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TECHNICAL MEMDRANBEM SEM-m-64-7

)V0 100 F t . DIA PARACHUTE (G-11A) WITH INTERNAL CANOPY

PHASE I STUDY

HERMAN ENGEL JR.

CKEV. EQUIPMENT DIVISION

DIRECTORATE OF CHE'. SUBSYSTEMS ENGINEERING

MAY 1964

RESEARCH AM) TECHNOLOGY DIVISION

X

J NOTICES

Ivhen Government d r a w i n g s , s p e c i f i c a t i o n s , or o ther d a t a are used f o r any purpose other t h a n i n c o n n e c t i o n w i t h a d e f i n i t e l y r e l a t e d Government procurement o p e r a t i o n , the U n i t e d S t a t e s Government t h e r e b y i n c u r s no r e s p o n s i b i l i t y nor any o b l i g a t i o n w h a t s o e v e r ; and t h e f a c t t h a t the Govern-ment may have f o r m u l a t e d f u r n i s h e d , or i n any way s u p p l i e d the s a i d draw-i n g s , s p e c i f i c a t i o n s , or o t h e r d a t a , i s not t o be r e g a r d e d by i m p l i c a t i o n or o t h e r w i s e as i n any manner l i c e n s i n g the h o l d e r or any o t h e r person or

13 c o r p o r a t i o n , or c o n v e y i n g any r i g h t s or p e r m i s s i o n t o m a n u f a c t u r e , u s e , or s e l l any p a t e n t e d i n v e n t i o n t h a t may i n any way be r e l a t e d t h e r e t o . \o

U N O A H A I L L I B R A R Y KANSAS CITY, MQ

ABSTRACT

FTLGM-TM-63-lOiw t i t l e d " I n t e r n a j . Parachute Study" p r e s e n t s the d a t a obta ined i n the t e s t i n g of t e d i o u s s i z e s of i n t e r n a l canopies a t s e v e r a l l o c a t i o n s w i t h i n and above the s k i r t of the G-11A p a r a c h u t e . S e v e r a l r e e f i n g l i n e l e n g t h s were a l s o cons idered f o r t h i s program. 'This r e p o r t e x t r a c t s d a t a from FTLGM-TM-63-IO4A, i n c l u d e s e x t r a c t i o n s from Yuma T e s t S t a t i o n Report of DAT P r o j e c t No. ATA 62057, "Opening C h a r a c t e r i s t i c s of G-11A Cargo Parachute" and s e r v e s t o i n c o r p o r a t e c o n c l u s i o n s and recom-mendations on the f e a s i b i l i t y of r e d u c i n g the opening time of l a r g e d i a m e t e r c a r g o p a r a c h u t e s .

TABLE OF CONTENTS

I PURPOSE

I I OBJECTIVES

I I I INTRODUCTION

IV DISCUSSION

V CONCLUSIONS

VI RECOMMENDATIONS

REFERENCES

Page 1

Page 1

Page 1

Page 1

Page 2

Page 3

Page 6

APPENDICES

APPENDIX I - E x t r a c t s from T e c h n i c a l Memorandum No. Page 7 FTLGM-Wi-63-lOiiA, t i t l e d " I n t e r n a l P a r a -chute S t u d y " , dta 3 September 1963

APPENDIX I I - E x t r a c t s from Yuma Test S t a t i o n Report of Page 12 DAT P r o j . No. ATA 62057, t i t l e d "Opening C h a r a c t e r i s t i c s of G-11A C a r g o " , 2 A p r i l 63

X

APPENDIX I I I - Proposed Phase I I C l u s t e r T e s t Progress Page 17

LIST OF FIGURES ' J

FIGURE I - Opening Force vs Opening Time Page 4

FIGURE I I - A l t i t u d e Loss vs Opening Time Page 5

T e c h n i c a l Memorandum SEM-TM-6it-7 i i i

I . PURPOSE

The purpose of t h i s report i s t o supplement the 6511th Test Group (Parachutes) Technical Memorandum FTLGM-TM-6_;-101iA, t i t l e d " I n t e r n a l Parachute Study" and Yuma Test S t a t i o n Report of DAT P r o j e c t No. ATA. