32' S in 45'

Since the speed of a i r c r a f t A i s 100 kno t s , then:

100 BC .530 .707 - - - -

100 (.707) .530 BC =

BC = 133 knots (Airspeed of a i r c r a f t B)



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S t e p 2. Angle 1 p l u s a n g l e 2 p l u s a n g l e 3 e q u a l s 180'.

Theref o r e :

Angle 3 = 180 - (angle 1 + a n g l e 2)

Angle 3 = 180 - (45 + 32)

Angle 3 = 103O ( C o l l i s i o n ang le )

S t e p 3. Using t h e l a w of s i n e s , f i n d c l o s u r e speed:

AB - - AC S i n a n g l e 2 Sin a n g l e 3

Since from s t e p 2 , a n g l e 3 = 103' then:

AB = AC S in 32' Sin 103'

Since t h e t r i g o n o m e t r i c t a b l e s do no t go h i g h e r t h a n 90°, we cannot use t h e f i g u r e 103'. However, we know t h a t S i n X = S i n (180 - X ) , t h e r e f o r e :

- AB - AC S i n 320 S i n 7 7 @

100 .974 .530

= AB

100 (.974) .530 AB =

AB = 183.77 k n o t s ( c l o s u r e speed)

C) Consider a s i t u a t i o n such as t h a t i n Rule 4.

a ) The fo l lowing is known:

The s c r a t c h mark on a i r c r a f t A w a s made i n a forward d i r e c t i o n and proceeding towards t h e l e f t s i d e of a i r c r a f t A.

The speed of a i r c r a f t A w a s 100 knots .

The speed of a i r c r a f t B w a s 150 knots .

The smaller s c r a t c h a n g l e on a i r c r a f t A w a s 30°.

The l a r g e r s c r a t c h a n g l e on a i r c r a f t A was 150°.

Because a i r c r a f t B w a s e n t i r e l y consumed by f i r e , no s c r a t c h marks could be found on i t .

Both a i r c r a f t w e r e a t t h e same a l t i t u d e .



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b ) BY examinat ion, t h e €allowing can be deduced:

Since t h e s c r a t c h marks proceed forward and t o t h e l e f t s i d e of a i r c r a f t A , then a i r c r a f t B approached from t h e rear and t h e r i g h t s i d e . (WHY? We know . t h a t a i r c r a f t B w a s f a s t e r . Since the marks on A were made i n a forward d i r e c t i o n , then B approached from t h e rear. S ince t h e marks on A a l s o proceeded toward t h e l e f t s i d e of A , then B approached from t h e r i g h t s i d e of A . )

The l a r g e r of t h e two ang le s between t h e s c r a t c h l i n e and l o n g i t u d i n a l axis on a i r c r a f t A i s measured s i n c e i t is t h e s lower a i r c r a f t and w a s be ing over- taken; t h e r e f o r e , t h e ang le used is 150°. I n a d d i t i o n , s i n c e t h e sum of ang le s 1 and 2 is obviously g r e a t e r than 900, then t h e co l l i s . ion a n g l e must be a c u t e (Rule 7 ) .

c ) So lu t ion t o f i n d :

What the s c r a t c h a n g l e s probably were on a i r c r a f t B.

The c o l l i s i o n angle .

The c losu re rate.

Step 1. Using t h e law of s i n e s w e s o l v e for t h e s c r a t c h ang le 2:

BC - - AC Sin a n g l e 2 S in ang le 1

- 15 O - 100 S in ang le 2 S in 105'

Since S in 150° = Sin (180 - 150) then:

- 15 o - 100 S i n ang le 2 S in 3OU

100 (Sin 30') 150 S i n ang le 2 =

100 (.5) 150 S in ang le 2 =

S i n a n g l e 2 = .3333

Angle 2 = 19' 28 ' (Probable s c r a t c h ang le on a i r c r a f t B )

S t e p 2.

Angle 3 = 180 - (angle 1 + ang le 2)

Angle 3 = 180' - (150' + 19' 2 8 ' )

Angle 3 = l o o 28' ( C o l l i s i o n ang le )



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Step 3. Using law of s i n e s t o f i n d c l o s u r e speed :

BC - AB - S i n 150° Sin 19O 28'

AB _c - 15 O - -

15 . 333

150 ( . 3 3 3 ) .5 AB =

AB = 99.9 kno t s ( c l o s u r e speed)

D ) It can be seen t h a t i f t h e two a i r c r a f t were i n t h e same v e r t i c a l p l ane but i n d i f f e r e n t h o r i z o n t a l p l anes ( i n i t i a l l y d i f f e r e n t a l t i t u d e s , bu t converging) , t h e problems may be. so lved i n t h e same manner as i l l u s t r a t e d .

The only d i f f e r e n c e would be t h a t t h e s c r a t c h marks i n d i c a t i n g t h e relative p o s i t i o n s would be on v e r t i c a l s u r f a c e s such as t h e s i d e s of t h e f u s e l a g e , cowling, v e r t i c a l f i n , etc. Any s c r a t c h e s found on h o r i z o n t a l s u r f a c e s would probably be p a r a l l e l t o t h e

. l o n g i t u d i n a l a x i s of each a i r c r a f t .

6. Graph

Working t h e problems o u t t r i g o n o m e t r i c a l l y w i l l obviously g i v e more nearly a c c u r a t e r e s u l t s t h a n o t h e r methods. It is academic whether o r n o t such extreme accuracy is needed i n a l l s i t u a t i o n s . The re fo re t h e fo l lowing graph w i l l p r o v i d e a qu icke r method t o a r r i v e a t t h e s o l u t i o n , i n a d d i t i o n t o e l i m i n a t i n g t h e need f o r t r i g o n o m e t r i c t a b l e s (Figure 11-16 1.

Using t h e same problem as t h e second problem above, w e know t h a t a i r c r a f t A w a s t r a v e l l i n g 100 k n o t s , t h e s c r a t c h mark on A was from f r o n t t o rear and measured 45O, t h e s c r a t c h mark on B w a s f r o n t t o r e a r and measured 320.



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SCRATCH ANGLES

AIRSPEED

F i g . 11-16

Given: Scratch mgle on aircraft A equals 45'. Scratch angle on aircraft B equals 32'. Airspeed of aircraft '4 equals 100 ktc.

8. Speed of aircraft ß. 3. Closure s p e d .

Find: i . Collision angle.



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7. C o l l i s i o n ' of Two A i r c r a f t Operating i n D i f f e r e n t H o r i z o n t a l and D i f f e r e n t Vertical P lanes

a) T h i s c o n d i t i o n , probably t h e most common, would a t once appea r t o be a

I f one o r both a i r c r a f t are combination of t h e v e r t i c a l and h o r i z o n t a l s i t u a t i o n s p r e v i o u s l y d i scussed . with some m o d i f i c a t i o n , p a r t i c u l a r l y i n t h e speed category. climbing o r descending, t h e n a n a d j u s t m e n t must be made i n o r d e r t o a r r i v e a t a c o r r e c t speed f o r t h e computation of t h e h o r i z o n t a l t r i a n g l e . Once t h e h o r i z o n t a l t r i a n g l e is so lved , it is a s imple matter t o c o n s t r u c t t h e v e r t i c a l t r i a n g l e and s o l v e it. of rate of c l imb o r s i n k on h o r i z o n t a l speed is shown i n t h e graph a t t h e end of t h i s sect ion.

T h i s is t r u e

The e f f e c t

b) Consider t h a t t h e h o r i z o n t a l a s p e c t s of t h e c o l l i s i o n have been so lved and t h e f o l l o w i n g t r i a n g l e ABC h a s been cons t ruc t ed :

Fig. 11-17

The l i n e CG i s then c o n s t r u c t e d by b i s e c t i n g t h e c o l l i s i o n a n g l e C. Th i s d i v i d e s t h e l i n e of relative motion AB i n t o two segments: AD and DB. From geometry i t is known t h a t t h e s e two segments are p r o p o r t i o n a l t o t h e s i d e s of t h e t r i a n g l e o r AC/AD = BC/BD. towards a i r c r a f t B a l o n g t h e l i n e AB t o t h e p o i n t D. t o t h e p o i n t D.

In o t h e r words, as a i r c r a f t A p r o g r e s s e s t o t h e c o l l i s i o n p o i n t C , i t a l s o moves Likewise, a i r c r a f t B moves a l o n g AB

The p r o j e c t i o n of t h e l i n e CB (path of a i r c r a f t B) on l i n e CG is r e p r e s e n t e d by t h e l i n e CF. The p r o j e c t i o n of t h e l i n e AC (pa th of a i r c r a f t A) is r e p r e s e n t e d by t h e l i n e CE. The l e n g t h s of t h e l i n e s CF and CE w i l l be used i n t h e f o l l o w i n g drawing t o c o n s t r u c t t h e v e r t i c a l a s p e c t s of t h e c o l l i s i o n . Two drawings are used, s i n c e i t is p o s s i b l e t h a t a i r c r a f t A w a s above B or v i c e v e r s a .

The t r i a n g l e which r e p r e s e n t s t h e v e r t i c a l c r o s s s e c t i o n of t h e f l i g h t is now solved i n t h e same manner a s ' t h e h o r i z o n t a l t r i a n g l e .

Fig. 11-18



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c ì "e h a v e n o w determined, through s c r a t c h mark a n a l y s i s , both t h e horizon- t a l and v e r t i c a l a s p e c t s of t he f l i g h t . 'ïhe a c t u a l movement of t h e a i r c r a f t obviously took p l ace i n a p lane which i s the r e s u l t a n t of t h e h o r i z o n t a l and v e r t i c a l p lanes . I f the problem is cons t ruc t ed i n t h r e e dimensions by p l a c i n g a drawing of t h e h o r i z o n t a l niovement pe rpend icu la r t o a drawing of t h e v e r t i c a l movement, t h e r e s u l t a n t plane is e a s i l y seen . The fo l lowing drawing i l l u s t r a t e s t h i s :

The, red t r i a i i g l e A E X is t h e r e s u l t a n t p lane . The v i s i b i l i t y t h a t each a i r c r a f t would have of t h e o t h e r is now r e a d i l y determinable .

d ) The fol lowing graph, F igu re 11-20,concerns t h e e f f e c t of v e r t i c a l speed an h o r i z o n t a l speed. To u s e t h e graph, e n t e r a t t h e rate of climb ( o r s i n k ) , proceed h o r i z o n t a l l y t o t h e curve of t h e a i r s p e e d of t h e a i r c r a f t ( i n d i c a t e d o r t r u e ) , then proceed v e r t i c a l l y , and read t h e h o r i z o n t a l a i r s p e e d component. In t h e sample i l l u s t r a t e d , t h e a i r c r a f t i s cl imbing a t 4 O00 f e e t p e r minute, and t h e i n d i c a t e d a i r speed i s 150 kno t s . The h o r i z o n t a l component is found t o be about 196 knots . I t i s obvious t h a t i f t h e h o r i - z o n t a l speed i s known and t h e ind ica t ed o r t r u e a i r s p e e d is known, then t h e ra te of c l imb may be found. I n o t h e r words, i f any two of t h e t h r e e f a c t o r s are known t h e t h i r d may be found by t h e u s e of t h e graph.

F i g . 11-19



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APPENDIX 11.- Mid-air C o l l i s i o n Analysis 11-21

EFFECT O F VERTICAL VELOCITY ON HORIZONTAL VELOCITY

EFFECT OF VERTICAL VELOCITY ON HORIZONTAL VELOCITY



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11-22 ?“anual of A i r c r a f t Accident I n v e s t i g a t i o n

8. Sample Problem Involv ing Simultaneous Hor izonta l and V e r t i c a l Movement

A . Known F a c t s about A i r c r a f t A.

1) Fron! t h e ground speed computed from t h e t i m e s over two known r a d i o f i x e s , t h e t r u e a i r speed a long a h o r i z o n t a l pa th was found t o be 100 knots .

2) ’Lhe repor ted a l t i t u d e between t h e same two f i x e s e s t a b l i s h e d a r a t e of climb of 600 f e e t p e r minute.

3 ) A s c r a t c h mark was found on t h e upper r i g h t wing of t h e a i r c r a f t which proceeded i n a forward and inboard d i r e c t i o n , making an ang le of 60’ with t h e l o n g i t u d i n a l a x i s . S m a l l p i e c e s of meta l were miss ing i n a few p l a c e s a l o n g t h e s c r a t c h mark, l e a v i n g h o l e s i n the sk in .

4 ) Scra t ch marks were found on the r i g h t s i d e of t h e fuse l age which proceeded i n a forward and down d i r e c t i o n , making an a n g l e of 20° wi th t h e l o n g i t u d i n a l a x i s .

5 ) The a i r c r a f t w a s a Cessna 172.

B. Known F a c t s About A i r c r a f t B.

1) Scra t ch marks were found on t h e unde r s ide of t h e l e f t wing and proceeded i n an a f t and inboard d i r e c t i o n making a n ang le of 450 wi th t h e h o r i z o n t a l . P i eces of metal which matched the h o l e s on t h e r i g h t t o the r i v e t heads a long the s c r a t c h marks.

wing of a i r c r a f t A were found s t i l l a t t a c h e d

2) Sc ra t ch marks were found on t h e l e f t s i d e of t he f u s e l a g e and proceeded i n an a f t and upward d i r e c t i o n making an ang le of go wi th t h e l o n g i t u d i n a l ax i s .

3 ) The a i r c r a f t was a Beechcraft Bonanza.

1

Lis; . 11-21



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C. S o l u t i o n :

By u s i n g t h e knowledge from t h e f a c t , s and app ly ing t h e p r i n c i p l e s of s c r a t c h mark i n t e r p r e t a t i o n , w e hope t o learn t h e manner i n which t h e two a i r c r a f t came toge the r . We w i l l de te rmine t h e unknown speed of a i r c r a f t B, and whether i t w a s c l imb ing , descending , o r l e v e l . t h e o t h e r a i r c r a f t .

It w i l l be p o s s i b l e t o de te rmine which p i l o t had t h e b e s t o p p o r t u n i t y t o see

1) Let u s f i r s t examine t h e s c r a t c h marks, and c o n s t r u c t a drawing of t h e i r re la t ionsh ips .

a ) H o r i z o n t a l s c r a t c h marks.

From Rule 4 it may be determined t h a t a i r c r a f t A w a s t h e slower a i r c r a f t ; it w a s ove r t aken by a i r c r a f t B, and a i r c r a f t B approached a i r c r a f t A from t h e r i g h t wing. The angle of 45' is t h e s c r a t c h a n g l e t o be used on a i r c r a f t B whereas t h e l a r g e a n g l e of H O 0 is the s c r a t c h a n g l e t o be used on a i r c r a f t A.

A

F i g . 11-22

b) Vertical s c r a t c h marks.

From Rules 13, 14, and 15 it may be determined t h a t a i r c r a f t A w a s t h e slower a i r c r a f t , and t h a t r e l a t i v e l y , a i r c r a f t B w a s above a i r c r a f t A. of 160° on a i r c r a f t A should be used and t h e s m a l l a n g l e of go on . a i r c r a f t B should be used. It is n o t y e t known whether o r no t a i r c r a f t B w a s descending o r l e v e l . We do know from t h e f a c t s t h a t a i r c r a f t A w a s c l imbing , and by c o n s u l t i n g t h e graph w e can determine t h a t i t s t r u e a i r s p e e d w a s 100.2 kno t s .

The l a r g e r ang le

2 ) L e t u s f i r s t c o n s t r u c t a h o r i z o n t a l drawing of t h e p robab le c o l l i s i o n path.

Label t h e t r i a n g l e ABC wi th A be ing t h e s lower a i r c r a f t , B t h e f a s t e r , and C t h e po in t of c o l l i s i o n . angles . h o r i z o n t a l speed of a i r c r a f t B y and the c l o s u r e speed of t h e two a i r c r a f t ( l i n e AB).

Label t h e known f a c t s such as t h e known speeds and s c r a t c h W e may now s o l v e t h e t r i a n g l e t o de te rmine t h e h o r i z o n t a l c o l l i s i o n a n g l e , t h e

a) C o l l i s i o n Angle

Angle C e q u a l s 180 - (120 + 45) wh ich -equa l s 15'.



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b) Speed of a i r c r a f t A.

Using t h e graph, F igure 11-19, t h e speed of a i r c r a f t B i s found t o be 1 2 2 knots .

c ) Closure rate.

Usirig t h e same graph, t h e c l o s u r e r a t e is found t o be 36 knots .

n

B

Fig. 11-23

3 ) Using t h e same t r i a n g l e , b i s e c t ang le C and cons t ruc t as i n F igure 11-17. This is f o r t h e purpose of determining t h e v e r t i c a l a s p e c t s . Label wi th t h e f a c t s known and computed s o f a r , i .e . , Speed of A: 100 knots , Speed of B: 1 2 2 knots , C o l l i s i o n ang le C: 1 5 O , e tc .

Fig. 11-24

Tf t h e drawing i s made t o scale, then t h e l e n g t h s of t he l i n e s CE a n i CF may Otherwise they may be so lved t r igonomet r i ca l ly o r by be measured and converted t o speeds.

t h e use of the graph, F igure 11-20.

a ) Line CE

Since Angle C is b i s e c t e d , h a l f t h e a n g l e of 1 5 O i s 74".

CE 1 (I o cos 7 p --

CE .9Y1 = - 100

C E = 99.1. knots



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b) Line CF

I n a similar manner, L ine CF may be found t o be e q u a l t o 120.9 knots .

4 ) Now t h e v e r t i c a l t r i a n g l e may be drawn and so lved .

Fig. 11-25

About t h e a b o v e t r i a n g l e s we know t h e fol lowing:

EC e q u a l s 99 knots .

CF e q u a l s 121 kno t s .

Angle 1 ( s c r a t c h a n g l e on B) equa l s 9'.

Angle 2 ( s c r a t c h a n g l e on A) equa l s 160'.

Rate of c l imb on a i r c r a f t A is 600 f e e t p e r minute . would be r ep resen ted by t h e l i n e AE. unknown, bu t would be r ep resen ted by l i n e BF.

C o l l i s i o n a n g l e C e q u a l s 180 - (160 + 9) o r 11:

From t h e graph , F i g u r e 11-20, which d e a l s w i t h t h e e f f e c t of rate of climb on h o r i z o n t a l speed, t h e speed of l i n e AC may be determined. T h i s is found t o be 99.5.

From t h e s c r a t c h a n g l e graph, F igu re 11-16, w e cab now de termine t h e speed l i n e BC. T h i s was found t o be 122 knots .

The rate of c l o s u r e (Line AB) is found i n a similar manner t o be 68 knots .

From t h e graph , F i g u r e 11-20, o r mathemat ica l ly , t h e r a t e of s i n k of a i r c r a f t B may now be determined s i n c e we know t h e h o r i z o n t a l speed CF and t h e descending speed BC. This was found t o be 1 800 f e e t p e r minute.

On t h e drawing t h i s The rate of c l imb of a i r c r a f t B is

* It is apparent from t h e c a l c u l a t i o n s i n t h i s s e c t i o n t h a t t h e d i f f e r e n c e between t h e ind ica t ed o r t r u e a i r s p e e d and t h e h o r i z o n t a l component i s i n s i g n i f i c a n t a t t h e lower r a t e s of c l imb o r s ink . I n fac t it is p r a c t i c a l l y i m p o s s i b l e t o de te rmine t h e d i f f e r e n c e s on a graph u n l e s s t h e s c a l e is so l a r g e a s t o be unwieldy. of climb, a h i g h e r degree of accuracy is p o s s i b l e by s o l v i n g t h e t r i a n g l e s mathemat ica l ly r a t h e r than by use of t h e graph.

The re fo re a t t h e lower r a t e s



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11-26 ?lanual of A i r c r a f t Accident I n v e s t i g a t i o n

k) From the same graph, t h e t r u e a i r s p e e d of a i r c r a f t B may now be de te r - mined by comparing the rate of c l imb ( 1 800 f e e t p e r minute) with 122 knots horizontal . speed. The a i r s p e e d i s found t o be 123.3 kno t s ,

5) We can now summarize what w e have learned:

A i r c r a f t A A i r c r a f t B

True Airspeed 100.2 kno t s

Rate of Climb 600 f.p.m. Rate of Descent 1 800 f.p.m.

True Airspeed 123.3 knots

P o s i t i o n of a i r c r a f t B as viewed from a i r c r a f t A:

120° t o t h e r i g h t and 160' above t h e nose.

Pos i t i on of a i r c r a f t A as viewed from a i r c r a f t B:

45' t o t he l e f t and 9' below t h e nose.

Co l l i s ion angles :

Rates of c losu re : Hor i zon ta l ly : 36 h o t s , v e r t i c a l l y : 68 knots .

Above and t o the r i g h t rear.

15O h o r i z o n t a l l y and 11' v e r t i c a l l y .

Resul tan t c losu re rate: 43 knots (This is found by comparing t h e h o r i z o n t a l c l o s u r e ra te wi th the combined rates of c l imb.)

6 ) Conclusions

Since a i r c r a f t A was a Cessna 172 which i s a h igh wing monoplane type , t h e thought immediately occurs t h a t t he p i l o t o r o t h e r occupants c o u l d ' n o t have seen t h e approaching a i r c r a f t B. An examination of t he scale drawings of t h e Cessna 1 7 2 revea1.s t h a t t h e p i l o t could not have scen a i r c r a f t B. However, t h e occupant of t h e r i g h t rear seat could have seen a i r c r a f t B i f he had the occas ion t o look t o the rear and upwards.

The p i l o t of the Bonanza ( a i r c r a f t B ) , by looking t o t h e l e f t and s l i g h t l y down should have e a s i l y seen a i r c r a f t A , provided t h a t weather cond i t ions were suc.h t h a t v i s i b i l i t y was good. Since t h e r e s u l t a n t c l o s u r e ra te w a s found t o be 43 knots , t h e a i r c r a f t would have been .7 n a u t i c a l miles a p a r t , one minute before t h e c o l l i s i o n o r 1 . 4 n a u t i c a l miles apar t , two minutes p r i o r t o c o l l i s i o n .

9. Summary

It i s obvious t h a t two a i r c r a f t w i l l not n e c e s s a r i l y fo l low unswerving s t r a i g h t l i n e s f o r an i n d e f i n i t e per iod and u l t i i na t e ly c o l l i d e . r e v e a l t he r e l a t i v e p o s i t i o n s a t and j u s t p r i o r t o impact. can be determined on ly bv cons ider ing the s c r a t c h marks w i t h t h e o t h e r f a c t s learned dk r iiig t h e i nves t ign t ion.

The s c r a t c h marks w i l l ï h e r e f o r e , t h e e n t i r e s t o r y

The accuraLy of t h e r e s u l t s i s d Funct ion of t h e accuracy and quan t i ty or f a c t u a l information found. d i sprove evas ive a c t i o n . incumbent on t h e i n v e s t i g a t o r t o accumulate a l l the € a c t s p o s s i b l e .

I t i s p o s s i b l e t h a t s c r a t c h mark evidence w i l l prove or Who was a t f a u l t m y i n most cases be d e f i n i t e l y proved. I t i s



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APPENDIX 11.- Mid-air C o l l i s i o n Analys is 11-27

For I n t h e t r ea tmen t of t h e problems, c e r t a i n o t h e r f a c t o r s were omi t ted . example, it is recognized t h a t a l l a i r c r a f t do no t c l imb n o r descend a long a pa th p a r a l l e l t o t h e l o n g i t u d i n a l a x i s . Therefore , t o be more a c c u r a t e , t h e r e l a t i o n s h i p of t h e l o n g i t u d i n a l a x i s t o t h e f l i g h t pa th must be cons idered , and a c o r r e c t i o n a p p l i e d t o t h e s c r a t c h angle . e r ed . problem o r i n t h e case of a mult i -engine a i r c r a f t with one eng ine f e a t h e r e d .

This may be a f u n c t i o n of f l a p s , c l imb speed , etc.

S i m i l a r l y , yaw was no t consid- This s i t u a t i o n is q u i t e p o s s i b l e wi th t h e V-tai led Beechc ra f t used i n t h e sample

I n every c a s e of mid-air c o l l i s i o n , i t is impor tan t t h a t each s t e p i n t h e process of i n v e s t i g a t i o n be performed c a r e f u l l y . c l a r i f y each s t e p of t h e s o l u t i o n as i t is performed.

It is sugges ted t h a t ske t ches be made t o

A sugges ted s tep-by-step procedure fo l lows:

1. Determine whether o r no t one a i r c r a f t ove r took t h e o t h e r o r whether t h e c o l l i s i o n was t h e head-on type.

E i t h e r p l a c e a sc ra t ched p i e c e from one a i r c r a f t b e s i d e t h e sc ra t ched p i e c e from t h e o t h e r a i r c r a f t o r s i m u l a t e by a drawing.

P l ace t h e p i e c e s i n such a p o s i t i o n t h a t t h e l o n g i t u d i n a l a x i s of one a i r c r a f t is p a r a l l e l t o t h e l o n g i t u d i n a l a x i s of t h e o t h e r . t h e rear toward t h e nose of both a i r c r a f t .

Now view both p i e c e s as though you were looking from

I f one s c r a t c h mark s l a n t s t o t h e l e f t and t h e o t h e r t o t h e r i g h t , t hen t h e a i r c r a f t approached i n a head-on manner and t h e c o l l i s i o n a n g l e was obtuse. smaller a n g l e between t h e l o n g i t u d i n a l ax is and t h e s c r a t c h mark on each a i r c r a f t . (Rules 2 and 5 . )

The re fo re , measure t h e

I f bo th s c r a t c h marks s l a n t t o t h e l e f t , one a i r c r a f t over- t o o k t h e o t h e r w i th t h e f a s t e r a i r c r a f t be ing t o t h e r i g h t of t h e s lower . (Rule 4 , t o p i l l u s t r a t i o n of F igu re 11-2.)

I f bo th s c r a t c h marks s l a n t t o t h e r i g h t , one a i r c r a f t over- t o o k t h e o t h e r w i th t h e f a s t e r a i r c r a f t be ing t o t h e l e f t of t h e s lower. (Rule 4 , lower i l l u s t r a t i o n of F igu re 11-2.)

I n both d and e , measure t h e l a r g e r a n g l e between t h e l o n g i t u d i n a l a x i s and t h e s c r a t c h mark on t h e s lower a i r c r a f t , and t h e small a n g l e on t h e f a s t e r a i r c r a f t . (Rule 4 . ) The s lower a i r c r a f t is t h e one on which t h e s c r a t c h mark w a s made i n a forward d i r e c t i o n . (Rule 4 . )

Follow t h e s a m e procedure f o r t h e v e r t i c a l s c r a t c h marks, i f any.

2. Draw t h e t r i a n g l e s a s desc r ibed i n t h e sample problems, p r e f e r a b l y t o s c a l e .

3 . Solve e i t h e r mathemat ica l ly o r by t h e use of t h e graphs .



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MANUAL OF A I R C R A F T ACCIDENT I N V E S T I G A T I O N

A P P E N D I X 1 2

F I R E I N V E S T I G A T I O N

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APPENDIX 12.- Fire Investigation 12-1

APPENDIX 12

F IR E I NVE ST I GAT I ON

The follaring i s a verbatim e x t r a c t f r o m t he A i r c r a f t Fire - . i u e s t i g a t i m Manual 1972 (NFPA No. 422M-1972). Assocfa t ion ( I n t e r n a t i o n a l ) , 60 E u t t e r p a r c h S t r e e t , Boston, Mass., U . S.A.

I t i a issued by the National Fim Protec t ion

400. Evidence

401. relationship so that not always can a precise temperature be concluded. 15000F for a few minutes may leave an appearance quite similar to a lesser value for a longer time period. which case limit points are more closely defined. but investigators can usually trace or plot a fire pattern to a source point by studying the relative temperatures and the position of the burned or overheated point.

402. a particular system comprising material, oxidant, ignition source, environment, and conditions. ordinary match - unless the steel happens to be in the form of loosely packed steel wool. Such distinction in material form is often overlooked in interpreting fire data.

403. 7000 series. 7000 is one using zinc as the major alloy, about 5-6%. 95% aluminum and mst include very small percentages (by chemical content) of other metals such as titanium, silicon, manganese, magnesium, etc. The melting points of the sheet used is generally around 1180O F, but a few alloys may melt as low as 980-1000° F. forgings or castings will melt at temperatures as low as 950° F. found are Temper and Strain hardening designators. zinc plus small amounts of eight other elements, is solution heat treated, and artificially aged.

In most cases of evidence of temperature attained, there is a time-temperature A temperature of

There are sometimes definite points at which a change occurs, in Laboratory analysis is sometimes needed,

Fire resistance is not a property of a particular material but is a characteristic of

For example, ordinary steel at room air temperature is not ignitable with an

Most aluminum sheet and forging ingots used for aircraft components are the 2000 and The 2000 is an alloy using copper as the major alloy material, about 4-5%;

All the alloys are more or less

Very few The letters sometimes

For instance, 7075-T-6 has 5.1-6.1%

404. basic characteristics of the metal, i.e. from ductile to brittle,and their failures will not necessarily remain the same in appearance. Plating also tends to change the characteristics.

Various types of heat treating and strain hardening are used which often change the

405. leaving bright cracks and fissures. as little wrinkled bags. the red range, forming oxides at edges and thin sections.

When aluminumalloys are heated to the melting range, they wrinkle and pull apart, If heated sufficiently to form droplets, they appear

On the other hand, iron alloys will tend to bum when heated into

406. Fire damage to metal is mainly in loss of strength; i.e. 7075-T-6 alloy loses 10% of its strength when heated 30 min. at 400° F; 10 min. at 4500 F; 3 min. at 5500 F; or 2 min. at 600° F. but an approximation of the time involved is necessary to determine the maximum temperature.

Hardness tests can be used to determine the amount of temperature exposure,

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12-2

407. Titanium discolors from tan to light blue, to dark blue, to gray with increasing temperature. at about llOOo F, increasing in thickness with time at temperature, and the bluish color comes. appreciable oxide scale is formed which flakes off. allotropic transformation (from alpha to beta type) and oxidation rate is increased considerably. quickly, are hard to detect, and almost impossible to extinguish. (Ti) fires is complex; for rotor blades the sequence may be:

Manual of Aircraft Accident Investigation

It has a high affinity for gases when heated, and a scale will begin to form

Around 1200-1500° F the grey or yellowish shade appears. At about 1300O F an About 1620' F, it undergoes all

Titanium fires in turbine engines have been of concern for some time; they start The mechanism of Titanium

a) A Ti rotor blade may rub against the engine case and, with the low thermal conductivity of Ti, the temperature of the blade increases rapidly;

The Ti melts at about 3100° F (Note - steel melts at about 2700' F); b)

c) The molten Ti absorbs O2 to form Ti02 which boils, bums, and stabilizes around 5600' F;

The Ti02 will continue to form and burn as long as there is air supply. The molten Ti at very high temperature will melt through steel engine cases very rapidly. routing of fuel and oil lines in the lower sector of the engine.)

d)

(For this reason, engine design should preclude the

LOS. blue, to black. When examining this metal, the investigator should check both sides; the side which has the lighter blue was the side opposite the heat source, and the heated area will be smaller in circumference.

Stainless steel discolors starting at 800-900' F from tan to light blue, to bright

409. brown at 600" F; and are black at 700° F. Glass cloth fuses at 12000 F. at SOOo F. known; i.e. Nylon spaghetti melts at 250-350° F.

410. off completely at 900-950° F. overheating depth. Tt would be un?.iicely to rind the metal beneath damaged without finding the paint hurned all the way t h rcugh . without apparent "surface" burning.

Zinc chromate paint primers start t o tan at 450° F; are brown at 500' F; are dark Cadmium plating starts to discolor at 500' F.

Silicone rubber blisters at 700' F. Neoprene rubber blisters Wire insulation is a good guide to lower temperature ranges if the material is

Aircraft paints soften at 400° F, discolor at 600° F, blister at 800-850' F, and burn Sectioning Che paint with a sharp knife will disclose the

Severe scorching will blacken the surface without darkening in depth.

It is possible to char primer beneath the heat resisting aluminm paint

411. Temperature Limits of Selected Materials

The investigator should carefully note those materials which did ignite, those that melted, and those materials that were damaged by the presence of heat.

Tables 1 and 2 are listings c7f selected materials which give a range of auto-ignition tenperatures and temperature limits which damage or distort materials. transport aircraft.

Table 3 shows melting points of metals and alloys used in present aircraft. Familiarity w i t h various aircraft metals and alloys and the knowledge of for what and where they are used in the aircraft is essential to the investigator.

The materials listed are usually found in private o r commercial

1 6 / 4 / 7 3 No. 3



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Table 1

Auto-ignit ion* Temperature (OF) of Selected Materials

Canvas Denatured Alcohol Hydraulic Hose (Buna-N-Rubber ) Leather Nylon-covered wire Glass matts Lubricating Oil (MIL-1-7808) Plywood Rubber-covered wire Vinyl-covered wire Rubber-asbestos material Styrene Teflon

OF

2 04 750 950 850 1000 950 790 900 900 900 900 914

1050

Table 2

Temperature Limits for Selected Materials (OP)

OF

Glaze or electrical porcelain 2250 Enamel flakes 1200-14 O 0 Glass softens 1400-1600 Paraffin wax melts 129 Zinc melts 786 Silver soldera melt 1165-14 50 Silicone rubber (coneiderable softening at sustained service) 425

Cellulose - (Filled melamine, heat distortion) 400 Nylon (polyamide), heat distortion 300-360 Melamine - formaldehyde (filled) , heat distortion 2 66-4 O0

Paper/Phenolic, delamination and distortion 250 Styrene elastomer, distortion at sustained service 220

Polystyrene, distortion 210 Methyl Methacrylate, heat distortion 210 Plastic vinyl chloride, heat distortion 185

* Spontaneous combustion (ICAO) .

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Table 3

Mel t ing P o i n t s of Some A i r c r a f t Metals and Al loys (OF)

Aiuminum a l l o y s Brass bea r ings Cadmium Chromium Copper I ron Lead Magnesium a l l o y s Manganese Mercury Molybdenum Nickel Selenium S i l i c o n S i l v e r S t a i n l e s s steel Tin Titanium Tungs t e n Vanadium

OF

1220-1250 1600-2000

609 3430

1981-2000 2802

621 1202-1250

2273

4760 2651 428

2605 1760 2700 449

3100 6170 3150

-39.9

412. When e l e c t r i c a l w i r e b reaks wi th no c u r r e n t f lowing , t h e break is c l e a n and d i s p l a y s a t y p i c a l cup and cone f r a c t u r e wi th necking down. When c u r r e n t is flowing, it a r c s on breaking , causing l i t t l e b a l l s of ox id i zed metal t o form on t i p s of t h e s t r a n d s . e x t e r n a l t o t h e wi r ing bundle b u m s t h e o u t s i d e f i r s t and t h e conductor i n s i d e is c l e a n and b r i g h t , except where t h e i n s u l a t i o n is burned through. c u r r e n t b u m from i n s i d e o u t , and t h e conductor w i l l be dark and ox id ized , perhaps wi thou t damage t o t h e o u t e r cover. The t i n c o a t i n g on copper w i r e w i l l d i f f u s e i n t o t h e cooper a t tempera tures above i t s me l t ing point of 449’ F and become rough o r even d isappear .

413. Examination of any l i g h t bu lbs a v a i l a b l e w i l l h e l p i n de te rmining whether o r n o t e l e c t r i c a l power was on i n a p a r t i c u l a r system a t impact. w i l l show whether o r n o t t h e bulb was i l l umina ted a t impact, when t h e bulb was shock-loaded. I f t h e f i lament w a s h o t a t impact, i t w i l l s t r e t c h and d i s t o r t s u b s t a n t i a l l y ; i f t h e f i l a m e n t w a s cold a t impact, i t w i l l b reak but w i l l n o t d i s t o r t o r s t r e t c h from i t s o r i g i n a l shape and p a t t e r n . I f t h e g l a s s s h a t t e r e d and t h e f i l amen t exposed, it w i l l t e l l t h e s t o r y b u t w i l l ox id i ze and d i s c o l o r qu ick ly . system ope ra t iona l s t a t u s a t impact, provided f a i l u r e l i g h t s and warning l i g h t bu lbs s u r v i v e any subsequent f i r e i n t h i s a r e a . Doc 6920-AN/855/4 f o r f u r t h e r r e sea rch i n t o f i re o r i g i n . )

414. ins tan taneous combustion o r explos ion o c c u r s , when no soo t ing i s left) so t h a t tests may n o t be success fu l i n i d e n t i f y i n g o r d i f f e r e n t i a t i n g between these and v a r i o u s o t h e r hydrocarbon l i q u i d s which nay be found about a i rc raf t . r e s idues .

A f i r e

Wires burned because of excess

The f i l a m e n t s of small bu lbs

Th i s whole procedure i s of v a l u e i n determining t h e

(Refer t o Part III, 7.3 “ E l e c t r i c a l Systems” of I C A 0

Hydrocarbon f u e l s used i n a i r c r a f t a l l l eave a s i m i l a r s o o t r e s i d u e (except when

Cleaning f l u i d s , o i l s , e t c . , may l eave s imilar

16 /4 /73 No. 3



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APPENDiX 12.- Fire Investigation 12-5

415. aviation fuels; Aviation gasoline (AVGAS), the kerosene grades (JET-A, JET A-1, JP-5, JP-6), and the blends of gasoline and kerosene (JET B, JP-4). these fuels are set forth in the table below, but a brief comparison is given to focus attention on their differences.

a)

Flammability Characteristics of Aviation Fuels. There are three basic types of

The flammability characteristics of

All petroleum fuels, in order to burn, must be vaporized and mixed with air in specified proportions. AVGAS has a strong tendency to vaporize, and as a result, will always have considerable vapors mixed with the air over the surface of the liquid. In a closed tank, so much fuel vapor will be given off by AVGAS that the fuel-air mixture may be too rich to burn. When any fuel is in contact with air, it will continue to eva- porate until the air is saturated.

Kerosene grade fuel ordinarily has a low tendency to vaporize, and in a closed tank the fuel vapor will ordinarily have too lean a mixture to

their flash point. the bulk of the fuel to flash point; this can be done by wicking the fuel on an absorbent material which can be heated locally (hot spot) until the fuel ignites. The local hot spot on the wick will furnish sufficient vapor to sustain the flame. Such conditions could occur accidentally during crash and post-crash conditions.

b)

~ burn. However, kerosene grade fuels can be ignited by heating above It is possible to ignite such fuels without heating

c) Fuels that are a blend of AVGAS and kerosene retain most of the worst fire characteristics of both fuels. The vapor mixture in a closed tank is normally neither too rich nor too lean, flambability limits are over a wide temperature range, auto-ignition temperature is low, and flame spread is almost as fast as with AVGAS.

(Refer to Table 4.)

416. When heated, skydrol (a Trade Name hydraulic fluid commonly used in present aircraft) gives off a white misty vapor which is acrid and choking. dark colored and viscous, then it changes to a dark charred material, then a white fluffy deposit appears after prolonged heat. smoke. odor is evident. about 9 2 5 O F.

When burned, the residue is first

When burned, it has a yellowish flame with white If Skydrol is heated and a piece of aluminum is placed in it, an acetylene-type

Skydrol 500 has a flash point of about 440° F and auto-ignition occurs at

417. The aging of fluids (such as oil and hydraulic fluid) is caused by their increasing acidity. due to the fact that the average aircraft gets a complete fluid change by volume at least four times per year. A l l flash points designated in 415 refer to the standard sea level pressure; decreased pressure reduces the flash point and increases volatility. cannot burn until in the vapor state, and the mixture ratio determines whether it is too lean or rich to burn.

418. have similar l o w flash points. sometimes are used by the unwary or ignorant (see NFPA N o s . 410D and 410F). accumulation in areas of the aircraft would be hazardous. combustible should be accurately traced and determined in all aircraft fires.

This process tends to lower the flash point, but may be considered negligible

Fuels

Skydrol also has this same requirement.

There are many cleaning agents, such as mineral spirits, Varsol, Oleum, etc., that These fluids should not be used in aircraft cleaning but

Spillage or The origin and source of any

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1 >-6 Manua 1 of A i r c r a f t Accident Invest i g a t i o n

419. F lu id samples should always be obta ined from t h e f l u i d and f u e l source o r s u p p l i e r as soon as p o s s i b l e , even though i t may not appear t o be p e r t i n e n t t o t h e f i r e sequence. T h i s a p p l i e s to h y d r a u l i c f l u i d s , c leaning a g e n t s , e t c . , a s w e l l as f u e l systems. A l l f l u i d l i n e s should be t r aced and inspec ted f o r b reaks , c r acks , cha f ing , and loose f i t t i n g s . I d e n t i f y t h e tub ing by t h e co lo r code or t h e schematic drawings i n t h e a i r c r a f t manual. Color codes may vary between some manufacturers or d i f f e r e n t d a t e s of manufacture.

_ - A-

-5OOF

-75OF to -850F

1 .4% 7.6%

-50°F t o +3OoF

420. I n f e r n a l machines, a c c e l e r a n t s and incend ia ry dev ices used by a r s o n i s t s (such as t h e m i t e penci1.s) gene ra l ly burn above 3000° F , and some o f them 450O-50OO0 F. d i e n t s €o r t hese devices are w e l l known to chemis ts and l a w a u t h o r i t i e s . The evidence l e f t w i l l d i f f e r from normal a i r c r a f t combustibles. Check man i fe s t and bay t o determine t h a t cargo w a s aboard v e r s u s what was a c t u a l l y found, e s p e c i a l l y wi th r e f e r e n c e t o any restricted a r t ic les of cargo.

The ing re -

+95OF t o +1450F -lO°F t o +3OoF

None -6OOF

0.6% 0.8% 4.9% 5.6%

+95OF t o +165OF -1OOF t o +lOO°F

Table 4

Flammability C h a r a c t e r i s t i c s of Avia t ion F u e l s t

C h a r a c t e r i s t i c s

-

F r e e z e P o i n t

Vapor P r e s s u r e (Reld-ASTM D323-58)

F l a s h P o i n t (By Closed-Cup Method at Sea Leve l )

F l a s h P o i n t (By A i r S a t u r a t i o n Method)

Flarmuabi l i ty L i m i t s Lover L i m i t Upper L i m i t Temp. Range f o r Flam. Mix tu res

Au to - ign i t ion Tempera ture

B o i l i n g P o i n t s I n i t i a l End

Pool Ra te of Flame Spread*

Gaso l ine I Blends of G a s o l i n e and Kerosene Kerosene Grades

AVGAS 1 JET :i-:-' J E T A-1 I JET B and JP-4

-76'F [ ~ -4OOF -6OOF

5.5 t o 7.0 l b / s q . in. 0.1 l b / s q . in. I 2 . 0 t o 3.0 l b / s q . in .

+825OF t o +960°F

llO°F 32 5OF 45OoF

t F o r f u r t h e r i n f o r m a t i o n s e e NFPA No. 407, Appendix A. *In m i s t foam, r a t e o f f lame s p r e a d i n a l l f u e l s is v e r y r a p i d .

1 6 / 4 / 7 3 No. 3



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500. Determining the CrashIFire Sequence

501. General. cation of observation and logic to the physical evidence available. must always be thoroughly evaluated. they observed fire before the crash, when in fact fire occurred at impact. occurrence of in-flight fire is relatively rare. For this reason the investigator must be very careful in correlating statements with evidence revealed by examination of the wreckage. The establishment of the fact that fire did occur in flight and determining its cause will result in action to correct future occurrences. Generally, in-flight fire may be distinguished from post impact fire by these points:

Détermining the CrashIfire sequence is accomplished primarily by the appli- Witness corroboration

In past investigations, witnesses have stated that The actual

After assembling the wreckage, parts subjected to an in-flight fire will be burned more severely than parts subjected to ground fire.

The smoke and soot pattern of an in-flight fire follows the airflow, and there will be clear spaces downstream from rivets and skin splices.

The smoke and soot pattern of a ground fire is sporadic (generally upward) and in different directions from the natural air flow of flight. Struc- tural parts subjected to ground fire generally have twigs, leaves, etc., outlined in the smoke or soot.

In-flight fires are usually very hot, burn through metal parts, and leave less metal residue than ground fire. metal deposits helps to distinguish inflight from ground fire.

Analysis of flow direction of molten

502. Methods of Determining the CrashIFire Sequence

a) Parts not subjected to ground fire

(i) The most logical place to begin the investigation is to locate parts not subjected to ground fire and examine them for evidence of inflight fire. Evidence to look for is smoke, soot, heat discoloration, charred sealant and metal spray. Before considering such evidence as positive indication of inflight fire, the investigator must have knowledge of normal appearance of such parts after extensive normal operation. For example, the normal soot deposit within the aft fuselage of the military F-100 is made during ground operation; the negative pressure in the engine inlet duct is used to draw cooling air through the aft compartment from the annulus around the tail pipe, drawing some exhaust gases back into the compartment with the cooling air, leaving a normal deposit of soot on the interior of the aft fuselage. Such normal deposits must be distinguished in order to correlate all the evidence.

(2 ) Erroneous conclusions may be reached when examining heat discolora- tions since they are a relative function of both time and temperature. The same discoloration can be achieved by exposure to a low temperature for a long period of time (normal operation) as will result from a high temperature exposure for a short period of time (fire). The discoloration of titanium exposed to 600' F for 260 minutes will be

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the same as that resulting from exposure to 1000° F for 15 minutes. This applies to most other metals as well, within certain temperature ranges. If the metal has a known temperature point at which chemical change occurs (such as titanium - par. 407), this will place a boundary on the temperatures reached. The higher.norma1 operating temperatures of modern aircraft have dictated the increased use of stainless steel and titanium, both of which acquire a blue heat discoloration at these high normal operating temperatures. Inves- tigators should check with maintenance personnel of the airline involved when evaluating both smoke and soot deposits and heat discoloration.

One method of determining whether a part has been subjected to ground fire is to note the location of the part in relation to the apparent ground fire area. Parts or molten metal droplets may be shed in flight and found along the flight path. Other parts may be thrown completely clear of the fire area by the impact or an explosion. Even parts found within the ground fire area may be free of ground fire damage. Frequently parts are buried under a protective covering of dirt, both at the initial point of impact and at the point of rest Sometimes the crash scene will be just a hole in the ground and the wreckage must be dug out, in which case the ground fire is very small except for initial explosion, with the parts protected from ground fire by the dirt covering. If the crash site is swamp or water, the parts may be shrouded. Subsequent to ground fire fighting, the parts may be covered by foam, dry chemical or may be submerged below the level of unburned fuel. In some cases parts may be trapped or en- closed in other parts which protect them from the ground fire.

The location in which a part is found may not be completely decisive in determining the crash/fire sequence, but close examination should provide additional information. The evidence to look for is the relation of the effects of the fire to the results of the physical disintegration. The existence of bright scratch marks, scuffs and smears in the soot, and discolored areas indicates that disintegration occurred after the soot and/or discoloration had formed from inflight fire. Soot in torn edges indicates that fire occurred after disintegration, as well as discoloration of torn edges and scratches. in a part after being thrown clear of impending ground fire area may be sufficient to discolor exposed surfaces; however, this is more apt to occur with parts of large mass.

In many accidents where inflight fire existed, metal spatter deposits are found on areas removed from the fire source area. These can be analyzed to determine the content and possibly the portion of the aircraft from whence they came. The slipstream of chimney effect from inflight airflows, or even compartmental airflows, are strong enough to carry large globs of molten metal quite a distance and impact them onto cold objects. is the so-called aluminum "brooms trawl' or "feathering" effect common in inflight fire investigations. Basically, when aluminum in a near molten state is shock loaded, such as in a crash impact, the material will exhibit an extremely delaminated appearance resembling broom- straws or having feathered edges. This phenomenon can only occur under the above circumstances and is thus positive evidence of an existing fire prior to impact or inflight explosion,

This is not always true because residual heat remaining

Another indication of inflight fire

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APPENDIX 12.- F i r e I n v e s t i g a t i o n 12-9

(6) Flame tempera tures reached by f u e l , o i l , and h y d r a u l i c f l u i d s i n ambient a i r a r e normally i n t h e range of 1600-2000° F, b u t t h e tern-. p e r a t u r e s reached by i n f l i g h t f i r e s may exceed 3000° F due t o t h e forced d r a f t e f f e c t o f a i r f low. have "chimney" e f f e c t s i n f l i g h t ; f o r example, i n t h e t a i l a r e a a f t of p r e s s u r e bulkheads, t h e air t ends t o f low up t h e i n s i d e of t h e f i n and o u t i f t h e r e are passeges through which it can flow - o r a f t e r f i r e h a s made such passage.

The source of f i r e can f r equen t ly be l o c a l i z e d a t t h e pp in t of g r e a t e s t damage o r a t a point i n d i c a t i n g t h e g r e a t e s t amount of hea t . A broken or l e a k i n g f l u i d l i n e r e s u l t i n g i n f i r e can be l o c a t e d by c a r e f u l i n s p e c t i o n of t h e damage. of a sh o r , s o o t may i n d i c a t e t h e source of f i r e ; such samples should be ob ta ined b e f o r e they a r e d i s s i p a t e d by wind o r r a i n .

Many i n t e r n a l a r e a s of a i r c r a f t

(7)

Analys is of samples

( 8 ) Soot p a t t e r n s a r e formed as a r e s u l t o f s o o t d r i f t i n g wi th t h e air stream u n t i l i t s t r i k e s . a n o b j e c t t o which i t can a t t a c h i t s e l f by means of t h e unburned oils it c o n t a i n s and by e l e c t r o s t a t i c a t t r a c - t i o n . One p o i n t t o remember is t h a t s o o t w i l l n o t a t t a c h i t s e l f ta s u r f a c e s which are hea ted over about 700° F. which show t h e g r e a t e s t i n t e n s i t y of f i r e may c o n t a i n l i t t l e o r no soot.

There fo re , a r e a s

(9) It w i l l be necessa ry t o r e c o n s t r u c t t h e a i r c r a f t from t h e remaining p a r t s in o r d e r t o d e t e c t a pattern. t h e a i r c r a f t , i f there is a d e t e c t a b l e pattern i n t h e d i r e c t i o n of t h e i n f l i g h t a i r f l o w , an i n f l i g h t f i r e i s i n d i c a t e d . Conversely, if t h e r e is n o t c o n t i n u i t y of p a t t e r n a c r o s s l i n e s of f a i l u r e , t h e p a t t e r n s were formed a f t e r t h e a i r c r a f t d i s i n t e g r a t e d . The shape8 of t h e p a t t e r n s w i l l be a f f e c t e d by any o b j e c t which t ends t o shroud o r b lock ano the r p a r t . The shrouded p a r t w i l l show t h e gene ra l ou t - l i n e of t h e o b j e c t doing t h e shrouding. such an o u t l i n e b u t t h e p a r t which d id t h e shrouding is n o t t h e r e , t h e p a t t e r n must have occurred be fo re d i s i n t e g r a t i o n . Conversely, i f both t h e o u t l i n e and t h e shrouding p a r t a r e found i n r e l a t i o n but t h e shrouding p a r t is n o t normally i n t h i s p o s i t i o n on t h e a i r p l a n e , t h e p a t t e r n was formed a f t e r d i s i n t e g r a t i o n .

Fol lowing r e c o n s t r u c t i o n of

I f a p a r t is found wi th

b ) Heat i n t e n s i t y i n v e s t i g a t i o n s

(1) Heat i n t e n s i t y is another means by which t h e c r a s h I f i r e sequence can be determined. Th i s method is becoming more p reva len t a s more of t h e h ighe r h e a t r e s i s t a n t m a t e r i a l s are used in modem a i r c r a f t . The flame tempera tures of p o s t - c r a s h I f i r e s i n which combust ibles l i k e g a s o l i n e , JP-4, l u b r i c a t i n g o i l , and hydrau l i c f l u i d s a r e being consumed i n s t i l l a i r is normally i n t h e range of 16000 F t o 2000' F. The flame tempera tures of i n f l i g h t f ires a r e u s u a l l y i n excess of 3000O F due t o t h e forced d r a f t of t h e s l i p s t ream and lo - compartment coo l ing a i r f l o w . The e f f e c t of t h e f o r c e d d r a f t is t o cailse t h e f u e l l a i r r a t i o t o be more n e a r l y s to i chomet r i c . p a r t s which have a mel t ing po in t i n e x c e s s of 2000° F, l i k e s t a i n l e s s steel and t i t a n i u m , a r e found showing ev idence of me l t ing , i t i s a s t r o n g i n d i c a t i o n t h a t i t occurred i n f l i g h t . The i n d i c a t i o n is

Therefore , when any

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stronger if the part is found in an area in which investigation showed that the ground fire was not intense. because it is possible for ground fire to exceed 2000° F due to strong ground winds, or peculiar piling of the wreckage may cause a chimney effect whereby the fire causes its own draft. In addition, materials like magnesium which burn with an intense flame may be present. to melt stainless steel or titanium exists is very small and is the result of some localized jet effect, similar to a welder's torch.

It is not conclusive

Usually the area in which a flame temperature hot enough

c) Existence of fire conducive conditions

(1) Frequently a failure or condition which would logically produce fire is found before any evidence of inflight fire is found. cumstantial evidence should be proved or disproved by thoroughly investigating the possibility of inflight fire evidence in the wreckage.

This cir-

(2) Such circumstantial evidence is almost infinite in variety. be a burn-through of the engine, disintegration of high-speed rotating parts, electrical shorting, etc. Electrical arcing damage can usually be differentiated from fire damage. very localized as to both metal removal and heating. Damage will have an eroded appearance and there may be metal splatter similar to that produced in arc welding. The strands of copper wiring will be fused together, and usually little beads are formed on the ends. Such fusing and beading does not occur from fire. The difference is probably due to the heating rate and intensity. When heated externally, the heating rate is relatively slow. on the surface of the strands, and the scale prevents fusing. In addition, the intensity of m s t fires, particularly those on the ground, is not sufficient to melt copper (about 2000° F).

It m y

Damage from electrical arcing is

This permits a scale to form

(3) A word of caution in regard to evidence which indicates that an inflight failure or fire condition existed. impact may produce such evidence. connection. steel and aluminum, only finger tight in the wreckage and thus indicate that an inflight leak existed. Loose "B" nuts may be caused either by mechanical damage or fire. Loosening by mechanical damage is usually evident by the mechanical condition of the connector and its attaching lines. probably due to annealing and relief of the stresses which consti- tuded the torque. loose, it is not the result of fire.

A ground fire or the

It is not uncommon to find numerous "B" nuts, both An example is "B" nut line

The loosening by fire is

If a "B" nut is more than a quarter of a turn

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MANUAL OF A I R C R A F T A C C I D E N T I N V E S T I G A T I O N

A P P E N D I X 1 3

S T A T E S ' F L I G H T RECORDER P L A Y B A C K F A C I L I T I E S AND T E C H N I Q U E S

This Appendix contains information on f a c i l i t i e s avai lable and techniques used i n some Sta tes f o r f l i g h t recorder playback.

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13-1 I APPENDIX 13.- S t a t e s ' F l i g h t Recorder Playback F a c i l i t i e s and Techniques

APPENDIX 13

STATES' FLIGHT R E C O R D E R P L A Y B A C K

FACILITIES AND TECHNIQUES

CANADA

THE NATIONAL AERONAUTICAL ESTABLISHMENT

FLIGHT RECORDER PLAY BACK CENTRE

SUMMARY

L

A Playback Centre has been established that isacquiring unique experience in recovering and analysing information from a wide range of aircraft audio and data recorders. In particular, the Centre has been designed to handle all cockpit voice recorders and flight data recorders fitted to Canadian civil and military transport aircraft.

Recorders are forwarded to the Centre whenever incidents or accidents warrant investigation by the authorities concerned. The playback facilities have been designed with special emphasis on the problems that might be encountered in these cases. Routine monitoring is also conducted on the military systems for maintenance purposes.

Current and future capabilities of the Centre are summarized and examples given of some ob the work that has been undertaken. The types of recorders that are routinely handled are given in Tables 1, 2 and 3. Digital data formats that can be processed are listed in Table 4.

1. O INTRODUCTION

Over a period of many years, the National Aeronautical Establishment has provided the Ministry of Transport and the Department of National Defence with assistance in the investigation of aircraft accidents. With the introduction of flight. data recorders and cockpit voice recorders on transport aircraft, the Flight Research Laboratory in particular has provided expertise in the read-out and analysis of the recorder information. From 1967 to 1972, this work was confined to civil transport aircraft accidents and incidents. For the more advanced magnetic recording data systems, due to the lack of suitable facilities, .information was recovered using playback equipment available at t,he maintenance hases of the major airlines or at t h e recorder system maitufacturer's plant.

In November 1971. the National Research Council proposed to the Ministry of Transport and the Department. of National Defence that a comprehensive facility should be set-up at the Flight Research Laboratory to handle read-out. and analysis of all types of flight data and cockpit voice recorders fittea to Canadian civil and military transport aircraft. In making the proposal, it was iioted that the Flight. Research Laboratory was unique in combining exper?ise and a bzck-up organization covering all !.?IC wlCviiiit fields of Eight recording systems including design and manufactiire of andogue and digitai rys!-rns, digital cornpiit.er proqrarnming, flight operations, aerodynamic performance, aircraft stabiiity and control and aircraft systems.

The t w n departments agreed ti; jointiy funà the purchase of the mr?iority of the equipment with the National Research Council providing the staff, accommodation an<! hack-up faciiities, and work commenced in setting up the Centre in September 1972.

For the Ministry of Transport. the Centre was required to develop the capability of handling all the wide range of recorders in service on Canadian civil transport ai: c raft with emphasis primarily on playback of information in the event of incidents and accidents. For the Department of National Defence, the requirement differed in that only one basic combined voici! and data system was being

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Manual of A i r c r a f t Accident I n v e s t i g a t i o n 13-2

installed in their transport aircraft, and that the Centre was required to handle routine playback and analysis of information to check on the flight recorder systcm serviceability as well 2s to investigate any incidents or accidents.

In developing the facilities, i t was decided to place special emphasis on the recovery of information that had been degraded either by physical damage to the recording medium or by extreme environmental conditions such as might occur in incidents or accidents.

This report outlines the current status of the Centre, including details of its existing and planned future capabilities.

2.0 GENERAL FEATURES OF THE PLAYBACK CENTRE

The Playback Centre is situated in two rooms at the Flight Research Laboratory. A plan view of these rooms is illustrated in Figure 1. The walls of the rooms are sound insulated for security purposes and to minimize interference from external disturbances. A quiet air conditioning system has been provided to cope with the maximum likely number of persons that may be present during a major investigation.

A separate internal shielded room, a Rayshield Series 81-A, has been installed as shown in Figures 1 and 2. This room provides an environment relatively free from electromagnetic interference in which tapes may be copied and also an acoustically quiet area for listening to audio recordings. It is also a convenient dark room for an optical comparator. The shielding provides 110 db attenuation :)f cdectric fields and 60 to 100 db attenuation of magnetic fields, depending on the frequency. Acous- tic attenuation varies from 30 to 70 db over the audio frequency range. One hundred and fifteen volt power supplies of 60 and 400 Hz, both with 25 amp. rating, are available in the room. These are both fed through line filters providing 100 db attenuation at frequencies above 14 KHz.

All essential equipment is provided in the Centre for the dismantling of the flight recorders and photographic equipment is readily available to record the various stages followed in this process. Electrical connectors and both 115V 400 Hz and 28V DC power supplies have been arranged to permit playback of the data without removal of the recording medium from the flight recorder where this is preferable, and the recorder design permits, for routine monitoring purposes or for incident investigations.

Two similar Ampex AG-445B variable speed tape transports are available for playback of W-inch or %-inch magnetically recorded tapes. Various playback head assemblies can be attached to these transports to cope with the ten different tapes currently in use. The playback heads are mounted in these assemblies using a modified EPOI LP-6 Profile Projector as an optical comparator to ensure accurate alignment.

One of the tape transports, illustrated in Figure 3, has been modified to include several features desirable for playing back damaged tapes. These include:

(i) Digital speed display.

(ii) Variable tape tension.

(iii) A co-belt system to assist in maintaining good head contact when the tapes are creased without using excessive tape tension.

(iv) Adjustable tape guides for badly aligned tapes. These have been made long enough to prevent tape misalignment due to local edge snags or tears that might be present, particularly on metal foil tapes.

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APPENDIX 13.- Example of a F l i g h t Recorder Playback Centre 13-3

3.0 PLAYBACK OF COCKPIT VOICE RECORDINGS

The Centre is currently equipped to replay tapes from four basic types of cockpit voice recorder. They each provide the last 30 minutes of four channels of audio information. Details of the tapes concerned are given in Table 1. For incidents or minor accidents provision has been made to replay the tapes in the flight recorders. In the case of major accidents or damaged recorders, the tape can be removed from the recorder and replayed on one of the Ampex tape decks.

The tapes are replayed in the shielded room to minimize external interference and are copied on to a Sony TC-654-4 four track tape recorder with the two most relevant tracks also being copied on to a stereo cassette using an Advent 201 cassette deck. The cassette copy is sent to the accident investigators. If considered desirable, the remaining two audio tracks may be recorded on the reverse side of the cassette. The equipment is illustrated in Figure 4.

During the copying process, two selected channels may be monitored either by stereo h a d - phones or via a two channel Kenwood KA-4002 amplifier by a pair of Dynaco A25 loudspeakers. To improve intelligibility, either channel may be switched through a URE1 Universal Audiri Model 565 Filter Set containing high and low pass filters and two band-pass or band-rejection filters of variable width.

The four track copy tape may then be used to make written transcriptions of the speech, again using the Filter Set when required. Alternatively, if a long transcription becomes necessary, the process may be expedited by replaying a cassette copy on a Lexicon Varispeech 1 unit that permits the speed to be varied from Ih to 2% times the normal value with no change in the pitch of the sounds. (At the slowest speed, it has also been found useful for confirming the sequence of rapidly occurring events.) This unit, utilizing a digital technique, does of course suffer from the limitation that it de- grades the quality of the signal slightly by introducing some ‘“splicing” noise from the recombination of digitized samples.

In addition to the four types of cockpit voice recorder referred to, three audio channels are also combined with a serial digital data channel in the Leigh military transport recorder systems. Play- back techniques for these systems are described in Paragraph 4.3.1.1.

4.0 READ-OUT OF FLIGHT DATA RECORDINGS

There are three basic types of flight data recorders currently in use in Canada as follows:

(i) Those using metal foil recording mediums with stylus marking on the foil.

(ii) Multiplexed analogue FM systems recording on magnetic tape.

(iii) Serial digital magnetic recording systems.

These vary considerably in complexity in that, whilst the first typt: are normally mcnitonng only five basic parameters, the latter two usually cover from approximately 20 to 50 measured parameters as well as a large number of bi-state or ON-OFF signals. The equipment and techniques available M recover data from these different systems are outlined below.

4.1 Stylus Marking on Foil

Details of the different models of these recorders in use in Canada are given in Table 2. The Aviation Safety Engineering Laboratory of the Ministry of Transport, located in a National Research Council building close to the Flight Research Laboratory, has a Jones & Lzmson Epic 14 Optical Comparator with a digitai display of x, y Co-ordinates that is used to measure the position of the stylus indentation marks on the foil. The optical system provides magnification up tc x100 and the

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image may be photographed if required. A foil mounting system is being developed to Playback Centre specifications to allow rapid setting up of the foil using suction to hold the foil flat over the section where measurements are being taken. A punched paper tape output is also being arranged to speed up the reading operation and to allow the data to be processed on the computer system at the Playback Centre.

4.2 Multiplexed Analogue FM Systems Recorûing on Magnetic Tape

The few systems of this type in use on Canadian aircraft are all Royston Midas equipment. The majority are operated by Air Canada who also have a playback machine for data recovery. In view of the small number of these systems being used and the specialized nature of the playback machine, no attempt has been made to duplicate the playback capability at the Centre.

The Air Canada machine does, however, have one limitation. Due to a high playback rate of 100 x record speed, the individual frequently sampled normal acceleration measurements cannot be seen on the chart recorder output. An analogue FM tape recorder with a wide speed range is available at the Flight Research Laboratory and has been used to enable this fine detail to be recovered.

4.3 Digital Magnetic Systems

These constitute the majority of the data recording systems in use in Canada. The various systems and details of their associated recorders are given in Table 3. Al1 the systems basically utilize the same phase encoded serial digital format. There are, however, a number of detailed variations in the formats of the different systems. These are summarized in Table 4.

A single playback facility utilizing an Interdata Model 70 mini-computer has been developed to process all data formats. This is illustrated in Figure 5 and described in Paragraph 4.3.4.

In general, provision has been made to supply the serial digital data signal either directly from the flight recorder or through playback of the recording medium removed from the recorder. Detailed provision for each type of recorder is described in the following paragraphs.

4.3.1 Leigh Instruments Data Systems

4.3.1.1 Canadian Armed Forces Transport Aircraft

The flight data recorders used on these aircraft are unique in that they are not provided with armoured protection for crash survival as in all the civil aircraft systems. The recorder is a small reversing-tape unit manufactured by Leigh Instruments that is installed in a light flush-mounted aero- foil device fitted to t.he rear portion of the fuselage. The device also incorporates a locator beacon and is designed to separate from the aircraft when it first strikes the ground or experiences major structural failure in flight.

The system also differs from the civil aircraft ones in that it combines three audio channels with one digitai channel and retains only the last 30 minutes of data.

For routine monitoring of the aircraft systems, a plug-in unit has been developed for the flight recorder providing ready access to all record and monitor head signals, with tape direction selection and indication, and audio monitoring of all three audio channels. A flight recorder ready for playback is shown in Figure 6. During playback, the data channel is fed to the computer for transcription into parallel format on nine track tape and for selected chart read-outs whilst all four channels, Le. audio and data, are re-recorded in the original format on four track %inch tape.

In the event of a major accident, the tape would be removed from the recorder and replayed on the reel-to-reel tape deck in the shielded room. If the tape were damaged significantly, all eight tracks would be copied simultaneously with the data channel that is in the forward direction being simultaneously processed on the playback facility.

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APPENDIX 13.- Example of a F l i g h t Recorder Playback Cen t re 13-5

4.3.1.2 Air Canada DC-9 Aircraft

The system on these aircraft utilizes a Fell CO 1000 flight recorder. The recorders involved have undergone several modifications and in their present form contain a %-inch recirculating tape loop with eight sequential serial digital data tracks retaining the last 49 hours of data. In line with Air Canada procedures, no provision has been made' for replaying the tape in the flight recorder, the tape being transferred to the reel-to-reel tape deck for data recovery.

4.3.1.3 Canadian Regional Carriers

The Leigh Instruments data systems fitted to a variety of aircraft operated by these carriers utilize a recorder that is basically the Fairchild A-100 cockpit voice recorder modified to run a t a r e duced tape speed and to record eight sequential serial digital data tracks on its recirculating tape loop so that the last 14 hours of data are retained. Provision has been made for replaying the tape either in the fiight recorder or on the reel-to-reel tape deck.

4.3.1.4 Air Transit STOL Service D.H. Twin Otter Aircraft

As part of the Ministry of Transport STOL development programme, these aircraft are fitted with a data acquisition system with a nine track parallel format airborne recorder. For accident investigation purposes, the aircraft also carries a modified version of the Fairchild A-100 cockpit voice recorder recording two tracks of audio information and one track of the data output in serial digital format. Provision has been made for replaying the accident recorder tape either in the flight recorder or on the reel-to-reel tape deck.

4.3.2 CP Air Garrett &Research Systems

These systems, fitted to the majority of CP Air's aircraft, use the Davail Type 1190 re- cycling wire recorder. This recorder contains two 1.5 mile lengths of 0.0023 inch diameter stainless steel wire, senai digital data being recorded on one wire whilst the other is being re-wound.

For incidents and accidents where the recorder is undamaged, provision has been made for recovering the data directly from the recorder. In the event that the recorder is damaged, the Davail replay unit shown in Figure 7 is utilized. This unit will accept the reels from the recorder, or in the event that these are damaged, allow transfer of the wire to other reels for subsequent data recovery. The unit is fitted with two playback heads, one to provide the data signai for processing and the other to permit monitoring of the information on an oscilloscope. Three different wire speeds may also be obtained by interchanging gear trains.

4.3.3 ARINC 573 Data Systems

These systems are now in service with a number of Canadian operators. The system manufacturers concerned are Teledyne, Hamilton Standard and Garrett AiResearch. I t should be noted that the Teledyne data format differs from the others in having the Barker code in the synchronization word in reverse order. The playback facility has been designed to accept both formats.

Data recovery procedures depeiid primarily on the type of flight recorder used. There are two types currently in service, namely the Lockheed 209 and the Sundstrand 573A Digital Flight Data Recorders. These are hoth reversing tape systems with sequential track switching for the serial digital data. The Lockheed recorder uses %inch mylar tape with six tracks of data whilst the Sundstrand uses %-inch Vicalloy metal tape with four tracks of data.

4.3.3.1 Lockheed 209 Digital Flight Data Recorder

Three modes of data recovery are available. For incidents or minor accidents, the Playback Centre has a portable Lockheed Model 235 Copy Recorder that can be connected to the fiight recorder in the aircraft and will drive i t a t thirty times its normal speed aiid copy threE tracks of data

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13-6 Manual o€ A i r c r a f t Accident I n v e s t i g a t i o n

simultaneously. By this means, the full 25 hours of recorded data can be copied in 17 minutes without disturbing the aircraft system. The copy tape so obtained can then be replayed at the Centre.

Alternatively, the flight recorder itself can be removed from the aircraft and replayed at the Centre without removing the tape. Finally, in the event of a major accident or damage to the recorder, the tape may be removed and replayed on a reel-to-reel tape deck.

4.3.3.2 Sundstrand 573A Digital Flight Data Recorder

For this recorder, data can be recovered from the unit at thirteen times the record speed by connecting the recorder to the Sundstrand DFDR Playback Unit as shown in Figure 5. Again, if the recorder is damaged, the tape can be removed and replayed on the reel-to-reel tape deck.

4.3.4 Digital Data Processing

The facility developed to process the serial digital data signal utilizes an Interdata Model 70 mini-computer. Programmes are filed on nine track %-inch tape and loaded into the computer memory rising one of the Cipher units illustrated in Figure 5. Playback head signals from the flight recording medium are first amplified and re-shaped to closely approximate the original square-wave bi-phase signal fed to the recorder. The circuits used depend on the type of recorder and data recovery rate. The clock transitions are extracted from this bi-phase signal and three-quarters of the bit time past each of these transitions, the bi-phase data is sampled to determine whether a data transition has occurred.

The 3/4 time is generated either by pre-setting a variable capacitance or by a technique developed in the Flight Research Laboratory where it is based on either the preceding bit time or the average of the time of three preceding bits. This latter technique allows the processor to remain locked on to the data through large variations in the data rate such as may occur during run-down of a recorder after an accident or in the event that excessive wow develops in the signal.

The information is then converted to a parallel format in one of three interfaces that have been designed to process the three different serial digital formats detailed in Table 4 and re-recorded on to one of two Cipher nine track tape recorders. At the same time, up to six parameters may be selected through the computer terminal for conversion to analogue signals that can be displayed on the Gould Brush 260 pen recorder shown in Figure 5. The recorded time or elapsed time based on the data rate or combination of these two times is displayed during this operation.

Consideration has been given to procedures to be adopted in the event that an original flight tape is damaged in an accident. Facilities are being provided to amplify and re-shape the signals from all data tracks simultaneously on the first playback of the tape so that the re-constituted serial digital signals may be re-recorded directly on a Hewlett Packard 3900 recorder during processing of one selected track.

However, during this copying process and the subsequent playback, some deterioration of the data quality is inevitable. The programmes transferring the signal that is being processed on to the nine track tape have therefore been designed to transfer all data bits, even if data synchronization is temporarily lost. An additional programme has been developed that permits reconstruction and printout of the serial digital sequence from the nine track tape. This printout may then be studied to try and determine where errors occurred in the processing of the bit sequence and hence permit manual resynchronization of the short periods of data concerned. This technique has been used on several occasions.

From the nine track tape, a comprehensive computer programme permits display of up to six parameters or groups of up to three bi-state signals on the pen recorder. From the same source, a second comprehensive programme enables printout of the recorded binary numbers of up to eight parameters in decimal or octal format interspersed with the derived time every five or ten seconds. This is normally done on the Data Products high speed line printer.

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APPENDIX 13.- Example of a F l i g h t Recorder Playback Cen t re 13-7

For some of the earlier systems, a library of programmes have also been written to enable printout of a prearranged selection of the parameters in engineering units using standard calibrations again interspersed with the derived time every five or ten seconds.

A newer procedure being developed enables the assembly of a file of conversion sub-routines and standard constants for each aircraft typelrecorder system combination, the appropriate file being used with a standard conversion programme to convert the raw data on the nine track tape into en@- neering units in floating point format and to re-record this on to a second nine track tape. The latter tape will then subsequently be used for printout of any desired grouping of parameters,. for further computation, or for plotting purposes. Provision is being made for the conversion constants t o be modified for any particular aircraft depending on the calibration data that are available and for these constants to be stored a t the beginning of each data file for future reference.

For plotting purposes, a Tektronix Model 4014-1 terminal with a large CRT display is being obtained to-replace the standard Teletype machine. This terminal will permit extensive graphic dis- plays and has the capability of transferring the information on to a hard copy as required. A 3û-inch Calcomp Model 563 Plotter is also available €or larger scale plots.

5.0 ANALYSIS OF RECOVERED INFORMATION

5.1 Assessment of Reliability of the Recovered Data

An important part of any accident or incident investigation involving flight recorders is to check the accuracy and reliability of the recovered data by every means that is available. Techniques that have been used at the Flight Research Laboratory have included:

(a) Integration of normal acceleration time histories and comparison with differentiated pressure altitude data.

(b) Determination of aircraft total energy to ensure that only smooth variations occur.

(c) Cross-checking of angular rates of rotation and attitudes via the akcraft equations of motion.

(d) Derivation of terrain variations from pressure and radio altimeter data and comparison with geographic contours.

Accurate synchronization of cockpit voice and flight data recordings has also often permitted various cross-checks between reported and recorded parameters.

5.2 Reconstruction of Aircraft Flight Path

Once the data have been checked, comparison of available related parameters concerning the aircraft motion such as pressure altitude, radio altitude, airspeed, ILS deviations etc, permits the selection of an estimated time history of the flight path. Wind corrections may have to be based on estimated values unless the aircraft’s true geographic position is accurately known at more than one point.

Once the x, y , and z Co-ordinates of the flight path have been derived, a computer programme has been formulated that enables this path to be plotted for purposes of illustration as if it were viewed from any desired position in space. A sample plot from Reference 1 is given in Figure 8. An extension of the programme permits the nose, wing-tip, and fin tip positions also to be plotted relative to the centre of gravity based on the aircraft attitude data, when available, SD that a view of the aircraft at any instant may be superimposed on the flight path.

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5.3 Spectral Analysis of Audio Recordings

Audio recordings, either from the aircraft cockpit voice recorder or from ground units monitoring A.T.C. Communications can be the most important source of information in accident investigations. Spectral analysis of these signals may be used to obtain hard copies 0; speech characteristics to differentiate between crew members or to derive information such as turbine speeds from background noise.

For rapid spectral analysis of this type with ready correlation between the chart output and the audio input, the Playback Centre has the Base Ten LGK100 Voice Scan Spectograph illustrated in Figure 9. With this unit, the audio signal to be analysed is recorded on to a full width track on a %-inch mylar tape and the section to be analysed then formed into an effective loop, normally of 2.4 seconds duration, that is scanned by a rotating head assembly at high speed. The output of the analogue spectral analysis is fed to a stylus marking an electrically sensitive paper mounted on a drum. Diagrams produced are plots of frequency versus time with the amplitude of the various frequencies denoted either by the'intensity of marking or by contour plots. Frequency ranges of 50 Hz to 4 KHz or 50 Hz to 8 KHz iiiay be selected, the bandwidth of the scanning filter being either 45 or 300 Hz. Charts may also be made of amplitude versus frequency at selected instants in time.

When finer resolution of frequency is found necessary, Federal Scientific Real Time Analysers are available in other NRC laboratories. Synchronized photography of the CRT display of the frequency spectrum has been arranged using a Milliken 16mm camera.

5.4 Routine Data Monitoring

Routine playback of flight recorders from military transport aircraft at the Playback Centre is primarily intended to aid in identifying and rectifying defects in the flight recorder systems. How- ever, the information obtained during this work is also scanned closely for any unusual events. Since the fraction of the total aircraft flying hours being examined is extremely small, such events are rare.

One particular case, that demonstrates potential benefits of comprehensive data monitoring, resulted when a recorder from a turboprop aircraft that had suffered a propeller reduction gearbox failure during landing was replayed. It was noted that the torque data for the engine concerned were very noisy throughout the recording prior t o the landing. During a playback made three months earlier, it had been observed that the same engine had some noise on the torque signal but the cause had not been identified. Similar noisy signals had previously been observed and reported on four other engines fitted to different aircraft. This was brought to the attention of the maintenance personnel who decided to remove them for inspection. In each case, damage was found suggesting that total gearbox failure was imminent. The vibration was apparently not evident to the flight crews and the aircraft torque indicators were sufficiently damped that they did not respond to the frequencies involved. Thus the recorder system was instrumentai in avoiding the hazards and cost associated with four in-flight engine failures.

6.0 RESEARCH AND DEVELOPMENT

6.1 Detailed Analysis of Playback Head Signais

During Check-out of serial digital data systems, detailed study of the playback head signals has been found necessary. For small data samples, a Tektronix 466 storage oscilloscope has been used with a Polaroid camera to provide a permanent copy. For longer samples, a high speed Consolidated Recording Oscillograph with mirror galvanometers having a frequency response that is flat up to 5000 Hz is used. If the head signal decreases in amplitude for a short period for any reason and becomes too small for processing, it may still be possible, though tedious, t o read the data manually from the photographic record that is produced.

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APPENDIX 13.- Example of a F l i g h t Recorder Playback Cent re 13-9

When difficulties were encountered with data recovery with one system 'using a reversing tape, the oscillograph records were invaluable in isolating the cauce. I t was found that the track that had previously been recorded in the reverse direction was being partially erased due to capacitively induced signals in the reverse erase head. This was readily cured by isolating both sides of each erase head instead of only one side when the tape direction was such that they were not required to be operating. 4 fault that caused similar problems was also rapidly tracked down by the same technique to stray signals in a reverse record head that superimposed high frequency noise on a previously recorded data signal.

The oscillograph records have also been found useful for checking the effectiveness of erase heads by studying the recordings on the short section of tape that came to rest between the erase and record heads when the system was shut down.

6.2 Measurement of Wow and Flutter in Serial Digital Data Signals

The computer interface that has been developed to enable the computer to remain locked on to a serial digital signal through large variations in the data rate utilizes a high frequency clock and counts the number of cycles between each transition in the signal. This information is extremely useful in indicating the wow and flutter in the data signal. A programme has therefore been written to store these counts in the computer memory for subsequent reading at low speeds on to a chart recorder.

Using this system, difficulties wit.h data recovery on one early design of recorder were readily tracked down to a 30 Hz oscillation in the tape motion that was excited during touchdowns, rotations on take-off, and in turbulence. Sample results are shown in Figure 10. Application of the technique to one track of an airborne nine track parallel format recorder tape was also valuable in isolating problems in its incremental mode of operation.

6.3 Specification of Flight Recorder System Requirements

Experience in the Flight Research Laboratory with recording systems and analysis of the resulting information has resulted in many recommendations for the improvement of requirements for flight recorders. Some typical examples are given below.

6.3.1 Vibration Environment Tests

Present requirements for vibration testing of recorders cover only translational motion. However, the tape motion of some recorders has been found to be sensitive to angular motions in the plane of the tape reels due to the combined inertia of the reels and tape. The vibration requirements need to be expanded to cover this case.

6.3.2 The Use of Anti-_4Iiasing Filters

In sampled data systems, any frequencies in a signal prior to sampling that exceed the Nyquist frequency, i.e. N / 2 Hz, where N is the sampling rate in samples per second, can induce apparent low frequency variations in the data that do not exist in the original signal. To avoid these undesirable effects, it is essential to filter out any high frequencies prior t o the sampling. With flight data recording, the effect is usually most evident in accelerometer signals and it is therefore particularly desirable that correct anti-aliasing filtering should be applied to these measurements.

6.3.3 Sampling Rates

The sampling rates that are required in data recording systems depend largely on the occurrences that the system is designed to monitor. They are obviously restricted by the data rate and/or recording capacity being used and their choice is very much a matter of compromise.

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However, experience with analysis of the data has indicated the sampling rates that are desirable for the various parameters. For example, for derivation of effective rigid-body motions of the aircraft centre of gravity at high speed, a minimum rate of five times per second appears desirable. For engine thrust parameters, important variations can be missed during rapid power variations if it is sampled less than once every two seconds. A number of recommendations have been made along these lines to the relevant authorities.

7.0 CONCLUSIONS

The Playback Centre that has been described provides a capability for extracting the maximum amount of information from a wide range of audio and data recorders even when the quality of the recording has been significantly degraded. Experience gained in trouble-shooting systems during the development stage has been of substantial benefit in this regard.

Future plans should enable the Centre to remain abreast of new developments and thus continue to promote safety in the operation of transport aircraft.

......

NOTE: The above paragraphs desc r ibe t h e c a p a b i l i t i e s of t h e Centre as of l a te 1975. The Tektronix Terminal mentioned i n t h e last paragraph of 4.3.4 above has been used t o d i sp l ay cockpi t ins t rument readings . By record ing both voice and d a t a on the same t ape i t is p o s s i b l e t o l i s t e n t o the CVR record ing and watch se l ec t ed instrument i n d i c a t i o n s on t h e te rmina l i n "real t i m e " . of g r e a t va lue t o the s a f e t y i n v e s t i g a t o r .

Since t h a t t i m e s e v e r a l new techniques have been developed.

When t h i s c a p a b i l i t y is r e f i n e d i t i s expected t o be

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APPENDIX 13.- Example of a F l i g h t Recorder Playback Centre 13-11

Num ber Recorder Recording of

Medium Tracks

4 Collins 1/4-inch Mylar Base Model 642C-1 Tape Loop

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114-inch Mylar Base Tape Loop

114-inch Vicalloy Reversing Tape

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APPENDIX 13. - States' F l i g h t Recorder Playback F a c i l i t i e s and Techniques 13-25

AUSTRALIA

FL IGHT RECORDERS - TECHNIQUES FOR DATA

EXTRACTION FROM ANALOGUE FLIGHT DATA RECORDERS

1. - - INTRODUCTION

S ince 1963 when t h e A u s t r a l i a n requirement f o r t h e c a r r i a g e of f l i g h t r e c o r d e r s by c i v i l a i r c r a f t f i r s t became e f f e c t i v e , f l i g h t d a t a r e c o r d e r s have been used i n t h e cour se of i n v e s t i g a t i o n s i n t o a i r c r a f t a c c i d e n t s . They have a l s o been used, much more f r e q u e n t l y , i n t h e a n a l y s i s of a i r s a f e t y i n c i d e n t s t o assist i n e s t a b l i s h i n g a s p e c t s such a s a i r c r a f t performance, p a r t i c u l a r l y when r e l a t e d t o a c c e l e r a t i o n and t o t a l energy, f l i g h t p a t h s , ground t r a c k s , etc.

I n a d d i t i o n t o t h e d e t a i l e d a n a l y s i s of a c c i d e n t and i n c i d e n t f l i g h t s f o r a i r s a f e t y i n v e s t i g a t i o n purposes , ana logue f l i g h t d a t a r e c o r d i n g s o f r o u t i n e f l i g h t s have als'o been analysed t o e s t a b l i s h t y p i c a l o p e r a t i o n a l envelopes f o r t h e major makes and models of A u s t r a l i a n r e g i s t e r e d a i r c r a f t . The r e s u l t s i n t h e form of g r a p h i c a l p r o f i l e s , e .g . take-off and approach envelopes of a i r s p e e d s and h e i g h t s above t h e runway ve r sus t i m e , have been v a l u a b l e t o i n v e s t i g a t o r s as a s t a n d a r d f o r comparison wi th d a t a from an i n c i d e n t f l i g h t . The a b i l i t y t o make t h e s e comparisons h a s l e d t o e a r l y r e c o g n i t i o n of s p e c i f i c avenues o f - i n v e s t i g a t i o n n o t o the rwise e v i d e n t , though, of course , it is s t i l l necessa ry t o make a d e t a i l e d e v a l u a t i o n of t h e recorded d a t a i n t h e l i g h t of t h e s p e c i f i c c i rcumstances of t h e a c c i d e n t l i n c i d e n t f l i g h t .

F l i g h t d a t a r e c o r d e r s are r e q u i r e d t o be c a r r i e d by a l l A u s t r a l i a n a i r c r a f t which are t u r b i n e powered and c e r t i f i c a t e d t o o p e r a t e i n excess of 5 700 kg maximum weight. Cur ren t ly t h e u s e of 5-parameter ana logue r e c o r d e r s i s dominant, b u t Boeing 747 a i r c r a f t , and s i m i l a r a i r c r a f t , a r e r e q u i r e d t o r e c o r d a d d i t i o n a l parameters . Also, as from J u l y 1977 a l l turbine-powered a i r c r a f t w i t h a maximum c e r t i f i c a t e d weight i n excess of 29 O00 kg app ly ing f o r A u s t r a l i a n r e g i s t r a t i o n are r e q u i r e d t o record t h e a d d i t i o n a l parameters . The r eco rd ing of t h e a d d i t i o n a l pa rame te r s is be ing achieved by t h e u s e of d i g i t a l f l i g h t d a t a r eco rde r s : t h e A u s t r a l i a n f l i g h t d a t a r e c o r d e r a n a l y s i s l a b o r a t o r y i n c l u d e s , t h e r e f o r e , f a c i l i t i e s f o r r ecove r ing d a t a bo th from t h e analogue r e c o r d e r s which i n s c r i b e on metal f o i l and from d i g i t a l f l i g h t r e c o r d e r s which u t i l i z e magnetic t a p e a s t h e r eco rd ing medium.

A i r S a f e t y I n v e s t i g a t o r s involved i n f l i g h t r e c o r d e r a n a l y s i s have gained e x t e n s i v e expe r i ence i n t h e performance i n s e r v i c e of t h e analogue f l i g h t d a t a r eco rde r and i n t h e p rocess of d a t a recovery. Over 2 250 f l i g h t s have been examined and read o u t i n t h e cour se of a c c i d e n t and i n c i d e n t i n v e s t i g a t i o n s over r e c e n t y e a r s . Experience i n t h e recovery of d a t a from d i g i t a l f l i g h t r e c o r d e r s , a l though b e i n g accumulated a t a rate of approximately 40 occur rences a n n u a l l y , i s a t p r e s e n t less e x t e n s i v e . Th i s paper is accord ing ly conf ined t o a d e s c r i p t i o n of t h e t echn iques developed f o r d a t a e x t r a c t i o n from analogue f l i g h t d a t a r e c o r d e r s , i n p a r t i c u l a r t h e Sundstrand Model F-542 series r e c o r d e r and t h e Lockheed A i r Service Model 109 series r e c o r d e r .

The A u s t r a l i a n Department of Transpor t A i r S a f e t y I n v e s t i g a t i o n Branch would be p l eased t o d i s c u s s more f u l l y t h e methods o u t l i n e d i n t h e fo l lowing paper . any comments, c r i t i c i s m s o r exchange o f i d e a s on t h e t echn iques a v a i l a b l e f o r analogue o r d i g i t a l f l i g h t d a t a r e c o r d e r read-out would b e welcomed from o t h e r a u t h o r i t i e s .

Also

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2 . - .- E I G H T RECORDER INFORMATION EXTRACTION

2.1.- Equipment

T h e p r i n c i p a l i t e m of equipment used f o r read-out of analogue recorder f o i 15 is a p r e c i s i o n measuring machine which provides f o r movement of a t r i n o c u l a r microscopf.: over a 255 mm x 155 mm f l a t t a b l e . i n x a n d Y Co-ordinates and t h e s e may be recorded a u t o m a t i c a l l y o r b y t ypcwr i tp r , :)r celayed t o a ccimputer i n s t a l l a t i o n . photographic record of t h e € o i l ( s e e Figure 11).

7 . 2 . - O u t l i n e of Methods

The p o s i t i o n of t h e microscope is d isp layed d i g i i a l l y

The t h i r d eyepiece is p r o v i d e d for a c:.lri::l .? .itt,ic!inient. f ï j r a

The recorder f o i l i s clamped under g l a s s on the f l a t t a b l e , and the referer ice l i n e on t h e f o i l i s a l i g n e d wi th t h e X-axis of t r a v e l o f t h e mi.croscope by f i n e adjustment of t h e t a b l e and t h e c ross -ha i r eyepiece on t h e microscope. The Y-axis d i g i t a l read-out i s theLi zeroed CJE t h e referenc.e Line. 4 s u i t a h l c X-axis ( t ime.) z e r o i s s e l e c t e d and a l l suiis:ec:-?<!nt rruvemc'!its of ti:&: micros.:.cp; a r e dispI.rtyec! :!ri ;he d l g i t a l J i spl. ; iy ( i n inches t o fou r decimal p l a c e s ) as displacement from t h e X datum and Y datum. Using hand-operated c o n t r o l s , t h e i n s c r i b e d traces on t h e recorder f o i l a r e fol lowed v i s u a l l y by incremental movement o f t h e microscope i n both t h e X and Y d i r e c t i o n s . When t h e eyepiece c ross -ha i r r e t i c u i - e is a l i g n e d wi th a p o i n t on a Lrace s e l e c t e d f o r read-out, a b u t t o n may be pressed and t h e d isp layed X and Y Co-ordinates can b e p r i n t e d by t h e t y p e w r i t e r . The p r i n t e d measurements are then manually converted t o t i m e (XI and p a r a m e t e r v a l u e s ( Y ) , e .g . f e e t , k n o t s , e tc . , by r e f e r e n c e t o unique c a l i b r a t i o n informat ion f o r t h c ' p a r t i c u l a r recorder from which t h e f o i l w a s removed. A l t e r n a t i v e l y t h e e l e c t r o n i c Co-ordinate ou tpu t of t h e meäsuring machine and t h e c a l i b r a t i o n d a t a may be fed d i r e c t l y t o a mini-computer f o r automatic d i g i t a l d a t a processing. The parameter v a l u e s are t h e n graphed a g a i n s t t i m e t o a scale s u i t a b l e f o r i n v e s t i g a t i o n purposes o r are used as i n p u t w i t h o t h e r d a t a f o r more complex c a l c u l a t i o n s .

Another approach is t o use t h e photographic a t tachment t o t a k e a series of photographs of t h e traces. v a l u e g r i d i s drawn over t h e photographs, based on t h e c a l i b r a t i o n d a t a f o r t h e r e c o r d e r .

These are then arranged as a mosaic and a parameter engineer ing-

2.3.- Refinements t o Read-out Process

In o r d e r t o o b t a i n a f i n a l read-out which is as a c c u r a t e as t h e record ing system w i l l a l low, i t is necessary t o eliminate as many known s o u r c e s of e r r o r as p o s s i b l e . The fol lowing are of importance.

2 . 3 . 1 . - C a l i b r a t i o n Information

When t h e d a t a recorder has n o t been damaged, c o n s i d e r a t i o n s h o u l d ' b e g iven t o having t h e r e c o r d e r c a l i b r a t i o n checked and t o us ing t h i s more up-to-date informat ion f o r t h e read-out.

When t h e maximum accuracy p o s s i b l e is e s s e n t i a l , t h e f o i l engraved dur ing t h e c a l i b r a t i o n process should b e obtained from t h e o p e r a t o r and c a l i b r a t i o n f i g u r e s determined using t h e same equipment as t h a t used f o r t h e a c c i d e n t / i n c i d e g t f l i g h t read-out. This procedure w i l l e l i m i n a t e t h e p o t e n t i a l f o r e r r o r s produced by mechanical d i f f e r e n c e s between t h e overhaul o r g a n i z a t i o n ' s c a l i b r a t i o n measuring equipment and t h e i n v e s t i g a t i n g a u t h o r i t y ' s read-out equipment.

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2.3.2.- E s t a b l i s h i n g t h e T i m e C o r r e l a t i o n Between Traces

a )

Th i s t y p e o f r e c o r d e r p rov ides a d i s c r e t e o p e r a t i n g band a long t h e t a p e f o r I t i s designed s o t h a t cams on a common s h a f t s t r i k e s t y l i which impr in t

Sundstrand ( U . D . C . ) Model F-542 S e r i e s Recorder

each s t y l u s . c u t s on a f o i l medium as it p a s s e s ove r a narrow r o l l e r . I n t h e o r y , s imultaneous r ead ings of the v a r i o u s parameters should b e recorded on a s t r a i g h t t i m e r e f e r e n c e a c r o s s t h e tape . However, i n p r a c t i c e t h e s t y l i t i p s may n o t n e c e s s a r i l y s t r i k e t h e t a p e on t h e exact t o p of t h e r o l l e r c u r v a t u r e . T h i s w i l l produce s imul t aneous ly r eco rded s t y l i s t r i k e s s t agge red ahead of and behind t h e optimum t i m e r e f e r e n c e . Th i s s t a g g e r between traces sometimes r e p r e s e n t s 10 o r more seconds o f t i m e d i f f e r e n c e between t r a c e s and is a f a c t o r which needs t o be e l i m i n a t e d , as f a r a s p o s s i b l e , i n t h e read-out p rocess . Otherwise, s u b s t a n t i a l e r r o r s i n c o r r e l a t i o n between traces w i l l r e s u l t . For example, i f t h e recorded a i r s p e e d a t touchdown (touchdown determined by i n s p e c t i o n o f t h e g trace) is i n e r r o r due t o a 10 second c o r r e l a t i o n e r r o r t hen t h e speed shown at touchdown cou ld b e i n e r r o r by s e v e r a l knots . traces and c o r r e c t i n g t h e t i m e s f o r each read-out p o i n t by t h e r e l e v a n t amount.

T h i s type of e r r o r can b e d e a l t w i t h by measuring t h e d i f f e r e n t i a l between t h e

One way of measuring t h i s s t a g g e r i s by c l o s e l y examining t h e end of t h e r eco rd where t h e las t v a l i d s t y l u s s t r i k e s are u s u a l l y d i s c e r n i b l e among t h e random engravings a s s o c i a t e d w i t h t h e f i n a l impact o r t h e removal of t h e f o i l from t h e r eco rde r ( s e e F igu re 1 2 ) . I f t h e end o-f t h e r eco rd does n o t show p o s i t i v e p o s i t i o n s f o r t h e last s t r i k e s , then t h e f o i l should b e examined f o r an e a r l i e r occas ion when t h e r e c o r d e r w a s stopped and t h e t a p e manually advanced, such as d u r i n g a r o u t i n e r e c o r d e r i n s p e c t i o n . A f u r t h e r s o u r c e of end-of- t race i n f o r m a t i o n is t h e p i e c e of t a p e produced du r ing t h e r e c o r d e r c a l i b r a t i o n check.

For r e c o r d e r s i n which t h e movement of t h e t a p e w a s uneven, an a d d i t i o n a l method of de t e rmin ing t h e t i m e s t a g g e r between traces is a v a i l a b l e . Th i s minor f a u l t produces a 'bunching' of t h e s t r i k e p a t t e r n , i.e. t h e r e w i l l b e s e v e r a l s t r i k e s c l o s e t o g e t h e r , where t h e t a p e w a s moving more s lowly than t h e des ign speed, followed by a pe r iod when t h e s t r i k e s a r e more open ly sp read where t h e tape moved more quick ly . p a t t e r n is produced a t r e g u l a r i n t e r v a l s a s t h e f o i l take-up mechanism o p e r a t e s . The longer gaps i n t h e r eco rd ing f o r each parameter should i d e a l l y b e l i n e d up a c r o s s t h e t a p e a s t h e cams are on a common s h a f t . I n p r a c t i c e , however, t h e parameters are s t agge red t o some e x t e n t and t h e t i m e d i f f e r e n c e s between traces can be determined f o r t h e cam-driven parameters (but n o t f o r t h e con t inuous ly r eco rd ing b i n a r y channels) by measuring a t t h e s e d i s c o n t i n u i t i e s i n t h e t r a c e s ( s e e F igu re 13).

This

- t o use t h e g trace as t h e z e r o datum and then t o measure t h e o t h e r t r a c e s as i n f r o n t o f , o r b e h i n d , . t h e g trace. Examination and measurement o f t h e traces on t h e t a p e i n t h e s e ways will n o t r e s o l v e t h e t ime-stagger problem e n t i r e l y , f o r t h e g t r a c e is recorded 10 t i m e s per second, whereas t h e o t h e r parameters are u s u a l l y recorded a t 1 second i n t e r v a l s - any one of 10 g - s t r i k e s may correspond w i t h a s t r i k e of t h e o t h e r parameters . may be a r e s i d u a l e r r o r of up t o 0.9 seconds between t h e g - t r ace t i m e and t h e o t h e r t r a c e s a f t e r t a k i n g t h e measurements and making t h e c o r r e c t i o n s .

When measuring t h e t i m e s t a g g e r between t h e traces i t is u s u a l l y convenient .

Thus t h e r e

F u r t h e r r e f inemen t may be p o s s i b l e , i f t h e complete r e c o r d e r mechanism is a v a i l a b l e t o t h e read-out s p e c i a l i s t , and i f a c l o s e examinat ion of t h e re la t ive p o s i t i o n s of t h e one second c a m , t h e one-tenth second cams, t h e s t y l i and t h e marks on t h e t a p e , is made prior to removal of the foil magazine from t h e r e c o r d e r .

All t h e traces shou ld be measured f o r s t a g g e r , i n c l u d i n g t h e r e f e r e n c e l i n e ,

These Y - a x i s ' c o r r e c t i o n s must be a p p l i e d a t t h e r e l e v a n t s t agge r -co r rec t ed as Y-axis c o r r e c t i o n s w i l l need t o b e a p p l i e d i f t h e r e f e r e n c e l i n e d e v i a t e s from a s t r a i g h t l i n e . t i m e s i n a l l t h e o t h e r traces.

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b) Lockheed A i r S e r v i c e Model 109 S e r i e s Recorder

The comments r ega rd ing t h e Sundstrand Model F-542 series reco rde r are a l s o p e r t i n e n t t o t h e Lockheed A i r Se rv ice Model 109 series reco rde r . Although t h e r e are s u b s t a n t i a l d i f f e r e n c e s between t h e s e two types of r eco rde r s , t h e read-out s p e c i a l i s t should be aware t h a t t h e Lockheed r eco rde r t r a c e s a l s o do no t always conform e x a c t l y t o t h e geometric s p e c i f i c a t i o n s f o r t h e ins t rument . a s s o c i a t e d wi th t h e des ign of t h i s r eco rde r , t h e r e may be s m a l l a d d i t i o n a l d i sp lacements . The t o t a l real d isp lacements ( t ime s t a g g e r between t r a c e s ) should be determined by measurement p r i o r t o read-out, r a t h e r than by r e l y i n g on t h e equipment s p e c i f i c a t i o n s . The compl ica t ion produced by t h e s t y l i moving i n a r c s a l s o needs t o b e taken i n t o account when determining t h e s t a g g e r between traces produced by t h i s type of r eco rde r .

2.3.3.- Determination of Y-axis Datum S h i f t s

I n a d d i t i o n t o t h e time d isp lacements

When a pos t -acc ident c a l i b r a t i o n check of t h e r e c o r d e r performance is n o t p o s s i b l e , t h e read-out specialist should be consc ious of t h e p o s s i b i l i t y of t h e r e having been a s h i f t i n t h e datum f o r any parameter s i n c e the last r o u t i n e c a l i b r a t i o n . s h i f t s have been found t o r e s u l t from a s l i g h t bending o r t w i s t i n g of t h e s t y l u s a r m o r head i n t h e course of t h e normal ope ra t ion of t h e r eco rde r .

Such

The v a l u e of a datum s h i f t may be determined as fo l lows , u s ing i n d i c a t e d a i r speed ( I A S ) as an example. p r i o r t o t h e commencement of t h e a c c i d e n t f l i g h t take-off run. s t eady r eco rd ing of IAS is determined and t h e Y-axis d i s t a n c e from t h e r e f e r e n c e l i n e is noted, co r rec t ed f o r d e v i a t i o n i n t h e r e fe rence l i n e (bea r ing i n mind t h e t i m e s t a g g e r between t h e t r a c e s ) , and compared w i t h t h e ze ro a i r s p e e d c a l i b r a t i o n f i g u r e . The d i f f e r e n c e i n measurement between t h e two f i g u r e s r e p r e s e n t s t h e datum s h i f t f o r t h i s parameter, and a l l Y-axis readings should be c o r r e c t e d f o r t h i s s h i f t . The p o s i t i o n s e l e c t e d f o r measuring t h e min imum recorded IAS should b e confirmed by reference t o o t h e r c l u e s i n d i c a t i n g t h a t t h e aircraft w a s s t a t i o n a r y , e.g. a i r c r a f t on a heading corresponding t o a ramp park ing p o s i t i o n , no heading changes and l i t t l e o r no g a c t i v i t y .

Examine t h e per iod when t h e a i r c ra f t w a s on t h e ground By i n s p e c t i o n , t h e minimum

The o t h e r parameter darum s h i f t s may b e s i m i l a r l y determined us ing a p p r o p r i a t e in format ion , f o r example;

f o r a l t i t u d e , u se ramp o r runway p r e s s u r e a l t i t u d e compared wi th recorded p r e s s u r e a l t i t u d e ;

f o r heading, u se take-off runway magnetic alignment compared wi th t h e mean recorded a i r c r a f t magnetic heading d u r i n g t h e take-off run;

f o r v e r t i c a l a c c e l e r a t i o n , u se t h e average recorded l g s t y l u s p o s i t i o n , which can b e determined by scanning a l e n g t h of t h e a c t i v e g trace us ing t h e t r a v e r s i n g microscope moving p a r a l l e l t o t h e r e f e r e n c e l i n e . a Y-axis r ead ing a t a p o i n t where t h e a i r c r a f t i s known t o be s t a t i o n a r y and t h e g trace is showing no a c t i v i t y .

This i s u s u a l l y more r e l i a b l e than t a k i n g

2.3.4.- Applying Cor rec t ions f o r T i m e S tagger and Datum S h i f t

Having determined t h e va lue of t h e X-axis t i m e s t a g g e r and Y-axis datuni s h i f t f o r each parameter, each p o i n t of t h e d e t a i l e d read-out must-then be c o r r e c t e d f o r t h e r e l e v a n t s t agge r and s h i f t p r i o r t o de te rmining t h e f i n a l eng inee r ing va lue by r e fe rence t o t h e c a l i b r a t i o n curve, and t h e t i m e by r e f e r e n c e t o t h e rate o f - t a p e movement.

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APPENDIX'13. - S t a t e s ' F l i g h t Recorder Playback F a c i l i t i e s and Techniques 13-2,9

Rather t han apply t h e c o r r e c t i o n s t o each read-out p o i n t i n d i v i d u a l l y , t h e read-out machine may be mechanical ly a d j u s t e d t o compensate f o r t h e c o r r e c t i o n s p r i o r t o commencing read-out , o r a c o m p u t e r f c a l c u l a t o r programme may b e set up t o perform t h e c o r r e c t i o n s f o r each parameter .

3 . - SELECTION OF THE MOST SUITABLE METHOD OF READ-OUT

A common method of read-out n e c e s s i t a t e s t h e d o l l o w i n g of each trace i n t u r n

Once t h e c o r r e c t i o n s mentioned i n t h e p rev ious paragraphs have been wi th t h e microscope and t h e t a k i n g of f r e q u e n t r ead ings eo as t o d e f i n e t h e shape of t h e t r a c e adequa te ly . a p p l i e d , t h e e n g i n e e r i n g v a l u e s of each parameter are de r ived by r e f e r e n c e t o c a l i b r a t i o n d a t a , t a b u l a t i o n s , e tc . The e n g i n e e r i n g v a l u e s are then graphed a g a i n s t t i m e u s i n g s u i t a b l e s c a l e s . In a d d i t i o n t o b e i n g time-consuming, e s p e c i a l l y where t h e r e is an a c t i v e g trace ( r e c o r d i n g a t 600 s t r i k e s p e r minute) , t h i s method m y b e u n s a t i s f a c t o r y from o t h e r p o i n t s of view. T,ockheed A i r S e r v i c e Model 109 series r e c o r d e r s (see F i g u r e 1 4 ) , i t h a s been found t h a t t h e g t r a c e f r e q u e n t l y i n c l u d e s a p e r i o d o f a c t i v i t y where t h e sequence of excur s ions i s not d i s c e r n i b l e because t h e trace o v e r l a p s t h a t p rev ious ly r eco rded , t h u s p r e c l u d i n g t h e r ead ing of s e q u e n t i a l events . Iii t h e s e cases, and i n o t h e r s where t h e s c r i b e sequence is d i f f i c u l t t o f o l l o w o r shows unusual behaviour (see F igure 15), a method which produces a photographic p r e s e n t a t i o n o f f e r s advantages.

For example, when conduct ing a read-out of t h e g trace of t h e

Genera l ly , t h e advantages o f a pho tograph ic p r e s e n t a t i o n are a s a v i n g i n read-out t i m e where traces are ve ry a c t i v e and a p r e s e n t a t i o n which w i l l pe rmi t anyone viewing t h e f i n a l p roduc t - t h e photograph - t o p rov ide h i s own assessment of t h e i n t e r - p r e t a t i o n and t h e importance of t h e d i f f i c u l t s e c t i o n s of t h e traces.

However, t h e photographic method h a s a major l i m i t a t i o n i n t h a t t h e p rocess e n l a r g e s a t a c o n s t a n t scale i n bo th X- and Y-axes and l a r g e heading changes produce excess ive ly ' t a l l ' photographs. T h i s l i m i t a t i o n can be overcome by producing a composite read-out i n which, f o r example, t h e d i f f i c u l t g trace is photographed b u t t h e o t h e r t r a c e s a r e read o u t as d e s c r i b e d earlier and are then graphed t o t h e s a m e t i m e s c a l e a s t h e photographed t r a c e .

One method of photographic read-out which has been s u c c e s s f u l l y used is as fol lows: s e c t i o n s of t h e trace are photographed a t s u i t a b l e X- and Y-axis i n t e r v a l s s o a s t o provide a mosaic of p r i n t s which are t h e n c u t t o f i t a l o n g s i d e one a n o t h e r u s i n g pattern-matching t echn iques and t h e s c a l e d X- and Y-axis i n t e r v a l s . The o r i e n t a t i o n of t h e i n d i v i d u a l photographs i n azimuth is easier i f t h e photographs a r e t aken through a f i n e o v e r l a i d g r i d , o r a t least i n c l u d e t h e microscope eyepiece c r o s s - h a i r r e t i c u l e . C a r e f u l c o n s t r u c t i o n of t h e mosaic i s r e q u i r e d t o p rec lude t h e accumulat ion of c o n s t r u c t i o n e r r o r s .

Once t h e mosaic i s completed, t h e X- and Y-axis s c a l e s are c o n s t r u c t e d us ing t h e s c a l i n g change due t o photography and t h e c a l i b r a t i o n f i g u r e s f o r t h e parameters. I n t h e case of Lockheed A i r S e r v i c e Model 109 series r e c o r d e r s , t h e t i m e s c a l e g r i d w i l l i n c l u d e curved s e c t i o n s ( f o r IAS and a l t i t u d e ) based on t h e a r c s through which t h e s t y l i move. The c o r r e c t i o n s f o r t i m e s t a g g e r between t r a c e s , datum s h i f t s and d e v i a t i o n s i n t h e r e f e r e n c e l i n e m u s t a l s o b e taken i n t o aczount a s i n the normal g raph ic read-out p r e s e n t a t i o n .



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I

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Fig. 11.- Analogue F l i g h t Data Recorder Read-out Machine



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APPENDIX 13. - States' Flight Recorder Playback Facilities and Techniques 13-31

end of valid t race

ranào;m'--c engraving caused by extracting magazine from recorder

Fig. 1 2 . - An End of Trace (LAS Secorder)

t - nor t ra

m a l .ce

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___-- Copyright International Civil Aviation Organization Provided by IHS under license with ICAO


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Fig. 13.- Uneven Tape Movement (Sundctrand Recorder)

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APPE'NDIX 13. - S t a t e s ' F l i g h t Recorder Playback F a c i l i t i e s and Techniques 13-3 3

SEGONffi !

Fig . 14 . - Photo Read-outs Showing D i f f i c u l t G Traces (LAS Recorder)

) 0 / 3 / 78 No. 8 Copyright International Civil Aviation Organization


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Fig. 15.- Photo Read-out Showing Unusual Scatter (Sundstrand Recorder)

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APPENDIX 13.- S t a t e s ' F l i g h t Recorder Playback F a c i l i t i e s and Techniques 13-35

UNITED KINGDOM

1.- FLIGHT DATA RECORDER

The Accidents I n v e s t i g a t i o n Branch of t h e Department of Trade (AIB) has f a c i l i t i e s f o r t h e r e p l a y of t h e fo l lowing c ra sh -p ro tec t ed d i g i t a l r eco rd ing systems:

Sper ry SADAS Epsylon EFDAS AO and A l P l e s sey PV710, PV726 and PV740 Hamilton Standard ARINC 573 Teledyne ARINC 573

When recorded on Dava11 o r Penny & G i l e s s teel w i r e cassettes, steel w i r e r e c y c l i n g r e c o r d e r s o r s t e e l t a p e r e c o r d e r s .

Expansion is planned d u r i n g 1977 t o i n c l u d e Sundstrand and Lockheed r e c o r d e r s .

Read-out equipment f o r a l l types of f o i l r e c o r d e r is a v a i l a b l e on government premises and commercial equipment i s a v a i l a b l e f o r t h e r e p l a y of MIDAS FM r eco rde r s .

The A I B has access t o commercial equipment f o r t h e r e p l a y of d i g i t a l quick- access (AIDS) r e c o r d e r s f o r t h e systems s p e c i f i e d above.

2.- COCKPIT VOICE RECORDER

The A I B has comprehensive mul t i - t r ack playback, f i l t e r i n g , a n a l y s i s and copying equipment f o r any 4- t rack 1 1 4 inch (6.3 nun) t a p e cockp i t v o i c e r eco rde r , i nc lud ing t h e fo l lowing:

F a i r c h i l d A100 series C o l l i n s 642C Sundstrand V557 Normalair Garrett 1 1 5 1 V O O

Note.- Copies can be produced i n 4- t rack , 2- t rack o r P h i l i p ' s cassette format.

During 1977 i t is in t ended t o extend t h e f a c i l i t y t o inc lude 8- t rack v e r s i o n s such as Sundstrand A557A and A557B.

3.- POLICY

Charges w i l l n o t normal ly be made f o r r e p l a y services concerning i n v e s t i g a t i o n s i n which an Accredi ted R e p r e s e n t a t i v e o f t h e United Kingdom p a r t i c i p a t e s . I n o t h e r cases charges may have t o be made t o cove r t h e c o s t of o p e r a t i n g playback equipment and t h e t i m e of s p e c i a l i s t personnel .

301 3/ 78 No. 8



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APPENDIX 14

ACCIDENT REPORT FORMS

A s mentioned i n P a r t I V , Chap te r 4 , t h i s a p p e n d i x c o n t a i n s forms used i n some States. These fo rms are i n c l u d e d f o r i n f o r m a t i o n o n l y .

Pages 14- 1 t o 14-22 Acc iden t r e p o r t form (Canada) Pages 14-23 t o 14-40 Acc iden t r e p o r t form ( A u s t r a l i a ) Pages 14-41 t o 14-50 G e n e r a l A v i a t i o n a c c i d e n t r e p o r t form (USA) Pages 14-51 t o 14-61 Aerodrome s t a t u s r e p o r t form (UK)

Communications t r a n s c r i p t form (France)

30 / 5 / 7 7- No. 7



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APPENDIX ,14.- Accident Report Forms 14-1

AT ( N a m e of nearest gazetted place)

G E O G R A P H I C CO-O R D I N A T E S DATE V A Y _ _ _ _ _ _ _ M O N T H _ _ _ _ _ _ _ _ Y E A R _ _ _ _ _ _ _

D E P A R T M E N T O F T R A N S P O R T

A I R C R A F T ACCIDENT INVESTIGATION DIVISION

PRO V I N C E

TIME (Standard T i m e Local)

REGIONAL REF.

N A M E

C I N I D .

REPORT OF THE INQUIRY INTO A N AIRCRAFT 1-

A D D R E S S

0 ACCIDENT 0 DISAPPEARANCE 0 INCIDENT 0 1-

A T C L I C E N C E N U M B E R

NEAR MISSO

7 A P S a 7 A 0 CONS'?.

H . Q . U S E O P E R . C O D E

OTHER 0

NAME: S A M E A S O W N E R 0 OPERATOR 0 O R

FOR INSTRUCTIONS SEE REVERSE SIDE OF EACH PAGE

1

PERSONNEL IDENTIFICATION@

OWNER

OPER- ATOR

PILOT

IN

COMMAND

OTHER

CREW ON o BOARD

N A M E : S A M E A S O W N E R 0 O R I A.T.C. L I C E N C E CLASSIF ICATION T H I S FLIGHT

ADDRESS:

AODRESS:

I STATUS i U N A U T H O R I Z E D a OWNER i R E N T E R 0

U S E R

I F N O T I

OR I

1 S P E C I F Y : l I

E M P L O Y E E u B O R R O W E R 0

O T H E R 0

N U M B E R O N B O A R D I F L I G H T F L I G H T NO. O F C A B I N E N G I N E E R r 3 O B S E R V E R 'I A T T E N D A N T ( S 1

NONE T~ THIRD PILOT 0

MATERIAL IDENTIFICATION R E G I S T R A T I O N M A K E M O D E L T O T A L HRS. M A X I M U M C E R T . Y E A R O F M A N U F A C T U R E

Al R- T A K E - O F F W E I G H T

CRAFT I I I I

CATEGORY

I I LANDING GEAR A M P H I B I O U S cx F L O A T S r.7

LANDING GEAR CON F IGURATION

CI O T H E R 0 T R I C Y C L E

TAILWHEEL n u WIN C/ROTO R

CZI : L A N E O L O W - WING

I=1 c3 HI GH-WI N G

iPECíAL EQUIPMENT

A I R - D R O P

C H U T I S T ) M A G N E T O M E T E R C X

S L I N G /

W A T E R S P R A Y B O M B I N G ! - x D U S T

G E A R n O T H E R MONSOON

F O T H E R S P E C I F Y :



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- Manual of A i r c r a f t Accident Trìvest i g a t ion

INSTRUCTIONS Pages 1 and 2 of the form are to be submitted to Headquarters within 15 working days

of the occurrence The remaining pages are to be submitted os soon as possible after the investigation

i s complete Photographs should be included as they assist in presenting an understandable

statement of the circumstances of an occurrence. They should be appropriately identified, affixed to 8 V x 11" sheets of white bond and inserted between pages 8 and 9 of the report.

explained on the reverse side of the same sheet Questions which are identif ied w i t h a circled number: e.g. @ , are further

Upper case X's are to be used to indicate selected squares A l l substantiating documents, reports, etc. are to be appended following page 12 Occurrences, which are the result of a col l is ion of two or more moving aircraft w i l l

be reported on two or more report forms, ¡.e., one form for each moving aircroft.

This report intends to provide a standard means of comrnunicoting concisely and accurately, the factual findings of aircraft accident investigators. It has been designed with the workload of the investigator in mind. The arrangement of the data i s deliberately keyed to the probable sequence of events inherent in any aircraf t accident. In this way a clear picture of what happened w i l l be conveyed from the mind of the investigator to the reader of the repart.

o

It i s important that every section of the report be carefully completed since i t i s a source document for accident prevention activit ies. Should an investigator decide that the form does not adequately accommodate a particular accident, the investigator should supplement the report with notes at appropriate places.

The intent here is t o cleorly establish the relationship between the aircraft and certain specific persons and the relationship of those persons to each other. The total complement of persons on board the aircraft should be accounted for in this section.

o

@ Crew member i s defined os any person involved in the operation of the aircraft. In cases where a student pi lot or licenced pi lot i s receiving training the instructor i s normally classified as the pi lot in command and the trainee as the second pilot.



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APPENDIX 14.- Accident. Report Forms 14-3

M O D E L ENGINE(S) M A K E

S E R I A L do. N U M D E R I N S T A L L E D

I 1 I

POWER T U R B O -

P I S T O N 17 C O M P O U N D TYP E sup E R c H A R G E 0

P I S T O N Lx R A T E D w.p.

J E T J E T T U R B I N E W I T H T U R B O A F T E R B U R N E R 1.1 PROP n TUMINEU

O T H c R 0 I F OTHER S P E C I F Y

PROPELLER (S) M A K E

R A T S O THRUST

S E R I A L NO. M O D E L

T Y P E

F I X E D F I X E D V A R I A B L E C O N S T A N T C O N S T A N T S P E E D WOODEN 1.3 M E T A L 0 P I T C H [i S P E E D L I F U L L Y F E A T H E R I N G TT]

ENVIRONMENT IDENTIFICATION @

SUCTYPE

N O T R E V E R S I B L E 0 R E V E R I I m L E 0

OPERATION 1 LOAD

SCOPE THIS F L I G H T

I N T E R N A T I O N A L r-1 L O A D DESCRIPTION

N O N E c.3 FREIGHT’ E X P R E S S

C A R G O / P A S S E N G E R S PASSEN.=ERS

DOMESTIC rL: P A R A C H U T I S T 0

S E R I O U S M I N O R KILCED I N J U R Y I N J U R Y UNINJURED

P I L O T - I N -

C O M M A N O .- -

O T H E R C R E W

P A S S E N G E R S

PERSONS O U T -

S I D E A I R C R A F T - -

S P E C I F Y :

B Y C I V I L A V I A T I O N I N S P E C T O R I S ) O N L Y 0

o B Y C I V I L A V I A T I O N A N D A I R W O R T H I N E S S

I N S P E C T O R S

B Y A I R W O R T H I N E S S I N S P E C T O R I S ) O N L Y

o O

B Y C O R R E S P O N D E N C E

D. N. H. W. ASSIS T A N C E

n T E C H N I C A L / M E T A L L U R G I C A L E X A M .

0 P E S T I C I D E S

C I T O W E R S P O L E Y

W A T E R / C H E M l C A L

P H O T O u E O U I P M E N T

n F E R T I L I Z E R

0 F I S H E G G S FI s w

I

OBJECTIVE@

ADVERTISING rx C O N T R O L 0 D E M O N S T R A T I O N r3 FIRECONTROL n H O I S T I N G r 7 I N S P F C T I O N FJ

S E A R C H LI RECREATION T E S T I N G s U ~ v ~ y r;; S P R A Y / D U S T / r-j S E E D I N G

T R AN SPO R T A T I O N CI] SPEC1 F Y .

T O W I N G 1-1 TRAINING F E R R Y I N G POSITIONING [:I O T H E R [I]

PRELIMINARY VERSION OF ACCIDENT@ P R O V I D E A B R I E F H I S T O R Y O F T H E F L I G H T A N D N A R R A T E A S M A N Y O F T H E C I R C U M S T A N C E S O F T H E A C C I D E N T AS A R E K N O W N A T T H I S T I M E ,

B E G I N N I N G W I T H T H E F I R S T I R R E G U L A R I T Y O F T H E F L I G H T .

PRELIMINARY POST-OCCURRENCE DATA A I R C R A F T DAMAGE NUMBER OF CASUALTIES INVESTIGATION

N O N E

M I N O R 17

S U B S T A N T I A L Lx D E S T R O Y E D L7

U N K N O W N r x 23-0003 18-63)



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14-4 Manual o í Aircraft Acci.tlent Invest igatioi i

In order for the reader to properly appreciate the environmental problems which might have affected the aircraft and/or pilot, he must have accurate knowledge of the details of the operation.

o

The word selected here should be that which mast closely describes the intent of the operation. Choice of the proper word w i l l accurately portray the environment hazards inherent in the flight.

o

This paragraph w i l l normally contain the type of information which is quickly available, ¡.e. horndiscussion with the pilot, crew, passengers or eye witnesses. The statement should be as brief as possible, but clear.

o



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APPENDIX 14.- Accident Report ,Forms 14- 5

A L L T Y P E S

T O T A L H O U R S

PRE-OCCURRENCE C O N D I T I O N S - CREW

T H I S D U A L O N T H I S U / C S I N G L E M U L T I A C T U A L N I G H T R O T O R - X - C O U N T R Y C R A F T T Y P E T H I S T Y P E C O N F I G U R A T l O h E N G I N E E N G I N E I N 5 T R U M E N T

I

I H R S . L A S T 9 0 D A Y S

LICENCES AND PERMITS H E L D

CANADIAN .n FOREIGN

NONE (-3 A I R L I N E

U N K N O W N 0 T R A N S P O R T

S E N I O R C O M M E R C I A L

S T U D E N T P R I V A T E a P E R M I T

F L I G H T N A V I G A T O R E N G I N E E R u G Y R O P L A N E G L I D E R 0

BALLOON o M A I N T E N A N C E E N G I N E E R

C O M M E R C I A L o

I

AIRCRAFT CLASSIFICATIONS H E L I C O P T E R O N L Y

S I N G L E - E N G I N E L A N D 0 S I N G L E - E N G I N E S E A I - 1

I T O T A L T H I S F L I G H T T O T A L L A S T 3 D A Y S F L Y I N G I I

L I R C R A F T T Y P E ENDORSEMENTS

H O U R 5 A W A K E S I N C E L A S T R E S T P E R I O D

RATINGS N O N E 0

I N S T R U C T O R C L 1

I N S T R U C T O R cL z n I N S T R U C T O R C L 3 u

I N S T R U M E N T 1 n I N S T R U M E N T 2 0

B L O C K A I R S P A C E 0 N I G H T

T I M E HRS. 1 H R5. HRS.

WEATHER BRIEFING ACCREOI TED

B R I E F E R L-! OTHER BRIEFINGS DOCUMENTS CARRIEC FLIGHT PLAN FILED

N O N E

C O M P A N Y r . ; F A C I L I T Y ¡ '

O T H E R [ - , U N K N O W N [ -1 PILOT . ,

O T H E R O B S E R V E R 1 A C C R E D I T E D ~

F O R E C A S T E R

.- , F L I G H T O R

C H E C K L I S T M A N U A L NONE 1-1 c o c K p ' T [.I! O P E R A T I N G 0 N O N E [ -1 SVFRET

U N K N O W N !.Il R O U T E [I! 4 U E 0 U A T E I N A D E O U A T E -~, IFR / C O N T R O L L E D

D E P b f i T U R E V F R CY! V F R [ - # v FRCII I P H O C E U U R E S ! T J o P E R A T I o N

S E L F B R I E F I N G i - !

__ ACH ER ENC E TO PLAN

V F R j F L I G H T N O - 17 T I F I C I T I O N -

A R R I V A L .. P R O C E D U E E S [ N O T A M S [II A D E Q U A T E j ~ ] I N A D f . O b A T € . ( ~

I F R I F R ' .--

PHASE OF FLIGHT DURING WHIC

GROUND -~ -___

N O D E V I A T I O N cj

FIRST IRREGULARITY O C C U R R E D

'AKEOFF

A L T E R A T I O N F O R WX [-:!

- AIDS AVAILABLE ~ . H . F D F DME v o a T L C A N ILS L S R P C R L D F

____.__.. I N A I R C R A F T

O N GROUND

__ IN USE B Y A/C AT TIME OF OC.

A L T E R A T I O N F O R T R A F F I C 'i

B E C A M E L O S T LI1

- L O R A N L.F. R N G N O N E

A L T E R A T I O N F O R U / S ill O T H E R

S P E C I F Y :

NAVIGATION AND APPROACH AIDS

L I F T O F F i . ]

H O V E R 111

I N - F L I G H T

C L I M B CII D E S C E N T CJ

C R U I S E

L E V E L T U R N [ 1 i C L I M B I N G

T U R N I D E S C E N D I N G

T U R N '" T R A N S L A T I O N [

H O V F R [I]

LANDING

I N I T I A L A P P R O k C H 17

FIN L L A ' P R O A C H

F L b R E [ I ]

H O V t R 1;)

T O U C H - D O W N - 1

R U N - O U T I - 1

T U R N - O F F 11 R A D I O C O M M U N I C A T I O N S

L O A D DROP I--]

L O b O > O S l T I O N I N G [?

E O U I P M E N T I A D E O U A T E 1 1 I N A D E O U A ~ E [ ' ]



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14-6 Nanual of A i r c r a f t Accident I n v e s t i g a t i o n

The purpose of this section i s t o identify the man being reported on the remainder af the page and to define his function with respect t o the aircraft. A lso included ore the flying background focts which indicate h i s level of proficiency.

o

A pertinent crew member i s one who con or did affect the course or conduct of the f I i gh t. o

Example 1: A student pilot al lows a swing to develop on takeo f f and the instructor is unable to correct before a ground loop results. In th is case a seperate page for each i s required. On the other hand, during cruising fl ight the engine fo i ls suddenly and the instructor takes over control and strikes a fence during the forced landing. Complete a page for the instructor only.

Example 2: The aircraft coll ides with ramp vehicle while taxiing. No page need be completed for navigator or f l ight engineer if carried on board.



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APPENDIX 14.- Accident Report Forms 14-7

PRE-OCCURRENCE CONDITIONS

MATERIAL o DESCRIPTION OF SYSTEM CONDITIONS

Condition A - NOT DETERMINED S - SERVICEABLE

A I B 1 s I u B - NOT INSTALLED U - UNSERVICEABLE

I I C A N O P Y W I N D S C R E E N

1

FUNCTION COMPONENT/SUB.SYSTEM NATURE OF COMPONENT AFFECTED CAUSING PROBLEM SUB-SY I T EM FAILURE

I 1 I I ] D E - I C I N G - A I R F R A M E I I I

PR E-

I I I 1 ELECTRICAL SYSTEM - U P T O CONSUMER DE VICE^

LAS. FUELON BOARD CALCULATED MIXTURE CARL HEAT POSITION L ~ s R I ~ H ~ L E A N = AUTOO HOTU P A R T I A L = COLDO A.U.W.

K T S IMP. GALS.

C OF G

I I

OCCURRENCE

AT

I I I I I R A D I O N A V I G A T I O N SYS?EM-AURAL. VIS. AUTO.

A F T O F FORWARD O F D A T U M 0 POSITION _ _ _ _ _ _ _ _ _ _ _ _ _ 7. M A C O R _ _ _ _ _ _ _ _ _ I N S D A T U M 0

A F T O F F O R W A R D O F D A T U M 0 Z E M F s s i E

R A N G E _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 7. M A C T O _ _ _ _ _ x M A C O R _ _ _ _ I N S T o _ _ _ _ I N S D A T U M o I A S . POWER SETTING LANDING GEAR POS? FLAP POSITION

GROUND 1 K T S CONTACT

up o FULL o F I X E D G E A R ~-7 DOWN [I P A R T I A L u DOWN o

N O N E LT P A R T I A L 0 U N L O C K E D u UP 0 N O F L A P S 0 A S Y M M E T R I C LT



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- Manual of Aircraft Accident Invest igat ion

@ The intent of th is poge i s to col lect as much information as practicable about the condition of aircraft which hove become involved in accidents, The conditions described here may or may not have a bearing upon the occurrence but must be conditions which the investigator i s able to prove existed a t the beginning of the accident sequence.

When completing the page, each item should be checked off i n the appropriate square on the left hand side. In the columns oppa;ite any "U" condition which i s indicated, the investigator need only select wards which ore mast descriptive of his findings.

Example: - A helicopter on takeoff began an uncontrollable turn and the investigation revealed a fractured ta i l

rotor driveshaft. This information would be recorded thus:

Ta i l Rotor Blades, Structue, Drive

The foregoing example bears directly upon the occurrence. But supposing the investigator also discovered that the VHF was unserviceable, i t should also be recorded and might appeor thus:

RadioCommuni- p H F l Transmitter

The requirement to record a l l preexist ing mechanical irregularities arose from our failure in the past to immediately recognize some of these failures and malfunctions as accident cause factors. Consequently, searching out and recording a l l preexist ing irregularities w i l l permit the reassessing of many accidents i n the light of more recently acquired knowledge.

@ Ta assist in assessing the conditions of flight, certain v i ta l data are necessary. The dara recorded in this section w i l l probably be based on facts gleaned from examination of the wreckage. For some items such as fuel quantity, some calculations may be necessary to convert amount of fuel on board after the accident to amount of fuel on board at the t ime of the first irregularity of the flight.



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APPENDIX 14.- A c c i d e n t Report Forms 14-9

AIRCRAFT CONDITIONS HEIGHT A G L

F T

TERRAIN E L E V A T I O N - .LAYER

F T . A S L

VISIBI L ITY

AT

HEIGHT AIRCRAFT

.- .____ .__ . MII.ES

PRECIPITATION

N O N E 0 R A I N 0 D R I Z Z L E 0 SNOW 0

F R E E Z I N G D R I Z Z L E 0 H A I L 0

F R E E Z I N G u R A I N 0 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ - - - L I ' G H T 0

M O D E R A T E 0 H E A V Y 0

ENVIRONMENT CONDITIONS@ AT POINT OF FIRST IRREGULARITY OF FLIGHT IF APPLICABLE@

CLOUD N O N E 0 U N K N O W N 0

A M O U N T V E R T I C A L E X T E N T fi H T . A G L H T . A S L

LOWEST

SECOND F T F T F T / I o

L A Y E R F T F T F T /I o

B L O W I N G C L O U D 0 D U S T 0 SNOW 0

PHENOMENA F O G 0 H A Z E 0 P R E C I P I T A T I O N 0 eLoWING S A N D o C R Y S T A L S o RESTRICTING 0 0

I C E

TEMPERATURE ELECTRICAL SPECIAL HAZARDS , A T , A I R C R A F T HEIGHT

N O N E 0 B I R O S 0 P A R A C H U T I S T 0 ACTIVITY

A I R FR A M E C o U N K N O W N 0 I C I N G 0 T U R B U L E N C E 0

U N K N O W N 0 T A L L S T R U C T U R E 0 W H I T E O U T 0 A I R T R A F F I C 0

O T H E R 0 U N K N O W N 0

G L A S 5 Y S T A T I C 0 H O A R . F R O S T 0 W A T E R 0 A T AIRCRAFT HEIGHT

" S T . E L M O 5 FIRE 0 . SPECIFY. :

TRUE

- D I R E C T I O N

K T S VIOLENT D I S C ~ A R G E 0 S P E E D

N O N E 0 U N K N O W N 0 B A S E H T . T O P H T . A M O U N T

LOWEST 0 B R O I E N 0

F T O V E R C A S T 0 BASE F T A G L A G L

SCATTERED 0 SECOND

LAY ER F T BROKENO F T

A G L A G L OVERCAST 0 TEMP ERATURE DEW POINT AT GROUND O V E L A T G R O U N o L E V E L _ _ _ _ _ _ _ _ _ _ F. U N K N O W N 0 _ _ _ _ _ _ _ _ V. U N K N O W N 0 WIND A T G R O U N D L E V E L UNKNOWN 0 DIRECTION SPEED

M A G N E T I C 1 4 . p . ~ .

WEATHERDATA . SOURCE

E Y E W I T N E S S 0 P I L O T 0

o M E T . O B S E R il A T I O N S

A F T E R C A S T 0

VISIBILITY PRECIPITATION N O N E 0 R A I N 0

A T SURFACE _ _ _ _ _ _ _ MILES R V R _ _ _ _ _ _ _ _ FT.

FREE z IN 0 U N K N O W N 0 R A I N 0 RESTRICTING PHENOMENA '

B L O W I N G o ' OuST o D R I Z Z L E 0 S N O W 0 N O N E 0 H A Z E 0 P R E C I P I T A T I O N 0 B L O W I N G SAND'O . .

BLOWING F O G 0 I C E C R Y S T A L S 0 SNOW 0 DRIZZLE O H A I L 0

S M O K E 0

U P W A R D CHARACTERISTICS

S T E A D Y SWINGING 0 G U S T Y 0 C O M P O N E N T 0 S U B S I D E N C E 0

M O U N T A I N S 0 HILLS 0

R O L L I N G 0 F L A T 0

A E R O D R O M E 0 S W A M P I M U S K E G 0 C L E A R I N G T I D A L W A T E R D N O N E 0 T R E E I S ) 0

H I G H G R O U N D 0 R O A D O BUSH O LAKE^ TOWER(S1 0 B U I L D I N G S 0

U R B A N A R E A 0 R I V E R 0 P O L E L I N E 0

I

OBSTRUCTIONS T O T.O./LDG. RUN V I T A L DATA RUNWAY IAVERAGE PROFILE I SLOPE IN

I DEGREES LE V E LOI

N O N E 0 V E H I C L E S 0 U S A B L E L E N G T H

D I T C H E S I H O L E S 0 A N I M A L S 0 F T I

HAZARDS

N O N E 0 FILM 0 W A T E R

PUDDLES 0 P A T C H E S 0 I C E

S L U S H 0 S O F T 0

R O U G H 0 D R I F T S 0 SNOW

L GHT b $I&!-

"",'E,"' 0

GENERAL

P A V E D 0

G R A V F L 0 5 O i i 0

S A N O

5 N O A Û

I C E 0 A 4 T E R 0

f i 3 C d o

N I G H T u RIDGES, 'SANDBARS 0 SNOW B A N K 0 ELEVATION 1 D A R K 0 POSTSIFENCES O O T H E R 0 UP N I G H T

SPECIFIC

C O N C R E T E

A S P H A L T 0 C O M P A C T E D 0

L O O S E o LOW

V E G E T A T I S N I GRASS

H I G H W A V E S 0 S W E L L S 0



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Environment conditions refer to a l l conditions external to the subicct aircraft. This includes: a l l weather conditions, ground or air traffic, obstructions, surface conditions, etc. Since these conditions at the time and place of the first irregularity of f l ight can be different from the conditions where the aircraft came to rest, the conditions i n both instances must be recorded.

o

@ The point of the first irregularity of the fl ight can be best described as that point at which there were definite symptoms that something had gone wrong. The details in this section w i l l help to develop an understanding of the adequacy of the aircraft and the pilot’s judgement. I f the first irregularity occurred near ar on the ground i n the immediate vicinity of the place where the aircraft came to rest, this section i s to be omitted.

@ Regardless of the circumstances o f the accident, this section w i l l always be completed. As with the previous section, the details w i l l provide some evidence of aircraft adequacy and indicate the degree of sk i l l and judgement applied by the pilot. Con- ditions in the area where the aircraft came to rest strongly influence the degree of aircraft breakup and the occupant’s chances of survival.



--`,,```,,,,````-`-`,,`,,`,`,,`---


A L C O ) . O L B L 0 0 0 S U G A R F000 P O I S O N I N G

H Y POX1 A C A R B O N M O N O X I D E E X P L O S I V E S R E S I D U E

O PRE-OCCURRENCE C O N D I T I O N = CREW

O T H E R T E S T IS) D R U G S

P E S T I C I D E S

PHYSICAL

S X C ES81 V E N O N E 0 P E R S P I R A T I O N 0

EMOTIONAL

F A T I G U E 01

DROWSINESS 0 F E V E R I S H N E S W H O T 0 P A I N 0

OIARRMOLA

S T O M A C H

N U M B N E S S 0

C R A M P S o D I Z Z I N E S S 0

V I S I O N O I F F I C U L T I L S 0

C O L D / C M I L L S 0

O

O

D E P R E S S I O N C O N F U S I O N 0

E L A T I O N A N G E R 0

L I S T L E S S N E S S 0 I M P A T I E N C E 0

N E R V O U S N €9. A N X I E T V I T E N S E N E S S 0 P”EoCCUPA’~oN 0

O T H E R :

N O N E E X P E R I E N C E D 0

M E D I C A L P R O F I L E

I P L A C E

D A T E

R E S T R I C T I O N S I M P O S E D RECEIV1N.G SP E C I F Y I M E D I C A L I Y E S 0 N O 0

N A M E A N W O R N U M B E R O F M E D I C A L E X A M I N E R I

C A R B O N M O N O X I D E F O O D P O I S O N I N O E X P L O S I V E S R E S I D U E H Y P O X I A N O N E P E R F O R M E D

IMEDICAL ANALYSIS - REGIONAL M E D I C A L OFCICER TO oiscuss A N Y MEDICAL F A C T O R S WHICH. IN HIS OPINION, WERE INVOLVED IN THE



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- Manual of Aircraft Accident Investigation

The requirement here i s similar to that for material. The background of the mon, and some measure of how we l l he is functioning physiologically and psychologically is vital t o an understanding of the occurrence.

o '

@ Testing in cases where the pilot made some error of omission or commission should be routine. The investigator w i l l hove no serious dif f iculty in cases where the individual was killed. Regulations provide the authority for autopsies. In cases where the person survived, physical examination and testing con be carried out only with his co- operation. Wherever possible, quantitative results w i l l be reported in this section.

@ Again, a cooperative attitude on the part of the individual w i l l be necessary i n order to complete this section. I f the individual has a genuine interest in aviation he w i l l not hesitate to provide the necessary data.

@ Since this section can apply to more than one person, the maximum readings obtained are to be reported here.



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APPENDIX 14 . - Accident Report Forms 14-13

OCCURRENCE DESCRIPTION @ FIRST IRREGULARITY OF FLIGHT @

I N A R R A T E T H E E V E N T (SI WHICH F IRST INDICATED T H A T T H E FLIGHT W A S N O T PROCEEDING AS DESIRED.

RESULTANT ACTION (5) O REACTION (5) 0 N A R R A T E A L L T U E A C T I O N S O F T H E P I L O T ; A L L T H E R E A C T I O N S OF T U E A I R C R A F T TO P I L O T D E M A N D S : ALL I N T E R A C T I O N S O F P I L O T . ?IR- C R A F T , A N O E N V I R O N M E N T .

TERMINAL EVENT @ D E S C R I B E T H E M O V E M E N T S O F T H E A I R C R A F T FROM T H E M O M E N T B E Y O N D WHICH C O R R E C T I V E A C T I O N C O U L D N O T B E E X P E C T E D TO R E T R I E V E T H E S I T U A T I O N . O R F R O M T O U C H D O W N P R E C E D I N G A L A N D I N G U N D E R E M E R G E N C Y C I R C U M S T A N C E S .

9 C I R C L E T H E S I L H O U E T T E S W H I C H M O S T C L O S E L Y D E S C R I B E A N G L E O F G R O U N D C O N T A C T

9 D R A W A S Q U A R E A R O U N D S I L H O U E T T E S T O D E S C R I B E A T T I T U D E O F A I R C R A F T A T R E S T

F R O N T b

E L E V A T I O N

S T A R B O A R D b

E L E V A T I O N

2 3 -0003 (8-69)

___

-30. - 1 0 . O " 10' 30' 45. 60' 90' 120- 135. 150. 180.

- J : .- 4

I

- _ ~ .._ - Copyright International Civil Aviation Organization Provided by IHS under license with ICAO


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The description of the occurrence is divided into three areas so that the sequence of events is more readily understood. I f the paragraph headings are r igidly applied there should be no dif f iculty in defining the l imits of each of the three areas of interest.

o

The first irregularity of f l ight i s the in i t ia l event in the sequence leoding up to the termination of the occurrence. In some instances i t may be separoted by considerable time or distance from the terminal event, such as the case in which a pi lot becomes lost and continues the f l ight unti l fuel is. exhausted. Or in other instances may be closely related to the terminal event as in a swing preceding a ground loop following a normal approach.

o

In this paragraph, it is essential that the pilot’s response t o the first irregularity be clearly described. A l l subsequent actions and reactions must be included, up to the point where any corrective action i s obviously futile.

o

A description of the terminal event is useful mainly in understanding the reason for the extent of damage to the aircraft or the seriousness of the injuries. The position of the aircraft a t rest, of course influences the problem of evacuating the occupants.

o



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APPENDIX 14.- Accident Report Forms 14- u 1 ELEVATIL VIEW OF LOCALE @

S K E T C H IN S I G N I F I C A N T R U N W A Y S . O B S T R U C T I O N S , F L I G H T P A T H , E T C .

.. SHOW I M P O R T A N r ~ ~ S T A N C E S . DIMENSIONS.

o PLAN VIEW OF LOCALE S K E T C H IN S ~ G N I F I C A N T L A N D I N G A R E A . O E S T R U C T I O N S . A I R C R A F T P A T H . E T C .

S H O W IMP0 R T A N T DI S T A N C E S . DIM EN S I O N S .

NíMog.)



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Both views should show the f l ight path of the aircroft where possible and a l l @obstructions, other aircraft, landing areas, etc., which are pertinent to the occurrence.

@There i s no need to make the drawing to scale, providing a l l important dimensions, distances and heights ore indicated. Where possible indicate the aircraft speed at significant points on the f l ight poth. Elevotions and slopes should be shown. Include o wind arrow and location of eyewitnesses.



--`,,```,,,,````-`-`,,`,,`,`,,`---


CREW F A T A L SERIOUS MINOR - P I L O T - I N . C O M M A N D i 3 rx r 2

cT1 r 3 n S E C O N D P I C O T

T H I R D P I L O T

F L I G H T E N G I N E E R

4 L L O T H C R C R E W - N U M B ï R

1 3 I I 1 L7 L r i E! r7

I

POST OCCURRENCE C O N D I T I O N S

UNINJURED

c:IJ l-3

TT1 rx

PERSONNEL

H E A D C H E I T ' , ~ ~ ~ ~ S P I N E A R M I S I H A N O I S I L E G I S 1 ~~~~ I N T E R N A L

-- INJURY PATTERNS C R E W / N O . O F CICRSONS

P A S S ' N O O F P E R S O N S

P E R S O N S O U T S I D E

-

M A S S I V E

__ PASSENGER (SI - N U M B E R I I I PERSONS OUTSIDE A/C I I=

-

n

1 P A S S E N G E R S -- EVENT CAUSING INJURY NO. O F P E R S O N S I N V O L V E D C R E W

C O N T A C T W I T H P R O P E L L E R / l N T A K E / E X H A U S 1

F E L L F R O M A S R C R A F T $ O R THROWN1

-

AIRCRAFT

DEGREE OF N O N E 0

P E R S O N S O U T S I D E r / C

U N K N O W N 0'

S T R U C K B Y A I R C R A F T

B U R N S O N L V

B U R N S F O L L O W I N G O T H E R I N J U R I E S

C R U S H E D IN W R E C K A G E

P U L L E 0 U N D E R W A T E R

C A M E IN C O N T A C T W I T H M A I N ROTOR

C O N T A C T W I T H T A I L R O T O R

O T H E R I S P E C I F Y I

)i

M I N O R 0

.x

SUBSTANTIAL 0

D E S T R O Y E D L7

ENVIRONMENT

CAMACE PATTERN

E N G I N E 0 P R O P E L L E R 0

N O N E 0 A C T F U S E L A G E 0

C O C K P I T 0 E M P E N N A G E 0 N A C C L L E I S I 0

N O S E

W I N G I S I 0 U N O E R C A R R I A G E 0

M A I N R O T O R 0 T A I L R O T O R 0

T O T A L 0

PROPERTY DAMAGE

N O N E 0

M I N O R u . E X T E N S I V E 0

IS-0001 (8-69)

EVENT CAUSING DAMAGE

A I R a O R N E C O L L I S I O N 0 A I II e O R N E C O L L I S I O N A N O O R O U N O I M P A C T 0

C O L L I S I O N O N G R O U N W W A T E R 0

E X P L O S I O N 0

F I R E 0

A C R I A L B R E A K UP 0

S U D M C R G S N C E 0 C R O U UD/ W A T E R

I M P A C T 0

O T H E R 0

S P E C I F Y :

OBJECT OF AIR COLLISION

A I R C R A F T 0

S i R D ( U 0

D U I L D I N I 0 DETACH- P O R T I O N

O C A I R C R A C T

C O L L ~ U I P O S T (S I o T O W C R o

T I I C E L U L 7

wIREISI n

OTHER o O T H E R A I R B O R N E

O D J O C T

I P E C I F V :

3BJECT OF GROUND COLLISION

A I R C R A F T 0 D U I L O I N O n

D I T C H 0 RIOOC 0

SNOWBANK 0 o w c n 0 SPEC1 C Y :

PROPERTY DAMAG ED

R E S I O E N C E 0 V E H I C L E 0 S A R N / S T O R A G E 0 C E N C C 0

P U B L I C U T I L I T I E S I N S T I L L A T I O N 0

F A R M C R O P a O T H C R 0 S P E C I F Y : ,

A I R C R A F T 0 Copyright International Civil Aviation Organization Provided by IHS under license with ICAO


--`,,```,,,,````-`-`,,`,,`,`,,`---


' OXYGEN M A S K

CEVICES

LIFE = PROTECTION DATA

F I L T E R MA,K P A R A C H U T E

LI FE V I S T I I N DI V I Du A L HELMKT F L O T *TION O E V I C E

CRASH PROTECTION DEVICES

CREW

PASSENGERS

CRASH EVACUATION

NUMBER BEING USED

NORMAL E S C A P C P O I I T A 9 L L EXTINGUISWCR E S C A P E

AIRCRAFT, EQUIPMENT C S C A P C .LID. L A O D C W I O P C DIN G H V O X I T S H A T C U a S

I I

NUMBER INSTALLED

NUMBER USED

NUMSER FAILED IN OPERATION I I I

o O

I

NUMBER FAILED IMPROPER OPERATION O NUMBER FAILED IN USE O

O

n o O

O O O o

O 0

o o

o O

O a o O

o O

REMARKS AND RECQMMENDATIONS

PERTINENT a NOT PERTINENT SEARCH AND RESCUE SEARCH SUCCESS BY

PRIVATE A G E N C Y CI 0.0.1. o

. C O M M E R C I A L [-J O T H E R a A G E N C Y

SP E C I F I : R.C.M.P. n

SURVIVAL

DURATION L E S S T H A N 4 HRS 0

L7 4 HRS. BUT LESS T H A N I 2

12 HRS. eu^ LESS TH AN z4 El I D A Y BUT T H A N z n z D A Y S BUT L E S S T H A N 4 n 4 D A Y s eu T L E S S TH AN 7 LT 7 D A Y S BUT L E S S T H A N I 4 C- 4 D A V S OR M O R E c7

PERTINENT 0

TYPE

G R O U N D [-I!

C O M B I N ED A I R / B O A T Cl

G R O U N D I A I R 1 - 1 C O M B I N E D 7.-

A L L u

. ~~

- LOCATING METHOO

AL:ToMATlc a P Y R O T E C H N I C S V I S U A L L7

NOT PERTINENT ITj

DEVICES P R O T g C T I V E

CLOTWING F I R S T E M E R G E N C Y WEAPON FI SHIN C F I R E IL E E P I N G

0 AG A I D K I T G E A R S O U R C E R A T I O N S T E N T

AVAILABLE-NOT USED r2 C3 o n r i cl n cn NOT AVAILABLE [Ti CJ n El C3 n Ci o FAiLED-IMPROPER USE n E cT1 c3 n c3 r-i c3

r:i rx 13 cl cs1 n r3 NOT SATISFACTORY L I

REMARKS AND RECOMMENDATIONS: 23-0001 O691

(101 Copyright International Civil Aviation Organization Provided by IHS under license with ICAO


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INVESTIGATOR’S APPRAISAL @ I N O I C A T E W H I C H I T E M S O F T H E R E C O R D E D F A C T U A L D A T A . IN THE V I E W O F THE I N V E S T I G A T O R , C A U S E D T H E A C C I D E N T .

D E S C R I B E IN N A R R A T I V E H O W T H E I T E M S I N T E R A C T E D T O C A U S E T H E A C C I D E N T .

RECOMMENDATIONS @

FOR REGIONAL USE

CAUSES -



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o AS briefly os possible the Investigator should express his opinion of the cause(s) of the occurrence and the reasons for his opinion.

@ The recornmendotions requirad here are those which the Investigator believes will prevent recurrence of similor mishaps.



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INVESTIGATION

o REGION AL SUPERINTENDENT COMMENTS

HRS.

I

E L A P S E D T I M E FROM

A C C I D E N T T O R E C E I P T O F

N O T I F I C A T I O N B Y R 6 G I O N HRS.

E L A P S E D T I M E FROM

ACCI DENT TO INVESTIGATOR'S

A R R I V A L O N T H 6 S C E N E

CASH: C O O T O F F A R E S . C H A R T E R S , ETC.:

R E G I O N A L S U P T . A C C I D E N T I N V E S T I G A T I O N D A T I

R E G I O N A L C O N T R O L L E R . C I V I L A V I A T I O N D I T I

DOCUMENTS SuPponTtNG TUE oETAILS OF Tulf REPORT AND APPENDED UERETO

POLICE R e P O R T 0 M A T E R I A L

M E D I C A L R E P O R T 0 L A B O R A T O R Y R f i C O R T 0 WIATMER INCORMATION 0

C R I M E L A B O R A T O R Y R E P O R T 0 P A T H O L O G I S T ' S R E P O R T 0 PILOT'S STATKMENT (51 O A T C TAPE/TRINSCRICTION 0

C O R O N E R ' S R E P O R T 0 C A S U A L T Y L I S T 0 W I T N E I S L S ' S T A T L M f i N T 1 5 1 0 T E C H N I C A L RLPORi5 0

MAPS AND C H A R T S 0 PASSFNCER STATEMENTS 0 O T H E R 0 S P E C I F Y :

ADMINISTRATIVE DETAIL

EXPENDITURES A L L O T H E R C A S H E X P E N S f i S

T O T A L C A S H E X P E N D I T U R E S

M*N*OURs: T I M E S P E N T O N T H I S C A S E B Y A C C I D E N T I N V E S T I G A T O R I S I I N C L U D I N G T I M E . HOURS.

H.Q. USE ~ ~~ _______._

CAUSE FACTORS ASSIGNED -. ______



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@ procedures, techniques, etc. If he believes some addition or deletion to investigation regulations or policies should be made, suggested changes should be outlined here.

The Regional Superintendent i s invited to comment upon occident investigation



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- ~~

~ C o t m o N w E A L T H OF AUSTRALIA A l RCRAfT ACCIDENT INVESTIGATION D E P A R T M E N T OF CIVIL AVIATION SUMMARY REPORT

R*f*'*nco

Hoight o.n.a.1. (10 Doto

Mako ond Model Rogiatrotion

7. RELEVANT EVENTS 1

i 1

Volid io Cortifico- Vol id from of

Airwwlhimrm

I i

8. OPINION AS TO CAUSE

I I

CA 149A (1968)

Oporo(0r (- d d n m a ) Rog8slawd Ornor ( n o w ond oddrors) Dogroo of dorogo to oircroft

0th.r po*y i . r i o * d

Lost or intsndod dcportuio point Timo of doporturo Mort point 01 intondd londing Purpoao of flight Closa of oparotion

Nam. Stotus Ago Clors of Iicmco Howr on typo Toi01 hours 7

Dopro. of in luy

N o m e stotui Dopvar of inpty N-O Stotu. ~ogt.. 01 inluty '

Repulotion or Odor No. Notuo d conirwontion



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‘Fil. 9. CHARTS ,DIAGRAMS ,OR SKETCHES

I Indicate appropriate title

?ag.

?

ACCI DENT =LLGHT IMPACT WRECKAGE WITNESS RUNWAY OR LOCALITY P A t H MARKS DISTRIBUTION LOCATION STRIP DATA

LEGEND

I OTHER (Doaciibo )

SCAL E NORTH POINT n



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Filo 10. PHOTOGRAPHS

Poo.

(Photogrophs displayed should nonnolly include a general view of the occident locolity, a view showing the extent of damage to the aircroft, and such other views of ground marks, aircmft components or items necessor>. to suppor~ the occident .analysis. Wherever possible phomgmphr oi the coc&pit or cabin i n h r l w should bo inc1ud.d m ossist in fhm c r m h injury reseorch pmg-.)

:option

:A i 49c ( i96a ) 10 - PHOTOGRAPHS Copyright International Civil Aviation Organization Provided by IHS under license with ICAO


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14-26 Manual of A i rc ra f t Accident Inves t iga t ion

11. AIRCRAFT DATA Filo Pogo

Moint. Releos. I i ruad

AIRCRAFT DAMAGE - L i s t the principal compornnis which were ¿onrap.¿ in or os o result of the occidoni : describe the mode of damage and indicate degree on¿ couse o4 damag. to mach compormnt by Inrednp I ( impoc?) F (fire) or O (other) in opproprioh R.H. Column. IF REPAIRABLE, WHAT IS ESTIMATE OF COST ?

If no, Stoto rooson Wo. i t Volid ot Curiont Until

Componont I====

0.foctiv. compon.nt

Modo of Domogo

Oporoting Timo (hr$ TYP. 01 inspoetion Maior 0*'*ct Toid Since O d u i Sinco Inspection Roport No.

I i

Moko a d modo1

I

AIRCRAFT CONTROLS AND EQUIPMENT

Danogo ea Aircroft



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Fi Io 11. AIRCRAFT DATA (Cont'd)

Pogo

'7 I I Troo a Fonce I . I

láûo 135" 120' 90. 60' 4 9 30' 0' r)' 45. do. 90. l P . 135. 150. 180.

-%\ + f NA/ + k i t + .t'lfiy+.

r VIEWED FROY SIDI!

-10' 0' - 10. 30' 0. 60' 90. In). 135. 1w 180.

?RINCIPAL IMPACT

I i+i I 8.

u$

w w w x

I #

1 I

I

I

!

I F i r m Ground Rocks 0 Runroy or Rood 0 Trooi i

I Dthmr (Describo 1 A i r c r H empennit I m d v d 1 O W i r o Building á p a d (kts)

OCCURRENCE OF FIRE

Rolled

Aff mctd A n a (X)

Sronda' Ahor 1 mpact 0 In Flight U O n Ground .

ûouncod Slid C o r t r h r l d Dug In )Other (descri bo)

OVEnALL CONDITION

I Cockpit 1 Intoct

CONDITION OF COCKPIT COMPONENTS ( L-Loft, R-Right, F-Forword, A- Aft.)

I I I I I I I I I I I

11 - AIRCRAFT DATA (Cont'd) u CA149E (1968) '



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J4- 2 8 Manual of Aircraft Accident Investigation

FtIa Pope

11. AIRCRAFT DATA (Cont'd)

FORWARD FUSELAGE LONGITUDINAL DEFORMATION

NOTE 11 lure logc i s subsiontiol ly intoct h o w a v r deloimad, select tha potnt on i t now fuithast forword, describe i t ond maosu~a the distonca olong or p o r ~ l l o l to th. noimol longitudinol 0 x 0 s of tha oiicrolt l i o n th is pomt to tha Iront of th- p i l o t ' i saofwhen fu l l y forward.

Description 01 Point ( th is may o l i o b. indicotod in photogrophm at Saction 10) Di stonca

Ins

Remarks

I

(Surnoma ond initiols)

P I L O T E X P E R I E N C E (hours)

A G R I C U L T U R A L R A T I N G

S P E C I A L E X P E R I E N C E (en ta i toto1 hours or unknown ago ins t any s ign i f i can t items) Totol Lost two yaors Los t 90 dors

Fixed Wing

Rotary Wing

! T h i s tvDe of oircroft

Agriculturol Instrument

Night flying Instruction

Gliding SimuIotoi

LAST Dot.

u Unknown U N o i ralavont

C O N T R O L S E A T O C C U P I E D

- - PROFiClENCY CHECK

Wos pilot rao r ing corractow spastoclas 01 tima of occident? Yo. [3 No

Front Raor Le f t Right Unknown

~ ~ ~~

RESTRICTIONS (specify)

IDUAL CONTROLS AVAILABLE/ ~ ~ e ~ o t o i I Ailaron Ruddar Throttle Steering Brokes

Occupation Dote 01 birth Licence endorsed lor this oircroft ri Y.. n No I INSTRUMENT R A T I N G

cNSTRUCTOR R A T I N G

I A G R I C U L T U R A L R A T I N G

1 s t C l o r a Clos, 1 Cl.rr 3 I C l o r s 5 None 2nd Closs Clos. 7 c i o s s 4 Unknown 1 ~ ~ ; ~ ~ ~ "

A 8 C None Unknown I 1

c l o i s 1 Closs 2 Nona Unknown I

' P I L O T E X P E R I E N C E (hours) 1 Totol

I

S P E C I A L E X P E R I E N C E (enter total hours or unknown ogoinrt ony s ign i f i can t items) Lost two p e r s Lost 90 doys

1 F i x e d Wing

R o t o r y Wing

I i n i s t y p t of a9rcroft

I - A S T PROFICIENCY CHECK 3 o t e

' Y P O -

1 1 1 I l 1

LICENCE RESTRICTIONS (spacify)

Was pilot wearing correctvve 1 spoctocles a i tima 01 occident? c] No

Agricultural

Instruc?ion

Clidtng

Test ing

Damonatrotion

Instrument

Nigh? l ly ing

Simulator

Commond

i C O h Ï R O L SEAT OCCUPIED 1 Front Raor Lett Right Unknown

[DUAL CONTROLS A V A I L A B L E Elevator Aileron Rudder Throttle Steering BioCes



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APPENDIX 14. - Accident Report Forms. 14-29

€ E T (Mini)

SARTIHE (htr)

Filo Pogo 13. FLICHT DATA I

Enduionco (Min.) Cons. IO** Hoight (fi) 0 NOSAR

lo Focility .

I

I

I To

I C N o n e

I

0th.r (doserib) Souco of mot. informtion Rout. forocost

nNight O D o w n =Dusk

W l n á spood ond diioction Tomprrotwo

* F o Dav

Cloud typi/omount Bos. o.m.s.1. Visibility

f t m i l o s

i HEIGHT ( Ibs) Tako off Londing

1 Emergency equipment (dosstab.) I

L I 14. METEOROLOGICAL DATA

Weight (Ibs) How ostoblishod

I I By telephono I AIOO fOrOc05t

,

A I R C R A F T

LIMITS 0 I Aircraft b a r i c weight (tncluics empty weight, 0 8 1

ond ternorat lo equipmant)

Flight c r e w (Fio .................... )

P o s s e n g e r r (No .................... ) I Boggogo (Pieces .................. ) Freight (P ieces ................ ....) or Hopper contents

Fu01 (Imp.golis .................... )

I Fu,el/Lood deductions

! We,ght o1 occident

A I R C R A F T C E N T R E OF G R A V I T Y D a t u

LIMITS 0 I Forward

I I

c] Unknown Position ot lost toko off

Position at occidont I 0 Unknown

A G R I C U L T U R A L H O P P E R L O A D

Contmnts (dosci~bm)

Lood 01 inpoct (Ibs)

0 Roportod n Dischorgo rolvm position

bump offoctod I f yos. amount (X) n Y.* n N~ U U I

, LOADING CONTROL Idescribe briefly unrotiafactoty feoturos of loading c o n t d such as miscolculations. inodrquoto laad rocurity, impmperly consigned dongomus goods otc.) I

CA 149G (1968) 13 . FLIGHT DATA 14. METEOROLOGICAL DATA is. LOAD DATA



--`,,```,,,,````-`-`,,`,,`,`,,`---

~~


Filo 16. CONTRAVENTIONS OF REGULATIONS AND ORDERS

Pop.

CA 149H (1968) 16. CONTRAVENTIONS OF REGULATIONS AND ORDERS



--`,,```,,,,````-`-`,,`,,`,`,,`---




--`,,```,,,,````-`-`,,`,,`,`,,`---

File 18. SEQUENCE OF EVENTS

CA 149K (1968)

Poe.

18. SEQUENCE OF EVENTS



--`,,```,,,,````-`-`,,`,,`,`,,`---


Fil. 19. ANALYSIS OF THE CAUSE

Pop.



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14-34 Manual of Aircraft Accident Invest i g a t ioii

20. ACCIDENT PREVENTION Fi lo Pogo

22. PARYICIPATION IN THE INVESYIGAYION ----- ----- r: -___ -----._ Name A f f i I i á t ion -1 ---p.-- ---- I

1



--`,,```,,,,````-`-`,,`,,`,`,,`---


CA 149N (1968) CONTINUATION SHEET



--`,,```,,,,````-`-`,,`,,`,`,,`---


Age 3 Male

0 Female

realmen1

Yeors c

None 0 Hospitolised

F t i s t old

I Page

F i le INJURY REPORT

used by this occupont

o Pilot [I ~ossenger Other (describ.)

0 Other crew O Unknown

Weight

Ibs. Nome of Doctor

Nome of Hospitol

~ ~ ~~~

NOTE - Use i r p u 31.. lorm o . icrol i n c t i ~ I y ~ c * C I F E P ? when vhWri i o x r i n g . or and hen-s no I C Y C ~ C deceleration occurred.

r o c h pctron mniured etthet in oi icraf i or on ground In addition complete relevont sections of form for each perron in

the occident involved o wheels-up londing ar on undercowiage collapse ar rettoction whilst opevoting on the ground (a) oircroft involved has a perrnisstble proas weight in e n c e s i of 12,500 Ibr, or (b l the occldent occurred

c

i e g ~ c c o f in lui l

Fatal O M i n o r

S s r i O u 5 O N 0 1

1. OCCUPANT INJURY

Coinell Burns Whem did accvpont carne to rest No. No.

~

uvnorn. and I n i t i a l s Address

a , , lmenl

L] None 0 Hospiialised

I FIG 1 - SEATING Shade oll occupied seats ond mark with X reo1

0 Foto1 0 Mtnoi

Cornell No.

Nome of Doctor

0 h r i O U 8

Burns Na. Namm of Hospitol

@ B o c k w a i d 0 Inside I I 0 întoct 0 Collopsed 0 Burnt

Foswoid a Down 0 Outside 1 0 Distorted 0 Portly collopsed

I I I v i o I Evocuotion time

l emorh i

o U u

Use double l i n e s to show seo1 bocks

2. OTHER PERSONS- INJURY

I l

I I

3. SAFETY EQUIPMENT

I F I G . 2 - SEAT AND HARNESS DAMAGE 'SV': o c ; , or hornerr f l t tcd



--`,,```,,,,````-`-`,,`,,`,`,,`---


Mor Injury C0us.d By Control Column i If Yws, Spwcify i O R i m O S p o L w rJContiol .Column

0 Yes o No i O H u b O Y o k o O S t i c k

F i lo Pagw

INJURY REPORT (Cont'd)

Did Occupont Hit Bock Of k a t in F r a t

0 ïws O"

3. SAFETY EQUIPMENT (Cont'd) Auto Lock Control

Row1 brokw functiond

Manual Lock Control *as in.itao reel

fitted 0 Avoiloblo 0 Engogod Monufoctuiwi and/or model

O y e s O N E a % i l o b l w 0 E"4opd 0 a"

FIG. 3 NOTE Indicate on Fig. 3 the following

(o) Scrotches, gouges, stains, burns and apwcify bv -hot s t r u c t u ~ w thwsa were cousod;

(b) Any strucvurol damage to tho ahwll , (c) Any domogw to antwino1 sling or chin strops; (d) Any mocks on or damag. to gogq1.s;

(ATTACH PHOTOGRAPHS I F HELMET MARKED OR DAMAGED. IMPOUND HELMET I F BADLY DAMAGED)

I

5. CAUSE OF INJURY

3ccupont Hit (More thon ano itom niay bo markad)

a Cvoshpad

0 Cooming

0 Windscrwen

0 Windscra.n Fiome

Initrumwnts

0 instrininnt Ponal

O Instrunnnï Pmwl Structurw &ow

0 Ovwihood Brocoi

O O v w i h r o d Panels

0 O v w r h d Controls

0 Sido Structwo

0 Door Hondlwi

üaer Posts

0 Pioiwctioni (Knobs w k . ) O G r o u n d or Eitwmol Obimet 0 Structure not idwntif iwd

Nor Occupont inlured By Ib iects Or Other Person 3atng Thrown Onto HBm

?.marks

i I f Y.., S p c i f y

c] Y.. O"

CA46 1 B ( 1 969)



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14-38 Nanual of Aircraft Accident Investigation

FULL N A M E

C3hiMONWEALTH O F A U S T R A L I A DEPARTMENT OF C I V I L AVIATION

NORMAL ADDRESS

WITNESS REPORT

Signatur0 of Poison Giving Roport

Filo I

Date

1 Pogo NO.

I I

TEMPORARY ADDRESS ( i f applicable) OCCUPATION

e 1 10 ASSIST IN THE INVESTIGATION OF W E I N U D E N T / K C l D E N T INVOLVING AIRCRAFT Vn - . I STATE AS FOLLOWS :-



--`,,```,,,,````-`-`,,`,,`,`,,`---


Filo SPECIALIST REPORT

Poe.

CA 1571 (1968) SPECIALIST REPORT .



--`,,```,,,,````-`-`,,`,,`,`,,`---

14-40 Manual of Aircraft Accident Tnvestigation

APPENmX PII. Paga Na. I N VE S l l GATO R ' S N O1 E SJUQJCCT



--`,,```,,,,````-`-`,,`,,`,`,,`---


I I I I I

5. PLANNED INTERMEDIATE POINTS OF LANDING ACTUAL TIME ACTUAL TIYL

LOCA T I ON LOCAT ION Amm. D.C. A R R . DEP.

I SERVICE, IF ANY, A T LAST POINT OF DEPARTURE



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NTSB F o n 6120.1. PILOT/OPERATOR REPORT PMOTOG R A PH

WITNESS STATEME NTS FLIGHT PLAN

PASSENGER LIST NT$B Form 61M.b. MID-AIR COLLISION

FLIGHT COMMUNICATIONS NT$B Form 61M.4b, AERIAL APPLICATION/CROP CONTROL

WEATHER REPORTS ENGINEERING REPORT

OTHER f D 8 ~ c d b e )

INSTRUCTIONS

i

I n i w i ?N/A? in dl spaces where items nre not applicable.

When PM weight and/or center of q a v i t y are determined lo be involved in the operaion. d e m i h e in the narrative, and l is t computations.

Funieh all required i d o w i o n on pilots aboard the aircraft O C C U ~ Y ~ ~ pilot meas (indudem s ide by s ide mnd tmndem cob figmuion).

include only the pertinent pdu~1ogic.l &/or toxicologicù iníormrtion in the n r r a i v e w c t w a of tbc report.

i n accidencs invoìvhg imding or tmkeoffa. give ai i saviron- mental factom, ¡.a.. miway &U. temin. o b u n c t i o n hci&ts. disrinces, phase of flight aircraft coifipmtian, etc.

For the purpose of wreckage examination, helicopter components have been divided into eight groups. These p u p s apply to dl basic helicopters now in general use. The damage classification columns have been divided into two par t s ( l and 2) for the engine p w p . and four paris ( F (forward), L (left). A (aft). and R (right)) for the main rotor group. This h a s been done to adapt the form for use on twin-engined and/or tandem or side-by-side intermeshing rotor configured helicopters. The m i n rotor control system includes the entire system from the collective and cyclic controls back thmugh the various link- ages to the b l d e s themselves. This would include all control l i d i y s . hydraulic boosn. servo p d d l e s . weights, or any i tem . p p l i u b l e to the control or the main rotor. The same criteria would apply to the tail rotor control system.

DEPWITIOWS

For une in th i s reporc. the bllowiw rorda or p b a M defined M follows:

FATAL INJURY - Any injury d i c h resalts in death within 7 days.

SERIOUS INJURY - Any injury wbicb ( i ) n?quins hospital- iwtion for m o k ihm 4ô hours, commenein8 within 7 days from the date the injury was received; (2) rcwlta ia a fracture of any bone (except simple fractures of 6 i g e r ~ . toes. or nose); (3) involves lacerations which cause severe hemorrhages. nerve, muscle. or tendon dumage; (4) involves injury to any internal organ; or (5) involves second or third degree burns, or any bonis affecting more than 5% of the body surface.

SUBSTANTIAL DAMAGE - In aircraft of 12.500 pounds maximum certificated takeoff weight or ICM mans d m o a p or structural failure reasonably estiinstad to cost $300.00 or m r e to repair.

DESTROYED - Consumed by fire. dcmolisbed or damaged b e p n d repair.

OPERATOR - Any p e s o n who canses or authorizes the operation of an aircraft, such M the owner, lessee, or bailee of an aircraft.

PUWOSL OF FLIGHT PLEASURE - Flying by individuals in which the principal reamn is pleasure and not associated with business or profession.

BUSINESS - Flying &ne by an individual in h is own, com pany owned, rented or l emcd aircraft in connection with h is profession or occupation, or in furtherance of the business of h i s company.

CORPORATE EXECUTIVE - Use of aircraft owned or lease and operated by a corporation or business for the transport^. tion of personnel or in the conduct of the fim?s business and which are flown by professional pilots.

AIR TAXI - Flying which at the time of the accident. is being done under and in accordance with the provisions of a valid Air Taxi Operator?s Certificate.

INSTRUCTIONAL - Flying accomplished under the supervision and/or direction of an accredited instructor.

PRACTICE - Proficiency or training flying which is not under the direction and/or supervisionof an accredited instructor.

OTHER - Specific kind of flying or type of activity being done at the time of the accident, ¡.e.. pipe line patrol, ferry, test, fish spotting experimental demonstration, etc.

I A I T ACHMENT CH ECK LI ST I



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APPENDIX 1 4 . - Accident Report Forms 14-43

A T OCCURRANCE

TERRAIN FEATURES (Check m o i s than

ELEVATION one I f necsaaary)

UNKNOWN MIXED I

PRIOR TO T A K E O F F A F T E R T A K E O F F

METHOD 9. FLIGHT

BRIEf ED ON YES BY METHOD !YES B Y

WEATHER- ' I NO 1 NO

I4.AIRCRAFT COMPONENT IN- VOLVED WITH OBSTACLE

1 1 - 1 I I I I I

13. ObälOr\. SINCL b b ï . Pl inclpi Impe l 'z 11 .c.c. 12. F u e L LAST TAKEOFF WIRES BRUSH

K .i CONDITION AMT ON 'OARo f JET

1. I TREES I I BUILDING

A T TAICEOFF I NO [ OTHER fSprClly> OCTANE RATING

RIGHT WING FUSELAGE MAIN ROTOR LANDING GEAR I P R O P E L L E R

NOSE L E F T WING

I I 1 I I I 4

15. MOVEDAFTER PRINCIPAL IMPACT

1 NO I6.CONDITION I S O F T OTHER fSp*cily) ON GROUND

HARD 17. FIRE I N F L I G H T OF GROUND

Y O ( G l u &at.)

10. SKETCH OF IMPACT POINTS (Sketch p u o . -,ka with dimrialon mnd n u ~ r t l c hmdlng; includr initlal rnd iiNf i m p c t Pdnta

17. APPROXIMATE ATTITUDE AT IMPACT IN RELATION TO HORIZON USE ONLY WHEN SUPPORTED BY OOCUMENTEO EVIDENCE .C IRCLE AIRPLANES I N THREE VIEWS TO I NOICATE APPROXIMATE ATTITUDE A T TIME OF IMPACT WITH OBJECTS PRIOR T O HITTING GROUNDi O R A 1 SQUARES AROUND A I R P L I N E S TO INDICATE APPROXIMATE A T T I T U D E A T T I M E O F IMPACT WITH GROUND.

VIEWED FROM FRONT VIEWED FROM ABOVE



--`,,```,,,,````-`-`,,`,,`,`,,`---


WRECKAGE DISTRIBUTION

WITNESS LOCATION

PROBABLE OTHER fDemcribo) FLIGHT PATH

RUNWAY DATA (nth rbidcœumnenl)

S C A L E

N

NTûB Pami 6110.4 PAGE 3



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APPENDIX 1 4 . - A c c i d e n t R e p o r t Forms 14-45

S E A T BELTS

TRIYTABS



--`,,```,,,,````-`-`,,`,,`,`,,`---


RPM NO. I

ENGINE R P U

NO. 2

L A N D I N G G E A R I N S T A L L E D

FIXED I I TRICYCLE I } IEELS AMPHIBIOUS OTHER O&iify> I RETRACTABLE 1 I CONVENTIONAL .OATS SKIDS

H O U R I

H O U R S

F

up 'OWN LO:&C R E T R A C T A B L E G E A R A T I M P A C T

L E F T

RIGHT

NOSE OR T A I L

RIGHT CYLINDER HEAD TEMPERATURE

OIL PRESSURE

DOWN ( G i n DUAL CONTROLS æ-o

L E F T

OYESONO OVES UNO FUEL NAIN RIGHT

i AUXILIARY L E F T V A L V E S

SITION A N D READINGS

TRIM POSIT1ONS L E F T RIGHT FIXED S E T T I N G S IAmt. of Deflect irn) TRAL

RUDDER RUDDER

AILERON

COMPONENT COMPONENT

I N S T R U M E N T R E A D I N G S

REMARKS NEEDLE FREE UN- SWINGING KNOWN INSTRUNENT

READING

SETTING ALTIMETER

NAGNETIC COMPASS

AIRSPEED

I 1 I ~ ~~

CLOCK

04RECTIONAL GYRO

I R A T E OF CLIMB UP 1 I I

- 1 OIL TENPERATURE

MANIFOLD PRESSURE

OTHER <Specify)

I

REMARKS/OTHER

NT8. Conii 81îû.4 PAGE 3



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APPENDIX 14 . - Accident Report Forms 14-47

1 STUDENT INSTRUMENT I I SINGLE ENGINESEA

OTHER ISpacify) OTnER ISpscify)

T Y P E RATINGS

i

PATHOLOGIC AL AN D/ OR TOXICOLOGICAL E X AMIN AT ION P E R F 0 RUED

'm NO n YES f E x t m r )

PILOT FLIGHT TIME f To nean.< h o u )

FAA OPER %TOR'S OTHER fSPecifyJ M U R C E PILOT'S O F INFO. FLT . LOG RECORDS .STIY*TE

LAST 24 HOURS T Y P E

l (6l MULTI ENGINE I I I I I I I I

LAST 90 DAYS T O D A T E I ( 1 1 i n i s MUE AND MODEL

0 1 NIGHT

0 1 D A Y

I I I I 1 ' . . " , I I' .'' " ' : f V, ' >, TOTAL 15. 6. 7 . 81

8. Sacond Piloï

DU AL SOLO DU AL )(>LO T O T AL W A L SOLO TOTAL

I I

D/ OR TOXICOLOGICAL

C 4 C T U A L

S I M U L ATEO (4 ) WSTRUYENT

(SI SINGLE ENGINE

I l l T H I S M A K E AND M O D

12) NIGHT

(31 D A Y

'181 G L I D E R

rsn form 6120 4 P A G E 6

I I

I71 ROTORCRAFT I r 4 I 1 I



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14-48 Manual of Aircraf t Accident Invest igat ion

21. A I R C R A F T HISTORY

A K E MODEL

SOURCE O F INFORMATION

SERIAL NO. REGISTRATION MARK

N

TRANS- PROVI- RESTRICTED LIMITED iSUANCE D A T E NORMAL,

TYPE UTIL ITY , PORT SIONAL ACROBATIC

E XPERI- MENTAL

PROGRESSIVE

PERIODIC (Give date of laat inmpection)

) A T E OF LAST PERIODIC INSPECTION

I I L

PROPELLERS~R~TORS

TYPE D A T E AIRC. HOURS AT T I Y E O F INSPECT I ON

TIME SINCE SINCE L A S T

OVERHAUL N S P E C T I O N NO. MAKE AND MODEL SERIAL NO.

t 1 I

T Y P E OF INSPE~TION

Ro.

1

2

TIME SINCE NEW OR OVERHAUL MAKE AND YODEL S E R I A L NO.

MAKE AND MODEL

REGISTRATION MARK

N

NAME AUDIODRESS OF OWNER



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APPENDIX 14 . - A c c i d e n t Report Forms 14-49

DATE

TtOM AFFIL IAT ION

AGENCY SIGNATURE

U S GOVERNMENT PRMTINC OFFICE 1867 O - 18,-681 NTSB Fan) 6110.4 PAGE 0



--`,,```,,,,````-`-`,,`,,`,`,,`---

CA0 FomQS-1 CIV IL AERONAUTICS BOARD

AIRCRAFT ACCIDENT REPORT FLIGHT INVOLVING AERIAL APPLICATION/CROP CONTROL

(REV. 11-64] C A B ACCIDENT IDENT. NO.

1. ACCIDENT LOCATION IDENTI FICATION

D l 1 E TIME

'2. PILOT FLIGHT TIME- DAY O F FL IGHT íBetween rnidnt&hí and 10-DAY PERIOD PRIOR TO ACCIDENT T O T A L HOURS AERIAL APPLICATIONS j i im- of oretdrn1J

I T o ne.iresl hour)

3. TYPE OF AERIAL APPLICATION OPERATION 4. KIND OF CROPS -____---- ZEEDING CROPS I SPRAYING FORESTS BEAUS PASTURE

SEEDING F 0 7 E S - S SPRAYING TOWNS CLOVER PEAS

FERTIL IZ ING (DUST I AGITATING TREES CORN POTATOES

FERTIL IZ ING 'L ICUI D l ANTCFROST OPERATION COTTON RICE

KNOCKING F R U I T O F F F L A X SAGE 3EFCLIAT ION !DUST'

_.____

ES h . - ~


DEFOLIATION (LIQ'J ID)

SPRAYING CROPS

FEFIRY ____-- -

SU3VEY OF AREA GRAPES SPINACH

CHASING BIRDS FOREST-TREES STRAWBERRIES

TOBACCO ! PRACTICE FRUIT ORCHARDS

DdSTING CROPS TEST ICALIB. EQUIP.) I GRAIN F I E L D S TOMATOES

OTYER CUSTING OTHER (IdeniifyJ L E T T U C E OTHER ( Ident i fy) !Identify'

MESQUITE

MOSQUITO CONTROL i

5. C H E C A L S USED

DRV-rOXIC

- DRY-NOhTOXIC

LIOCID-TOXIC

Ll WJlD-NONTOXIC

BRAND O F CdEMICAL '

6. TOXIC EXPOSURE 7. TOXIC ANTIDOTES DURATION ( I f uied h i n e operation)

EXPOSURE T O P ILOT 15 MINUTES OR LESS 30 MINUTES OR LESS

AVAIL ABLE-USED

NOT AFFECTED AVAILABLE-NOT USED - I I HOUR OR LESS NOT A V A I L A B L E I 2 HOURS OR LESS UNKNOWN

3 HOURS OR LESS AFFECTED I N FL IGHT

8 . RESPIRATOR AFFECTED ON GROUND . - ' 'OURS OR LESS AVAIL ABLE-USED PRIOR TO FL IGHT

UNKNOWN

AVAILABLE-NOT USED S HOURS O R LESS

OVER I HOURS NOT A V A I L A B L E

UNKNOWN UNKNOWN



--`,,```,,,,````-`-`,,`,,`,`,,`---


............................... ............................... ............................... ...............................

............................... ............................... ...............................

............................... ............................... ............................... ...............................

...............................

AERODROME STATUS REPORT

Note.- b o s s out or add items t o s u i t the part icular aerodrome

THIS I S TO CERTIFY THAT AT THE TIME OF THE ACCIDENT TO .................................. ............................ ON ................... lg................................ AT

............................ HOURS G W , THE STATE OF THE ................................

........................ AERODROME AND I T S ASSOCIATED EQUIPMENT WAS AS FOLMWS:

RUNWAYS IN USE I RUNWAYS I N USE I RUNWAYS IN USE I I

I. (a) DIMENSIONS ....................................... (b) ELEVAL'IONS ........................................ ( c ) GRADIENT ........................................... (d) LANDING S T R I P DIMENSIONS ( I F GRASS) .............. (e) POSITION OF THRESHOLD (WHETHER

DISPLACED) ...................................... ( f ) SURFACE CAMBERED/FLAT ............................ (8) TYPE O F SURFACE .................................. (h) STATE OF SURFACE (i.e. SLUSH, WET,

DRY ETC.)........................................ ( i ) BRAKING ACTION ASSESSMENT ........................ (j) DIRECTION OF CIRCUIT ............................. (h) PECULIARITIES OF RUNWAYS ( I F ANY) ................ (1) PECULIARITIES OF APPROACH PATH

( I F ANY) ......................................... (m) GENERAL REMARKS:-

(n) DETAILS OF WORK I N PROGRESS

_. (o) NOTAMS APPLICABLE AT THE TIME

I I (p ) WEATHER ACCIDENTS

Compile a list of all take-Offs,

Landings and overshoots du r ing t h e

twelve hour pe r iod preceding t h e

a c c i d e n t ; g iv ing the RVR, time of each

movement, and name of persons r eco rd ing

t h e information.

(9) HOW RVR MEASURED?

( r ) WHEN WAS RL7R EQUIPMENT CHECKED AND BY WHOM?



--`,,```,,,,````-`-`,,`,,`,`,,`---

14-52 Manual of A i r c r a f t A c c i d e n t Inves t iga t ion

2. A ROUTINE CHECK OF THE RUNWAYS AND MANOEUVRING AREA HAD BEEN MADE ON ............ .......................... 19... . .AT ................................. HOURS GMT,

BY ............................... AND LOGGED AS ................................

AT HAND I N ATC

SURFACE W/V ....................................................................... MAX. GUST W/V ..................................................................... HORIZONTAL V I S I B I L I T Y ............................................................. PRESENT WEATHER ................................................................... CLOUD ............................................................................. TDO?EXATURE ....................................................................... DEW POINT ......................................................................... QNH................................................................................ RVR ............................................................................... ACTUAL WEATHER AT TIME OF ACCIDENT ................................................ QFE ...............................................................................

................................................................................... ................................................................................... LIGHT CONDITIONS .................................................................. COMMENCDfENT/END OF C I V I L TWILIGHT ................................................ TIME ( G m ) ........................................................................ ORIGINAL CURRENT MET REPORT

TO BE ATTACHED ................................................................... NAME OF ATC CONTROLLER MAKING MET

OBSERVATIONS AND QUALIFICATIONS .................................................. OTHER PERTINENT MET INFORMATION ...............................................

................................................................................. I N THE ........................... LOG BOOK, WHICH I S PRODUCED HEREWITH.

PASSED TO AIRCRAFT

WEATHER INFORMATION

3.



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APPENDIX 14.- Accident Report Forms * 14-53

EMERGENCY/DISTRESS INFORMATION

4 . ATC KNOWLEDGE OF, THE AIRCRAFT STATE OF EMERGENCY/DISTRESS PRIOR TO THE ACCIDENT (IF APPLICABLE) :

5. ACTION TAKEN: (a) DETAILS:

( b ) NATURE OF STANDBY INSTITUTED - .................................................... ' WHICH ENTAILS THE FOLLOWING ACTION:

(c) TIMES (GMT) OF STANDBY ON ..................... OFF ........................... ( d ) BY WHOM:

(e) ANY OTHER ACTION TAKEN:

( f ) GENERAL REMARKS:

TO INCLUDE TIME OF NOTIFICATION OF ACCIDENT TO:

(i) ATCC SUPERVISOR

(ii) , ACCIDENT INVESTIGATION DUTY OFFICER:

(iii) POLICE

(iv) NAME OF FIREMAN-IN-CHARGE ON DUTY :



--`,,```,,,,````-`-`,,`,,`,`,,`---

14-54 Manual of Aircraft Accident Investigation . xi

INTENSITY ON/OFF

6 . APPROACH (a) HIGH INTENSITY CENTRE LINE

(b) LOW INTENSITY CENTRE LINE AND BAR (WHITE) ............................................................... AND BAR (RED) .................................................................

(c) SODIUM CENTRE LINE AND BAR ..................................................... (d) OTHER LIGHTS (IF ANY) ..........................................................

7. R W A Y (a) ELEVATED HIGH INTENSITY ........................................................ (b) ELEVATED LOW INTENSITY ........................................................ ( c ) FLUSH, MEDIUM INTENSITY ........................................................

(BI-DIRECTIONAL) .............................................................. (f) OTHER LIGHTS (IF ANY) .......................................................... (d) FLUSH, MEDIUM INTENSITY

( e ) VASI's .........................................................................

8. THRESHOLD (a) ELEVATED HIGH INTENSITY (GREEN) ................................................ (b) ELEVATED LOW INTENSITY (GREEN) ................................................. (d) STOPWAY LIGHTS (RED) ........................................................... (e) OTHER LIGHTS ................................................................... ( c ) FLUSH ..........................................................................

9. TAXIWAY

(a) GREEN CENTRE LINE .............................................................. (b) RED STOP BAR ................................................................... (cl BLUE/AMBER EDGE ................................................................ (d) BLUE/BLUE EDGE ................................................................. (e) MARKERS ........................................................................ (f) OTHER LIGHTS ...................................................................

10. OTHER AIRFIELD LIGHTS

(a) LOCATION BEACONS ............................................................... (b) IDENTIFICATION BEACONS ......................................................... (cl OBSTRUCTION .................................................................... (d) OTHER LIG"ïS ...................................................................

11. VISUAL SIGNALS USED (IF ANY): ...................................................... 12. GENERAL REMARKS EXPANDING THE ABOVE INFORMATION IF NECESSARY:

* LIGHTING IN USE

REMARKS

13. A ROUTINE CHECK HAD BEEN MADE OF THE FOLLOWING LIGHTS .............................. .................................................................................... .......................................... ON ................................. 19..

AT ............................... HOURS GMT, BY ................................... AND LOGGED IN THE ............................ LOG BOOK, WHICH IS PRODUCED HEREWITH.



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APPENDIX 14.- Accident Report Forms . 14-55

(b) GCA/PAR ........................................ ( c ) W A R .......................................... (d) ILS ............................................ (e) NDB ............................................ (9) VDF ............................................ (h) DME .............................................. ( f ) RR ............................................. (i) VOR ..............................................

RADIO AND RADAR AIDS

, I

14. THE AIDS AVAILABLE AND THEIR OPERATING STATE WAS AS FOLLOWS:

.............................. .............................. .............................. .............................. .............................. .............................. .............................. ............................... .............................. .............................. .............................. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...............................

(a) R/T FREQUENCIES USED WITH AIRCRAFT ............................................ ON/OFF 1 SERVICEABILITY I REMARKS

1

(j) SBA ................................... (k) ................................... i i j ................................... (m) GENERAL REMARKS:....................... (n) POSITION OF ILS/LOC. BEACON ........... (o) POSITION OF ILS/GP DATUM .............. (p) POSITION OF NDB ....................... (9) POSITION OF VOR ....................... (r) NOTAMS CONCERNING NAV AND COM .........

........ ........ ........ ........ ........ ........ ........ ........ ........ ( 6 ) SPEECH RECORDING EQUIPMENT

(i) SERVICEABLE/UNSERVICEABLE/NOT INSTALLED (DELETE AS APPROPRIATE). (ii) HAVE THE TAPES BEEN IMPOUNDED? ... LOCATION? .........................

(iii) HAS THE DIVISIONAL CONTROLLER BEEN INFORMED? ........ BY WHOM? ....... *(iv) HAVE COPIES OF TAPES BEEN TAKEN? ..... WHEN? ...... BY WHOM? ..........

TRANSCRIPTION UNIT? ................................................. (v) HAS A WRITTEN TRANSCRIPT BEEN MADE LOCALLY OR BY THE

15. ROUTINE CHECKS HAD BEEN MADE OF THE FOLLOWING ..................................... ............................... ON ............................................ 19. .

AT'....................,... HOURS G m , BY ......................................... AND LOGGED IN THE ................................................. LOG BOOK, WHICH

IS PRODUCED HEREWITH.

* If applicable. I t is generazly desirable t o impound the tapes by means of a Standing Order, then aZ1 further action in re la t ion t o the tapes i s performed under the d irec t supervision, or instruction, of the investigator.



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14-56 Manual of A i r c r a f t A c c i d e n t I nves t iga t ion

GENERAL INFORMATION LIKELY TO A S S I S T THE INVESTIGATION

16. (a) AERODROME LICENCE

(i) PRODUCED FORSCRUTINY....,.............................................

(ii) DATE OF I S S U E ........................................................ (iii) LAST I N S P E C T I O N .................... BY .............................. ( iv) CATEGORY ............................................................. (i) LOCATION O F F I R S T A I D ROOM ........................................... (b)

(ii) EQUIPMENT LAST CHECKED BY ............................................ (iii) NAMES OF LOCAL PRACTITIONERS NOMINATED FOR ATTENDANCE

AT AN ACCIDENT ...................................................... ( iv) NAMES OF DOCTORS I N ATTENDANCE AT ACCIDENT ...........................

( c ) G I V E DETAILS OF:

(i) NO. OF CRASH/FIRE VEHICLES ON AERODROME .............................. (ii) NO. O F CRASH/FIRE VEHICLES USED ...................................... (iii) DATE AND TIME OF LAST PRACTICE ....................................... (iv) DATE AND TIME OF LAST I N S P E C T I O N BY D F S ..............................

(v) V I S I T I N G F I R E BRIGADES I N ATTENDANCE ................................. (d) PLAN OF A I R F I E L D SHOWING, INTER A L I A , "BREAK-OUT" P O I N T S AND ARCS OF NON-

V I S I B I L I T Y FROM CONTROL TOWER

(e) NAMES OF ATC PERSONNEL ON DUTY AT THE TIME TELEPHONE NO.

SATCO ......................................................................... ATCO i / c ...................................................................... RUNWAY CONTROLLER ( S .......................................................... APPROACH CONTROLLER(S) ........................................................ AERODROME CONTROLLER .......................................................... GROUND MOVEt-ENTS CONTROLLER ................................................... MOVEMENTS CLERK OR ATCA ....................................................... MARSHALLING VEHICLE DRIVER .................................................... WORKS ENGINEER I N CHARGE ...................................................... DUTY ELECTRICIAN ..............................................................

. .

CONTROLLERS' L ICENCES, ATC INSTRUCTIONS AND/OR ORDERS TO BE PRODUCED I F NECESSARY.



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APPENDIX 14.- A c c i d e n t R e p o r t F o r m s 14-57

17. T H I S C E R T I F I C A T E HAS BEEN COMPILED WITH THE CO-OPERATION O F THE FOLLOWING OFFICERS:

(a) PAGE Y2.NAME ..................... DUTY .............. TELEPHONE NO,............

(b) PAGE 2. NAME ..................... DUTY .............. TELEPHONE NO.............

(c) PAGE 3 . NAME ..................... DUTY .............. TELEPHONE NO.............

(d) PAGE 4 . NAME ..................... DUTY .............. TELEPHONE NO.............

(e) PAGE 5. NAME ..................... DUTY ...i.......... TELEPHONE NO.............

( f ) PAGE 6 . NAME ..................... DUTY .............. TELEPHONE NO.............

LOCATION .................................. SIGNED ................................. TIME..................... HOURS (GMT) NAME (BLOCK CAPITALS) ........................

........................................ DATE .............................. 19.. RANK/APPOINTMENT/DUTY ..................

........................................ TELEPHONE NUMBER .......................



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TRANSCRIPT OF TELEPHONY

- AND RADIOTELEPHONY COMMUNICATIONS AND TAPE-RECORDINGS

I n v e s t i g a t i o n i n t o t h e acc ident t h a t occurred on ............. - Subject of t r a n s c r i p t :

- Centre of aerodrome concerned:

- Designat ion of u n i t :

- Frequency:

- Date and per iod covered by a t tached e x t r a c t :

- Date of t r a n s c r i p t :

- N a m e and p o s i t i o n of o f f i c i a l i n charge of t r a n s c r i p t i o n serv ice :

- C e r t i f i c a t e by o f f i c i a l i n charge of t r a n s c r i p t i o n serv ice :

I hereby c e r t i f y :

- That t h e accompanying t r a n s c r i p t of t h e telephony o r radiotelephony communication tape-recording r e t a i n e d a t t he p re sen t t i m e i n t he premises of ... has been made under my superv is ion .

- That i t was examined and checked by me .

- That no changes have been made t o t h e e n t r i e s i n Columns 2 , 3, 4 and 5, which con ta in only c l e a r l y understood i n d i c a t i o n s i n t h e i r o r i g i n a l form.

Done a t

S igna t U r e

On



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TRANSCRIPTION INSTRUCTION

1. The t i m e s shown i n t h e t r a n s c r i p t should be expressed i n GMT. Whenever poss ib l e , t h e words underl ined i n t h e communications correspond t o t h e t i m e s i g n a l emi t ted a t t h a t p a r t i c u l a r i n s t a n t .

2. A l l s i g n i f i c a n t f a i l u r e s during a communication s h a l l be ind ica t ed by a space of approximately two ( 2 ) c m between two words, When necessary, t h e du ra t ion of t h e i n t e r r u p t i o n s h a l l be s p e c i f i e d i n t h e "Observations" column.

3. Doubtful words s h a l l be ind ica t ed i n column 5, and t h e i r p o s i t i o n i n t h e communication (column 4) s h a l l be shown by a ser ies of Xs. I f deemed use fu l , explana t ions may be given i n t h e "Observations" column. Per iods of poor r ecep t ion , i f any, s h a l l be ind ica ted .

4 . U n i n t e l l i g i b l e p a r t s s h a l l be mentioned i n column 6 with t h e i n d i c a t i o n "un in te l l i g ib l e" , and t h e i r p o s i t i o n i n the communication (column 4 ) i nd ica t ed by a series of ques t ion marks. u s e f u l , explana t ions may be given i n t h e "Observations" column, and i f poss ib l e t h e number of missing words and t h e length of t h e u n i n t e l l i g i b l e l i s t e n i n g per iod s h a l l be given.

If deemed

5. Whenever t h e person i n charge of t h e t r a n s c r i p t i o n cons iders i t d e s i r a b l e t o provide an i n t e r p r e t a t i o n based on h i s knowledge of t h e f a c t s , it behoves him t o do so i n t h e "Observations" column.



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EXAMPLE OF TRANSCRIPTION FORMAT

Page no. Date:

To From T i m e Communications Doubtf u1 words Observat ions

Col. 1 Col. 2 Col. 3 Col. 4 Col. 5 Col. 6

ENAC A / C 0900.10 ENAC Cont ro l from Alpha Vic to r do you read m e ?

A/C ENAC

ENAC A/C

A / C ENAC

ENAC A / C

ENAC A / C

0900.20 Alpha Vic to r ENAC i r ead you f i v e by f i v e . Over.

0900.3 E Contro l from Alpha Vic to r w e have c rossed t h e FIR a t O S E ze ro e i g h t f i v e e igh t - l eve l seventy- Es t imat ing De l t a po in t at xxx Requesting c l ea rance descend F l i g h t Level 50 f i v e zero over .

0900.2 Alpha Vic tor ENAC p l ease confirm your e s t ima te t o po in t ? ? ? ?

0901.00 ENAC Alpha Vic tor Roger standby

0 9 0 1 . ~ ENAC Alpha Vic tor Confirm my e s t ima te t o po in t Del ta a t 0903 zero n ine zero t h r e e over.

Hes i t a t ion 2 - 3 seconds

0903 in t e r f e rence from o the r t ransmiss ion

Un i n t e l l i g i b l e word, but very l i k e l y Delta ( c f . contex t )

S igna ture of Person-in-charge:

(sgd)



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Page no. Date: -

To From

Col. 1 Col. 2

A/C ENAC

ENAC A / C

A/C ENAC

ENAC A/C

A / C ENAC

T i m e Communications

Col. 3 Col. 4

0902.00 Roger Alpha Victor from ENAC you estimate Delta point 0903 zero nine zero three and request clearance t o descend t o l e v e l f i f ty-f i v e zero co r rec t ?

0902.20 Affirmative E from Alpha Victor

0902.2 Alpha Victor from ENAC c leared t o descend t o l e v e l xxx f i v e zero a f t e r c ross ing Delta point QNH Quebec November Hotel 1015 One Zero one f i v e

0903.20 E Alpha Victor Roger I a m now cross ing Delta point and commencing descent t o l e v e l f i v e zero

0904.20 Roger Alpha Victor t r ans fe r t o frequency 127.8 OUT.

Doubtful Observations words

Col. 5 . Col. 6

€ i f t y

Hes i ta t ion 1 t o 2 seconds

Signature o€ Person-in-charge:

(sgd)



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APPENIIX 15

CONVERSION TABLES AND DIAGRAMS

Conversion t a b l e s

I n t h e following conversion t a b l e s t h e c e n t r e column g ives the u n i t d e s i r e d from 1 t o 100, while t h e a p p r o p r i a t e conversion appea r s on e i t h e r s i d e . For example t o convert 20 inches t o cent imetres t ake 20 i n t h e c e n t r e column of t he Centimetres - Inches t a b l e and look on t h e same l i n e i n t h e cm. column, you w i l l f i n d 50.80, so 20 in . = 50.80 cm.)

Centimetres - Inches Metres - Feet Kilometres - S t a t u t e Miles Kilometres - N a u t i c a l Miles Metres/Sec. - Hundred Ft./Minute Metres/Sec. - Knots Kilogrammes - Pounds Degrees Ce l s ius - Fahrenhei t M i l l i b a r s - Inches of Mercury L i t r e s - Imper i a l Gal lons U.S. Gallons - I m p e r i a l Gal lons Table of Grades

15-1 15-2 15-3 15--4 15-5 15-6 15-7 15-8 15-9 15-10 15-11 15-12

Diagrams

Wind Component 15-13 Rate of Turn, i n Te rms of Bank and

True Airspeed 15-14 Inc rease i n S t a l l i n g Speed r e l a t e d t o

Angle of Bank 15-15 Rate of Descent .ind Approach Speed

r e l a t e d t o Angle of Descent 15-16 Distance and Height r e l a t e d t o S igh t ing

Angles 15-17 Distance and Height r e l a t e d t o S igh t ing

Angles i n Normal Approach 15-18

30/5/77 No. 7



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APPENDIX 15.- Conversion T a b l e s and Diagrams 15-1

CENTIMETRES - INCHES C m in.

2. 54 5. 08 7. 62

10. 16 * 12.70

15. 24 17. 78 20.32 22.86 25. 40 27.94 30. 48 33.02 35. 56 :x. 10 40. G 4

45. 72 4. 26 53. $0 53. 34 L55. PE S8. 42 6û. 96 63. 50 66.04

71. 12 73.66 76.20 78.74 81.28

xi. ia

68. sa

83.82

sa. 90 86.36

91.44 93. 98 ?!fi* 52 '.!i>. 0 ,; :<, ?. 5:, !,>.i. 1.ï i'.,,. i i

;Ï::j" 22. 1 ; :. ''6 li-. .f.,

i 1.:. C-:.: i 1 '. .?::

li,,

. . .

; : ) 1 -I , - 1. ..II i2 4. 3 8 . : i.? :, r,:'!

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20 2 1 22 23 24 25 26 21 28 29 30 31 32 33 34 35 Liti 37 38 ,%J

-13

4 1 'i%

.I 2 4L 35 ?f;

4 i L.+r

&;i

.:,!I

o. 3937 O. 787 1. 181 1.575 1. 969 2. 362 2. 756 3. 150 3. 543 3.937 4. 331 4. '724 5. 118 5. 512 5. 906 t i . 299 6. 693 '7. 087 7. 480 7. 874 8.2138 8 .661 9.055 3. 449 9. 843

10. 236 10. 630 11. 024 11. 417 11.811 12. 205 12.598 12.992

13. 780 14. 173 14. 567 i 4 !)til 1:1. 354 Ir:. : t ! . 142 it;. 535 i,,. 229 i:, :323 1 :. 7 1 7 13. 110 Il. .5Cl'I !3. 3% i?. 291 x. 63,

13. 3ati

* / .

. .

i CIQ in. , 129.54 132.08 134.62 137. 16 139.70 142.24 144.78 147.32 149.86 152.40 154.94 157. 43 160.02 162.56 165. 10 167. 64 170. 18 173. 72 175.2ti 177. 80 180.34 182.8s 185.42 187.96 190.50 193.04 195. 58 198. 12 200.66 203. 20 205.74 208.28 210.82 213.3ti 215.90 218.44 220.98 223. 52 226. O b

228. G O 231. 11 233. UP 236. '22 238.76 341.30 243. Ei4 246. 33 2%. 92 15 I. 46 250. O0

51 52 53 54 55 56 57 58 59 60 61 62 ti3 64 ti5 66 67 68 69 70

7 1 72 73 74 15 76 71 78 79 80 8 1 82 8 3 8 4 Y5

a7 d h e 9 90 91 92 Y3 34 95 Fi ii 97 38 39

100

al;

20.079 20.472 20.866 2 1.260 21.654 22.047 22.441 22.835 23.228 23.622 24. 016 24.409 24.803 25. 197 25.59 1 25.984 26. 375 26. 772 21. 165 27.559 27.953 2P. 347 28. 74C 29. 134 29.528 29.92 1 30. 315 30.709 31. 102 31.496 31.890 32.284 32. 677 33. o7 1 33. G 5 33.856 34.252 34. G4ti 35.02') 35.43: 35.82" 36.22 1 3ti. 61 f 3i. 005 37.402 37. 735 38. 189 36. sa3 38. c ; ' ~ 39.370

15/7/76 No. 5



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Manual of Aircraft Accident Invest igat ion --___ ___-__ I

15-3

METRES - FEET

m ft.

o. 30s 0. 6 1 o. Y1 1.22 1. 52 1. 83 2. 13 2. 44 2. 74 3. o5 3. 35

3.9G 4. 27 4. 57 4. 88 5. 18 5. 49 .5. 79 (i. 10 6. 40 G . 71 7. 0 1 7. 32 7. 62 7. 52 8. 23 8. 53 8. e 4 9. 14 Y. 45 9.15

10.06 10.36 10. 67

Ili. 9 7 11.2s Il. 58 11. ES 12. 19 12. 50

13. 11 13. 41 1s. 7 2 14. 0: i4 33 14.63 14.94 15 .21

3. b6

12. so

1 2 3 4 S t i

7 8 Y IO I! 12 13 i -i I 5 16 J7 18 19 20 2 1 22 2 5 2 4 25 '26

S i 28 2s 3u 3 1 32 Y3 34 35 36 3;' 38 3 9

4G 11 12 4 :i -1 4 ,! i 1 LJ

'i i.; -1 -j

-i 5 4 2 5 i)

3.281 6. 56 O. 8 4

13. 12 16. 40 13. 69 22.97 26. 25 ZY. 53 32.81 36.09 39. 3': 42.65 4s. Y3 49. 21 52. 49 55.77 55.02. fi2.34 65. ti2 68. YO 72. 18 75. 46 78. 74 62. 02 65. 30 88.58 51.86 95. 14

101. 7 1 104. 99 108.27 111.55 114. 63 118. li 121. 33 i5.i. 6; 127. 95 131. 23 134. 51 137. E0 141. 06 144.56 14 7 . 04 i.50. il2 .>-I. 2c 15;. 45 16C. S G 164. 04

sa. 43

l i ."

m

15.54 5 1 15. 8S 52 16. 15 5 3 16. 46 S 3

16.76 5 5 17. 9'7 5 ii 17. 3'1 5 7 17. í 2 68 17. 98 5 9

1 8 . 2 9 60 16. 59 t j i

18. SO tj 2 19. ai, 6 3 19. 51 64 19.81 65 20. If 66 20. 42 67 su. ?3 58 2 1. ij3 6 >? 21.94 '70 2 1. :;,i 7 1 21. Y:, 72 22.25 ; . I

22 . s u 7 3

22.89 -/ j

23. It '7 6 23.4: 77 ;>s. 1-1 Ï8 24.08 7 9 24. 38 eo 24. 69 81 %4.9(' 82 25.39 ö s 25.t;o 8 4

5 5 26. Li 8:;

2.6. 82 E:! a:. 13 u.

2 7 . 4 3 9 c: 27 . 7.1 91 28. 0.1 92 28. 3:) 9 :3 28.65 94 '26. u ci 95 z:!. 21; '? ij 214. 5 : 9 -; 2!J. 8; 98 30. ia 99

/,e

. - . . n,. .-. LI,. 32

2 i,

30. .fi .mo

ft.

167. 32 170. 60 173.88 177. 17 180. 45 is3. 73 !87. 0 1 SYO. 2Y 193.27 196. 85 260. 13 203.41 20% 69 209. Li?

213.26 216.54 L l 3 . 8 2 223. 10 2?6. 38 ,229. 1;6 &<li.. !I4 2146. 22 n.;q. z,i,;

'J.12. '-13 ;!%. i i6 243. 34

252. ti3

229, 19 ,262. 47 .?C<j. 75

'269.03 272. :n 27.5. 59 278. E7 202. 15

.4.3

.il

. IO

0 - I

?O" -

-II ,

7..- c 1 ,.,a. . I

. 5 6 30 1.84 305. 12 308.40 311.68 314. Y6 318.24 3% i. 5.2 224.80 :32<3. oe

15/? /76 No. 5



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15-3 _-- APPENDIX 15.- Conversion Tables ~ _ _ and Diagrams -

K I L O M E T R E S - S T A T U T E M I L E S

km mi. k m mi.

1. 6093 3. 219 4.828 6. 437 8. 047 9.656

11.265 12. 875 14.484 16.093 17. 703 19.312 20.921 22.531 24.140 25. 749 27.359 28.968 30.577 32. 187 33. 796 35. 406. 37. 015 38. 624 40.234 41.843 43.452 45.062 46. 6'11 48.280 49.890 51. 499 53. 108 54. 718 56. 327 57. 936 59.546 61. 155 62.764 6 4 374 65.983 67. 592 69.202 70.811 72. 420 74. 030 75.639 77. 249 78.858 80.467

1

2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 3 1 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

O. 6214 1.243 1.864 2. 485 3. 107 3.728 4.350 4.971 5.592 6.214 6.835 7. 456 8.078 8.699 9.321 9.942

10.563 11. 185 11.806 12.427 13.049 13.670 14.29 1 14.9 13 15.534 16.156 16.777 17.398 18.020 18. 641 19.262 19.884 20.505 21.127 21.748 22.369 22.99 1 23.612 24.233 24.855 25.476 26.098 26.7 19 27.340 27.962 18.583 29.20 4 29.826 30.447 31.069

82. O77 83.686 85.295 86.905 88. 514 90. 123 91.733 93.342 94.951 96.561 98. 170 99.779

101.389 102.998 104.607 106.217 107.826 109.435 111. o45 112.654 114.263 115.873 117. 482 119. o91 120.701 122.3 10 123. 9 19 125.529 127. 138 128.748 130. 357 131.966 133.576 135. 185 136.794 138.404 140.013 141.622 143.232 144.8 41 146.450 148.060 149.669 151.278 152.888 154.497 156. 106 157. 7 16 159.325 160.934

5 1 52 53 54 55 56 57 58 59 60 6 1 62 63 64 65 66 67 68 69 70 7 1 72 73 74 75 76 77 78 79 80 8 1 82 83 84 85 86 87 88 89 90 9 1 32 93 94 95 96 97 98 99

10 o

31.690 32.3 11 32.933 33.554 34. 175 34.791 . 35.418 36.039 36.661 37.282 37.904 38.525 39.146 39.768 40.389 41.011 41.632 42.253 42.875 43.496 4 4 117 44.739 45.360 45.981 46.603 47.224 47.846 48.467 49.088 49.7 10 50.331 50.952 51.574 52.195 52.8 17 53.438 54.059 54.681 55.302 55.923 56.545 57.166 57.788 58.409 59.030 59.652 60.273 60.894 61.516 62. 137

15/7/76 No. 5



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KILOlrlETRES - IiAUTICAL M I LES

km N M km N M

1.8532 3.706 5. 560 7. 413 9.266

11. 119 12.972 14.826 16.679 18. 532 20.385 22.238 24.092 25.945 27.798 29.651 31.504 33. 358 35.211 37. 064 38.917 40. 770 42. 624 44.477 46.330

50. 036 51.890 53.743 55.596 57. 449 59. 302 61. 156 63. O09

48. 183

64.862

68.568 66. 715

70. 422 72.275 74. 128 75.981 77.834 79.688 81.541 83. 394 85. 241 87. 100 88.954 90.807 92. 660

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20 2 1 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

o. 539ti L 079 L 619 2. 158 2. 698 3.238 3. 771 4.317 4.856 5.396 5.936 6. 475 7. 015 7.554 8.094 8.634 9. 173 9.713

10.252 10. 792 1 L 332 11.871 12. 411 12. 950 13. 490 14.030 14. 569 15. 109 15. 648 16. 188 16. 728 17. 267 17.807 18. 346 18. 886 19. 426 19. 965 20. 505 2L 044 2 L 584 22. 124 22.663 23.203 23. 742 24.282 2 4 822 25.361 25.901 26. 440 26.980

94.513 96.366 98.220

100.073 101.926 103.779 105.632 107.486 109.339 111. 192 113.045 114.898 116.752 118.605 120.458 122.31 1 124. 164 126.018 127.871 129.724 131.577 133.430 135.284 137. 137 138. Y90 140.843 142.696 144.550 146.403 148.256 150. 109 151.962 153.8 16 155.669 157.522 159.375 16; 1.228 163.082 164.935 166. 788 168.641 170.494 172.348 174.201 176.054 177.507 179.760 181.614 183.467 185.320

51 52 53 54 55 56 57 58 59 60 6 1 62 63 64 65 66 67 68 ti9 70 7 1 72 73 74 7s 76 17 78 79

8 1 82 83 8 4 85 86 87 88 89 90 9 1 92 93 94 95 96 97 98 99

10 o

no

27.520 28.059 28.599 29. 138 29.678 30.218 30.757 31.297 31.836 32.376 32.9 16 33.455 33.995 34.534 35.074 35.6 14 36. 153 36.693 37.232 37.772 38.322 38.851 39. 391 39.930 40.470 41.010 41.549 42. 089 42. 628 43.168 43.708 44.247 44.787 45. 326 45.866 46.406 46.945 47.485 48.024 48.564 49. 104 49.643 50. 183 SO. 722 51.262 51.802 52.341 52.881 53.420 53.9605

15/7/76 No. 5



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.G'PFNDIX 15.- Coilversion l'ables and Diagrams 15-5 - - _ _ ______.--

METRES/SEC , - HUiJDRED FT, / M I IJUTE I

tnetresjsec 100 ft. /min metresfsec 100 ft /min

O. 508 1. 02 1. 52 2. 03 2. 54 3. 05 3. 56 4. 06 4. 57 5. O8 v. 59 8. 10 u. 60 7 . 1 1 7. 62 8. 13 8. :;4 9. 14 Y. 65

10. 16 10.67 Il. 18 11. 68 12. 19 12. 70 13. 2 1 13. 72 14. 22 14.73 15. 24 15.75 Ib. 26 16. 76 17.27 17. 78 18. 29 15. 80 19. 30 19.81 20.32 20.83 21.34 21.84 22. 35 22. 86 23. $7 23.35 24.38 24.89 25. 40

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 Lu) 41 42 43 44 45 46 47 35 49 50

1.969 3. Y4 5 .91 7. 87 9. 8 4

11.81 13.78 15. 75 17.72 19.69 21.65 23.62 25.59 27.56 29.53 31.50 33. 47 35. 43 37. 40 39. 37 41.34 43 .31 45.28 47.24 49.21 51. 18 53. 15 55. 12 57.09 59. 06 61. 02 62.99 64.96 66.93 68.90 70.87 12. a4

76. 77 '78.74 80 .71 82.68 84. 65 86 .61 38. 58 90.55 92. 52 94. 49 96. 46 98.43

74. ao

25.91 26.42 26.92 27. 43 27.94 28. 45 28.96 29.46 29.97 30.48 30.99 31.50 32.00 32.51 33.02 33.53 34.04 34.54 35.05 35. 36 36.07 36.58 37.08 37.59 38. 1 0 38.61 39.12 39. 62 40. 13 40.64 41. 15 41.67 42. 16 42.67 43. 18 43.69 44.20 44.70 45.21 45.72 46.23 46.74 47.24 47. 75 48.26 '48.77 49.28 49.78 SO. 29 50.80

5 1 52 53 54 55 56 57 58 59 60 6 1 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 8 1 82 83 84 85 86 87 88 89 90 9 1 92 93 94 95 96 97 98 99

100

100.39 102.36 104.33 106.30 108.27 110.24 112.2 1 114.17 116.14 118.11 120.08 122.05 124.02 125.98 127.95 129.92 131.89 133.86 135.8 3 137.8 O 139.76 141.73 143.70 145.67 147.64 149 E l 151.58 153.54 155. 5 1 157.48 159.45 161. 42 163.39 165.35 167. 32 169.29 17 1.26 173.23 175.20 177. 17 179. 13 181. 10 183.07 185. 0 4 187. O 1 188.98 190.95 192.9 1 194.88 196.85



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15-6 Manual of Aircraft Accident Irivest igat ion

METRES/CEC - KNOTS

m/sec kt m/sec kt

O. 515 1. 03 1. 54 2. 06 2.51 3. o9 3. 60 4. 12 4. 6 3 5. 15 5. 66 6. 18 6.69 7.21 7. 72 8.24 8. 75 9.27 9. 78

10.30 10.8 1 11.33 11. 8 4 12.36 12.87 13. 38 13.90 14. 41 14.93 15. 44 15.96 16. 41 16.99 17.50 18. 02 18.53 19. o5 19.56 20.08 20.59 21.11 21.62 22. 14 22.65 23. 11 23. G8 24.20 24. 71 25.23 25. 74

1 2 3 4 5 6 I 8 9

10 11 12 13 14 15 16 17 18 19 20 2 1 22 2 3 24 25 26 27 28 29 30 3 1 32 33 34 35 36 31 38 39 40 41 42 43 44 45 46 47 48 49 50

1.943 3.89 5. 83 7. 77 9. 71

11.66 13.60 15. 54 17. 48 19. 43 21.31 23.31 25.25 21.20 29. 14 31.08 33.02 34.97 36.91 38. 85 40.80 42.14 44.68 46.63 48. 51 SO. 51 52. 45 54. 40 56. 34 58.28 fio. 22 62. 17 64. 11 66.05 68. O0 69.94 71.88 73.83 75.77 '17. I 1 79.65 8 1.59 83.54 $5. 48

89. 36 71.31 33.25 95. 19 97. 13

87.42

26.25 26. 77 27.28 27.80 28.30 28.82 29.33 29. 85 30.36 30. 88 31. 39 31.91 32. 42 32. 94 33. 45 33. Y7 34.48 35.00 35.51 36. 03 36.54 37. 06 37. ri7 38. O9 38. G O 39. 12 3!1. G3 40. 15 40. u7 41. 18 41. 69 42. 2 1 42. 72 43. 24 43. 75 44.27 14.78 45. 29 45.81 46.32 46.84 17. 35 17.87 48.38 48. 90 49. 41 19. !j3 so. 44 so. !j(; 51. 47

51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 1 7 78 79 80 81 82 Y3 84 85 86 8'1 88 89 90 9 1 92 93 Y4

95 96 9;

98 9 o

100

99.08 10 1. 02 102.96 104.91 106.85 108. 79 110.13 112.68 114.62 l l G . 56 118.51 120. 45 122.39 124.33 126. 28 128.22 130. 16 132. 11 134.05 135.99 137. 33 139. xs 141.82 143. 7t1 145. 70 147.65 143. 5!) 151.53 153. 47 155. 42 157. 36 153. 30 16 1. 25 163. 19 165. 13 167. O7 169.02 170.96

174. 84 178. I Y 178. 73 180. 67 182. 61 18-1. 56 Hi) . .i0 1SF. 44 190. 3'3 192.33 194. 27

172. :)o

15/7/76 No. 5



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APPENDIX 15.- Conversion Tables and Diagrams 15-7

KILOGRAMMES - POUNDS kn lb. kl3 lb.

o. 4539

1.361 1.814 2.268 2.722 3. 175 3.629 4. 082 4. 536 4.990 5.443 5.897 6.350 6.804 7.257 7.711 8. 165 8. 618 9. 072 9.525 9.979

10.433 10.886 11.340 11. 793 12. 247 12.701 13. 154 13.608 14.061 14. 515 14.969 15. 422 15. 876 16. 329 16. 783 17. 237 11.690 18. 144 18. 597 19. 051 19. 504 19. 958 20. 412 20.865 21. 319 21. 772 22.226 22.680

o. 907 1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20 2 1 22 23 24 25 26 27 28 29 30 3 1 32 33 34 35 36 37 38 39 40 4 1 42 43 44 45 46 47 48 49 50

2.205 4.41 ,

6.61 8.82

11. o2 13.23 15. 43 17.64 19.84 22.05 24.25 26.46 . 28.66 30.87 33.07 35.27 37. 48 39.68 41.89 44. o9 46.30 48.50 50.71 52.91 55. 12 57.32 59.53 61.73 63.93 66. 14 68. 14 70.55 . 72.75 74.96 77. 16 79.37 81.57 83. 78 85.98 88. 19 90.39 92.60 94.80 97.00 99.21

101. 4 1 103.62 105.82 108. 03 110.23

23. 133 23.587 24.040 24.494 24.948 25.401 25.855 26.308

.26.762 27.216 27.669 28. 123 28.576 29.030 29.484 29.937 30.391 30.844 3 1.298 31.751 32.205 32.659 33. 112 33.566 34. o19 34.473 34.927 35.380 35.834 36.287 36.741 37. 195 37.648 38. 102 38. 555 39.009 39.463 39.9 16 40.370 40.823 41.277 41.731 42. 184 42.638 43. o91 43.545 43.999 44.452 44.906 45.359

5 1 52 53 54 55 56 57 58 59 60 6 1 62 63 64 65 66 67 68 69 70 7 1 12 73 74 75 76 77 78 79 80 8 1 82 83 84 85 86 87 88 89 90 9 1 92 93 94 95 96 9 1 98 99

100

112.44 114.64 116.85 119.05 121.26 123.46 125.67 127.81 130.07 132.28 134.48 136.69 138.89 141. 10 143.30 145.51 147.71 149.91 152. 12 154.32 156.53 158.73 160.94 163. 14 165.35 167.55 , 169.76 17 1.96 174. 17 176.37 178. 57 180. 78 182.98 185. 19 187.39 189.60 19 1. 80 194.01 196.21 198.42 200.62 202.83 205.03 207.24 209.44 211.64 213.85 216.05 218.26 220.46

151 7/76 No. 5



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DEGREES CELSIUS - FAHRENHEIT - _._.

O C OF O C OF O C 9

-45. o -44.4 -43.9 -43.3 -42.8 -42.2 -41. I -41; 1 -40.6 -40. o -39.4 -38.9 -38.3 -31.8 -31.2 -36. I -36. 1 -35.6 -35. o -34.4 -33.9 -33.3 -32.8 -32.2 -31.7 -31.1 -30. 6 -30. O -29.4 -28.9 -28.3 -27.8 -27.2 -26. I -26.1 -25. 6 -25. O -24.4 -23.9 -23.3 -22.8 -22.2 -21.7 -21. 1 -20.6 -20. o -19.4 -18. 9 -18.3 -17.8

- 49 -48 -41 -46 -45 -44 -43 '-42 -41 -40 -39 - 38 -31 -- 36 -35 -34 -33 -32 -3 1 -30 -29 -28 -27 -26 -25 -24 -23 -22 -2 1 -20 - 19 - 18 - 17 - 16 - 15 - 14 - 13 - 12 -11 - 10

-9 -8 -1 -6 -5 -4 -3 -2 -1

O

-56.2 -54.4 -52.6 -50.8 -49. o -41.2 -45.4 -43.6 -4L 8 -40. o -38.2 -36.4 -34. 6- -32.8 -3L O -29.2 -27.4 -25.6 -23.8 -22. o -20.2 -18.4 -16.6 -14.8 -13. o -11.2

-9.4 -7.6 -5.8 -4. o -2.2 -0.4

l.4 3.2 5. o 6.8 8. 6

10. 4 12.2 14. O 15.8 17. 6 19.4 2 2 2 23. O 24.8 26. 6 28. 4 30.2 32. O

-11.2 -16. 7 -16. 1 -15. 6 -15. o -14. 4 -13.9 -13. 3 -12. 8 -12.2 -11.7 -11.1 -10. 6 -10. o -9. 4 -8. 9 -8. 3 -7. 8 -7.2 -6. I -6. 1 -5. 6 -5. o -4. 4 -3. 9 -3. 3 -2. 8 -2.2 -1. 7 - 1. 1 -0. 6

O O. 6 1.1 1. 7 2. 2 2. 8 3. 3 3. 9 4. 4 5. o 5. 6 6. 1 6. 7 7. 2 I. 8 8. 3 8. 9 9. 4

10. o

1 2 3 4

5 6 I 8 9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 4.4 45 46 47 48 49 50

33.8 35. 6 37.4 39.2 41. O 42.8 44.6 46.4 48.2 50. O 51.8 53.6 55. 4 57.2 59. o 60. 8 62.6 64. 4 66. 2 68. o 69. s i l . 6 73.4 75.2 77. o 78. 8 80. 6 82.4 84.2 86. O 87.8 89. 6 91. 4 93.2 95. o 96.8 98. 6

100.4 102.2 104. O 105.8 107. 6 109.4 111.2 113. O 114.8 116.6 118. 4 120.2 122. o

10. 6 11. 1 11. 7 12.2 12.8 13. 3 13. 9 14. 4 15. O 15. 6 16. 1 16. 7 17.2 17.8 18.3 18.9 19.4 20.0 20.6 21. 1

22.2 22.8 23.3 23.9 24. 4 25. O 25.6 26. 1 26. 7 27.2 21.8 28 .3 28.9 29.4 30. O 30. 6 31. 1 31. 7 32.2 32.8 33. 3 33.9 34. 4 35. o 35. ti 36. 1 36. 1 37.2 37.8

21. a

51 52 53 54 55 56 SI 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 89 8 1 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

100

123.8 125.6 127. 4 129.2 131. O 132.8 134.6 136. 4 138.2 140. O 141.8 143. 6 145. 4 147.2 149. O 150. 8 152. 6 154.4 156.2 158. O 159.8 161. 6 163. 4 165.2 167. O 168. 8 170. 6 172. 4 174. 2 176. O 177. 8 179. 6 181. 4 183.2 185. O 186. 8 188. 6 1'30. 4 192.2 194. O 195. 197. 6 199.4 201.2 203. O 204.6 206. 6 208. 4 210.2 212. o

30/5! 7 7 No. 7



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15-9 __ -_ __- .- .._I_ APPENDIX 15.- Conversion Tables and Diagrams -____ _.I_-.--- ~~-

MILLIBARS - INCHES OF MERCURY

mb in.Hg

925 92 6 927 92 8 929 930 93 1 932 93 3 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 95 1 952 953 954 95 5 956 957 958 959 960 96 1 1362 963 964 965 966 967 968 969 97 O 97 1 972 973 974

27.32 27.35 27.31 27.40 27.43 27.46 27.49 27.52 27.55 27.58 27.6 1 27.64 27.67 27.70 27.73 27.76 27.79 27.82 27.85 27.88 27.91 27.94 27.97 27.99 28.02 28.05 28.08 28.11 28.14 28.17 28.20 28.23 28.26 28.29 28.32 28.35 28.38 28.41 28.44 28.47 28.50 28.53 28.56 28.59 28.67 28.64 28.67 28.70 28.73 28.76

--- mb in. Hg

975 976 977 9 78 979 980 98 1 982 983 984 985 986 987 988 989 990 99 1 992 993 994 995 996 997 998 999 1000 100 1 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 10 12

11013.21 1014 10 13

1015 1016 1017 1018 1019 1020 102 1 1022 1023 1024

28.79 28.82 28.85 28.88 28.91 28.94 28.97 29.00 29.03 29.06 29. o9 29. u 29.15 29.18 29.21 29.24 29.26 29.29 29.32 29.35 29.38 29.41 29.44 29.47 29.50 29.53 29.56 29.59 29.62 29.65 29.68 29.71 29.74 29.77 29.80 29.83 29.86 29.88

S - i K i q 29.97 30.00 30.03 30.06 30.09 30.12 30.15 30. 18 30.21 30.24

mb L H g

1025 1026 1027 1028 1029 1030 1031 10 32 10 33 1034 10 35 10 36 10 31 10 38 1039 10 40 1041 10 42 10 43 10 44 10 45 10 46 10 47 10 48 10 49 1050 1051 1052 1053 1054 1055 1056 1057 1058 10 59 1060 1061 10 62 1063 1064 1065 10 66 1067 1068 1069 1070 1071 1072 1073 1074

30.27 30.30 30. 33 30.36 30.39 30. 41 30. 45 30. 48 30.50 30.53 30. 56 30.59 30.62 30.65 30.68 30.71 30.74 30.77 30.80 30.83 30.86 30.89 30.92 30.95 30.98 3L o1 31.04 31.07 31. 10 31.13 31. 15 31. 18 3L 21 31.24 31.27 31.30 31.33 31.36 3L 39 3L 42 31. 45 31.48 31.51 31.54 3L 57 3L 60 31.63 31. 66 31.69 31. 72

15/7/76 No. 5



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15-1n Manual of Aircraft Accident i n v r s t i g a t i r 3 n ~ IC__ __ -_________ ___--

LITRES - IMPERIAL GALLONS

1 imp. gal.

4.54595 Y. o9

13. 64 13. 18 22.73 '1 7.. 553 21.82 36.37 10.31 45.46 50.01 54.55 59. 10 -- 3. 64 68.19 72.14 7'7.29 1.83

ati. 37 90.92 55.47

IO!?. o 1 i 3 4 56 109.10 ill. ô5 1i1.20 i2S. 74 127.29 13 1.83 136.30 140.93 145.47 150.02 1.54.56 159.11 163.66 158.20 r;2. '75 171.29 18 I. 84 186.38 190.93 1.35. 48 2iJY. O2 2114. 57

il '2 13.66 218.21 222.75 227.30

,i.-,;

1 2 3 4 5 6 n

8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 $6 41 48 49 50

O. 2 199; O. 440 O. 660 O. 880 L 100 1. 320 L 540 1.760 i. 980 2.200 2. 420 2.640 2.860 3.080 3. 300 5 520 3.740 3.960 4. 180 4. 400 4. 620 4. 840 5.059 5.279 5. 499 5. 719 5.939 6. 159 6.379 6. 599 6.819 7.039 7.259 7.479 7.699 7.919 8. 139 8.359 8. 579 8.799 9. o19 9.239 9. 439 9. 679 9.899 10. 119 10. 339 10.559 10.779 10.999

15

1 imp. gal.

231.84 236.39 240.94 245.48 250.03 254.57 259. 12 263.67 268.21 272.76 277.30 28 1.85 286.40 290.94 295.49 300.03 304.58 30Y. 13 313. Ô 7 318.22 322.76 327.31 331.86 336.40 340.95 345.49 350.04 354.59 359. 13 363.68 368.22 372. 77 37'7.32 38 1.86 386.41 390.95 395.50 400.05 404.59 409. 14 413.68 418.23 422.78 427.32 431.87 436.41 440.96 445.50 450.05 454.60

51 52 53 54 55 56 57 58 59 60 61 62 6 3 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 9 7 98 99 10 o

11.719 11. 439 11.659 1L 819 12 o99 12.319 12. 539 12.759 12 979 13. 199 13. 419 13.639 13. 858 14. 0'78 14.298 14.516 14. 738 14. 958

1s. 398 15. 618

15. i7a

15. s3a 16. 058 16. 278 16. 49a 16. ?i8 16.938 17. 158 17. 378 17. 598 17.818 18. 038 18. 258 18. 478 18. 698 18.918 19. 138 19. 358 19. 578 13. 796 20.018 20.233 20. 458 20.676 20. 89R 21. 118 2L 338 21. 558 21.778 21.998



--`,,```,,,,````-`-`,,`,,`,`,,`---

APPENDIX 15.- Conversion Tables and Diagrams 15-11

U t S , GALLONS - IMPERIAL GALLONS

-

U. S. gal. imp. gaL U.S. gal. imp. gai.

1.20095 2.402 3.603 4.804 6.005 7.206 8.407 9.608

10.809 E?. O10 13.210 , 14.411 15.6 12 16.8 13 18.014 19.215 20.416 21.617 22.8 18 24. o19 25.220 26.421 27.622 28.823 30.024 31.225 32.426 33.627 34.8 28 36.029 37.229 38.430 39.631 40.832 42.033 43.234 44.435 45.636 46.837 48.038 49.239 50.440 51.641 52.842 54.043 55.244 56.445 57. 646 58.847 60.047

1 2 3 4 5 6 7 8 3

10 11 12 13 14 15 16 17 18 19 20 2 1 22 23 23 25 26 27 28 29 30 3 1 32 33 34 35 36 37 38 39 40 4 1 42 43 44 45 46 47 48 49 50

O. 83267 L 665 2.498 3.331 4. 163 4. 996, 5.829 6.661 7.494 8.327 9. 159 9.992

10.825 11.657 12.490 13.323 14. 155 14.988 15.821 16.653 17.486 18.3 19 19. 151 19.984 20.8 17 21.649 22.482 23.315 24.147 24.980 25.8 13 26.645 27.478 28.311 29.143 29.976 30.809 31.641 32.474 33.307 34. 139 34.972 35.805 36.637 37.470 38.303 39. 135 39.968 40.801 41.634

61.248 62.449 63.650 64.851 66.052 67.253 68.454 69.655 70.856 72.057 73.258 74.459 75.660 76.861 78.062 79.263 80.464 81.665 82.866 84.067 85.267 86.468 87.669 88.870 90.071 91.272 92.473 93.674 94.875 96.076 97.277 98.478 99.679

100.880 102.081 103.282 104.483 105.684 106.8 85 108.086 109.286 110.487 111.688 112.889 114.090 115.291 116.492 117.693 118.894 120.095

5 1 52 53 54 55 56 57 58 59 60 6 1 62 63 64 65 66 67 68 69 70 7 1 72 73 74 75 76 77 78 79 80 8 1 82 83 8 4 85 86 87 88 89 90 9 1 92 93 94 95 96 97 98 99

100

42. 466 43.299 44.132 44.964 45.797 46.630 47. 462 48.295 49.128 49.960 50.793 51.626 52.458 53.29 1 54. 124 3,

54.956 55.789 56.622 57.454

59.120 59.952 60.785 61.618 62.450 63.283 64.116 64.948 65.781 66.614 67.446 68.279 69.112 69.944 70.777 71.610 72.442 73.275 74. 108 74.940 75.773 76.606 71.438 78.271 79. 104 79.936 80.769 81.602 82.434 83.267

s. 287

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15-12 .. ._ ..... _ _

TABLE

1 0 Angle linx

Manual of A i r c r a f t Accident I n v e s t i g a t i o n . . ____ _~

OF GRADES -

% Anale linx

o. 10 o. 20 O. 25 O. 40 O. 50 O. 80 1. O0 1. 05 1. 10 1. 15 1. 20 1. 25 1. 30 1. 35 1. 40 1. 45 1. 50 1. 55 1.60 1. 65 1. 70 1. 75 1. so 1.85 1. 90 1. 95 2. o0 2. 05 2. 10 2. 15 2. 20 2. 25 2. 30 2.35

O0 03' 25" Oo O@ 50" Oo 08' 35" Oo 13' 45" Oo 17' 10" Oo 27' 309 O 0 34' 20" Oo 36' 05" Oo 37' 50" Oo 39' 30" O0 41' 15' O 0 43' 00" O0 44' 40" O0 4s' 25" Oo 48' 05" O0 46' 50" 00 51' 35" O0 53' 15" O0 55' 00" Oo 56' 45" O 0 58' 25" 10 00' 10" lo 01' 50" 10 03' 35" 1 0 05' 20" 10 07' 00" lo 08' 45" 10 10' 30" 10 12' 10" lo 13' 55" lo 15' 35" lo 17' 20" 10 19' 00- lo 20' 50"

1000. o 500. O 400. o 250. O 200. o 125. O 100. o 95.24 90.91 86.96 83.33 80. o 76.92 74.07 IL 43 68.97 66.67 64.52 62.50 60.60 58.82 57. 14 55.56 54.05 52.63 5128 50.00 48.78 47.62 46.51 45.45 44.44 43.48 42.55

2.40 2.45 2.50 2.55 2.60 2.65 2.70 2.75 2.80 2.85 2.90 2.95 3. O0 3. 05 3. 10 3. 15 3.20 3.25 3.30 3.35 3.40 3.45 3. 50 3.55 3.60 3.65 3.70 3.75 3.80 3. 85 3.90 3.95 4.00 14.25

lo 22' 30" 10 24' 10" lo 25' 55" lo 27' 35" 10 29' 20" 10 31' 00" lo 32' 45" 10 34' 30" 10 36' 10" 10 37' 55" 10 39' 40" lo 41' 20" 10 43' 05" 10 44' 45" lo 46' 30" lo 48' 10" 10 49' 55" 10 51' 10" ! O 53- 21" 10 55' 05" 10 56' 45" lo 58' 30" 20 00' 15" 20 01' 55" 20 03' 40" 2O 05' 20" 20 07' 05" 20 08' 50" 2O 10' 30" 20 12' 15" 2O 13' 55" 20 15' 40" 20 17' 25" 80 07' Oû"

41.67 40.82 40. 00 39.22 38.46 37.74 37.04 36.36 35.71 35. o9 34. 48 33.90 33.33 32.79 32.26 31. 75 31.25 30.71 30. 30 29.85 29.41 28. Y9 25.51 26. 17 27.78 27.40 27.03 26.67 26.32 25.97 25.64 25.32 25.00

7. o 1

15 / 7 / 76 No. 5



--`,,```,,,,````-`-`,,`,,`,`,,`---

U'PEN

DIX

15.-

Conversion Tab

les and

DiaR

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15-13

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WIN

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8 12

16 20

24 18

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Provided by IH

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15-14 - Manual of A i r c r a f t Accident I n v e s t i g a t i o n

R A T E O F T U R N &groos/recond

4.0

3.5

3.0

2.5

2.0

1.5

1 .o

RATE OF TURN, I N TERMS OF BANK

BANK &g'WS

.Rate 1

- - -30

- 25

- 20

- <

AND'TRUE AIRSPEED

TRUE AiRSPEED NM/minute

EXAMPLE: T.A.S. = 4.16 NM/min. d= 30' Raie of turn = 2 . 5 . p ~ second

- 7.5

- 7.0

- 6.5

- 6.0

- 5.5

-5.0

- 4.5

- 4.0

- 3.5

-3.0

- 2.5



--`,,```,,,,````-`-`,,`,,`,`,,`---

APPENDIX 15. - Conversion Tables and Diagrams 15-15

I- L w c)

Lz: w a

? 0 W w a ul

INCREASE IN STALLING SPEED RELATED TO ANGLE OF BANK

40

35

I CONSTANT ALTITUDE

25 max

CONSTANT CL

,- L C e C - i - U I ! ! I I L ! U! ! ! ! ! ! U ! i ! ! ! ! -!! ! ! ! f " " u u Z

-- ANGLE OF B A N K - D E G R E E S -

1 5 / 7 / 7 6 No. 5



--`,,```,,,,````-`-`,,`,,`,`,,`---

15-16 M

anual of

Airc

raft A

ccident In

vestig

ation

.-

--

O

L- n

a

W

!u

v>

x

U

z a a 4 s Y

u

v1

.y

o

SJONX NI n3Z

idC H

3VO

üddV


ivil Aviation O

rganization P

rovided by IHS


AO

Not for R

esaleN



IHS

--`,,```,,,,````-`-`,,`,,`,`,,`---

APPENDIX 15 . - C o n v e r s i o n T a b l e s and D i a g r a m s

HEIGHT DISTANCE AND HEIGHT RELATED TO SIGHTING ANGLES 15-17

dnnn . ft

i2 500 - 1-

iIsee

11 O00 . -

10 500 - 1=

u 9 O00 - 8500

7 500 -

6 500 -

6 O00 -

5 O00 -

4 500 -I

4 O00 -

3 500 - 3 O00 - 2m

2 O00 - 1500

1 O00

c_

- __5M

-_ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 2 1 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 3 1 38 39 40 41 42 43 44 46 47 48 49 5ti 51 52 53 54 55 156 57 58 59 601 METRE x 100

3NM I DISTANCE 2 N M I 1NM 15/7/76 No. 5 Copyright International Civil Aviation Organization


--`,,```,,,,````-`-`,,`,,`,`,,`---

15-18

HE:

ft -

1 O00

950

900

850 - 800

750

I O 0

650

60 O

550

500 - 450

400 - 35 O

30 O - 25 O - 20 o

15 O

.al of Aircraft Accident Investigation

DISTANCE A N D H E I G H T RELATED TO S I G H T I ~ G ANGLES I N NORMAL APPROACH

No. 5

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 2 1 22 23 2 4 25 26 27 28 29 30 3 1 32 33 39 40 4 1 42 43 44 45 46 47 48 49 50 5 1 52 53 54 57 58 59 60 METRE loo

DISTANCE 1" I



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APPENDIX 16

ADDRESSES OF ACCIDENT INVESTIGATION AUTHORITIES

The fo l lowing list of addresses has been compiled mainly from information s u p p l i e d by t h e Nat ional C i v i l Avia t ion Departments. I n cases where o f f i c i a l data were lacking , information has been drawn from va r ious o t h e r sources . Dependent T e r r i t o r i e s have been included i f the information was a v a i l a b l e .

Non-Contracting S t a t e s and

Any e r r o r s o r changes should b e addressed t o the Sec re t a ry General, A t t en t ion A I G , I n t e r n a t i o n a l C i v i l Aviat ion Organizat ion, 1000 Sherbrooke Street West, S u i t e 400, Montreal, Québec, Canada, H 3 A 2R2. '

i 71 10186 No.10



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APPENDIX 16.- Addresses of Accident Investigation Authorities 16-1

+ Non-contracting State * Dependent territory

AFGHANISTAN President of Civil Aviation Opera'tions Ministry of Civil Aviation and Tourism Ansari Watt, P.O. Box 165 Kabul Republic of Afghanistan

Telephone: 61314 Cable : CIVAVIA Kabul AFTN : OAKBYAYX

ALBANIA Director of Sea and Air Transport

ALBTRANSPORT Kongresi i Përmetit No. 202 Tirana Republic of Albania

of the Ministry of Transport

Telephone : Telex: 2124 ASTRAN AB SITA: TIATOXH

3 55 - 4 2 - 3 3 3 6 0

ALGERIA Directeur General Entreprise Nationale pour la Secusité Aéronautique

1 Av. de l'indépendence B.P. 829 Alger Algerie

Telephone: (213) 66 33 03 Telex: ' 65070 AFTN : DAALYVYX

ANGOLA Direcçao Nacional de Aviação Civil Rua D. Miguel de Melo 92-6 Caixa Postal 569 Luanda Angola

Telex: 4118 DNAC AN Cable : AERONAUTICA Luanda AFTN: FNLUYAYX

ANTIGUA AND BARBUDA

See "Eastern Caribbean States"

ARGENT1 NA Junta de Investigaciones de Accidentes de Aviación

Comodoro Pedro Zanni 250 Edificio Cóndor, Capital Federal 1104 Buenos Aires Argentina

Telephone: (541) 322-2222 Telex: 21763 FUAER AR AFTN : S AB AY AY X

ARMENIA General Aviation Board 375042 Yerevan Airport-Zvartnots Armenia

Telex: AFTN : UGE EYAY X

243312

ARUBA* - Department of Civil Aviation Reina Beatrix International Airport Aruba

Telephone: 2970-32665, 36324, 36595 Facsimile: 297 8-23038 Telex: 5089 AIA AFTN : TNCAY AY X

AUSTRAL IA Bureau of Air Safety Investigation P.O. Box 967, Civic Square Canberra A.C.T. 2608 Australia

Telephone: (61-6) 274-6431, 6429 Facsimile: (61-6) 247-3117, 6474 AFTN : ASCOYLYX

AUSTRIA Bundesministerium fuer oeffentliche Wirtschaft und Verkehr Oberste Zivilluftfahrtbehoerde Radetzkystrasse 2 '

A-1030 Wien Austria

Telephone: (43) 222 71162 - 9205 Facsimile: (43) ,222 7130326 Telex: 61-3221155 VERMKA AFTN : LOWWYAYX

1 / 1 / 9 3 No. 11



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AZERBAIJAN Azerbaijan Airlines Concern Azadlyg, Prospect 11 37000 Baku Azerbaijani Republic

Telephone: 93-44-34 Facsimile: 929179 AFTN : UBBBYAYX

BAHAMAS Director of Civil Aviation P.Ü. Box N-975 Nassau-New Providence Bahamas

Telephone: (809) 32-77281, Facsimile: (809) 32-772811 Tel ex : BS109 CADAIR BS AFTN : MYNNYAY X

32-77117

BAHRAIN Director General of Civil Aviation Government of Bahrain Bahrain Internat ional Airport P.O. Box 586 State of Bahrain

Telephone: (973) 321133 Facsimile: (973) 333256 Telex: 9186 AIRCIV BN AFTN : OBBBYAYX

BANGLADESH Civil Aviation Authority of Bangladesh Flight Safety Kurmi tola Dhaka 1229 Bangladesh

Telephone: (880-2) 894705-9, 894870-4 Cable : CIVILAIR Dhaka AFTN : VGHQYAYX

BARBADOS Technical Director- Aviation Air Traffic Services Building Grantley Adams International Airport Christ Church, Barbados West Indies

BELARUS Civil Aviation Department 4 Ulitsa Aerodomnaya 220065 Minsk Belarus

AFTN : UMMUYAYX

BELGIUM Administration de l?Aéronautique Rue de la Fusee, 90 B 1130 Bruxelles Belgique

Telephone: (32 2) 72 40 211 Facsimile: (32 2) 72 40 201 Telex : 22715 DGAIR B AFTN : EBBSY HYX

BELIZE The Chief Civil Aviation Officer Belize International Airport P.0, Box 367 Belize City Belize

Telephone: (501) 025-2052 /2014 Cable : CIVILAIR Belize AFTN : MZBYAYX

BENIN Direction de L?Aéronautique Civile B.P. 372 Cot onou République du Benin

Telephone: (229) 30 10 98, 99 Cable : AEROCIVIL Cotonou AFTN : DBBBYAYX

B ERMüDA The Director of Civil Aviation Department of Civil Aviation 2 Kindley Field Rd St. George, GE CX Bermuda

Tel ex : 02903248 AVCIV BA Cable: ? AVCIV Bermuda AFTN : TXKFYAYX

Telephone: (809) 428-6592 Facsimile: (809) 428-2539 AFTN : TBPBYAYX

7/7/93 No. 11



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~ ~


BHUTAN The Director Department of Civil Aviation

Ministry of Communication Royal Government of Bhutan P.O. Box 291, Thimphu Bhutan

Cable : DIRCEVAVIATION Thimphu

and Transport

BOLIVIA Direccfon General de Aeronautica Civil Casilla Postal 9360 La Paz Bolivia

Telephone: (5912) 343520, 378129 Facsimile: (5912) 371347 Cable : AEROCIVIL La Paz AFTN: SLLPYAYX

BOTSWANA Chief Flight Safety Officer Department of Civil Aviation P.O. Box 250 Gaborone Botswana

Telephone: 371397 Facsimile : 3 537 O9 Telex: 2522 DCAHQ BD AFTN: FBHQYAYX

BRAZIL Centro de Investigaçao e Prevençao de Accidentes Aeronauticos - CENIPA

SHIS - QI05 - Area Militar 71600 - Brasilia - DF Brasil

Telephone: 01155-61-365 1461 Facsimile: 01155-61-365 1004 Telex : 0611152 CENIPA SBBR AFTN: SBBRYLYX

BRUNEI DARUSSALAM Director of Civil Aviation Ministry of Communications Brunei International Airport Bandar Seri Begawan 2015 Brunei Darussaiam

Telephone: 02-330142 Facsimile: 02-331706 Telex: 2267 DCA BU AFTN: WBS BYAY X

BULGARIA Civil Aviation Authority Accident Prevention and- Investigation

9, Levski Street Sofia - 1000 Republic of Bulgaria

Telephone: (359-2) 87-10-79, 87-37-57,

Telex: 22640 AVINS BG Cable : AVINS Sofia AFTN :

Service

87-18-28, 88-53-37

LBS FY LY X

BURKINA FASO Direction de l'Aviation Civile B.P. 1158 Ouagadougou O1 Burkina Faso

Telephone: (226) 30 64 88, 31 O1 37 AFTN : DFFVYAYX

BURUNDI Directeur de la Régie des Services Aéronautiques

B.P. 694 Bu j umbu ra République du Burundi

Telephone: 22.3707, 3797, 2196 Facsimile: 22.3428 Telex: 5190 AERO BDI AFTN : HBBAYAX

CAMBODIA Ministère des Travaux Publics et

Direction de l'Aviation Civile B.P.86 Phnom-Penh Cambodge

des Télécommunications

Cable: DACK Phnom- Penh AFTN : VDP PYAYX

CAMEROON Ministère des Travaux Publics et des Transports

Direction de l'Aviation Civile Yaoundé République du Cameroun

Telephone: (237) 303090, 300692 Telex: 8214 KN AFTN : FKKYYAYX

7/7/93 No. 11



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CANADA Transportation Safety Board of Canada P.O. Box 9120 Alta Vista Terminal Ottawa, Ontario CANADA K1G 3T8

Telephone: (819) 994-4254

Facsimile : ( 81 9 ) 997 -2 23 9 (819) 994-4359 (24 hour)

Telex : 053-4487 TSB HULL

CAPE VERDE ASA - Empresa Nacional de Aeroportos e Sagurança Aerea-EP

Servicio de Informaçäo Aeronáutica Aeroporto Internacional Amilcar Cabral Ilha do Sal Republica de Cabo Verde

Facsimile: (238) 41 15 70 Telex: 4032 ASA CV AFTN : GVACY OY X

CAYMAN ISLANDS* Director of Civil Aviation P.O. Box 277 George Town Grand Cayman West Indies

Telephone: (809) 949-7811 Facsimile: (809) 949-0761 Telex: 4458 CIVAV CP AFTN : MWCRYAYX

CENTRAL AFRICAN REPUBLIC

l'aviation civile Ministère des Transports et de

B.P. 941 Bangu i République Centafricaine

Telephone: 612307, 613315, 6106.36 Telex : 5209 RC AFTN : FEFVY AY X

CHAD - Direction de l'Aéronautique Civile B.P. 96 N ' Dj amena République du Tchad

Telephone: 29-09, 37.83 AFTN : FTTVYAYX

CHILE Dirección General de Aeronáutica Civil Correo 9 - Providencia Apartado 3 Santi ago Chile

Telephone: (562) 204 7715, 7737, 7676 Facsimile: (562) 2090532 Telex: 490532 DAITA CL AFTN : SCSCYAYX

CHINA Director General Civil Aviation Administration of China P.O. Box 644 Beijing 100710 China

Telephone: 558861 Telex: 22101 CAXT CN AFTN : ZBBBYAYX

COLOMBIA Departmento Administrativo de Aeronáutica Civil

Aeropuerto Internacional Eldorado Apartado Aéreo 12307 Bogota, D.E. Colombia

Telephone: 4139894 Facsimile: 4138091 Telex: 044620 DAAC CO AFTN : SKBOYAYX

COMOROS Direction Général de l'Aviation civile et de la Météorologie

B.P. 72 Moroni République Fédérale Islamique des Comores

Telephone: 73 06 20 - 23 13 Facsimile: (269) 731030 Telex: KO241 PUBLICKO AFTN : FMCNY AY X

CONGO - Direction Générale de L'Agence

B.P. 128 Brazzaville Congo

Telephone: (242) 81 09 94, 81 11 5 5 Facsimile: (242) 81 O0 04 Telex: 5388 KG AFTN : FCBVYAYX

Nationale de L'Aviation Civile

7 /7 /93 No. 11



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COOK ISLANDS Department of Civil Aviation P.O. Box 329, Avarua Rarotonga Cook Islands

Telephone: 20715, 20716 Facsimile: 682 20839 Telex: 62052 AVARUA AFTN : NCRGYAYX

COSTA RICA Dirección General de Aviación Civil Ministerio de Obras Publicas y

Apartado Postal 5026 San José Costa Rica

Transportes

Telephone: (506) 31 21 07 Facsimile: (506) 31 32 80 Telex: 2926 DGAC AFTN: MRS JYAYX

COTE DZ IVOIRE Agence Nationale de l'Aviation Civile et de la Météorologie (ANAM)

Section Enquête et Prevention des Accidents d'Aviation

15 B.P. 990 Abidjan 15 République de Côte d'Ivoire

Telephone: (225) 27 90 04 Facsimile: (225) 27 71 85 Telex: 43452 ANAM CI AFTN : D IAVYAY X

CROATIA Ministry of Maritime Affairs, Transport and Communication

Gruska, 20 41000 Zagreb Croat ia

Facsimile: 518-113 Telex: 21275 AFTN : LD Z AY AY X

CUBA Dirección de Seguridad Aeronáutica Instituto de Aeronáutica Civil de Cuba Calle 23, No. 64 La Rampa Vedado, Municipio Plaza de la Revolución Ciudad de la Habana 6 Cuba 10600

Telephone: 29-4437, (7-4671 24 hours) Facsimile: 70-3690 Telex: 511737 A CIV CU AFTN : MULHYAYX

CYPRUS Department of Civil Aviation 25, St. George's Hill Nicosia Cyprus

Telephone: ( 3 5 7 ) 2-446993, 2-303200 Facsimile: (357 ( 2-366547 Telex: 6055 CIVAIR CY AFTN : LCNCYAYX

CZECH REPUBLIC Civil Aviation Administration Ministry of Transport of

Director of Civil Aviation

P.O. Box 9 Nabrezi L. Svobody 12 110 15 Praha 1 Czech Republic

Telephone: (42-2) 231-4369 Faxsimile: (42-2) 232-1420 Telex: 121096 DOM1 C AFTN : LKPRYAYX

the Czech Republic

Administration

DEMOCRATIC PEOPLE'S REPUBLIC OF KOREA Director General Civil Aviation Administration Sunan District Pyongyang Democratic People's Republic of Korea

Telephone: 34519, 32339, 35589 Telex: 5471 JS KP Cable : CIVILAIR Pyongyang AFTN : 2 KKKYAY X

DENMARK Aircraft Accident Investigation Board 45, 1st Floor Jernbane Alle DK-2720 Vanloese DENMARK

Telephone: 45 31 711066 (0800-1600 hrs) 45 31 516611 (1600-0800 hrs)

Facsimile: 45 31719231 Tel ex : 16850 AIG DK AFTN : EKCHY LYX

7/7/93 No. 11



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DJIBOUTI Direction de l'Aviation civile et de la Météorologie

B.P. 2609 Djibouti République de Djibouti

Telephone: 351647 Telex: 5871 PRESIDEN DJ AFTN : HFFFYAYX

DOM IN ICA*


DOMINICAN REPUBLIC Direccibn General de Aeronáutica Civil Edificio Manuel Fernández Mármol Novena Planta Avenida 27 de Febrero Santo Domingo República Dominicana

Telephone: (1809) 689-2269, 3051, 3054 Facsimile: (1809) 687-4698 AFTN : MDSDYAYX

EASTERN CARIBBEAN STATES Directorate of Civil Aviation of

P.O. Box 1130 St. John's Antigua

Telephone: (809) 462-0907 Facsimile: (809) 462-4145 Telex: 2089 CIVILAV AK AFTN : TAPAYAYX

Eastern Caribbean States

Note: The Directorate of Civil Aviation is being operated in conjunction with States comprising the Organization of Eastern Caribbean States: Antigua and Barbuda, Dominica, Grenada, Montserrat, Saint Christopher and Nevis, Saint Lucia, and Saint Vincent and the Grenadines.

ECUADOR Dirección General de Aviación Civil

Telephone: 544-274 Facsimile: 5932-563995 Telex : 22710 DACUIO ED AFTN : SEQUYAYX

EGYPT - Central Department of Aircraft Accident 'Investigation and Prevention

Civil Aviation Organization Ministry of Civil Aviation Building P.O. Box 52, Cairo Airport Road Cairo Arab Republic of Egypt

Telephone: (202) 2449068-, (202) Facsimile: (202) 2470351 Telex: 21187 ACCID UN, 24430

EL SALVADOR Dirección General de Aeronáutica Aeropuerto de Ilopango San Salvador El Salvador, C.A.

Telephone: 27-0025, 27-0026 Facsimile: (503) 271962

666850

CANC UN

Civil

Cable : AEROCIVIL San Salvador AFTN : MSSSYAYX

EQUATORIAL GUINEA Ministerio de Transportes y Comunicaciones

Dirección General de Aviación Civil Calle 3 de Agosto, N" 45 Malabo Republica de Guinea Ecuatorial

Telephone: 3231, 3250 Telex: GE913 101 PUBMO Cab le : DIRAVIACIVIL MALABO

ESTONIA Civil Aviation Administration Tartu Rd 13 EE0105 Tallinn Estonia

Telephone: 7 0142 421235 Facsimile: 7 0142 422445 AFTN : ULTTYAYX

Departamento de Seguridad de Vuelo Buenos Aires 149 y Av. 10 de Agosto Casilla 2077 Quito Ecuador

7/7/93 No. 11



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ETH I O P IA Civil Aviation Authority P.O. Box 9 7 8 Addis Ababa Ethiopia

Telephone: 180266-77 Telex: 21162 CIV AIR ET Cable: CIVILAIR Addis Ababa AFTN: HAAAYAYX

FIJI - Civil Aviation Authority of Fiji Private Bag Nadi Airport Fiji

Telephone: ( 6 7 9 ) 723055 , 7 2 2 5 0 0 Facsimile: ( 6 7 9 ) 790325 Telex: 5299 CAAF FJ AFTN: NFHOYAY X

FINLAND Civil Aviation Administration Flight Safety Authority Accident Investigation Section P.O. Box 5 0 SF-O1531 Vantaa Finland

Telephone: ( 3 5 8 ) 0 8 2 7 7 1 Facsimile: ( 3 5 8 ) 08702304

AFTN : EFHKYAYX Telex: 12-1247 AVIA SF

FRANCE Bureau Enquêtes-Accidents 2 46, rue iecourbe 75732 Paris Cedex 1 5 FRANCE

Telephone: ( 3 3 ) 1 -48285002 , 40434026 Facsimile: ( 3 3 ) 1 - 4 8 2 8 00 4 6 Telex: 2 0 3 5 9 1 F AFTN : LFPSYLYX

GABON Secrétariat Général à l'Aviation Civile et Commerciale

B.P. 2212 Libreville République Gabonaise

Telephone : 7 6-08 -60 , 7 6- 1 4 -4 2 Telex: 5352 GO Cable : AVIACIVIL Libreville AFTN: FOOVYAY X

GAMBIA Department of Civil Aviation Yundum International Airport Banjul The Gambia, West Africa

Telephone: 82831, 82839 Facsimile: 82838 Telex: 2295 MINWOCOM GV AFTN : GBY DYAY X

GEORGIA + Department of Civil Aviation Tbilisi Georgia

AFTN : UGGGY AY X

GERMANY Accident Investigation Bureau Federal Office of Civil Aeronautics Postfach 3054 3 3 0 0 Braunschweig Germany

Telephone: 531-23550 Facsimile: 531-2355246 Telex: 952749 ACCID D AFTN : EDVBYLYX

GHANA The Director General Ghana Civil Aviation Authority Private Mail Bag Kotoka International Airport Accra Ghana

Telephone: 777320, 777476, 7 7 6 1 7 1 Facsimile: ( 2 3 3 ) 2 1 773293 Telex: 9 4 2336 GHACAA GH AFTN : DGAAYAYX

GREECE Civil Aviation Authority Aircraft Accidents Investigation Sect ion P.O. Box 7 3 7 5 1 GR-166 04 Helliniko Greece

Telephone: ( 3 0 ) 1 -9837906 , 9 6 9 9 5 7 6 / 7 Facsimile: ( 3 0 ) 1 8 9 4 7 1 0 1 Telex: 214444 AEROPOLIT Athens AFTN: LGACYAYX

7 / 7 / 9 3 No. 11



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GRENADA


GUATEMALA Dirección General de Aeronáutica Civil Aeropuerto Internacional 'La Aurora" Zona 13 Gua tema la Centro América

Facsimile: 366377 Telex : 3120 ACIVIL GU Cable : DAEROCIVIL Guatemala AFTN : MGGTYAYX

GUINEA Ministère des Transports et

Direction nationale de l'Aviation civile B.P. 95 Conakry République de Guinée

des Travaux Publics

Telephone: (224) 44 27 73 Facsimile: (224) 44 34 57 Telex: 22349 MITRANS AFTN : GUCY YAY X

GUINEA-BISSAU Direcção-Geral da Aviação Civil Caixa Postal 77 Bissau Republica da Guiné-Bissau

Telephone: 3961 Cable : AEROCIVIL Bissau AFTN : GGOVYAYX

GUYANA Civil Aviation Department Oranapai Towers, Wrightc Lane Kings ton P.O. Box 1006 Georgetown Guyana

Telephone: 56822, 61517 Facsimile: 592256800 Cable : CIVILAIR Guyana AFTN : SYTMYAYX

HAITI - Office National de l'Aviation civile Aéroport International de Port-au-Prince B.P. 1346 Port-au-Prince République d'Haïti

Telephone: 46-2218, 46-0220, 46-2701 Facsimile: 46-0998 Telex: AFTN : MTEGYAYX

2030465 CIVILAV 1"

HONDURAS Dirección General de Aeronáutica Civil Aeropuerto Internacional Toncontin Apartado Postal 30145 Comayaquela M .D .C. Honduras C.A.

Telephone: 331115 Facsimile: 33-3683 Telex: 1523 DGAC HO AFTN : MHTGYAYX

HONG KONG* Civil Aviation Department 46th Floor, Queensway Government Offices 66 Queensway Hong Kong

Telephone : 5 -8 62 43 32 Facsimile: 5-8690093 Telex: 61361 CADHK HX AFTN : VHHHYAYX

HUNGARY Head of Flight Safety Department Civil Aviation Administration H-1675 Budapest-Ferihegy Pf .41 Hungary

Telephone : i 36 1) 157 -8543 Facsimile: (361) 157-8808 Telex: AFTN : LHBPYEYX

22-4054 AIRPT H

ICELAND Civil Aviation Administration Reykjavik Airport 101 Reykjavik I ce 1 and

Telephone: 354-1-694100 Facsimile: 354-1-623619 Telex: 2250 FALCON IS AFTN : B ICAY AY T

7/7/93 No. 11



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INDIA Office of the Director General of

DGCA Complex Opposite Safdarjung Airport New Delhi 110003 India

Civil Aviation

Telephone: 4622494/95/99, 4622500 Facsimile: 011-4629221

AFTN: VI DDYAYG Telex: 31-74127 DGCA IN

INDONES IA Directorate General of Air Communications Jalan Angkasa I/2 Kemayoran Jakarta Indones ia

Telephone: (0211-4209348, 418016, 413417 Facsimile: 62-21-416779, 411169, 411457 Telex: 49482 CIVAIR IA AFTN: WIIXYAYX

IRAN, ISLAMIC REPUBLIC OF Civil Aviation Organization International Affairs and Air Transport

Mehrabad Airport Tehran Islamic Republic of Iran

Telephone: 668484 Facsimile: O11 (9821) 669732 Telex: 213889 EPD IR AFTN: OIIIYAYX

P.O. Box 11365-8315

IRAQ Directorate of Flight Safety General Establishment of Civil Aviation Saddam International Airport Baghdad Iraq

Telephone: Facsimile: Telex: AFTN:

8863999 (ext. 28278) 8880178 212500 YIA IK ORBSYAYX, ORBSYTYX

IRELAND Air Navigation Cervices Office Department of Tourism, Transport

Kildare Street Dublin 2 I re laild

and Communications

Telephone : 7 89522 Facsimile: 48 28 O0 46 Telex: 93478 TRDC EI AFTN : E IAAYAY X

ISRAEL Civil Aviation Administration P.O. Box 8 Ben Gurion International Airport 70 100 Israel

Telephone: 972-3-9712604 Facsimile: 972-3-9711480 Telex: 381000 CAATS IL AFTN : LLADYAYX

ITALY - Minister0 dei Transporti Direzione Generale Aviazione Civile Piazzale degli Archivi, 41 00144 Roma Italy

Telephone: 54841 Facsimile: (06) 8166517 Telex: 613080 LIJJYA I AFTN : LI J JYAY X

JAMAICA The Director of Civil Aviation Civil Aviation Department P.O. Box 8998 Central Sorting Office Kingston Jamaica, W.I.

Telephone: 922-7200/7249/7270/2739,

Facsimile: (809) 922-7265 Telex : 3702 CIVAV JA AFTN : MKJKYAYX

/8093/8096

JAPAN - Director-General Sec re ta ria t Aircraft Accident Investigation

Ministry of Transport 2-1-3, Kasumigaseki Chiyoda-ku, Tokyo 100 Japan

Commission

Telephone : 3 581-7 6 O9 Facsimile: 3580-7973 AFTN : RJTDYAYA

7/7/93 No. 11



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JORDAN Civil Aviation Authority P.O. Box 7547 Amman Jordan

Telephone: 896130 Facsimile: 891653 Telex: 21325 CIVAIR JO AFTN : OJAMYAYX

KAZAKHSTAN Deputy Minister Ministry of Transport ü1. Panfilova, -110 Alma-Ata 480091 Republic'of Kazakhstan

AFTN : UAAAYAYX

KENYA - The Chief Inspector of Accidents Directorate of Civil Aviation P.O. Box 30163 Nairobi Kenya

Telephone: 822950 (Ext. 238) Telex: KE 25239 DCA HQ AFTN: HKNCYAY X

KIR I BAT I The Director of Civil Aviation Ministry of Communications P.O. Box 487 Bet io, Tarawa Republic of Kiribati

Telephone: BET10 785 Tel ex : KI77022 Cable : MINCOM TAñAWA AFTN : NGTAYAYX

LAO PEOPLE'S DEMOCRATIC REPUBLIC Department of Civil Aviation 2 Pang Kham Street Vientiane Lao People's Democratic Republic

Telephone: 2094 Cable : AVIACIVIL Vientiane AFTN : VLAOYAY X

LATVIA Ministry of Transport of the

Aviation Department 58 Brïvlbas 226806 PDP Rlga Latvia

Republic of Latvia

Telephone: (0132) 281247, 280594 Facsimile: (0132) 217180 Telex: 161100 PTB SJ 1237 AVTO AFTN : UMRUYAYX

LEBANON Directorate General of Civil Aviation Beirut International Airport Lebanon

Telephone: 830850/830156 Telex: LE20314 DGACLN LE AFTN : OLDDYAYX

LESOTHO Director of Civil Aviation P.O. Box 629 Maseru 100 Lesotho

Telephone: (266) 322499, 324057 Facsimile: (266) 310188 Telex: . 4321 LO AFTN : FXMMYAYX

KUWAIT LIBERIA Directorate General of Civil Aviation Director of Civil Aviation P.O. BOX 17 SAFAT c/o General Manager Kuwait 13001 Roberts International Airport The State of Kuwait, Arabian Gulf Margibi Country

Telephone : 4310897 Robertsfield, Liberia Facsimile: (965) 4765796, 4711144 Telex: 23038 CIVAIR KT Telephone: 26 22 52 AFTN : OKhAY AY X Facsimile: 22 39 13

Telex : 44384 MINTRANS AFTN : GLRBYAYX

P.O. Box 1

7/7/93 No. 11



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LIBYAN ARAB JAMAHIRIYA Civil Aviation Authority P . O . Box 14399 Tripoli Libyan Arab Jamahiriya

Telephone: 35101, 35109 Facsimile: 37454 Telex: 20353 CALLY AFTN: HLLTYAYX

LITHUANIA Ministry of Transport of Lithuanian Republic

Civil Aviation Department Gedimino Av. 17 232679 Vilnius Lithuania

Telephone: (0070122) 621445 Facsimile: (0070122) 224335 AFTN : UMWWYAYX

LUXEMBOURG Ministère des Transports Direction de l'Aviation civile 19 - 21, Boulevard Royal Botte postale 590 L - 2 9 3 8 Luxembourg Telephone: (352) 478-1 Facsimile: (352) 46 43 15 Telex: 1465 CIVAIR LU AFTN: ELLXYAYX

MADAGASCAR Direction de l'Aviation Civile Service de l'Exploitation Aéronautique B.P. 921 Anosy - Antananarivo 101 Madagascar

Telephone: 246 04, 284 18 or 447 57 Facsimile: 304 44 AFTN: FMMDYAYX

MALAWI - Chief Civil Aviation Officer Private Bag 322, Capital City Lilongwe 3 Malawi

Telephone: 730122 Facsimile: 734231 Telex: 4736 AVIATION MI AFTN: FWHQYAYX

MALAYS IA Chief Inspector of Aircraft Accidents Department of Civil Aviation Wisma Yen San Lot. 1 3 A Jalan 225 46100 Petaling Jaya Selangor Daru1 Ehsan Ma lay s i a

Telephone: 03-7576666 Facsimile: 03-7571144 Telex: 20394 PENAWA MA AFTN: WMKKYAYX

MALDIVES Department of Civil Aviation 2nd Floor, Huravee Building Malé 20-05 Republic of Maldives

Telephone: 323507, 322406, 324988 Facsimile: 323039 Telex: 66034 CIVAV MF AFTN : VRMMYAYX

MAL I - Direction Nationale de l'Aéronautique civile

Ministère de l'gquipement et de l'Habitat B . P . 227 Bamako Républic du Mali

Telephone: 22.55 -24 Cable : AVIACIVIL Bamako AFTN : GABVY AY X

MALTA - Director of Civil Aviation Luqua Airport Luqua Cmr 02 Malta

Telephone: (356) 222936, 249170 Facsimile: (356) 239278 Telex: 1654 CAMLT WJ AFTN : LMMMYAYX

7/7/93 No. 11



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MAURITANIA Ministère du Commerce et des Transports Direction de l'Aviation civile Boîte Postale 91 Nouakchott République Islamique de Mauritanie

Telephone: 533-51, 535-78 Cable : MINITRANS PORTS

AFTN : GQNVYAYX Nouakchott

MONACO Service de l'Aviation Civile Héliport de Monaco MC 98000 Monaco Principautè de Monaco

Telephone: 93.15.80.24, 93.15.80.99 Facsimile: 93.15.87.08 Telex : 469525 MONAVI AFTN : LNMCYAYX

MAURITIUS Director of Civil Aviation Pla i s an ce Airport Plaine Magnien Mauritius

Telephone: (230) 6373531 Facsimile: (230) 6373164 Telex: 4896 DCAMAU AFTN : FIMPYAYX

MEXICO Dirección General de Aeronáutica Civil Secretaría de Comunicationsy Transportes Providencia No. 807 - 6' piso Colonia del Valle Codigo Postal 03100 México, D.F. Mexico

Telephone: 687-76-60, 523-66-42 Facsimile: 533-34-19 Telex: 1764154 ACIAME AFTN : MMMXYAYX

MICRONESIA, FEDERATED STATES OF Division of Civil Aviation Department of Transportation Kolonia, Pohnpei P.O. Box 490 Eastern Caroline Islands 96941 The Federated States of Micronesia

Facsimile: (691) 320-2383 Telex: 729-6807

MOLDOVA+ Ministry of Transport Bucuriev 12a 277004 Kichinev Moldova

Facsimile: (0442) 626438 Telex: 163169 PTBSU AFTN : UKIIYAYX

MONGOLIA Director General Division of Civil Aviation Ministry of Roads, Transport and

Chinggis Khan Street Ulaan Baatar 28 Mongol ia

Telephone: 325605 or 327828 Telex: 79323 CAA MH AFTN : ZMUBYAYX

Communications

MONTSERRAT*


MOROCCO Direction de l'Aéronautique civile B.P. 1073 Rabat-Principal Rabat-Maroc

Telephone: 07 735-27 Telex : 31772 M AFTN : GMMRYHYX

MOZAMBIQUE State Secretary for Civil Aviation P.O. Box 227 Maputo Mozambique

Telephone: 465025/34 Telex : 6-175 SEAC MO AFTN : FQHQYAY X

7/7/93 No. 11



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MYANMAR Department of Civil Aviation Yangon International Airport Extension Project Building Yangon International Airport Mingaladon, Yangon Myanmar

Telephone: 6 5 1 4 4 Telex: 2 1 2 2 8 CIVAIR BM AFTN : VYYYYAYX

NAMIBIA The Director of Civil Aviation Ministry of Works, Transport

Private Bag 1 3 3 4 1 Windhoek Nam i b ia

and Communications

Telex: ( 5 0 9 0 8 ) 7 0 9 Facsimile: ( 0 6 1 ) 2 2 4 0 6 0

NAURU Director of Civil Aviation Directorate of Civil Aviation Republic of Nauru Central Pacific

Telex: 3 3 0 8 1 Cable : GOVNAURU AFTN: ANAUYAYX

NEPAL Director General of Civil Aviation Department of Civil Aviation Babar Mahal Kathmandu Nepal

Telephone: 2 1 1 828 , 2 1 3 226, 2 1 5 1 1 4 ,

Facsimile: 9 7 7 - 1 - 2 2 6 4 2 9 Telex: 2 5 5 3 DCA NP AFTN: VNKTYAY X

2 1 5 1 1 6

NETHERLANDS ANTILLES+ Civil Aviation Department Seru Mahuma Z/N Curacao Netherlands Antilles

NETHERLANDS, KINGDOM OF THE Accident Investigation Bureau Aeronautical Inspection Directorate P.O. Box 575 2 1 3 0 AN Hoofddorp Kingdom of the Netherlands

Telephone: 0 2 5 0 3 - 6 3 1 0 8 Facsimile: 0 2 5 0 3 - 2 3 0 4 8 or 4 0 7 4 1 Telex: AFTN : EHAMYAYL

7 4 5 9 2 RLDLI NL

NEW ZEALAND The Chief Executive Transport Accident Investigation Commission

P.O. Box 1 2 1 0 Wellington New Zealand 6 0 0 0

Telephone: 6 4 - 4 - 4 7 3 - 3 1 1 2 Facsimile: 6 4 - 4 - 4 9 9 - 1 5 1 0 Cable : CIVAIR NZ

NICARAGUA Direccfon General de Aeronáutica Civil Ministerio de Transporte y la

Apartado Postal 4936 Managua Nicaragua

Const ruccf on

Telephone: 2 6 9 5 8 , 27515 , 27517 Facsimile: 2 7 5 1 6 Telex: 1 3 0 8 AEROCIVIL AFTN : MNMGYAYX

NIGER Direction de l'aviation civile Ministère des Transports

B.P. 7 2 7 Niamey République du Niger

et du Tourisme

MINTRANS 5249 NI AVIACIVILE Niamey

Telex: Cable : AFTN : DRRVYAY X

Telephone: 83933 Facsimile: i 5 9 9 9 ) 6 8 9 9 2 4 Telex: 1 1 0 2 DCA NA AFTN : TNCCYAYX

7/7/93 No. 11



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NIGERIA Federal Civil Aviation Authority Federal Ministry of Transport and

Air Transport Headquarters 14 Broad Street Lagos Nigeria

Telephone: 1-2631080, 1-2633426 Facsimile: 1-2637238 Telex : 26567 FCAA NG AFTN : DNLLYAYX

Communications

NORWAY Civil Aviation Administration P.O. Box'8124 Dep.

Norway N-0032 Os10 1

Telephone: 47-2-94 20 O0 Facsimile: 47-2-94 23 90 Telex : 71032 N AFTN : ENCAY AY X

OMAN - Directorate General of Civil Aviation and Meteorology

Seeb International Airport P.O. Box 1001 Muscat Sultantate of Oman

Telephone: 519210, 519310 Facsimile: 510122 Telex : 5418 DGCAOMAN ON AFTN: OOMSYAYX

PAKISTAN Headquarters, Civil Aviation Authority 19, Liaquat Barracks Karachi-4 Pakistan

Telephone: 481616, 482009 Telex : 29534 DGCM PK AFTN : OPHQYAYX

PANAMA Departamento de Prevencfon e Investigacíon de Accidentes

Direccfon de Aeronáutica Civil Arp. Marcos A. Gelabert, Via Israel Apartados 7501 y 7615 Panama 5, Panama

Telephone: 26-1622 Facsimile: 26-3860 Telex: 2057 CIVILAV PA AFTN : MPTOYAYX

PAPUA NEW GUINEAU Director of Air Safety Investigation Department of Civil Aviation -

P.O. Box 684 Boroko, NCD Papua New Guineau

Telephone: 271764 Facsimile: 272201 Telex: 22203 NE AFTN: AYPYYAYX

PARAGUAY Dirección General de Aeronáutica Civil Ministerio de Defensa Nacional 2" Piso Avda. Mariscal López y Vice Presidente Sánchez

Casilla de Correos 1568 Asunción Paraguay

Telephone: 211978, 207828, 211366, 204966

Fax : (59521) 210628 Telex: 5313 PY DGAC AFTN : SGASYAYX

PERU - Dirección General de Transporte Aéreo Ministerio de Transportes y

Avenida 28 de Julio #800 Lima-1 Peril

Comunicaciones

Telephone: 337800, 333166 Ext. 421 Telex: 25511 PE DIGECOM AFTN : S PL IY AY X

PHIL1 PPINES Air Transportation Office Ninoy Aquino International Airport Pasay City 1300 Philippines

Telephone: (632) 832-1961 Facsimile: (632) 833-1577 AFTN : R PMMYAY X

7 / 7 / 9 3 No. Il



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~~ ~ ~


POLAND General Commission of Air Accident

Ministry of Transport ul. Chalubinskiego 4/6 00-928 Warszawa 67 Poland

Investigation

Telephone: 223027, 244056 Facsimile: 298689 Telex: 817688, 816651 MTIGM AFTN: EPRLYAYX

PORTUGAL Cabinete de Prevençao e Investigaçao

Direcço-Geral da Aviaçao Civil Rua B, Edificio 6 Aeroporto de Lisboa 1700 Lisboa Portugal

Telephone: 351-1-8488151 Facsimile: 351-1-8473585 Tel ex : 12120 AERCIV P AFTN : LPMGYMYX

de Acidentes

QATAR Civil Aviation Department P.O. Box 3000 Doha State of Qatar

Telephone: 459459 Facsimile: 429070 Telex: 4306 CIVAIR DH AFTN : OTBDYAYX

REPUBLIC OF KOREA Aircraft Accident Investigation Division Civil Aviation Bureau Ministry of Transportation 122 Ponghae-dong 2-ga Chung-gu Seoul 100 Republic of Korea

Telephone: (02) 392-9705 Facsimile: (02) 392-9809 Telex: KK24778 MOTRANS AFTN: RKSLYAYX

ROMANIA Ministère des Transports Departement de l'Aviation civile Romanian Aeronautical Authority Soseaua Bucuresti - Ploiesti Km. 16,s Bucaresti Romania

Telephone: (400) 334372 Facsimile: (400) 792941 Telex: 11181 AIRBUH R AFTN : LRBBYAYA

RUSSIAN FEDERATION Air Transport Department Ministry of Transport Leningradsky Prospekt, 37

Russian Federation

Telephone: 155-55-98, 155-54-94 Telex : 411182 MGA AFTN: UWUYAYX

Moscow A-167

RWANDA Direction Générale de l'Aéronautique B.P. 898 Kigali République Rwandaise

Telephone: 75546 Cable : DIRAVIAMET Kigali AFTN: HRYRYAYX

SAINT CHRISTOPHER & NEVIS

See "Eastern Caribbean .States"

SAINT LUCIA


SAINT-PIERRE-ET-MIQUELON* Service de l'Aviation civile Blvd de Port-en-Bessin B.P. 4265 Saint-Pierre 97500 Saint-Pierre-et-Miquelon

Telex: 914439 DDE SPM Cable : AVIACIVIL Saint-Pierre AFTN : LFVPYAYX

SAINT VINCENT AND THE GRENADINES


7/7/93 No. 11



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SAMOA t Administrator of Civil Aviation and Acting Secretary to Government

Prime Minister’s Department P.O. Box 1 9 3 Apia The Independent State of Western Samoa

Telephone: 2 1 5 0 0 Telex: 2 1 MALO sx Cable : MALO APIA AFTN : NSA PY AY X

SA0 TOME AND PRINCIPE Direcção da Aviação Civil Caixa Postal 97 São Tomé República Dem. de São Tomé e Principe

Facsimile: 1 2 - 2 1 8 4 8 Telex : 2 4 5 DAC ST Cable : AERONAUTICA São Tomé AFTN : F PSTY AY X

SAUDI ARABIA Presidency of Civil Aviation P.O. Box 8 8 7 Jeddah 2 1 4 2 1 Saudi Arabia

Telephone: 0 2 6 6 7 - 3 6 2 4 or 6 6 7 - 3 6 6 4 Facsimile: ( 0 2 ) 6 4 0 - 7 8 7 7 Telex : 601093 CIVAIR SJ AFTN : OEJDYAYX

SENEGAL Direction de l’Aviation Civile B.P. 8184 Aéroport de Dakar-Yoff Senega 1

Telephone: 2 0 0 4 0 3 , 2 3 1 0 4 1 Facsimile: ( 2 2 1 ) 2 3 8 2 7 9 Telex : 5 1 2 0 6 SG AFT” : GOOYY AY X

SEYCHELLES Directorate of Civil Aviation P.O. Box 1 8 1 Victoria Mahé Republic of Seychelles

SIERRA LEONE The Director of Civil Aviation Ministry of Transport and Communications Ministerial Office Block George Street Freetown Republic of Sierra Leone

Telephone: 22106 , 2 6 1 9 1 or 25643 Telex: SE3 57 4 Cable : AIRCIVIL Freetown AFTN : GFLLYAYX

SINGAPORE Chief Inspector of Accidents Civil Aviation Authority of Singapore Singapore Changi Airport P.O. Box 1 Singapore 9 1 8 1 Republic of Singapore

Telephone: ( 6 5 ) 5 4 1 - 2 4 7 5 , 2483 Facsimile: ( 6 5 1 5 4 5 - 6 5 1 9 Telex: RS 2 1 2 3 1 AVIATEL AFTN : WSSSYAYX

SLOVENIA Civil Aviation Authority Kotnikova, 1 9 a 6 1 0 0 0 Ljubjana Slovenia

Telephone: ( 3 8 - 6 1 ) 1 1 6 0 1 8 , 1 1 7 1 3 7 Facsimile: ( 3 8 - 6 1 ) 1 1 7 1 7 8 Tel ex : 3 9 1 6 0 SL RUZPYU AFTN : LJLJYAYX

SOLOMON ISLANDS Civil Aviation Division Ministry of Aviation and Tourism P.O. Box G20 Honiara Solomon Islands

Facsimile: ( 6 7 7 ) 3 0 7 7 5 € 6 4 7 0 HQ Telex:

Cable : CIVILAIR Honiara AFTN : AGGHYAY X

Telephone: ( 2 4 8 ) 7 3 0 0 1 Facsimile: ( 2 4 8 ) 7 3 2 2 2 Telex : 2 2 3 9 DCA SZ AFTN : FSIAYAYX

7/1/93 No. 11



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SOMALIA Somali Civil Aviation Authority Flight Safety Division P.O. Box 1737 Mogadishu Somalia

Telex: 3033 MINTRAS Cable : CIVAIR Mogadishu AFTN : HCMMYAYX

SOUTH AFRICA Directorate of Civil Aviation Private Bag X193 Pretoria, 0001 Republic of South Africa

Facsimile: (012) 2902040 Telex: 321195 SA AFTN: FAHQYAYX

SPA IN - Dirección General de Aviación Civil C/Telemaco, 54 28027 Madrid Spain

Telephone: (34-1) 320 5017 Facsimile: (34-1) 320-5022 Telex: 27702 CIAIR E AFTN : L EACYAYX

SRI LANKA Department of Civil Aviation P.O. Box 535 Lotus Road Colombo 1 Sri Lanka

Telephone: 436324, 431324, 436552,

Facsimile: 91-1-440231 Telex: 22229 MINDEF CE AFTN : VCCCYAYX

432108, 433213, 435354

SUDAN - Director General of Civil Aviation Authority

Technical Services and Flight Safety P.O. Box 430, Blue Nile Avenue Khartoum Republic of Sudan

SURINAME Director of Civil Aviation P.O. Box 1981 Paramaribo - Zuid Suriname

Telephone: 497914, 498898 Facsimi le : Telex: 148 CIVPBM SN AFTN : SMPBYAY X

4 98 90 1

SWAZILAND Ministry of Transport and Communications ~

Directorate of Civil Aviation P.O. Box 2652 Mbabane Swaziland

Telephone: 42321 Ext. 156 Facsimile: 42364 Telex: 2104 WD AFTN: FDMBYAYX

SWEDEN - Board of Accident Investigation P.O. Box 125 38 S-102 29 Stockholm Sweden

Telephone: (46-8) 737 5840 Facsimile: (46-8) 737 5852 Telex: 12841 HAVKOM S

SWITZERLAND Département Fédéral des transports, des communications et de 1 #énergie

d'aviation Bureau d'enqu4te sur les accidents

Palais Fédéral Nord 3003 Berne Switzerland

Telephone: (41 31) 615517, 615544, 615520 (41 31) 385 83 33 (24 hours)

Facsimile: (41 31) 210957 Telex: 911235 AIBCH AFTN : LSSOYLYX

Telephone : Telex: 22650 DGCA SD AFTN : HSSSYAYG

7 23 6 O

7/7/93 No. 11



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SYRIAN ARAB REPUBLIC Directorate General of Civil Aviation 1 Sahet El-Najmeh P . O . Box 6257 Damascus Syrian Arab Republic

Telephone: 338720 , 3 3 1 3 0 6 , 3 3 1 3 0 7 Facsimile: 2 3 2 2 0 1 Telex: 411928 CIVAIR SY AFTN : OSD I YAY X

THAILAND The Director, Air Safety Division Department of Aviation 7 1 Soi Ngarmdu-Plee Tungmahamek Bangkok 1 0 1 2 0 Thailand

Telephone: 6 6 ( 2 ) 2860921-5 , 2 8 6 2 1 2 9 Facsimile: 6 6 ( 2 ) 2 8 6 3 1 3 9 , 2 8 6 2 8 2 4 Telex: 7 2 0 9 9 DEPAVIA TH AFTN : VTBAYAYX

TOGO - Direction de 1'Aviaton Civile B.P. 2 6 9 9 Lomé République Togolaise

Telephone: 213740 , 2 1 5 5 7 4 Facsimile: 2 1 0 8 6 0 AFTN: DXXXYAYX

TONGA Ministry of Civil Aviation P.O. Box 845 Queen Salote Road Nuku'Alofa Tonga

Telephone: 24045 , 2 4 1 4 4 Facsimile: 2 4 1 4 5 Tel ex : 66269 PRIMO TS AFTN : NFTNYAY X

TRINIDAD AND TOBAGO Director of Civil Aviation P.O. Box 552 Port of Spain Trinidad and Tobago

Telephone: 625 4 0 1 1 Facsimile: 1 ( 8 0 9 ) 6 2 5 - 3 4 5 6 Cable : CIVILAV Trinidad AFTN : TTPSY AY X

TUNISIA Ministère du Transport Direction Générale- de L'Aviation Civile 1 3 , Rue no 8006 - Monplaisir Tunis Tunisie

Telephone: 6 5 0 508 ; 6 5 0 495 ; 2 4 9 307 ; 650 499

Facsimile: 247 528 Telex: 1 3 5 4 5 CIVIAC TN AFTN : DTTVY AY X

TURKEY Directorate General of Civil Aviation Ministry of Communications and Transport 9 0 Sokak No: 5 Emek, Ankara, 0 6 3 3 8 Turkey

Telephone: ( 9 0 4 ) 2 1 2 46 35 , 2 1 2 45 7 9 Facsimile: ( 9 0 4 ) 2 1 2 4 6 8 4 Telex : 4 4 6 5 9 CAD TR AFTN : LTAAYAYX

UGANDA The Managing Director Civil Aviation Authority P.O. Box 5 5 3 6 Kampala Uganda

Telephone: ( 0 4 2 ) 2 0 3 1 1 or 2 0 1 0 1 / 2 Facsimile: ( 0 4 2 ) 2 0 1 3 5 Telex: 61313 UGA WORKS, 6 1 4 6 0 KAB QG AFTN : HUENYAYX

UKRAINE Air Transport State Administration o'f Ukraine Pr. Peremogi, 1 4 252135 , Kiev Ukraine

AFTN: UKKUYAYX

UNITED ARAB EMIRATES Directorate General Civil Aviation Ministry of Communications P.O. Box 900 Abu Dhabi United Arab Emirates

Telephone: 6 5 1 9 0 0 Facsimile: ( 9 7 1 ) 0 2 - 6 5 1 6 9 1 Telex: 22668 COMSAD EM AFTN : OMAEYAYX

1/1/93 No. 11



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UNITED KINGWM Air Accidents Investigation Branch Department of Transport Royal Aerospace Establishment Farnborough, Hampshire England GU14 6TD

Telephone: 0252 510300 Facsimile: 0252 540535 Telex: 858119 ACCINV G AFTN : EGGCY LY X

UNITED REPUBLIC OF TANZANIA The Chief Inspector of Accidents Ministry of Communications and Transport Accident Investigation Branch P.O. Box' 2819 Dar-es-Salaam United Republic Of Tanzania

Telephone: 29181/2/3/4, 44128/9 Facsimile: 46798 Telex: 41120 DIRECTAIR AFTN: HTDQYAYA

UNITED STATES National Transportation Safety Board 490 L'Enfant Plaza East, S.W. Washington, D.C. 20594 United States

Telephone: (202) 382-6600

Facsimile: (202) 382-6576 Cable : TRANSAFETY Washington, D.C. AFTN: KRWAY LY X

(202) 863-5100 (after hours)

URUGUAY Direcclon General de Aviación Civil Yi 1444 Montevideo

Telephone:

Telex: Cable:

Uruguay

UZBEKISTAN Department

908079 - 920965 al 67 - 906462/63 22631 DIRACIV W AEROCIVIL - MONTIVIDEO

of Civil Aviation Prole tars ka r j a, 4 1 Tashkent GSP-700060 Uzbekistan

Facsimile: (3712) 331885 Telex: 116169 POLET AFTN : UTTTY AY X

VANUATU Director of Civil Aviation Pacific Building Port -Vi la Vanuatu

Telephone: 2416, 2371, 3301 Facsimile: 678-3783 Telex: 1040 VANGOV AFTN : MNVYAYX

VENEZUELA Oficina de Inspectorfa Aeronáutica Parque Central, Torre Este, Piso 34 Apartado de Correos 17587 Caracas Venezuela

Telephone: 509-2403/2457/2404/2436 Facsimile: 509-2425 Telex: 24626 MTCAC VC

VIET NAM Director General Department of Aviation Ministry OP Transport and Communications 80 Tran Hung Dao Street Hanoi The Socialist Republic of Viet Nam

Telephone: 52079 Telex: 412242 BGTVT VT AFTN: VWVYAYX

YEMEN - Civil Aviation and Meteorology Authority P.O. Box 1042 Zubeiry Street Sana'a Republic of Yemen

Telephone: 272618/19/22 Facsimile: 274126 (0800 - 2000 hrs) Telex : 2334 CIVAIR YE AL AFTN : OYSNïAYX

ZAIRE - Direction de l'Aéronautique Civile B.P. 6514

République du Zalre

Telephone: 22986, 24812, 25709 Cable : CIVILAIR Kinshasa AFTN: F ZA B YAY X

, Kinshasa/N'dolo

7 / 7 / 9 3 No. 11



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ZAMBIA The D i r e c t o r Depar tment of C i v i l A v i a t i o n P . O . Box 50137 15101 Lusaka Zambia

Te lephone : F a c s i m i l e : 260 1 251841 T e l e x : 42280 ZA AFTN : .FLHQYAYX

2 28 11 4

ZIMBABWE Depar tmen t of C i v i l A v i a t i o n Carum House, 78 Manica Road P. Bag 7716 Harare Z, imbabwe

T e l e p h o n e : F a c s i m i l e : (263-4 ) 728110 T e l e x : 4738 ZW AFTN : FVHQYAYX

7 92 63 1

7 / 7 / 9 3 No. 11



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MANUAL OF AIRCRAFT ACCIDENT I N V E S T I G A T I O N

APPENDIX 17

L I S T OF NATIONAL LAWS AND REGULATIONS RELATING TO AIRCRAFT ACCIDENT INVESTIGATION

This Zist repZaces aZ7. l i s t s previously pubZished i n the Aircraft Accident Digest (inctuding Digest No. 19)

16/4/73 No. 3



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APPENDTX 17.- !,?.st of T,awas and Regulations 17-1 -- _-..I

APPENDIX 17

L i S T 3F N A T I O N A L LAWS AND R E G U L A T I O N S R E L A T I N G TO A I R C R A F T A C C I D E N T I N V E S T I G A T I O N

DATE --U_-

1959

I. 9 CA

17,05.67

10,030 70

%.08.47

92.12.5 7

29.03.58

LAWS AND REwmTxas ‘-.lip*

C i v i l Air Regulations:

0-5 - Definitions: A i m a i t Accident, Chief fiupcctar Accidents, Investigation,

Part 13 - Regulations governing the Inrcstig8tion of Civil A i r a a f t Accidents i n Afghanistan,

krmas y Mscctivas Generales para l a ~~~veatigaciiin de Accidentes de A v i a d ó n . T k x b actualizado Sno 19f2

b y NO 17,285 - código Aeronáutioo: d t u i o IX, -

Decreto No 934 - Normas para investigación de

Investigación de Accidentes de A r i a c i & .

accidentes de aeronaves cidles. No 299/1954, an l o que se re f ie re a las aeronaves civiles-

&&gast el Daart0

mC A i r Navigation Rcgulatlons, SoR. m. 112/194?, as aænded: Part XVI, - Accident Inquiry (Rtgs. 270-297;

The Federal Air Law: Part ‘bzII, - D) Inrrstfgetkm of c i v i l a i r c ra f t accidents,

Ordinance No, 68 relating to a i r c ra f t accidcnt investigation. Amended by (Xdinance Wo, 216 of 27 July 1965,’



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Bahrain

Bangladesh

Barbados

Belgium

30/5/77 No. 7 -

-

D!,Tt: -1_1

02.03.58

1952

27.12.63

18.10.66

19 10.71

25 . 01.72

31 00.72

1963


The Bahrain Aircraft Accident Regulation. Notice No. 2/1958.

Rie A i r Navigation (Invest igat ion of Accidents) Regulations, 1952.

Ordonnance .no 26/GRPDhíTP por -ant Code de 1 'AVi.a-,m Civ i l e e t Commerciale: Livre ler - T i t r e TV. - Des Accidents.

código Aeronáutico Boliviano.

Decree L a w No. 32. Brazilian A i r Code.

Decree No. 69565 creating the Aeronautical Accident Investigation and Prevention System.

Decree No. 70050. Regulation to Aeronautical Accident Investigation and Prevention Service (SIPAER).

W s t e r i a l Doc No. 77/61(3 creating t h e Investigation and Prevention Manual involving Aeronautical Accident.

L a w on civil aviat ion (Off ic ia l Gazette No. i - 4 January 1963): VI . - Section 44.



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APPENDIX 17.- L i s t of Laws and Regulations 17-3 i

hrmc i

Burundi

Canada

Cape Verde

Central African @ire

Chile

DATE

19 34

1937

1949

13.04.66

29.12.60

07.10 64

29 e 37.65

Or8*04.63

1951

30.01 068

I LAWS AEJD RECUUTIONS

I The Union of Burma Aircraft A c t , (XXII of 1934) : Section 7. - Power of the President of the Union of Burma to make rules fo r investigation of accidents.

nie Union o f Burma Aircraft Rules, as ammded: Part X. - Investigation of Accidents.

i Regulations relat ing t o Aircraft Accident' and incident Investigation (Notice to Airmen Na. 5/1949).

I Airteté-loi no 00i/î9 sur i a loi relative à i a navigation aérienne: luticle 11. - Eiaquetes.

7!he Air Regulations, Order i n Council P.C. 1960-1715 (SOR/61-10), as amendeä: P a r t I. Sec. 101. - interpretation; Section 102, 103, 104 - Application. Part VIII. Mv. III. - Aircraft Accident Investigation ( O r d e r i n Council P.C. 1967-413 - s0%/67-111, P.C. 1973-3552-SoR/73-686 1.

M r Navigation Order, Series VIII, No. 1 - Aircraft Accidents and !kissing Aircraft (SûR/64-433).

toi no 65-63 re la t ive à l 'aviation c i v i l e e t coaiirereialc: Livre I. - "itre 4 - Des Accidents (Articles 62, 63).

&ret no 78/pR/TP portant code! de l'Aviation c i v i l e ; Livre ler - Titre IV. - Des Accidents.

)(amta1 sobre Investigación de Accidentes de Aviación (Publicación de l a Dirección de Aeronáutica MT-4-O ) .

Ley No 16.752 fija organización y funciones y esrablece disposiciones generales a la Dirección de Aeronbtica : d t u î o II. - ~ r t . 3 O cl.

Rie tex t dces not exist i n the files of ICAO. 30/5/77 No. 7



--`,,```,,,,````-`-`,,`,,`,`,,`---

----

17-4

C0u:JTPTp.Y

China

Colombia

Congo, People's Republic of the

Costa Rica

cuba

czechos lovak Social is t ñepiblic

Deaocratic Kaiprchea

DIbTi:

26.12.68

18.10.49

27.11 . 57

18.09.64

18.08.52

04.11.76

06.04.74


UbIS AND REQJLATIOXS - -

Decreto No 3140 por e l cual se reorganiza el Departamento Administrativo de Aeronáutica Civil , se f i j a n sus funciones y se crea el Pondo Aeronáutico Nacional: II. Art . 4* c); III. A r t . 6 O 9); nt. Art. 11' f); V. A r t . 5O b), c), A r t . l6O.

)lanual de Reglamentos Aeronáuticos - Parte Octava - Seguridad A é r e a 80.0 informes Aeronáuticos, Accidentes e Incidentes de Aviación (Rev. No 24 - 8-4/70).

Ley General de Aviación Civi l No 762: Part I.-Tftulo I. Cap.2 Sección VIII. - Accidentes.

Decreto Ejecutivo No 47 - Regulaciorîes aéreas: Part V I . Accidentes. (La Gaceta, 12.12.57)*

Ley No 1160 por l a que se crea el "Inst i tuto de Aeronáu- t i c a Civi l de Cuba1*; A r t . 2. d) . (Gaceta Oficial No 30- 22.9.64, p. 585).

Air Navigation (Investigation of Accidents) Regulations, 1952.

C i v i l Aviation A c t No. ,127: Para 45. - Investigation

Investigation of Aircraft Accidents.

of Aircraft Accidents.

The text does not exist in the f i l e s of ICAO.

3015 177

No. 7



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APPENDIX 17.- L i s t of Lars and Regulations 17-5

Democratic Yemen

Denmark

lbn.l.dcan Bepublic

Ecuador

Egypt, A r a b Republic of

El Salvador

Equatorial Guinea

EtMopia

--- DATE

10.06o60

23.10.69

58e07.54

05.05.41

Gr3.04.77

22.12, fi5

ai.03.tii

27.08.62

LAWS AND REGULATICNS

The Civi l Aviation A c t . Caae i n to force on 1 January 1962: Chapter XI. - Investigation of Accident6 (Paras . 134-1441.

Ley N8 SO5 de Aeronáutica Civil: Cap. II. Sección Segunda - De l a Dirección General de Aeronáutica Civil: A r t . 18 ñ). Cap. XXIV. - De l a Investigación de Accidentes &xos ( A r t . 216-2221. Cap. XXVI. - Disposiciones corures a encuestas de accidentes y a búsqueda y salvamento (Art. 235-2461.

Acuerdo Ministerial No 7 - Reglamento de Aeronáutica Civil del Ecuudor: Titulo II. P a r t e 8.- investigaciones y encuestas de accidentes de ariaci&,

Decree - Air Navigation Regulations: Article 10.

Deme N0121/T-1977 of Mnfster of M s m and C i v i l Aviation concerning necessary action t o be taken i n case of accidents and incidents.

Decreto pio 2011 - Ley de Aeronáutica C i v i l : Título I, Cap. III. Del Departanento de Aviación - A r t . 12. XIXI Cap, XV. - De l a Investigación de Accidentes A6reos (Art. 173-1871.

investigation of Accident Regulations.

The C i v i l Aviation Decree No. 48/1962: 2. (b) ( A v ) - Power of the Civil Aviation Administration t o provide for Investigation of accidents,

30/S/77 No. 7



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COL'NTRY

f i j i

Finland

France

Gabon

Germany, Federal Republic of

DIiTE

11.12064

23,08068

21.04.37

03o01.53

O 3.06, 57

02o11.61

20.06.62

10.01.59

16.08.60

30/5/77 No. 7

The text does not exist i n the

!Che PiMiSh Air A c t , No. 595/1964, Came i n to force on 1 October 1968: Chapter II, - Paras. 56-62, Investiga, tion of Nrcraft Accidents..

The Finnish A i r Decree, No. 525/1968: Chapter 9, - Paras. 117-135..

Décret relatif à l a déclaration des accidents d 'aviation

Instruction inter ia inis tér ie l le re la t ive a l a coordinatioi de l'information jud ic ia i re e t de l'enquête technique e administrative en cas d'accident survenu a un aéronef français ou étranger sur le t e r r i t o i r e de l a nétropole et les t e r r i t o i r e s d'uitre-ner.

Instruction du Secrétaire d*Eta t aux Travaux Riblics, aux Transports et au Tourisme no 300 IííAC/SA, conrernan les disposit ions a prendre en cas d*ir&gular i té , d l incident ou d accident d aviatioh.

Arrêté r e l a t i f aux conunissions d'enquête sur les accidents d'aviation..

Arrêté portant organisation et at t r ibut ions du bureau quêtes - Accidentsw B 1 'inspection générale de 1 'aviation civi le .

The Aeronautics A c t , as amended up t o 5 April 1965: Article 32 6).

General administrative ru les with respect to the technical inqu i ry i n case of accidents occurring during the operation of a i rc raf t .

files of ICAO.



--`,,```,,,,````-`-`,,`,,`,`,,`---

APPENDIX 1 7 . - L i s t of Laws and Regulat ions 17-7

DATE

1958

¿3.08.71

11.05.68

28.10.48

180 08-52

03.09 5 7

1964

1964

09.05.64

14.080 34

23.03.37

LAWS m D REGJUTIONS

Civi l Aviation A c t : P a r t II. - Paragraph 8 - Investiga t ion of Accidents.

C i v i l Aviation (Accidents) Regulations, LI. 702/1971.

Royal Decree No. 324 on a i r c ra f t accident investigation..

Decreto No 563 - k y de Aviación Civil: Capítulo X. - Kk los siniestros aeronáuticos (Ar t . 116-1211.

A i r Navigation (Investigation of Acddents) Regulations, 1952.

Decreto No' 146 - Ley de Aeronáutica Civil: Título I. - Cap. II. - Dirección General de Aeronáutica Civil ( A r t . 6 X I I I ) ; Cap. XIV. - Investigación de Accidentes Aéreos.

L a w Decree No. 26 on C i v i l Aviation: Chapter V. - Extraordinary Flight Events (Article 25).

-der No. 27 on the enforcenrent of LarDecrce No. 26 of 1964: Articles 39, 40.

Aviation A c t : Chapter II. - Flight Accidents - Article 141-147 - investigation of ?light Accidents.

The Aircraft A c t , 1934: Section 7. - as amended : Power of Central Governuent t o raake rules f o r investigation of accidents.

The Aircraft Rules,. 1937, as amended: Part X. - Investigation of Accidents.

.n the f i l e s of ICAO.

30 15 177 No. 7



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17-8 Manual of Aircraft Accident Investigation _II_-

LALIS K?Il RECXJ7JIATIONC

Iran

Iraq

I s r a e l

I ta ly

Ivory Coast

Jamaica

Japan

13 74/75

19 36

09.02.57

1969

li . Cl. 25

21 . 04.42

26.12.63

1953

1966

12.10.73

Iraqi C i v i l Aviation Regulations No. 148 of 1974. Chapter (10) - Article (141) and Requirements No. 2 of 1975.

The A i r Navigation and Transport Acts 1936 t o 1566: Par t V I I . - Section 60 - Invest igat ion of Accidents.

Rie Air Navigation (Invest igat ion of Accidents) Regulations, S.1. No. 19/1957.

A i r Regulation 5?29/1969 - K.T. 2377 - Accident and Incident Investigation Conmittees..

Decree Law No. 356 - Rules for Air Navigation, as

The Navigation Code, approved by Royal Decree No. 327 of

amended : ' Chapter V ï I .

30 #arch 1942: Second Part - A i r Navigation - Investigation of Accidents ( A r t s . 826-833).

lai no 63b528 relative l ' a v i a t i o n c i v i l e e t comer- c la le : Livre Premier - Titre IV. - Des accidents.

lpe Air Navigation (Invest igat ion of Accidents) . Regulations, No. 37/1353.

. . The c i v i l Aviation A c t , Nó. 19/1966: P a r t II. S. - ,

Investigation of Accidents.

Aircraft Accident Investigation C o d s s i o n EstablishAp-nt Law, Law No. 113/1973.

o The text docs not exist in the files of ICAO. 30/5/77 No. 7



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~~~~~ ~

APPENDIX 17.- List of Laws and Rc

CCUNTRY

Jordan

Kenya

Kuwait

Lao People's D c i o c t a t i C Republic

Lebanon

Lesotho

Liberia

Libyan A r a b Jamahiriya

DATE -7

1953

1964

1965

11 O 1 49

1962

O1 . 03.65

06.03.66

i lat ions 17-

LAWS AND RECWWTIONS - Law Wo. 55 on Civil Aviation: investigation of Acddents (Article 106).

lhe E a s t African Civil Aviation A c t .

East African C i v i l Aviation (investigation of Accidents Regulation.

Aviation Law: Chapter III. - Sub-chapter 2 - Lading of Aircraft (Article 39).

C i v i l Aviation Regulations, effective &ly 1, 1963: Part I. - Definitions - (41) A i r c r a f t Accident; Part VIII. - Aircraft Accident investigation.

Royal U promlgating the Civil Aviation L a w Ib. 2 of 1965: Part Seven. - Aircraft Accidents îArticles 60-67).

nin is te r ia l Order Ro. 7 : Rules of investigation of A i r c r a f t Accidents.



--`,,```,,,,````-`-`,,`,,`,`,,`---

1.7110 Manual of Ai rcraf t Accident Invest igat ion - -- LAWS At;ü REQJLATIG:4S CWXTW

Madagascar

Malawi

Xal aysi a

Maldives

#ali

Malta

Mauritania

I)/,'fE

29.10.69

04.06.70

01.04.70

11.12.70

01.1.1.53

1969

15.01.62

05.03,69

1956

03.07. ó2

26.05.64

Instruct ion no 113 bis r e l a t i v e aux disposit ions à prenàre en cas d'accident d 'aviation.

Arrêté no 2239 portant rég lemnta t ion de l a Circulation Aérienne h Madagascar, Titre II, Chapitre I, paragraphe 2.1.1.4, not i f icat ion des inc ident ou accidents d 'aviation.

Aviation A c t No. 7/1970: Section 19. (11, (2) (u) (i), (ii), (iii), (iv)..

Aviation (Invest igat ion of Accidents) Regulations (G.N. No. 22/1970).

Air Navigation (Invest igat ion of Accidents) Regulations, (LON. 584/53).

C iv i l Aviation A c t No. 3/1969: Par t II. - Regulation of Civ i l Aviation - 3. ( 2 ) (41, (r!.

bi no 62-12 AN-RM r e l a t i v e à l 'Aviation Civile: lère P a r t i e - htre VI. - ~ e s enquêtes sur lec accidents d ' aviation.

Arrêté no 146/MTPC-DNT-l r e l a t i f à l a conduite dcs enquêtes concernant les accidents d 'aviation survenant s u r le territoire de l a République du Mali.

Civil Aviation ( Invest igat ion of hccidents ììeguiations.

i d no 62-137 portant Code de l 'Aviation c i v i l e : Artlcle 9 - Enquêtes.

Décret no 64.089 déterminant les règlements d 'appl icat ion de l a l o i no 62,137 du 3 ju i l le t 1962 portant Code de 1'Aviat.ion c i v i l e : lère P a r t i e - Titre V I . - Des enquêtes sur les accidents d 'aviation.



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APPENDIX 17.- L i s t of Laws and Regulations 17-11

CiiuNTRY

Plauritius

Mexico

DA%

27.12.49

18.10. 50

10 .08. 62

14.09 . 62

25 10.30

22.04.59

1969

19 36

22.09.36

-~ ~

LAWS AND REGULATIONS

Ley de Aviación Civil (Libro IV de la Ley de Vias Generales de ConinicacLÓn): Cap. XIV. - De los Accidentes y de 1amBÚsqueda y Salvamento ( A r t . 358-361

Reglamento para &queda y Salvamento e Investigación de Accidentes &reos (en vigor a partir del 1' de enero de 1951).

Dikret no 2-61-161 (7 Safar 1382) portant réglcrentatioi de l'aéronautique civile: lère Partie - Titre Vi.- Des enquêtes sur les accidents d'aviation (Arts. 106-114). L'article 108 est d i f i é par le décret No 851-67 du 26 janvier 1970 (18 Kaadal.

Arrêt6 du Ministre des Travaux Publics no 533-62 relati a la conduite des enquêtes concernant les accidents d'aviation sur le territoire narocah. lbdifié par 1 * Arret6 no 602-66 du 7 septembre 1966.

Ibzanbique

Nauru

Nepal

Netherlands, Kingdom of the

Dccree No. 20062. Air Narlgation Regulations: Chapter ViII.

Act No. 22 to control and regulate civil aviation: Section 5. - Power of His Xajesty's Governunt to issue rules pertaining to investigation of accidents.

avil Aviation (Investigation of Accidents) Rules..

Act regulating the Investigation of Accidents to Civil Aircraft (Stb. 1936, 522).

Order for the application of paragraph 2, Article 6, of the Act regulating the Investigation of Accidents to Civil Aircraft, 1936. (Aeronautical Msasters Act), Stb. NO. 579A/1936.

30/5/77 No. 7



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17-12 Manual of Aircraft Accident Investigation - __I

íAWS AIJU XEG'JLATIONS

Order No. LI/13958 r e l a t i n g t o the Assistants of t h e Preliminary Investigation ( A r t i c l e . 2 of the Order of 22 September 1936, stb. 579A).

Netherlands, Kingdom of the (Contd)

N e w Zealand

Nicaragua

Niger

Nigeria

Norway

Oman

Pakistan

The text does nc

_.

DIhTi:

04.08.59

21.11.67

11.11.53

19.11 . 64

18.05.56

17.07.62

28.10.65

16.12.60

08.02.61

19 o 07.60

23.03.3?

e x i s t i n i

Decree No. 23 - Article 1, para. 7 of the A c t regulat ing t h e Invest igat ion of Accidents t o Civil Aircraf t 5936 (Aeronautical Disasters A c t ) concerning the nomination of th& Aeronautical Council Members f o r the period January Ist, 1968 - December 31st, 1969.

The Civi l Aviation (Invest igat ion of Accidents) Regulations, Serial No. 152/1953.

C i v i l Aviation A c t No. 6W1964, a s amended on 1st Septemùer 1975: P a r t III. - Investigation of Accidents.

Decreto No. 176 - Código de Aviación Civil : Titulo II. - Cap. V. De l a Investigación de Accidentes Aéreos.

bi no 62-13 portant C a d e de l 'Aviation Civile: Livre ler - T i t r e IV. - Des Accidents ( A r t s . 63-65],

Civi l Aviation ( invest igat ion of Accidents) Regulations, L.N. 14/1'966.

The Civ i l Aviation A c t . Came i n t o force on 1 January 1962: (Paras. 166-168) . Chapter XI. C. - Invest igat ion of Accidents

marient a i r c r a f t accident ?le

Royal Decree establ ishing invest igat ion cormiission.

Civi l Aviation Ordinance (No. X X X ï I of 19601, corrected up t o 31 Xarch 1966: Section 7 - Power to make r u l e s €or invest igat ion of accidents.

Par t X. - Investigation of Accidents (Rules 68-77A.l. The Aircraf t Rules ' (corrected up t o 31 March 1966) :

! f i les of ICAO. (1)

30/5/77 No. 7

The substance of ICAO Annex 13 i s used i n pr inc ip le a t a i r c r a f t accident i n q u i r i e s i n NorWay. The Arinex i; p a r t i a l l y implemented as regulat ions through t h a t Decree. -



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APPENDIX 17.- List of Laws and Regulations 17-1 3

CiXIXfRY i- Panama

Papua New (brinca

Paraguay

Peru

phi l ipp i ne s *

Poland

Portugal

DATE

03.08.63

19 75

30.09.5 7

1 2 . 05.69

28.10.65

28.12.65

20.06.52

15.08. 73

31.05.62

25.10.30

08.05.77

07.03.61

LAGS AND REGULATIGJS

Decreto-Ley No 19 por el cual se reglamenta l a Aviación Título II. - Cap. V I I . - De l a Invest igad& Nacional:

de Accidentes Aéreos.

Civil Air Regulations: Part XIV. - Accident Inquiry (Regs. 282-309).

~ r y NO 469 - código Atronautica:

ResoluciÓn No 289 - Reglamento de l a Contsión Nacional

Titulo XVI. - Accidentes Aeronáuticas.

XnvestigadÒra de Accidentes A é r e o s .

Ley No 15720 de Aeronhtica civil : dh10 X. - Accidentes Cap. 1. Investigación.

Decreto Supremo No 16 - Reglamento de l a Ley de Aeronáutica Civi l del PeN: Accidentes (Artículos 124-132).

The C i d l A e r o M U t i C S A c t , NO. 776: Chapter V. - Section 32 - Power and Duties of the Adainistrator: (11) investigation of Accidents.

A d m i n i s t r a t i v e ûrder No. PSS-13.01 Series of 1973 Civ i l A i r Regulations governing Accident Investigation ïhvolving C i v i l Aircraft.

Civil Aviation A c t : P a r t V. - Chapter t m > - Articles 50.2 and 550

Decree No. 20.062 - A i r Navigation Regulations: Chapter VIII.

The Qatar Aircraf t Accident Regulatiom. Qatar C i v i l Aviation Regulations.

Aviation L a w No. 591: Chapter M. - Investigation of Accidents (Article 114).

30/3/78 No. 8



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17-14 Manual of Aircraf t Accident Invest igat ion

LnWj A N S REQJMTICNS L - --- c0uNrr.Y

Repblic of South V i e t - N a m

Romania

Rwanda

Samoa

sa0 lbme and Principe

Saudi Arabia

Senegal

Seychelles

S ier ra Leone

DI, TE I

03.13.53

23.01.71

01-08.63

05.02.63

10.12.53

1966

Decree No, 516 - The A i r Code of t h e Romanian People's Republic, Amended by Decree No. 204 of 11 Hay 1956 (B.O. No. 15) and No. 212 of 20 June 1959 (B.O., No. 17) Chapter VI. - Search and Rescue of Civi l Aircraf t i n Distress - Handling of F l igh t Accidents and Incidents.

b i portant règlementation de 1 'aviation c i v i l e : T i t r e I. - Article 11. Des enquêtes; Titre II. - Dispositions pénales - A r t i c l e 17p).

C i v i l Aviation A c t No. 6/1963(l): Part VïII. - Accident Inquiry.

loi No. 63-19 portant Code l 'Aviation Civile; Livre I V - Du personnel navigant, Titre premier - Dispositions Générales, Chapitre 2 - de l a d i sc ip l ine (Articles 143 à 146).

Civ i l Aviation (Invest igat ion of Accidents) Regulations (P.N. 144/53).

C i v i l Aviation A c t No. 33/1966: P a r t II. 'Section 4. - Investigation of Accidents.

'i) According to Third Schedule to t h i s A c t , the New Zealand C i v i l Aviation (InVeStigati.On of Accidents) Regulations, 1953, and all subsequent amendments thereto s h a l l continue to have effect a s p a r t of the Law of Western Samoa.

3 3 / 5 / 7 7 No. 7



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APPENDIX 17.- List of Laws and Regulations 17-15

DATE

1966

1969

13.09.65

26003.67

21.06.62

15.11.63

2 1 . O 7.60

28.03.74

29 03.50

04 . O5 . 55

1960

LAWS AM) REWLATIONS

Air Navigation A c t : P a r t II. - 12. Power to provide for investigation of Accidents.

The Air Navigation (Investigation of Accidents) (Civil Aviation) Regulations.

Decree-Law No. 13 - Organization of Civi l Aviation: Chapter I. Corarinications and Transport w i t h regard to Civi l Aviation - Article 8. - Investigation.

Ruictions and Powers of the Minister of

Decree No. 86 of Ministry of C o d c a t i o n s and Transport - C i v i l Aviation Regulations: Acciduit Report.

Article 30. -

Aviation A c t No. 74/1962: Section 12. - Investigation of Accidents.

Air Navigation Regulations, G.N. No. R. 1779, as arcndu up to 8 May 1970: Chapter 29. - Investigation of Accidents .

Ley No 48 sobre Navegación Aérea: Cap. XVI. - De l o s accidentes, de l a asistencia y salvamento y de l o s hallazgos.

Decreto 959 del Ministerio del Aire sobre investigación e informe de los accidentes de aviación civil.

Air Navigation A c t No. 15/1950, a s amended: P a r t I. Section 12. - Power to provide f o r investigation in to accidents.

Civ i l Air Navigation Regulations: Chapter XVI. - Accident inquiry.

The Air A c t , No. 49/1960: Chapter V. - Accidents and Insurance .

30/3/78 No. 8



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17-16

Swaziland

Sweden

Sui tzerland

Syrian Arab Republic

Thailand

Tunisia

30/5/77 No. 7

DIblL

12 12 48

02 10.59

O1 .04.60

01.09.54

07.06.55

23.11.54


UtWS AND REG'JUTIOWS --.

The Suedish Aviation Act, No. 297-1957, came into force on 1 January 1962: Chapter 11 - Paras. 7-13 - Aircraft Accident Investigation. (Latest revision 28 Februaky 1974).

h i fédérale sur ia navigation aérienne (entrée en vigueur le 15 juin 1950): Articles 23-26.

Loi fédérale concernant les enquêtes sur les accidents d'aéronefs, modifiant la loi fédérale sur la navigation aérienne de 1948.

Ordonnance sur les enquêtes en cas d'aecidents d'aéronefs.

nie Air Nahgation Act, (&E. 2497): Chapter 7. - Accidents .(Sections 63 and 64).

Civil Air Regulations No. 3 - Aircraft Accident Inquiry.

ALr Navigation (Investigation of Accidents) Regulations (G.N. 205/54).



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APPENDIX 1 7 . - L i s t of Laws and Rc

COu‘NTRY

Turkey

Union of Soviet Sodalist Republics

unitecl Arab Emirates

i

United Kingdom Dependent Territories

DATE

1964

1965

24.11.49

25.10.68

17.06.69

06.10.69

ula t ions 17-1

LAWS ANI) REGCLATíOIJ.5 -

SHD - T.28 - Regulation concerning aircraft accident report..

SHD - T.29 - Regulation concerning aircraft accident investigation report.

SHD - S.41 - Regulation concerning investigation of civil aircraft accident..

The East African Civil Aviation Act.

East African Civil Aviation (Investigation of Accidents Regulation.

“he Civil Aviation Act (12 and 13 Geo. VI, ai. 6 7 ) : Part 11. - Section 10 - Investigation of Accidents. The Civil Aviation Act, Eliz. II, Ch. 61: Section 23. - Pmvisions relating to aircraft accidentr The Civil Aviation (Investigation of Accidents) Regulations, S.I. 1969 No. 833.

The A i r Navigation (Investigation of Combined Military and Civil Air Accidents) Regulations, S.I. No. 1437/1969.

Article 76 of the Colonial A i r Navigation O r d e r s , 1961 to 1968, and Section 10 of the Civil Aviation Act, apply Lthe laater by virtue of the Colonial Civil Aviation (Application of Act) Order, 1952, as aacnd47 to the undermentioned Territories:

Belize Bermuda Brit i sh Antarctic Territories British Indian Ocean Territory Solomon Islands

30/5/77 No. 7 -



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17-18 Manual of Aircraft Accident Investigatian

LACS .\Il!! RLC?J!ATIONS LC3hTP.Y

united Kingdom Dependent Terri tories (cuntd)

Beraaida

Gibraltar

Guernsey

Hong Kong

Jersey

St. Vincent

DI, TE

19 12. 53

18.12.48

03.0l.o 5 2

28.06972

1972

17.09.75

08.01. 53

cayman Islands Falkland Islands (ïíalvinas) G i bra1 tar G i l b e r t Islands Hong Kong e n t s e r r a t St. Helena and Ascension St. Vincent 'Ruks and Caicos Islands Virgin Islands

Air Nadqation (Investigation of Accidents) Regulations, S.1. 1/54. Aaiended by S.1. No. 7 of 1958**

Air Navigation (Investigation of Accidents) Regulations.'

Air Navigation (Investigation of Accidents) Regulations.

!ike C i v i l Aviation (Investigation of Accidents) O r d e r 1972, SI 1972 No. 962.

Air Navigation (Investigation of Accidents) Regulations.'

Rie C i v i l Aviation (Investigation of Accidents) Order 1975, S I 1975 No. 1516.

Air Navigation (Investigation of Accidents) Regulations, (S.R.O. No. 6/53]..

me text doesnot exist i n the files of ICAO.

30/3/78 No. 8



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APPENDIX 17.- List of Laws and Regulations 17-19

CrYJJJ:JT:Ls

United Republic of Cameroon

U n i t e d Republic of Tanzania

U n i t e d States

DATZ

05.11 . 63

1964

1965

1958

19 74

UWS AluïC REGUWTIONS

Law No. 63-35 - Civil Aviation Code: Section I - P a r t IV. - Accidents (Articles 62-64). Section IV - Part III. - Discipline.

The E a s t African Civil Aviation A c t .

E a s t African Civil Aviation (Investigation of Accidents Regulation.

Federal Aviation of 1958 as arpnded (Public Law 85-726; 72 Stat. 731; 49 U.S.C. 13011,

T i t l e V I 1 - Aircraft Accident Investigation

independent Safety Board A c t of 1974 (Public Law 93-633 88 Stat. 2166; 49 U.S. Code 1901).

U.S. Code of Federal Requlations - Title 49 Transportation

Part 800 - Organization and functions of the National Transportation Safety Board and delegations of authority (41 FR 39753, September 16, 1976).

P a r t 801 - Public avai lab i l i ty of information (41 PR 39755, Septeiber 16, 1976).

P a r t 830 - Rules pertaining to the not i f icat ion and reporting of a i r c ra f t accidents o r incidents and overdue aircraft, and preservation of aircraft wredtage, arail, cargo and records (40 FR 30249, July 17, 1975).

P a r t 831 - Rules of Practice i n a i r c r a f t accident/ incident investigations (40 FR 30250, July 17, 1975) .

P a r t 835 - 'kstimony of Board employees (40 FR 30253, July 17, 1975).

U.S, Code of Federal Regulations - T i t l e 22 - Foreiqn Relations

P a r t 102 - Civil Aviation - U,S. a i rc rdf t accidents abroad and foreign a i r c ra f t accidents involving U.S. persons or property ( 2 2 FR 10871, Deceinber 27, 1957).

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CWNTRY

Upper Volta

Venezuela

Yemen

Yugoslavia

Z a i r e , Republic of i

30/5/77 NO. 7

I

12 . 05.69

02.02.55

O1 . 04 55

18,06.54

01.07,54

UrWS h t ? D REGUIATIOrJS

Ordonnance no 69-O25/PRES/PLTP portant Code de l'Aéronautique Civile: lère Partie - Titre VI. - Des Enqu6tes sur les Accidents d'Aviation (Articles 96-104).

Decreto no 23.826 - Reglaaiento para la investigación de accidentes de aviación de carácter civil.

Ley de Aviación Civil: Cap. X, - De los accidentes y de la birsqueda y rescate.

Air Navigation Law (plblished in the Official Gazette of the Federal People's Republic of Yugoslavia. No, 12/65): IV. - Accidents, Search and Rescue.

Ait NavigaFon Regulations, as amended: Part XVIII. -

Aviation Act ( ~ h . A.L. 22, 1965 Edition):

Investigation of Accidents.

Section 4.íï) (5) and (t); Section 13 - inquiries,



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MANUAL O F A I R C R A F T A C C I D E N T I N V E S T I G A T I O N

A P P E N D I X 18

S E L E C T I O N AND T R A I N I N G OF A C C I D E N T I N V E S T I G A T O R S

AND

A C C I D E N T I N V E S T I G A T O R C O U R S E S A V A I L A B L E I N S T A T E S

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APPENDIX 18.- I n v e s t i g a t o r s ' S e l e c t i o n , T r a i n i n g and Courses 18-1

ARGENTINA

Select i o n C r i ter i a

No spec i f i c s e l e c t i o n c r i t e r i a .

T r a i n i n a

S h o r t i n t e r n a l t r a i n i n g c o u r s e s f o l l o w e d by on-the- job t r a i n i n g .

Periodical mee t ings a re h e l d t o s t a n d a r d i z e c r i te r ia and t o u p d a t e p r o c e d u r e s i n t h e l i g h t o f new i n v e s t i g a t i n g t e c h n i q u e s p rov ided by S t a t e s or I C A O .

An Aircraft Accident P r e v e n t i o n Course i s p r o v i d e d a n n u a l l y a t t h e C e n t r e f o r Basic and Advanced T r a i n i n g and Research, w i t h a d u r a t i o n of 30 days.

AUSTRAL1 A

S e l e c t i o n Cr i te r ia

Essen t i a l

- a s t r o n g m o t i v a t i o n towards a v i a t i o n safety i n v e s t i g a t i o n work

- a n a p t i t u d e f o r i n v e s t i g a t i v e e n q u i r y and a sound approach t o problem s o l v i n g

- c o n s i d e r a b l e e x p e r i e n c e i n the A u s t r a l i a n c i v i l a v i a t i o n i n d u s t r y

- a p p r o p r i a t e manner i n d e a l i n g w i t h p e o p l e , i n c l u d i n g t h e a b i l i t y t o commun i c a t e re ad i 1 y

- either ho ld o r have h e l d a Commercial P i l o t L icence or e q u i v a l e n t and p o s s e s s wide e x p e r i e n c e as a p i l o t i n c l u d i n g some of t he f o l l o w i n g :

3 O00 h o u r s p i l o t t u r b i n e mult i - e n g i n e t r a n s p o r t g e n e r a l a v i a t i o n ( l i g h t a i r c r a f t ) h e l i c o p t e r i n s t r u c t ing/check i n g Chief P i l o t /OPS Manager VFR and IFR

- o r c o n s i d e r a b l e e x p e r i e n c e a s a p i l o t p l u s o t h e r r e l e v a n t t e c h n i c a l / t e r t i a r y - q u a l i f i c a t i o n s and e x p e r i e n c e

- a p p r o p r i a t e t e c h n i c a l knowledge of a i rc raf t performance and l i m i t a t i o n s

17/10/86 No. 1 O Copyright International Civil Aviation Organization


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18-2 Manual of Aircraft Accident I n v e s t i g a t i o n

AUSTRALIA (cont'd)

H i R h l V desirable

- Hold o r have h e l d a S e n i o r Commercial P i lo t L icence or e q u i v a l e n t

- C u r r e n t c i v i l p i l o t l i c e n c e s and r a t i n g s

- A b i l i t y t o write c o n c i s e , l u c i d and l o g i c a l r e p o r t s

Note: A p p l i c a n t s selected f o r i n t e r v i e w a re tes ted f o r a d m i n i s t r a t i v e a p t i t u d e .

Note: It is i m p o r t a n t t h a t an I n s p e c t o r ( A i r S a f e t y ) b e p h y s i c a l l y f i t and a c t i v e and tha t he does n o t s u f f e r any p h y s i c a l d i s a b i l i t y which might impede the s a t i s f a c t o r y performance o f h i s d u t i e s o r .which might p u t him i n dange r i n a remote l o c a t i o n .

Trai n i n g

On j o i n i n g t h e Bureau o f A i r Safety I n v e s t i g a t i o n , i n v e s t i g a t o r s a r e t r a i n e d i n t h e f i e l d by e x p e r i e n c e d i n v e s t i g a t o r s . c o u r s e s a t t h e Bureau i n Canber ra , A u s t r a l i a . These c o u r s e s i n c l u d e :

I n v e s t i g a t o r s are a l s o g i v e n formal '

- Basic I n v e s t i g a t i o n - two weeks

- Human F a c t o r s i n Accident I n v e s t i g a t i o n - one week

- Advanced I n v e s t i g a t i o n - one week

- Major Accident I n v e s t i g a t i o n Management - o n e week

- Selected c o u r s e s r u n by A u s t r a l i a n Av ia t ion I n d u s t r y

- Automatic Data P r o c e s s i n g

Courses conducted by t h e Bureau a r e open t o o f f i ce r s from a v i a t i o n d e p a r t m e n t s o f o t h e r c o u n t r i e s on request. p a r t i c i p a t i n g c o u n t r i e s a r e expected t o meet the c o s t s of fares and ac commod a t i on .

There is no charge f o r c o u r s e t u i t i o n b u t

A l l c o u r s e s a r e conducted i n E n g l i s h .

Sen io r Bureau s taff a t t e n d selected o v e r s e a s c o u r s e s as r e q u i r e d and p a r t i c i p a t e ' a s o b s e r v e r s i n o v e r s e a s a c c i d e n t i n v e s t i g a t i o n s by i n v i t a t i o n .

17110186 No. 1 O



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AUSTRIA

S e l e c t i o n C r i ter i a

I n v e s t i g a t o r s f o r o p e r a t i o n s , e n g i n e e r i n g , a i r t r a f f i c c o n t r o l and meteorology are selected by a comniicsion o f t h e M i n i s t r y of P u b l i c Economy and T r a n s p o r t , Department of C i v i l A v i a t i o n . They must have a h i g h s t a n d a r d o f knowledge i n t h e i r special f i e l d s ,

T r a i n i n a

P r i o r t o t h e :'irst i n v e s t i g a t i o n , t h e selected i n v e s t i g a t o r must p a r t i c i p a t e a t a cour se he13 cr accredi ted by t h e M i n i s t r y , whereby a n i n t r o d u c t i o n is made i n t o t h e Auct; , ian sys tev <if a::cìr:ent i n v e s t i g a t i o n , i n c l u d i n g law, methods o f iiivestiggat , i x L . ~ ~ e h t a t i í ~ ~ , photography, w r i t i n g of f i n a l r e p o r t s , e tc .

F u r t h e r , t9i? sslect,e! in:rcatigr-itor is t r a i n e d on t h e job as a d v i s e r , as member o f aìi i n v e s t i g a t i o n group anci f i n a l l y a s t h e i n v e s t i g a t o r i n c h a r g e .

BARBADOS

T r a i n i nR

Sefiior aviatiari p e r s o n n e l have been g i v e n s p e c i a l i z e d a c c i d e n t i n v e s t i g a t i o n and p r e v e n t i o n t r a i n i n g i n the U n i t e d Kingdom, U . S . A . and Sweden. A f u r t h e r programme o f s p e c i a l i z e d and f i e l d t r a i n i n g is b e i n g a r r a n g e d .

BELGIUM

Accident i n v e s t i g a t o r s a r e s e n t ab road f o r t r a i n i n g .

B E N I N

Trai n i n a

O u r a c c i d e n t i n v e s t i g a t o r has a t t e n d e d the a c c i d e n t i n v e s t i g a t i o n c o u r s e h e l d a t t h e B e i r u t C i v i l Aviat ior i S a f e t y C e n t r e .

17/10/86 No. 1 O Copyright International Civil Aviation Organization


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BOLIVIA

Select i o n C r i t e r i a

The a p p l i c a n t must:

- Have a prac t ica l knowledge of a v i a t i o n and of the f a c t o r s i nvo lved i n a i r c r a f t o p e r a t i o n s i n g e n e r a l .

- Be a commercial p i l o t o r have expe r i ence i n s p e c i a l i z e d a e r o n a u t i c a l f i e l d s .

- Be s u i t a b l e f o r t h e d u t i e s i nvo lved .

- Have a p t i t u d e for t h i s t y p e o f work.

- B e i n e x c e l l e n t p h y s i c a l c o n d i t i o n .

T r a i n i n g

The t r a i n i n g o f i n v e s t i g a t o r s is g iven a t Regional I n s t r u c t i o n C e n t r e s , s i n c e B o l i v i a d o e s n o t have t h e r e q u i r e d t y p e o f f a c i l i t i e s a t t h e p r e s e n t time.

S e l e c t i o n Cri ter ia

Genera l

A l l courses a re open t o government p e r s o n n e l , c i v i l i a n or m i l i t a r y , a n d t o employees o f a v i a t i o n - r e l a t e d companies.

S p e c i f i c

a. F l i g h t S a f e t y Course - To h o l d a v a l i d commercial p i l o t l i c e n c e , o r - To have a n e x t e n s i v e background as a n a i r c ra f t ma in tenance e n g i n e e r .

b. Human F a c t o r s Course - To be a medical d o c t o r o r a p s y c h o l o g i s t .

c. Material F a c t o r s Course - To ho ld a n e n g i n e e r i n g degree or have a n e x t e n s i v e background as a n

a i r c r a f t maintenance e n g i n e e r .

T r a i n i n g

After complet ion of one o f t he sa fe ty c o u r s e s , t r a i n i n g is conducted on a n

Southern C a l i f o r n i a ( . U . S . A . ) , C r a n f i e l d In s t i t u t e of Technology ( U . K . ) , Royal I n s t i t u t e of Technciogy (Sweden) and o t h e r s c h o o l s .

b a s i s . F u r t h e r t r a i n i n g is a l s o conducted a t t h e U n i v e r s i t y of

17/10/8Ó No.10



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BRAZIL (cont'd)

I n ves t i gat i on Cours es Ava i 1 a b l e

F l i g h t S a f e t y Course

H e l d a n n u a l l y a t the Aircraft Acc iden t I n v e s t i g a t i o n and P r e v e n t i o n C e n t e r (CMIPA). I t is a six-week c o u r s e c o v e r i n g t h e areas of S a f e t y Management, M a t e r i a l s , Human Factors, Environmental F a c t o r s and Accident I n v e s t i g a t i o n .

Human F a c t o r s Course

X e l d a n n u a l l y a t t he Aircraft Accident I n v e s t i g a t i o n and P r e v e n t i o n C e n t e r ( C E N I P A ) . I t is a one-week c o u r s e and c o v e r s the areas o f Phys io logy , Psychology and tne r e l a t i o n s h i p of these s u b j e c t s t o t h e advancement o f safety.

M a t e r i a l F a c t o r s Course

H e l d anr iual ly a t the Aircraft Accident I n v e s t i g a t i o n and P r e v e n t i o n C e n t e r ( C E N I P A ) . I t is a one-wepk c o u r s e and c o v e r s t h e areas o f S t r u c t u r e s , Systems, R e c i p r o c a t i n g and J e t e n g i n e s , and Accident P r e v e n t i o n i n t h e Maintenance Environment.

A l : c o u r s e s are g iven i n P o r t u g u e s e and are open t o f o r e i g n s t u d e n t s , a t t e n d a n c e be ing l i m i t e d t o a b o u t 60 s t u d e n t s . A p p l i c a t i o n s shou ld be made t h r o u g h t h e B r a z i l i a n Air Force Attachés a t t h e B r a z i l i a n Embassies or d i r e c t l y t o :

C E N I PA Min ist 6r i o da Aeronau ti ca Anexo - l o a n d a r 70045 - Brasi l ia - Brasil

BULGAR1 A

T r a i n i n g

The t n i n i n g o f pe:.sons wiio p a r t i c i p a t e i n a c c i d e n t i n v e s t i g a t i o n takes p i ace ab road .

CAMEROON

17/10/86 No.lL7 Copyright International Civil Aviation Organization


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18-6 Man u a l of A i r craf t Acci d e n t I n ves t i g a t i on

CAMEROCN (cont'd)

When n e c e s s a r y , the Commission is p r e s i d e d ove r by the Director o f C i v i l A v i a t i o n and is composed of r e p r e s e n t a t i v e s of d i f f e r e n t a d m i n i s t r a t i o n s , such as N a t i o n a l Defence, PTT, T e r r i t o r i a l A d m i n i s t r a t i o n , Jus t i ce , P u b l i c Health, I n t e r n a l S e c u r i t y , N a t i o n a l Gendarmerie, N a t i o n a l Documentation C e n t r e , Agency f o r the S e c u r i t y of Aerial Nav iga t ion i n Africa and Madagascar (ASECNA) , Bureau Véritas, and Cameroon A i r l i n e s .

T r a i n i n a

C i v i l A v i a t i o n o f f i c i a l s are t r a i n e d a t f o r e i g n s c h o o l s and i f n e c e s s a r y a t t e n d a c c i d e n t i n v e s t i g a t i o n c o u r s e s o r g a n i z e d i n d i f f e r e n t c o u n t r i e s under, t h e a u s p i c e s of I C A O .

CANADA


I n v e s t i g a t o r p o s i t i o n s f i l l e d have spec i f ic p r e - a s s i g n e d d u t i e s i d e n t i f i e d i n r e s p o n s e t o Canadian A v i a t i o n S a f e t y Board r e q u i r e m e n t s . I n v e s t i g a t o r s are selected i n competi t i o n for these p o s i t i o n s from p e r s o n s h a v i n g e x t e n s i v e e x p e r i e n c e i n one of t h e r e q u i s i t e a v i a t i o n s p e c i a l i t i e s i n c l u d i n g a i r c ra f t o p e r a t i o n s , ma in tenance /ove rhau l , e n g i n e e r i n g , a i r t r a f f i c c o n t r o l o r medicine. A l l p e r s o n n e l shou ld have p r e v i o u s e x p e r i e n c e i n a v i a t i o n sa'ety and must have c i v i l l i c e n c e s or s o c i e t y memberships i n t h e i r p a r t i c u l a r f i e l d , O p e r a t i o n s s t a f f are r e q u i r e d t o ho ld v a l i d fixed-wing A i r l i n e T r a n s p o r t P i l o t o r r o t a r y wing Commercial P i l o t L i c e n c e s w i t h Class I i n s t r u m e n t r a t i n g s . G e n e r a l l y , p o s i t i o n s are c l a s s i f i e d as o p e r a t i o n s o r t e c h n i c a l . T e c h n i c a l s t a f f normally perform f i e l d and l a b o r a t o r y s u p p o r t f u n c t i o n s . A l l i n v e s t i g a t o r s m u s t have r e p o r t - w r i t i n g a b i l i t i e s . S u c c e s s f u l c a n d i d a t e s are permanent ly employed and s h a l l no t have c o n f l i c t i n g i n t e r e s t s .

T r a i n i n g

New employees r e c e i v e on-the- job t r a i n i n g . F i e l d i n v e s t i g a t o r s take bas ic and advanced i n v e s t i g a t o r c o u r s e s p rov ided b y r ecogn ized c i v i l i n s t i t u t i o n s . S p e c i a l i s t , v o c a t i o n a l and p e r s o n a l development t r a i n i n g a r e p rov ided on an as-needed basis and f r e q u e n t l y i n c l u d e s p e c i a l t y a i r c ra f t , management and language t r a i n i n g . I n v e s t i g a t o r s a r e p rov ided w i t h t h e f a c i l i t i e s t o m a i n t a i n t h e i r c i v i l l i c e n c e s and memberships.

I n v e s t i g a t i o n c o u r s e s a v a i l a b l e

Only in-house c o u r s e s a r e b e i n g conducted a t p r e s e n t . Advanced i n v e s t i g a t i o n - r e l a t e d c o u r s e s w i l l b e developed and o f f e r e d t o i n t e r e s t e d p a r t i e s i n t h e f u t u r e .

171 1 O í 8 6 No. 1 O Copyright International Civil Aviation Organization


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APPENDIX 18.- I n v e s t i g a t o r s ' S e l e c t i o n , T r a i n i n g and C o u r s e s 18-7

CENTRAL AFRICAN REPUBLIC

T r a i n i n g

No t r a i n i n g c o u r s e s a re a v a i l a b l e . i n v e s t i g a t o r t r a i n i n g or a t t e n d e d a n i n v e s t i g a t o r course.

No c i v i l a v i a t i o n o f f i c i a l has r e c e i v e d

CHILE


C a n d i d a t e s a re selected from Officers of t h e C h i l e a n Air F o r c e on t h e b a s i s of t h e i r a e r o n a u t i c a l e x p e r i e n c e and knowledge.

T r a i n i n g

The Directorate G e n e r a l of C i v i l A v i a t i o n has a t p r e s e n t two a i r c r a f t a c c i d e n t i n v e s t i g a t o r s who were t r a i n e d a b r o a d and o b t a i n e d t he i r q u a l i f i c a t i o n s a t t r a i n i n g c e n t r e s r e c o g n i z e d by I C A O .

T r a i n i n g h a s o n l y been g i v e n on t h e g e n e r a l a s p e c t s of a c c i d e n t i n v e s t i g a t i o n d u r i n g advanced c o u r s e s f o r a i r p o r t a d m i n i s t r a t o r s h e l d a t t h e E s c u e l a T é c n i c a A e r o n á u t i c a d u r i n g 1972, 1973 a n d 1974.

COTE D ' I V O I R E

T r a i n i n g

Our a c c i d e n t i n v e s t i g a t o r was t r a i n e d a t t h e B e i r u t C i v i l A v i a t i o n S a f e t y C e n t r e i n Lebanon. He a l s o a t t e n d e d c o u r s e s a t t h e Paris Acc iden t I n v e s t i g a t i o n Bureau and a t I C A O H e a d q u a r t e r s i n M o n t r e a l .

CYPRUS

S e l e c t i o n Cr i t e r i a

I n a c c o r d a n c e w i t h t h e Cyprus l e g i s l a t i o n , t he M i n i s t e r o f Communicat ions and Works makes t h e a p p o i n t m e n t s of t h e a c c i d e n t i n v e s t i g a t o r s . The c r i t e r i a used f o r t h e s e l e c t i o n of i n v e s t i g a t o r s are m a i n l y e x t e n s i v e e x p e r i e n c e i n v a r i o u s f i e l d s of c i v i l a v i a t i o n , i . e . a i r t r a f f i c c o n t r o l , a i r crew o p e r a t i o n s and a i r p o r t managemen t .

T r a i n i n g

I n v e s t i g a t o r s a t t e n d the a c c i d e n t i n v e s t i g a t i o n c o u r s e h e l d a t t h e B e i r u t C i v i l A v i a t i o n S a f e t y C m t r e . _____- - -

Ncl.10 Copyright International Civil Aviation Organization Provided by IHS under license with ICAO


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I 8-8 Manual of Aircraft Accident I n v e s t i g a t i o n

CZECHOSLOVAKIA

Trai n i ng

From time t o t ime, courses and t r a i n i n g of acc ident i n v e s t i g a t o r s and o t h e r s p e c i a l i s t s involved i n acc iden t i n v e s t i g a t i o n are organized. These courses are provided f o r n a t i o n a l s or, ly, i n t h e Czech and Slovak languages.

DEMOCRATIC YEMEN

Train ing

Accident i n v e s t i g a t o r s a r e s e n t abroad f o r t r a i n i n g .

S e l e c t ion C r i t e r i a

The Department of Accident I n v e s t i g a t i o n ( D A I ) r e c r u i t s personnel w i t h ex tens ive knowledge of a v i a t i o n , and admin i s t r a t ive and t echn ica l /ope ra t iona l experience, The members must have a p ro fes s iona l p i l o t background and/or t e c h n i c a l q u a l i f i c a t i o n s from many years of experience in t he c i v i l or m i l i t a r y f i e l d . Also, p r i o r educa t ion and experience i n acc ident i n v e s t i g a t i o n is requi red . A p rescr ibed s tandard of medical f i t n e s s i s requi red .

Tra in ing

Addi t iona l t o the q u a l i f i c a t i o n s requi red , the i n v e s t i g a t o r s a re f u r t h e r t r a i n e d a t t h e U . K . A I B school , Col lege of Aeronautics, Cran f i e ld I n s t i t u t e of Technology in England, and J e t Engine Inves t iga t ion Course, Chanute A i r Force Base, U . S . A . P a r t i z i p a t i o n at nanufac turer l e v e l and company schools of s p e c i f i c a i r c r a f t .

Ir? vest i aa t i on Cours e s Avai 1 a bl e

N C j such f a c i l i t i e s a r e i iva i lab le i n Denmar’i:.

ECUADOR

I Se lec t ion and Tra in ing

Ai rc ra f t acc i d e r i t i m e s t . i g d t o r s a r e s e l e c t e d from t e c h n i c a l f l i g h t ope ra t ions w i s o n n e l . T r a i n 1 r . g i.? c.’v:>n at spec ia l i zed c e n t r e s abroad. - -. - -- - -- - . . . -. ,. - -__ - ____̂ .-~_--._II._ __---- ”-

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ECY PT

Select i o n C r i t er i a

Exper i ence i n one or more a e r o n a u t i c a l f i e ld s , t o g e t h e r w i th some p r e l i m i n a r y e x p e r i e n c e i n a c c i d e n t i n v e s t i g a t i o n .

T r a i n i n g

Accident I n v e s t i g a t o r s r e c e i v e t h e o r e t i c a l t r a i n i n g a t t h e B e i r u t C i v i l A v i a t i o n Safety C e n t r e .

E L SALVADOR

S e l e c t i o n and t r a i n i n g

E l Sa lvador is no t i nvo lved i n s e l e c t i o n and t r a i n i n g o f a i r c r a f t a c c i d e n t i n v e s t i g a t o r s . Courses f o r a i r c ra f t a c c i d e n t i n v e s t i g a t o r s are o f f e r e d a t the t r a i n i n g c e n t r e s C I A A C i n Mexico and C I P E i n Argen t ina .

ETHIO P I A


C a n d i d a t e s a re selected from F l i g h t O p e r a t i o n s I n s p e c t o r s and A i r w o r t h i n e s s I n s p e c t o r s .

T r a i n i n g

Accident i n v e s t i g a t o r s r e c e i v e t r a i n i n g a t r e c o g n i z e d t r a i n i n g i n s t i t u t i o n s .

F I N L A N D


When s e l e c t i n g a c c i d e n t i n v e s t i g a t o r s , e x p e r i e n c e and t h e o r e t i c a l knowledge of f l i g h t o p e r a t i o n s o r a e r o n a u t i c a l e n g i n e e r i n g are r e q u i r e d t o g e t h e r w i t h a n o v e r - a l l knowledge of a v i a t i o n .

T r a i n i n g

On-the-job t r a i n i n g combined w i t h s u i t a b l e c o u r s e s i n o t h e r c o u n t r i e s .

Courses a r e h e i d i n F i n l a n d on spec i f ic a i r c r a f t t y p e s and on a c c i d e n t i n v e s t i g a t i o n i n g e n e r a l .



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GERMANY, FEDERAL R E P U B L I C OF

S e l e c t i o n C r i t e r i a

Accident i n v e s t i g a t o r s are members o f t h e Accident I n v e s t i g a t i o n Bureau ( A I B ) of t h e Luftfahrt-Bundesamt ( F e d e r a l Off ice of C i v i l A e r o n a u t i c s ) . They r e q u i r e a p p r o p r i a t e q u a l i f i c a t i o n s and e x p e r i e n c e i n a v i a t i o n e n g i n e e r i n g and /o r f l i g h t 0pe ra t i . ons . The German A I B employs expe r t s i n t h e f i e l d s o f a i r w o r t h i n e s s , f l i g h t performance, e n g i n e s , e l e c t r o n i c s and other sys t ems , f l i g h t o p e r a t i o n s , e t c .

T r a i n i n a

Xewly employed i n v e s t i g a t o r s a r e t r a i n e d sfon the job" a s there a r e no s p e c i f i c AI(; c o u r s e s p rov ided . However, i n v e s t i g a t o r s a re a b l e ' t o m a i n t a i n t he i r f l y i n g p r o f i c i e i i cy arid t o a t t e n d t e c h n i c a l and o p e r a t i o n a l s e m i n a r s , c o u r s e s p rov ided by c i the r i m a n u f a c t u r e r s o r t e c h n i c a l i n s t i t u t i o n s , and i n t e r n a t i o n a l t r a i n i n g schools f o r i n v e s t i g a t o r s .

I n v e s t i gat i on c o u r s e s a v a i 1 a b l e

Triere a r e no f a c i l i t i e s a v a i l a b l e i n the Federal R e p u b l i c o f Germany f o r t h e t r a i t ì i n g of f o r e i g n s t u d e n t s desir ing t o q u a l i f y as a c c i d e n t i n v e s t i g a t o r s . However, there is a l i m i t e d c a p a c i t y f o r on-the- job t r a i n i n g o f f o r e i g n c a n d i d a t e s who have a l r e a d y r e c e i v e d basic t h e o r e t i c a l t r a i n i n g . The minimum d u r a t i o n of such on-the- job t r a i n i n g would b e two months. C a n d i d a t e s would b e r e q u i r e d t o speak e i ther German a r Eng l i sh .

GHANA


Crrndidates must have a i r c r a f t e n g i n e e r i n g and f l y i n g e x p e r i e n c e .

T r a i n i n n

Selected c a n d i d a t e s a t t e n d the Accident I n v e s t i g a t i o n a n d P r e v e n t i o n c o u r s e a t the B e i r u t C i v i l A v i a t i o n S a f e t y Centre.

GREECE


Accident i n v e s t i g a t o r s s p e c i a l i z i n g i n o p e r a t i o n a l a s p e c t s a r e expe r i enced m i l i t a r y o r c i v i l i a n p i l o t s o r e x - p i l o t s .

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APPENDIX. : 8 . - s Inves t iga to r s ' S e l e c t i o n , T ra in ing and Courses 18-11

GREECE ( con t ' d )

Accident i n v e s t i g a t o r s s p e c i a l i z i n g i n engineer ing a s p e c t s are a e r o n a u t i c a l engineers .

Tra in inn

P r inc ipa l i n v e s t i g a t o r s r ece ive i n i t i a l t r a i n i n g a t t h e B e i r u t C i v i l Aviat ion Safe ty Centre . They a l s o a t t e n d seminars , s h o r t courses and f a m i l i a r i z a t i o n courses i n o t h e r S t a t e s . Tra in ing of o t h e r i n v e s t i g a t o r s is ar ranged p w i o d i c a l l y , a t home or abroad; t h e courses inc lude p i l o t and engineer ing d3pe; t s a ? i n v e s t i g a t i o n . Authority for t h e 1:3aining of n a t i o n a l s only. Basic o r s p e c i a l i z e d courses are provided i n Greek and Engl ish.

Ad hoc arrangements are made wi th in t h e C i v i l Aviat ion

GUATEMALA


Basic q u a l i f i c a t i o n s

- Possess commercial p i l o t l i c e n c e w i t h not less than 500 .hours of f l y i n g time.

- Be a l i censed f i r s t c l a s s a i r c r a f t mechanic and an in spec to r of a i r c r a f t i n gene ra l .

- Eave experience i n one a r more of the fo l lowing f i e l d s : a i r t r a f f i c c o n t r o l , a i rwor th iness , and f l i g h t ope ra t ions .

- Personal requirements: Pa t i ence , capac i ty f o r l o g i c a l thought , and s k i l l in d r a f t i n g d e t a i l e d r e p o r t s .

Tra in ing

T+a i ri i r! g ~ - I

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HUNGARY


The a p p l i c a n t must :

- be a h o l d e r of a h igh -degree a e r o n a u t i c a l q u a l i f i c a t i o n ,

- be a n a e r o n a u t i c a l i n s t r u c t o r , and

- have completed a n a c c i d e n t i n v e s t i g a t i o n c o u r s e a r r a n g e d by a C i v i l A v i a t i o n I n s t i t u t e .

I N D I A


Two y e a r s ' a p p r e n t i c e s h i p o r a n e q u i v a l e n t t r a i n i n g i n a e r o n a u t i c a l e n g i n e e r i n g i n a r ecogn ized Fac to ry or work engaged i n t h e manufacture or repair and ove rhau l of a i r c ra f t a n d / o r e n g i n e s .

E ight y e a r s ' p rac t ica l e x p e r i e n c e i n the manufac tu re or r e p a i r and ma in tenance o f a i r c ra f t and/or e n g i n e s .

About f i v e y e a r s ' e x p e r i e n c e i n t h e i n v e s t i g a t i o n o f a i r c r a f t a c c i d e n t s , i n c l u d i n g mul t i - eng ined a i r c ra f t .

Exper i ence as a p i l o t of which a t l eas t some e x p e r i e n c e shou ld have been w i t h i n t h e l a s t two y e a r s .

Must have h e l d a p o s i t i o n o f r e s p o n s i b i l i t y i n the c o n t r o l o f manufac tu re o r i n s p e c t i o n of a i r c ra f t .

Experience i n t h e a d m i n i s t r a t i o n of a n a c c i d e n t i n v e s t , i g a t i o n o r g a n i z a t i o n which would p e r m i t t h e d i r e c t i n v e s t i g a t i o n of major a c c i d e n t s t o c i v i l a i r c r a f t i n acco rdance w i t h i n t e r n a t i o n a l s t a n d a r d s .

IRAQ - Select i o n C r i t e r i a

C a n d i d a t e s a re e n g i n e e r s h o l d i n g B.S. Cer t i f ica tes o f mechan ica l , a e r o n a u t i c a l and e l e c t r i c a l e n g i n e e r i n g .

T r a i n i n g

Selected c a n d i d a t e s a r e s e n t t o t h e B e i r u t C i v i l A v i a t i o n S a f e t y C e n t r e , C r a n f i e l d I n s t i t u t e of Technology, U . K . , and Royal I n s t i t u t e of Technology, Sweden.

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APPENDIX 18.- I n v e s t i g a t o r s ' S e l e c t i o n , Tr.aining and Courses 18-1 3

IRELAND

Se lec t ion C r i t e r i a

- Aeronaut ical engineer ing o r p r o f e s s i o n a l pilot..

- A t l e a s t 10 years' experience i n a v i a t i o n .

Tra in ina

A t courses a v a i l a b l e i n o the r States .

T r a i n i n a

A t courses a v a i l s a l e I n o tne r S t a t e s , mainly the U.S. FAA/NTSB course .

ITALY

Select ion C r i ter i a

The c r i t e r i a f o r s e l e c t i n g the members of the I n v e s t i g a t i n g Commissions depend on the t y p e of a i r c r a f t involved and t h e circumstances of t h e acc iden t .

A s a r u l e , I n v e s c i g i t i n g Commissions are made up a s fo l lows:

CFL~imar! [ s e i e ? t e d Lrom ci v i l a v i a t i o n o f f i c i a l s )

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ITALY (cont 'd) - Trai n i ng

An annual two-month Fl ight Safety course i s held by Mil i tary Aviation Authorit ies. T h i s course is attended by c i v i l av ia t ion o f f i c i a l s and covers t h e following subjects : accident invest igat ion and prevention; incident procedures; a i r t r a f f i c safety; incident experience; t h e mechanics of f l i g h t ; chemical research; f i r e f i g h t i n g services; aviat ion medicine and av ia t ion psychology.

JAPAN

Select ion C r i t e r i a --c

Candidat es must :

1 ) have a good general education with sound mind and body. the I C A 0 o f f i c i a l languages is an advantage.

Proficiency i n one of

2 ) be able t o analyse the f a c t s i n a i r c r a f t accident invest igat ion and be able t o write logical repor t s .

3 ) i n addi t ion, have a t l e a s t one of t h e following qua l i f ica t ions :

- Being qua l i f ied as Airman Licensing Examiner, P i lo t Check Airman, F l igh t Inspector, Ai rcraf t Evaluation Engineer or Air Traf f ic Controller w i t h over i O years experience ;

- Being qua l i f ied as Senior P i lo t w i t h over 10 years ' experience o r having over 10 years ' experience a f t e r completion of an Aircraf t Maintenance Officer Course (Self-Defense Forces);

- Having over 6 O00 f i y i n g hours' experience a s a p i l o t . Five years ' experience a s captain i n l a rge j e t t ransport a i r c r a f t is an advantage;

- Being qua l i f ied as F i r s t Class Aircraf t Mechanic, Airport Dispatcher or F i r s t Class Technical Radio Operator with over 1 O years ' experience;

- Having graduated from university majoring i n a i r c r a f t engineering, mechanical engineering, e l e c t r i c a l engineering, medical science, e t c . , w i t h over 10 years ' experience i n associated aviat ion f i e l d s .

Training

To maintain up-to-date knowledge, the Accident Invest igators s t u d y the S t ruc ture and performance of various k i n d s of a i r c r a f t , Also, invest igat ion techniques on many specialized subjects , such as f i i g n t recorders, human fac tors and observations on f rac ture a reas a r e taught. U.S. National Aircraf t Accident Investigation School.

Inves t iga tc rs a r e a l s o sen t t o the

-_---I_---

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A P P E N D I X 18.- I n v e s t i g a t o r s ’ S e l e c t i o n , T ra in ing and Courses 18-1 5

JORDAN

Se lec t ion Cr i te r ia

Accident I n v e s t i g a t o r s a re s e l e c t e d from Airworthiness . and .. Operat ions Inspec to r s and A i r Traf f ic C o n t r o l l e r s .

. . Train ing

A t courses a v a i l a b l e i n o the r S t a t e s .

KENYA


Accideat i n v e s t i g a t o r s art : se lect ,ed from Airworthiness I n s p e c t o r s , 0peration.s O f f i c e r s , P i l o t s , Ndvigators and Air Traf f ic Con t ro l l e r s . .

. . Traifiing

A t caurses avai lahi t? i n . o the r States. _-I-_______

LEBANON


kccidrnt i n v e s t i g a t o r s a r c s e l e c t e d from cand ida te s w i t h long experience i n a v i a t i o n .

Tra in ing __-_-__-

- t h e L e i r 1 . i t C i ~ i . ì Aviat ion Safe ty Cent re ,

..- Pi.? 5 . S . NCitl~)r?al AI r~ ra f t Acciderìt I n v e s t i g a t i o n School ,

- t P e Ir?stit!.:tc! of A v ; n t . i m Safet.y - Royal I n s t i t u t e of Technology, Sweden.

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18-16 Man ua 1 of A i r craf t Ac c i d e n t I n v e s t i gat i on

LEBANON (cont'd)

S e c t i o n 1 . - I n t r o d u c t i o n

- Purpose and scope of a c c i d e n t i n v e s t i g a t i o n - Article 26 of t h e Convent ion and Annex 13 . N a t i o n a l r e g u l a t i o n s . - Legal p o s i t i o n s .of i n t e r e s t e d par t ies . - Appointment o f s p e c i a l i s t s t a f f . - I n t r o d u c t i o n t o t h e I C A 0 Manual of Aircraft Accident I n v e s t i g a t i o n .

S e c t i o n 2. - Pre-Accident O r g a n i z a t i o n

- N e c e s s i t y for h a v i n g agreed "crash p rocedures" . - P r e s e r v a t i o n of wreckage. - Impounding of a l l recorded ev idence . - i n s t i t u t i o n of t h e i n v e s t i g a t i o n .

S e c t i o n 3. Method of Conduc t ing an I n v e s t i g a t i o n

I n t r o d u c t i o n . Conducting t he p r e l i m i n a r y su rvey . Photographic r e c o r d s and wreckage p l o t . Planning the i n v e s t i g a t i o n . C o l l e c t i o n of impounded and o t h e r r e l e v a n t documents. Examinat i o n s o f w i t n e s s e s . Wr e c kag e ex amin a t ion . St r u c t u r a l fa i l u r e . Post-mortem and medical examina t ions .

S e c t i o n 4. - The Accident Repor t

- E s s e n t i a l c o n t e n t s of the Repor t . - D i s c l o s u r e of a c c i d e n t i n v e s t i g a t i o n i n f o r m a t i o n i n cases o f l i t i g a t i o n .

S e c t i o n 5. - Accident P r e v e n t i o n P rocedures

- Review o f t h e c u r r e n t s i t u a t i o n . - Accident p r e v e n t i o n t e c h n i q u e s adop ted b y S t a t e s . - Accident p r e v e n t i o n t e c h n i q u e s adop ted by o p e r a t o r s . - Accident p r e v e n t i o n t e c h n i q u e s adopted b y manufac tu re r s .

MALAWI


Accident I n v e s t i g a t o r s a p p o i n t e d by t h e Director of C i v i l A v i a t i o n a r e e x p e r i e n c e d p i l o t s , a i r c ra f t e n g i n e e r s or O p e r a t i o n s Officers.

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APPENDIX 18.- I n v e s t i g a t o r s ' S e l e c t i o n , T r a i n i n g and Courses 18-17 -

MALAWI ( cont d)

T r a i n i n g

On-the-job. t r a i n j i n g and , i n t he f u t u r e , c o u r s e s p r o v i d e d by other States .

MALAYS1 A

S e l e c t i o n Cr i t e r i a --I-

Accident i n v e s t i g a t w c a re selected from f l i g h t o p e r a t i o n s p e r s o n n e l and a i r wor t h inesc su rveyor s .

T r a i n i n g

Accident i n v e s t i g a t o r s receive basic t r a i n i n g a t ICAO-sponsored c o u r s e s i n Manila ( P h i l i p p i n e s ) ô.nd a t C r a n f i e l d ( U n i t e d Kingdom).

MALDI VES


No s p e c i f i c s e l e c t i o n c r i t e r i a l a i d down so f a r . I n c i d e n t s and a c c i d e n t s w i l l be i n v e s t i g a t e d by t h e A i r S a f e t y S e c t i o n .

M A U R I T I U S

S e l e c t i o n Cr i t e r i a and T r a i n i n g

No a c c l d q i t I n v e s t i g a t o r is a p p s i n t e d on a permanent b a s i s . The D i r e c t o r o f C i v i l A v i a t i o n will appoint . t h e n o s t e x p e r i e n c e d o f f i c e r o r team o f o f f i c e r s t o carr'y out an i n v e s t l g a t i o n i f and when r e q u i r e d . Accident I n v e s t i g a t i o n and ?revrr i t , ion is fe3ti;r'?d i n t h e pr-gramme of t r a i n i n g o v e r s e a s of s e n i o r p e r s o n n e l .

M E X I CO


1 n v e s t . i g a t o r s a r e *a f f i c i a i s i r i t.he s e r v i c e of t h e Government of Mexico, a c t i n g as a e r o n a u t . i c a 1 in spec to r s , who a re selected from p e r s o n s w i t h a n e x t e n s i v e background i n a e r o n a a t ical. o p e r a t i o n s a n d i o r a i r c r a f t ma in tenance , commercial p i l o t s and a e r o n a u t i c a l e n g i n e e r s .

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18-18 Man u a l ' of A i r c r a f t A cci dent i n ve s l i gat i on

MEXICO (cont'd)

Training

Candidates wishing t o qual i fy a s aeronautical inspectors, who a t the same tirne a c t a s accident invest igators , attend a t ra in ing course a t the Internat jonal Centre for C i v i l Aviation Training (CIAAC), where t h e pr incipal subjects required f o r aeronautical operations a r e covered, a i r c r a f t accident invest igat ion having a prominent place.

NEM ZEALAND

Select ion C r i ter ia

These a r e based Invest igat ion. experience i n c

on the pr inc ip les i n t h e I C A 0 Manual of Aircraf t Accident .--

Qual i f ica t ions a r e : A comprehensive background of recent I-

i v i l o r mi l i ta ry aviat ion, operationdl and Lechfiical. Applicant to hold a senior commercial o r a i r l i n e t ransport p i l o t * l i cence w i t h 3 O00 hours f l y i n g a s p i l o t i n command, multi-engine, instrument and f l y i n g ins t ruc tor r a t i n g s and engineering o r s p e c i a l i s t technical quaii f i c a t i n n s and expeïience, including knowledge of a i r c r a f t systems, inc.dern pawerplants, f i x e d and r s t a r y wing aerodynamics. Sui table temperament, an ana ly t ica l mind, maturity of' judgement and a b i l i t y t o produce well-written technical papers and s t a t i s t i c a l analyses a r e important c r i t e r i a .

* Licensed a i r c r a f t maintenance engineers may be accepted w i t h 1 O00 hours a s pilot-in-command and a current Commercial P i lo t Licence.

T r a i n i i x

Newly selected invest igators receive 1 2 months' or,-tne-job t r a i n i n g i n the invest igat ion of l i g h t a i r c r a f t accidents. Their performance determines whether they s h o u l d be sent t o recognized accident invest igat ion schools. The formal courses included i n the inspectors ' t ra in ing a r e an i n i t i a l two-week accident invest igat ion course, a two-week hel icopter accident invest igat ion course, a one-week mountain survival and ice-climbing technique course, a human f a c t o r s course, a pol ice witness interviewing course, a two-month accident invest igat ion course and a two-week occupant s u r v i v a b i l i t y analysis course. I n addition, inspectors a r e given s u f f i c i e n t f ly ing time t o r e t a i n t h e i r p i l o t l icences and . ra t ings , f l i g h t deck fami l ia r iza t ion f l i g h t s on a i r l i n e a i r c r a f t and systems courses on each major a i r l i n e a i r c r a f t i n u s e i n New Zealand.

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APPENDIX 18.- I n v e s t i g a t o r s ' S e l e c t i o n , T r a i n i n g and C o u r s e s 18-1 9

NICARAGUA


Accident i n v e s t i g a t o r s are p roposed by the Chief of the Acc iden t I n v e s t i g a t i o n Board and a p p o i n t e d by t h e D i r e c t o r Genera l , and may b e p i l o t s w i t h , as a minimum q u a l i f i c a t i o n , a commercial p i lo t ; l i c e n c e , o r mechanics , or h o l d e r s of a c a t e g o r y A l i c e n c e , o r ATC p e r s o n n e l . A l l must be d u l y q u a l i f i e d and have t he r e q u i s i t e e x p e r i e n c e .

T r a i n i n n

On-the-job t r a i n i n g , i n a d d i t i o n t o a n annua l seminar of o n e mon th ' s d u r a t i o n and a t t e n d a n c e a t c o u r s e s t o b e p rov ided i n f u t u r e by other States.

T r a i n i nR

Our a c c i d e n t i n v e s t i g a t o r a t t e n d e d the a c c i d e n t i n v e s t i g a t i o n and p r e v e n t i o n c o u r s e a t t he 1 ' E c o l e n a t i o n a l e de l ' A v i a t i o n c i v i l e ( E N A C ) , F r a n c e .

OMAN

Select i on C r i t e r i a

P r o f i c i e n c y i n E n g l i s h .

-

Exper i ence i n o n e or more o f t h e f o l l o w i n g f i e lds :

- A i r w o r t h i n e s s

- F l i g h t O p e r a t i o n s .

Pe r sona l q u a l i t i e s des i red :

- PaLience and s t a b l e p e r s o n a l i t y

- Logica l t h i n k i n g

- A b i l i t y t o write d e t a i l e d r e p o r t s .

T r a i n i n g

.&tter.ddnce a? acc i ( ìen t i p v e s t i g a t i o n c o u r s e s . Review of T C A O , U . S . A . NTSB, an3 U . K . A I B Accident R e p o r t s ,

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PAPUA NEM G U I N E A

Select ion C r i t e r i a

Experience and general and s p e c i f i c knowledge of one or more aeronaut ical f i e l d s , e. g. f l i g h t operations, aeronautical engineering, e tc .

Training

On-the-job t ra in ing together w i t h attendance a t selected seminars, courses, e t c .

Select ion C r i ter i a

Accident invest igators a r e members o f t h e Equipment Department of the Directorate General of Air Transport of Peru. They a r e required t o have appropriate qua l i f ica t ions and experience i n aeronaut ical engineering and/or f l i g h t operations. Their experience covers the f i e l d s of airworthiness, f l i g h t performance, engines, e lec t ronic systems and other s p e c i a l i t i e s provided by the Peruvian Air Force.

Training

Recently recruited inves t iga tors receive on-the-job t r a i n i n g , s i n c e s p e c i f i c invest igat ion courses are not given.

POLAND

Trai n i ng

I n recent years, conferences on the invest igat ion of accidents t o a i r c r a f t not involved in a i r t ransport operations have been held. No spec ia l courses have been held recent ly; however, the need for courses is recognized.

PORTUGAL

The Directorate General of C i v i l Aviation h a s a t present three p i l o t s a s a i r c r a f t accident invest igators ; two of them were t ra ined abroad and obtained t h e i r qua l i f ica t ions a t t r a i n i n g centers such a s the Post-Mishap Course of the I n s t i t u t e of Aviation Safety, Royal I n s t i t u t e of Technology, Sweden. Another member is a n a i r t r a f f i c control expert.

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APPENDIX 18.- I n v e s t i g a t o r s ' S e l e c t i o n , ' T r a i n i n g and Courses 18-21

PORTUGAL (cont'd)


Depending on t h e t y p e of a i r c r a f t i n v o l v e d and t h e c i r c u m s t a n c e s of t he a c c i d e n t , t h e members a re s e l e c t e d from s e v e r a l s o u r c e s ( D i r e c t o r a t e Genera l of C i v i l A v i a t i o n , a i r t r a f f i c i n s p e c t o r s , c i v i l a v i a t i o n p h y s i c i a n s , e tc) .

S A U D I A R A B I A


P r o f i c i e n c y ' in: E n g l i s h .

Expe r i ence i n o n e o r more of the f o l l o w i n g f i e l d s :

- A i r Traf f ic C o n t r o l

- A i r w o r t h i n e s s

- F l i g h t O p e r a t i o n s .

P e r s o n a l q u a l i t i e s des i r ed :

- P a t i e n c e and s t a b l e p e r s o n a l i t y

- L o g i c a l t h i n k i n g

- A b i l i t y t o wr i te d e t a i l e d r e p o r t s .

T r a i n i n g

Attendance a t a c c i d e n t i n v e s t i g a t i o n c o u r s e s . Review o f I C A 0 and NTSB Accident R e p o r t s .

~

SENEGAL

T r a i n i n g

The Ch ie f of t h e Air T r a f f i c Bureau h a s a t t e n d e d a two-month a c c i d e n t i n v e s t i g a t i o n c o a r s e a t tihe C r a n f i e l d I n s t i t u t e of Technology o r g a n i z e d by t h e Accident I n v e s t i g a t - i o n Erarich, U . K.

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18-22 Manual of A i r c r a f t Acciderit i n v e s t i g a t i o n

SINGAPORE

Select i o n C r i t e r i a

C a n d i d a t e s must have e x p e r i e n c e i n a t least one of t h e f o l l o w i n g f i e l d s :

- F l i g h t O p e r a t i o n s ( p i l o t , f l i g h t e n g i n e e r o r n a v i g a t o r )

- Enginee r ing ( a e r o n a u t i c a l e n g i n e e r o r a i rc raf t s u r v e y o r )

- Air T r a f f i c Con t ro l

T r a i n i n g

Aircraft a c c i d e n t i n v e s t i g a t i o n c o u r s e s and t r a i n i n g a v a i l a b l e i n o t h e r , States. On-the-job t r a i n i n g under t h e g u i d a n c e of e x p e r i e n c e d i n v e s t i g a t o r s .

SPAIN

T r a i n i n g

Two o f the twelve members of the Nat i o n a l Accident I n v e s t i g a t i o n Commiss i o n have a t t e n d e d c o u r s e s i n a c c i d e n t i n v e s t i g a t i o n . One a t t e n d e d t h e F l i g h t S a f e t y and Accident I n v e s t i g a t i o n c o u r s e o f the U n i v e r s i t y of Sou the rn California a s w e l l a s t h e A i r Force c o u r s e a t Amarillo, Texas. The other a t t e n d e d t h e Post-Mishap c o u r s e of t h e I n s t i t u t e of Av ia t ion S a f e t y - Royal I n s t i t u t e of Technology, Sweden. Other members of t h e Commission w i l l also a t t e n d c o u r s e s i n o t h e r States. N a t i o n a l s emina r s w i l l be conduc ted by thcse members who have a l r e a d y been t r a i n e d i n o t h e r States.

SRI LANKA

T r a i n i n g

I n v e s t i g a t o r s h a v e been t r a i n e d abroad.

SURINAME

T r a i n i n g

Attendance of Accident I n v e s t i g a t i o n Courses . Review of ICA0 and NTSB Acc iden t Repor t s . On-the-job t r a i n i n g .

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SWAZILAND


Accident I n v e s t i g a t o r s w i l l i n i t i a l l y be selected from A i r Traff ic C o n t r o l O f f i c e r s and l a t e r from e n g i n e e r i n g and p i l o t cadres a l s o .

T r a i n i n g

Two A i r Traff ic C o n t r o l Off icers have completed a Government O p e r a t i o n s Course a t t h e B e i r u t C i v i l A v i a t i o n Sa fe ty C e n t r e ; o n e is now A i r p o r t Manager, t h e o t h e r is A i r Traf f ic S e r v i c e s Off icer . Those two Officers w i l l l a t e r undergo a d d i t i o n a l , and more s p e c i f i c , a c c i d e n t i n v e s t i g a t i o n t r a i n i n g .

SWEDEN


The Accident I n v e s t i g a t i o n Branch ( A I B ) r e c r u i t s p e r s o n n e l w i t h a good g e n e r a l working knowledge of a v i a t i o n and a d m i n i s t r a t i v e and t e c h n i c a l / o p e r a t i o n a l e x p e r i e n c e . The members g e n e r a l l y have a p r o f e s s i o n a l p i l o t ' s background o r a n ae r ' o i i au t i ca i e n g i n e e r i n g q u a l i f i c a t i o n and many y e a r s o f e x p e r i e n c e i n d i f f e r e n t p a r t s o f t h e c i v i l o r t h e m i l i t a r y a v i a t i o n f i e l d .

T r a i n i n g

T r a i n i n g is as f o l l o w s :

- S e r v i c e a t t h e A I B ( o n e t o two years) i n c l u d i n g a s s i s t a n c e i n i n v e s t i g a t i o n s

- Easic i n v e s t i g a t i o n c o u r s e a t the U.S. NTSE o r a t t he I n s t i t u t e of A v i a t i o n S a f e t y i n Stockholm

- F u r t h e r e d u c a t i o n a t the U.S. NTSB ( I n v e s t i g a t i o n Management)

- A 3 f a r a s p o s s i b l e , p i l o t d u t y b e s i d e s the i n v e s t i g a t i o n work

Inv?3f,igLìtor3 í'iac!H ouLside Lhe A I B are i r i most c a s e s tr'airied at. the I n s t i t u t e v f A v i a t i o n S a f e t y i n S t u c k k ~ ~ l m and p a r t i c i p a t e from time t o time i n t h e i n v e s t i g a t i o n of ûccidentc , and i n c i d e n t s i n the i r s p e c i a l f i e l d . R e c u r r i n g meeilrigiì for' exchange sf i n v z s t i g a t i o n e x p e r i e n c e s are p l a n n e d .

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SWEDEN (cont'd)

I n v e s t i gat i on Courses Avai 1 a b l e

I . An " A v i a t i o n Accident I n v e s t i g a t i o n Course" is g i v e n a n n u a l l y by t h e I n s t i t u t e of A v i a t i o n S a f e t y a t t h e Department o f A e r o n a u t i c s , The Royal I n s t i t u t e of Technology, S-100 4 4 , Stockholm 7 0 Sweden. T h i s c o u r s e i s two w e e k s l o n g and is g i v e n i n Eng l i sh . I t is open t o f o r e i g n s t u d e n t s b u t a t t e n d a n c e a t each c o u r s e is l i m i t e d t o a t o t a l of about 35 s t u d e n t s . The s u b j e c t s are as f o l l o w s :

1 . - C o - o r d i n a t i n g F a c t o r s . Programming

a ) Fundamentals

A v i a t i o n and H i s t o r y , t h e Mishap Continuum, P e r p e t u a t i o n of E r r o r , The Mishap A n a l y s i s System, The P r e v e n t i v e Programme.

b) P h i l o s o p h i e s

The H i s t o r y of S a f e t y , The Meaning of T e r m s , The D e c l a r a t i o n o f P o s i t i o n , The Q u e s t i o n of C o m p a t i b i l i t y , T h e De te rmina t ion o f Compat i b i 1 i t y .

c ) J u r i s d i c t i o n s

The F u n c t i o n s of Programming, The O r g a n i z a t i o n of I n v e s t i g a t i o n , The P r e p a r a t i o n of Mishap Repor t s , The C o r r e c t i v e Ac t i o n Agencies.

d ) Techniques

I n f o r m a t i o n S o u r c e s , I n f o r m a t i o n C o l l e c t i o n , I n f o r m a t i o n Development, S i t e C o n t r o l P rocedures , I n v e s t i g a t i v e Systems, 1 n v e s t i . g a t i v e P rocedures Pos t - M i s h a p .

e ) P l a n s

R e f e r e n c e s , O r g a n i z a t i o n , S t a t i s t i c s , O b j e c t i v e s , F u n c t i o n s , Log ist ic s , Communication, Annex es, Endorsement.

2 . - Hunan F a c t o r s

a 'P h y s i o1 ogy

Capab i l i t i e s and L i m i t a t i o n s , Disease and Hab i t s , A l t i t u d e , Motion and V e h i c u l a r Stresses, Aeromedical C o n t r i b u t i o n s t o Acc iden t I n v e s t i ga t ion.

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18-25 APPENDIX 18.- I n v e s t i g a t o r s ' Select ion, T r a i n i n g and Courses -. _I

SWEDEN (cont 'd)

b ) Psychology

A t t e n t i o n and P e r c e p t i o n , Judgement and Emotions, Motor F u n c t i o n and C o - o r d i n a t i o n , P s y c h o l o g i c a l C o n t r i b u t i o n s t o Acc iden t I n v e s t i g a t i o n .

3. - Material F a c t o r s

Aersdynami cs

S i g n i f i c a n c e of I n d w e d Drag, Probl3ms of Swept Wing, Take-off and Landing Techn iques , Ground Effect, High Speed F l i g h t , Gus t , Manoeuvre, Landing and Ground Loads, Aerodynamic C o n t r i b u t i o n s t o Accident i n v e s t i g a t i o n .

S t r u c t u r e s

Compcnent F a i l u r e Modes i n c l u d i n g Labora to ry Demons t r a t ions , Material FlacLure P r o s ? s s e s , S t r e n g t h and Lire Requirements , Requirements f o r Fa i lu re P r e v e n t i o n , F a i l u r e Analyses Techniques: F r a c t o g r a p h y , M e t a l l o g r a p h y , Frac t u r e Mechanics.

4. - P h y s i c a l F a c t o r s

Meteorology

R e s t r i c t i o n s t o V i s i b i l i t y , Turbulence i n F l i g h t , L i g h t n i n g , Hail and I c i n g , M e t e o r a l o g i c a l C o n t r i b u t i o n s t o Accident I n v e s t i g a t i o n .

F a c i l i t i e s

II.

III.

Route and Terminal T r a f f i c C o n t r o l , N a v i g a t i o n and Landing Aids , Runways, Marking and L i g h t i n g , F a c i l i t i e s , C o n t r i b u t i o n s t o Accident I nves t i g a t i o n .

The I n s t i t u t e of Av,ation S a f e t y a l s o has a n a c c i d e n t p r e v e n t i o n c o u r s e c a l l e d " A v i a t i o n Acc iden t P reven t ion" . Detailed i n f o r m a t i o n on t h i s c o u r s e cari b e o b t a i n e d fi,oni t h e I n s t i t u t e or from t h e Swedish Embassies.

F a c i l i t i e s

The c l a s s room i n s t r u c t i o n i s h e l d a t t he Royal I n s t i t u t e o f Technology. Modern a u d i o - v i s u a l a i d s a re p rov ided .

Lziboratcry d e m o n s t r a t i o n s a re unde r t aken i n the S t r u c t u r e s Labora to ry of t h e School of herorkìu tic: 5 .

The p r a c t i c a l i n v e s t i g a t i v e p a r t i c i p a t i o n is a t a Swedish A i r Fo rce Base wher;, a r e a l i s t i c a c c i d e n t s i t e has been s e t u p f o r t h e pu rpose .

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18-26' Manual of Aircraf t Accident I n v e s t i g a t i o n

SWITZERLAND

S e l e c t i o n Cri ter ia ,

1 ) I n v e s t i g a t o r s of g e n e r a l a v i a t i o n a c c i d e n t s r e q u i r e a Commercial p i l o t l i c e n c e wi th i n s t r u c t o r r a t i n g ,

2 ) I n v e s t i g a t o r s o f ' a c c i d e n t s which occurred i n I F R o r i n v o l v i n g h e l i c o p t e r s r e q u i r e co r re spond ing r a t i n g s .

The basic p r o f e s s i o n of a n i n v e s t i g a t o r p l a y s o n l y a secondary r o l e ; however, i t is i m p o r t a n t t h a t t h e c a n d i d a t e has a wide t e c h n i c a l knowledge. I t is des i rab le t h a t p i l o t i n v e s t i g a t o r s m a i n t a i n the i r f l y i n g s k i l l s . F l y i n g t r a i n i n g is t h e r e f o r e p a r t of t h e i r terms o f r e f e r e n c e .

Trainif ig

1 On-the-job t r a i n i n g under the guidance o f expe r i enced i n v e s t i g a t o r s .

2 ) A one- or two-day i n f o r m a t i o n and t r a i n i n g meeting is o r g a n i z e d from time t o time. I n v e s t i g a t o r s may a t t e n d c o u r s e s i n t h e U . S . A . or U . K .

THAILAND


Accident i n v e s t i g a t o r s a re selected from A i r w o r t h i n e s s I n s p e c t o r s , O p e r a t f c n s Officers, P i l o t s , N a v i g a t o r s and Air Traffic C o n t r o l l e r s .

T r a i n i n g

A t courses a v a i l a b l e i n T h a i l a n d and o t h e r States .

Trai n i n R

Basic a c c i d e n t i n v e s t i g a t i o n c o u r s e s abroad fo l lowed by on-the- job t r a i n i n g .

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UGANDA

Select i o n C r i t e r i a - Accident i n v e s t i g a t o r s are selected from A i r w o r t h i n e s s I n s p e c t o r s , O p e r a t i o n s Off icers , P i l o t s , N a v i g a t o r s and A i r Traffic C o n t r o l l e r s .

T r a i n i n g

A t c o u r s e s a v a i l a b l e i n o t h e r States.

U N I T E D KINGDOM


1 . I n s p e c t o r s of Acc iden t s ( O p e r a t i o n s ) a re r e q u i r e d t o i n v e s t i g a t e and r e p o r t on t h e o p e r a t i o n a l a s p e c t s of c i v i l a i r c r a f t a c c i d e n t s i n any p a r t of t he world.

Age - C a n d i d a t e s shou ld b e a t l e a s t 30 and p r e f e r a b l y under 40. - Q u a l i f i c a t i o n s and E x p e r i e n c e

a) C a n d i d a t e s must have e x t e n s i v e e x p e r i e n c e as pilot-in-command i n commercial o r m i l i t a r y a v i a t i o n and p o s s e s s or have r e c e n t l y p o s s e s s e d a n A i r l i n e T r a n s p o r t P i l o t ' s L icence .

b ) C a n d i d a t e s who d o n o t e n t i r e l y s a t i s f y these r e q u i r e m e n t s may b e c o n s i d e r e d i f they can d e m o n s t r a t e a n e q u i v a l e n t s t a n d a r d of t e c h n i c a l knowledge, f o r example as g r a d u a t e o f t h e Empire Test P i l o t ' s School .

c) C a n d i d a t e s must have t he a b i l i t y of a p p l y i n g p r o f e s s i o n a l and t e c h n i c a l knowledge to a i r c ra f t a c c i d e n t i n v e s t i g a t i o n and write c o n c i s e and r e p o r t s .

2 . I n s p e c t o r s of A c c i d e n t s ( E n g i n e e r i n g ) a re r e q u i r e d t o i n v e s t i g a t e and on t h e e n g i n e e r i n g a s p e c t s o f c i v i l a i r c ra f t a c c i d e n t s i n any p a r t o f world.

- Age - C a n d i d a t e s s h o u l d have 10 years ' p o s t - q u a l i f i c a t i o n e x p e r i e n c e .

Q u a l i f i c a t i o n s and ExDerience

l o g i c a l

r e p o r t t h e

a ) C a n d i d a t e s must have a n E n g i n e e r i n g d e g r e e o r b e a Chartered Eng inee r of have sa t i s f ied t h e academic and t r a i n i n g r e q u i r e m e n t s f o r c o r p o r a t e membership of one of t h e c o n s t i t u e n t i n s t i t u t i o n s o f t h e Counc i l o f Eng inee r ing I n s t i t u t i o n s .

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UNITED KINGDOM (cont'd)

b ) C a n d i d a t e s shou ld have a sound t e c h n i c a l and p r a c t i c a l knowledge of turbine-powered fixed-wing and ro t a ry -wing a i r c ra f t and a ? e r i o d o f employment i n a t least one of the f o l l o w i n g f i e l d s of a i r c ra f t e n g i n e e r i n g : d e s i g n , p r o d u c t i o n , maintenance, and i n s p e c t i o n .

c ) I t i s desirable tha t c a n d i d a t e s have had e x p e r i e n c e o f defect i n v e s t i g a t i o n and have had o p e r a t i o n a l f l y i n g e x p e r i e n c e , a l t h o u g h p o s s e s s i o n of a p i l o t ' s l i c e n c e is n o t n e c e s s a r y .

3 . I n s p e c t o r s of Acc iden t s ( E n g i n e e r i n g ) . F l i g h t r e c o r d e r s p e c i a l i s t s a r e r e s p o n s i a l e f o r f l i g h t data r e c o r d e r r e c o v e r y , r ead -ou t and a n a l y s i s and c o c k p i t v o i c e r e c o r d e r p r o c e s s i n g .

Q u a i i r i c a t i o n s and Exper i ence

a) Cand ida te s must h a v e a n Eng inee r ing or E l e c t r o n i c s d e g r e e o r be a Chartered Eng inee r o r have s a t i s f i ed t h e academic and t r a i n i n g r e q u i r e m e n t s f o r c o r p o r a t e membership of o n e o f t he c o n s t i t u e n t i n s t i t u t i o n s of t h e Counc i l o f Eng inee r ing I n s t i t u t i o n s .

b) c a n d i d a t e s shou ld h a v e a sound t e c h n i c a l knowledge o f e l e c t r i c a l , e l e c t r o n i c and i n s t r u m e n t a t i o n sys t ems used i n modern a i r c r a f t . Exper i ence o f r ead -ou t and a n a l y s i s o f f l i g h t data r e c o r d i n g systems i s e s s e n t i a l and knowledge of modern p u l s e code-modulated system is desirable.

c ) Some o p e r a t i o n a l f l y i n g e x p e r i e n c e would b e a n a d v a n t a g e , a l t h o u g h t h e p o s s e s s i o n of a p i l o t ' s l i c e n c e is n o t n e c e s s a r y .

Trai n i niz

T r a i n i n g of I n s p e c t o r s of Acc iden t s c o n s i s t s o f i n i t i a l t h e o r e t i c a l i n s t r u c t i o n f o l l o w e d by spec i f i c c o u r s e s o f i n s t r u c t i o n as f o l l o w s :

1 , I n s p e c t o r s - ( O p e r a t i o n s )

- U n i v e r s i t y c o u r s e on human factors.

- P i l o t ground c o u r s e s ( t o l icence-endorsement s t a n d a r d ) on major p u b l i c t r a n s p o r t a i r e r a f t .

- F l y i n g and s imula t ed f l y i n g t r a i n i n g i n one n a j o r p u b l i c t r a n s p o r t a i r c ra f t type .

- C o n t i n u a t i o n o f f l y i n g t r a i n i n g i n l i g h t , s i n g l e - and tw in -eng ined , a i r c ra f t .

- H e l i c o p t e r t l y i n g t r a i n i n g f o r s e l e c t e d I n s p e c t o r s .

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2 . I n s D e c t o r s ( E n n i n e e r i n n )

- Courses i n A i r w o r t h i n e s s and M e t a l l u r g y

- S p e c i f i c t y p e e n g i n e and airframe c o u r s e s

- F l y i n g t r a i n i n g and c o n t i n u a t i o n t r a i n i n g to PPL s t a n d a r d

- Courses on s p e c i a l equipment as and when c o n s i d e r e d n e c e s s a r y

P r a c t i c a l t r a i n i n g on c u r r e n t i n v e s t i g a t i o n s f o l l o w s i n p r o g r e s s i v e stages:

a) Observing and a s s i s t i n g s e n i o r c o l l e a g u e s a t i n v e s t i g a t i o n s o f a c c i d e n t s t o small p r i v a t e a i r c r a f t a t f i r s t , p a r t i c i p a t i n g l a t e r i n i n v e s t i g a t i o n s of a c c i d e n t s t o l a r g e r a i r c r a f t ;

b) Conducting i n v e s t i g a t i o n s under t h e s u p e r v i s i o n o f s e n i o r c o l l e a g u e s , p r o g r e s s i n g i n t h e same way from smaller a i r c ra f t t o l a r g e r o n e s ;

c) Conduct ing i n v e s t i g a t i o n s i n t o smaller a i r c ra f t a c c i d e n t s w i t h o u t s u p e r v i s i o n and a s s i s t i n g i n more compl i ca t ed i n v e s t i g a t i o n s ;

d) Conduct ing i n v e s t i g a t i o n s i n t o major p u b l i c t r a n s p o r t a i r c r a f t a c c i d e n t s , i n c l u d i n g t h e s u p e r v i s i o n of a Group as s p e c i f i e d i n t h e Group S y s t e m s , Annex I 3;

e ) Ac t ing as f u l l y q u a l i f i e d I n v e s t i g a t o r - i n - C h a r g e a t home, and as Un i t ed Kingdom Accredited R e p r e s e n t a t i v e ab road .

I n s p e c t o r s ( O p e r a t i o n s ) a re , on appointment t o t he Branch, ma tu re and e x p e r i e n c e d a v i a t o r s and f o r t h i s r e a s o n are expec ted t o become f u l l y competent i n two years . I n s p e c t o r s ( E n g i n e e r i n g ) take three years f o r two r e a s o n s . F i r s t l y b e c a u s e , a l t h o u g h h i g h l y q u a l i f i e d a c a d e m i c a l l y , t hey are i n g e n e r a l young p e r s o n s w i t h more l i m i t e d e x p e r i e n c e i n a v i a t i o n , and second ly because t h e s p e c i a l i z e d p r a c t i c a l t e c h n i q u e s o f wreckage a n a l y s i s and f r a c t u r e d i a g n o s i s and t h e d e t e c t i o n o f p h y s i c a l ev idence take l o n g e r t o a c q u i r e .

Accident I n v e s t i g a t o r Course A v a i l a b l e

A r e s i d e n t i a l c o u r s e o f 8 w e e k s ' d u r a t i o n on a i r c ra f t a c c i d e n t i n v e s t i g a t i o n is a v a i l a b l e on a n a n n u a l basis f o r s u i t a b l y q u a l i f i e d e x p e r i e n c e d p i l o t s o r e n g i n e e r s a t :

The C o l l e g e of A e r o n a u t i c s C r a n f i e l d I n s t i t u t e o f Technology C r a n f i e l d - Bedford MK43 OAL - England.

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UNITED REPUBLIC OF TANZANIA


Accident i n v e s t i g a t o r s a r e s e l e c t e d from Airworthiness I n s p e c t o r s , Opera t ions O f f i c e r s , P i l o t s , Navigators and Air Traffic Con t ro l l e r s .

Training

A t courses a v a i l a b l e i n o t h e r States.

UNITED STATES

Se l e'ct i on C r i ter i a

Appl-icants fo r t he p o s i t i o n of l ' A i r Safe ty Inves t iga to r s " m u s t have a minimum of 3 yea r s of genera l experience and 3 yea r s of spec ia l i zed experience f o r a t o t a l of 6 y- ear s .

Genera: Experience

Experience which provides a broad knowledge in one o r more of t he fol lowing: a i r c r a f t design; manufacture; maintenance ope ra t ions ; o p e r a t i o n a l requi rements ; or f a c i l i t i e s , p r a c t i c e s and procedures r e l a t i n g t o a v i a t i o n a c t i v i t i e s . This experience might be gained through working in o rgan iza t ions or p o s i t i o n s such as :

1 .

2.

? *

L!.

5 .

5 .

7 .

In the f l i g h t a c t i v i t i e s of scheduled or non-scheduled a i r c a r r i e r , a i r t a x i , c h a r t e r , commercial o r execut ive ope ra to r , using h e l i c o p t e r s o r mult i -engine a i r c ra f t .

I n an execut ive or superv isory capac i ty w i t h a scheduled a i r c a r r i e r i n charge o r f l i g h t ope ra t ions o r a i r c r a f t maintenance.

Operations o f f i c e r , engineer ing o f f i c e r , f l y i n g s a f e t y o f f i c e r , o r pilot-in-command w i t h a n i l i t a ry o r similar f l i g h t u n i t ,

An enployee of a government agency i n a t e c h n i c a l capac i ty concerned w i t h f l i g h t opera t ions o r s a f e t y i n f l i g h t .

A gro?iníi 31" f l i g h t i n s t r u c t o r or f l i g h t t e s t e r of airmen o r a i r c r a f t , Or ail aer ia l . a p p l i c a t o r or a e r i a l photographer.

I n the f l i g h t a c t i v i t i e s of a manufacturer of a i r c r a f t , a i r c r a f t engines , p r o p e l l e r s , o r av ion ic s equipment.

Experience i n a v i a t i o n which included a c t i v e p a r t i c i p û t i o n i n a i r c r a f t design, manufacturing o r maintenance i r 1 p o s i t i o n s which permit ted t h e appl icant t o acqui re a ccmprehens ive knowledge of a e r o n a u t i c a l des ign and/or maintenance methods, procedures and techniques.

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8 . Exper i ence as a s t a f f member of a l e g i s l a t i v e committee, r e g u l a t o r y agency, board o r f o u n d a t i o n hav ing i n v e s t i g a t o r y d u t i e s t h a t would p r o v i d e t h e r e q u i r e d bas i c background i n i n v e s t i g a t i v e and a n a l y t i c a l t e c h n i q u e s .

S u b s t i t u t i o n of Educa t ion f o r Genera l Expe r i ence

S u c c e s s f u l comple t ion o f r e s i d e n t s t u d y i n e n g i n e e r i n g , mathematics, p h y s i c s , sa fe ty , human f a c t o r s , b u s i n e s s a d m i n i s t r a t i o n , or law i n a n accredited college ( o r i n a non-acc red i t ed i n s t i t u t i o n a s descr ibed below) may be s u b s t i t u t e d f o r g e n e r a l e x p e r i e n c e a t t h e ra te of 9 months o f s t u d y f o r o n e y e a r o f s u c h e x p e r i e n c e t o a maximum o f 3 y e a r s ' e x p e r i e n c e .

The s u c c e s s f u l comple t ion o f c o l l e g e work i n non-acc red i t ed i n s t i t u t i o n s w i l l b e a c c e p t e d on t h e same bas is as i n d i c a t e d f o r a c c r e d i t e d c o l l e g e s , p rov ided t h a t such i n s t i t u t i o n s g i v e i n s t r u c t i o n o f d e f i n i t e c o l l e g i a t e l e v e l , and t h a t t h e S t a t e U n i v e r s i t y of t h e S t a t e i n which t h e i n s t i t u t i o n is l o c a t e d a c c e p t s t h e c o u r s e o r c o u r s e s and g i v e s advanced c r e d i t for them. ( I n t h o s e S ta tes where there is no S ta te U n i v e r s i t y , t h e e v a l u a t i o n ana a c c e p t a n c e of college c r e d i t as made by the S t a t e Department of Educa t ion w i l l b e a c c e p t e d . )

The a p p l i c a n t ' s e x p e r i e n c e and t r a i n i n g must c l e a r l y i n d i c a t e e x p e r i e n c e of the k i n d s l i s t e d below.

1 . The p l a n n i n g , o r g a n i z a t i o n , or s u p e r v i s i o n of work programmes.

2 . The w r i t i n g of n a r r a t i v e - s t y l e t e c h n i c a l r e p o r t s .

3 . The u s e of i n v e s t i g a t i v e equipment (cameras, h a n d t o o l s , measuring d e v i c e s , e tc .

4 . The p r e s e n t a t i o n of o r a l r e p o r t s .

S p e c i a l i zed Exper i ence

The r e q u i r e d 3 y e a r s ' s p e c i a l i z e d e x p e r i e n c e must have been o b t a i n e d i n o n e or more of t h e f o l l o w i n g a c t i v i t i e s :

1 . A s a n a i r c r a f t a c c i d e n t i n v e s t i g a t o r , o r f l i g h t s a f e t y o f f i c e r f o r a r ecogn ized agency, e i ther p u b l i c o r p r i v a t e .

2 . A s a t e s t p i l o t engaged i n e x p e r i m e n t a l - t y p e a i r c r a f t t e s t i n g .

3. A s a s u p e r v i s o r o f f l i g h t o p e r a t i o n s o r a i r c r a f t maintenance w i t h a n FAA c e r t i f i c a t e d f l y i n g s c h o o l o r FAA ce r t i f i ca t ed a i r c ra f t o v e r h a u l f a c i l i t y .

4 . A s an FAA Des igna ted P i l o t Examiner or Ins t rumen t R a t i n g Examiner.

5 . A s an FAA Des igna ted Maintenance Examiner ( I n s p e c t i o n A u t h o r i z a t i o n ) .

6 . A s an FAA Designated Airframe and Powerplants Exúminer.

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i 8-32 Manual of Aircraf t Accident Invest igat ion


7 . A s a supervisor of f l i g h t instruct ion i n a mi l i ta ry f l i g h t school, o r m i l i t a ry-c iv i l ian contract f l i g h t school.

8. A s Chief P i l o t , or supervisor of f l i g h t operations w i t h a corporation operating multi-.engine a i r c r a f t over 12 500 l b maximum take-off mass.

9 . A s Chief P i lo t , or supervisor of f l i g h t operations o r a i rcraf t maintenance w i t h a scheduled a i r t a x i operator.

C e r t i f i c a t e and Rat inns Reauired

Applicants must hold or have held w i t h i n the past two years a v a l i d Commercial P i l o t C e r t i f i c a t e wi th i n s t r u m e n t ra t ing , or a mil i tary p i l o t r a t i n g w i t h a n i n s t r u m e n t c e r t i f i c a t e . Prior t o e n t r y on duty, a l l appointees w i l l be required t o have a valid first- o r second-class Airman Medical Cer t i f ica te .

Flying Hours Required ( P i lot-in-command)

Minimum Minimum Time Time on Time on Required

To t a l Small * Multi-engine Within Last Grade Time Aircraft Aircraf t 5 years

GS-11 1500 CS-1 2 2000

500 1 O00

200 20 o

*Small Aircraft - Aircraf t weighing 1 2 500 l b or l e s s .

I n computing t h e f l y i n g time, each 2 hours acquired a s a Co-pilot o r a s an FAA c e r t i f i c a t e d f l i g h t engineer on a c i v i l a i r c a r r i e r may be subs t i tu ted for 1 hour of the pilot-in-command time i n meeting the minimum time requi red on multi-engine a i r c r a f t .

Experience as l i s t e d below acquired w i t h i n the most recent 5 years may be s u b s t i t u t e d for 500 hours of t o t a l f l i g h t time a s pilot-in-command a t the r a t e of 1 year of Such experience for each 100 hours . Also, experience as l i s t e d below acquired w i t h i n the nost recent 5 years may be s u b s t i t u t e d f o r the 300 nours of recent f l i g h t time a s pilot-in-command a t the r a t e of 1 year of such experience for each 100 hours.

1 . I n a technical capacity w i t h a municipal or S t a t e aeronaut ical agency.

2 . Full-time operator o r manager of a c i v i l a i r p o r t .

3. Full-time assignment a s a safety o f f i c e r , sa fe ty engineer, or o ther approved accident prevention s p e c i a l i s t posit ion i n aviat ion.

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APPENDIX 18.- Inves t iga tors ' Select ion, Training and Courses 18-33


Invest igat ion Courses Available

An A i r Safety Invest igator Basic Course, of three weeks' duration, is held a t l e a s t twice each year a t the National Aircraf t Accident Invest igat ion School a t Dulles Internat ional Airport, Washington, D . C . The school is operated by the National Transportation Safety Board ( N T S B ) . is open t o qua l i f ied government employees of other States. subjects a r e taught:

The course is given i n English and The following

1. 2. 3. 4. 5. 6. 7. 8. 9.

10. 1 1 . : 2. 13. 1 4 . 15. 16. 17. 18. 19. 20. 21. 22. 23 24. 25. 26.

28. 29. 30 31 * 32 * 33. 34.

27

Statutory author i t y Equipment f o r inves t iga tors Notif icat ion and c l a s s i f i c a t i o n '

Pre-departure and a r r i v a l a c t i v i t y Press/ insurance/ loca l author it i e s Invest igat ion development Maintenance records F l i g h t date recorder/cockpit voice recorder Photography A e r od y na m i c s re v i e w Aircraf t load i ng Strength of mater ia ls Laboratory or i en t a t ion Aircraf t s t r u c t u r e Aircraf t systems Aircraf t engines Aircraf t operations Airworthiness f i e l d exercise A i r t r a f f i c control Witnesses Weather Human f a c t o r s Helicopter case s t u d i e s Aircraf t performance Case processing and automation Team a c t i v i t y Reports Rep or t pro j ec t General av ia t ion case s t u d i e s Corporate j e t case s t u d y Wake turbulence case s t u d y I n - f l i g h t f i r e s t u d y case On-scene wrap-up Report project review

Questions r e l a t i v e t o t h i s course may Se addressed to :

The National Transportation Safety Board - Washington, D .C. 20594

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18-34 Manual of Aircraft Accident I n v e s t i g a t i on

URUCUAY

S e l e c t i o n Criteria

Same a s t h o s e r e q u i r e d f o r e n t r a n c e to t h e I n s t i t u t e s of Advanced T r a i n i n g .

A t t he I n s t i t u t e s of Advanced T r a i n i n g abroad.

VENEZUELA

Trai n i n R

Selected pe r sonne l a t t e n d a n a i r c r a f t a c c i d e n t p r e v e n t i o n and i n v e s t i g a t i o n course g i v e n by t h e Venezuelan Air Force, and are a l s o s e n t abroad t o a t t e n d re la ted cour ses. On- t h e - j ob t ra in ing .

Z A I R E


Accident i n v e s t i g a t o r cand idates a r e selected from p e r s o n s w i t h sound e x p e r i e n c e i n a i r c ra f t o p e r a t i o n s and a i rc raf t mechanic s.

ZAMBIA


Normally, p e r s o n n e l employed by t h e Department of C i v i l A v i a t i o n who h o l d o r have f a r -ne r ly held a p r o f e s s i o n a l p i l o t l i c e n c e a n d / o r a e r o n a u t i c a l e n g i n e e r l i c e n c e airworthiness I n s p e c t o r s ) a r e e l i g i b l e for s e l e c t i o n .

Howcver, any o t h e r a v i a t i o n p e r s o n n e l who have o b t a i n e d t r a i n i n g a n d / o r ?.:Wrience which p re supposes p r o f e s s i o n a l s t a n d a r d s i n t h e i r r e s p e c t i v e f i e l d s of s v i a t i o n , whether t h e y a r e employed by t h e Department o r n o t , a r e e l i g i b l e f o r : = e l e c t i o n by e i t h e r t h e i r own employers o r b y t h e Department. 2 W c a s e , a v a i l a b l e t o and a re normally a c c e p t e d as i f i v e s t i g a t o r s by t h e Department.

T h e y a re a l l , i n

T r a i n i n g

E l i g i b l e pet-sor:nel a r e sent. o v e r s e a s t o the U . K, (Crarif i e l d ) , Sweden and any n t h e r a p p r o p r i a t e i n s t i t u t i o r i t h a t i s approved.

- -- ~-

i7/10/86 No. 1 o



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APPENDIX 19

EXPERT ASSISTANCE AND FACILITIES AVAILABLE ON REQUEST FOR THE INVESTIGATION

OF MAJOR ACCIDENTS

A s a r e s u l t of Assembly Resolu t ion A21-20 and Council Decis ion C 83-4, State Letter AN 6/22 - 75/44 was d ispa tched t o States on 1 4 March 1975.

I n accordance w i t h Council Decis ion C 86-13, t h i s Appendix p r e s e n t s t he r e p l i e s of those S t a t e s which have n o t i f i e d I C A 0 t h a t they can: l lprovide, on r e q u e s t by o t h e r Cont rac t ing States, expe r t a s s i s t a n c e and f ac i l i t i e s f o r t he i n v e s t i g a t i o n of -major aircraft acc idents" .

I n t h i s con tex t , major a c c i d e n t s are understood t o b e those i n which a i r c r a f t of a maximum mass of 9 O00 kg o r more are involved.

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ICA0 PUBLICATIONS IN THE AIR TRANSPORT FIELD

The following summary gives the status and also describes in general terms the contents of the various series of publications in the air transport field issued by the International Civil Aviation Organization:

International Standards and Recommended Practices on Facilitation (designated as Annex 9 to the Convention) which are adopted by the Council in accordance with Articles 37, 54 and 90 of the Convention on International Civil Aviation. The uniform observance of the specifications contained in the International Standards on Facilitation is recognized as practicable and as necessary to facilitate and improve some aspect of international air navigation, while the observance of any specification contained in the Recommended Practices is recognized as generally practicable and as highly desirable to facilitate and improve some aspect of international air navigation. Any differences between the national regulations and practices of a State and those established by an International Standard must be notified to the Council in accordance with Article 38 of the Convention. The Council has also invited Contracting States to notify differences from the provisions of the Recommended Practices;

Council Statements on policy relating to air transport questions, such as charges for airports and air navigation services, taxation and aims in the field of facilitation;

Digests of Statistics which are issued on a regular basis, presenting the statistical information received from Contracting States on their civil aviation activities;

Circulars providing specialized information of interest to Contracting States. They include studies on trends in the air transport industry at a global and regional level and specialized studies of a worldwide nature;

Manuals providing information or guidance to Contracting States on such questions as airport and air navigation facility tariffs, air traffic forecasting techniques and air transport statistics.

Also of interest to Contracting States are reports of meetings in the air transport field, such as sessions of the Facilitation Division and the Statis,tics Division and conferences on the economics of airports and air navigation facilities. Supplements to these reports are issued, indicating the action taken by the Council on the meeting recommendations, many of which are addressed to Contracting States.



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Order No. 6920 Printed in ICAO



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(doc. 6920) manual of aircraft accident investigation

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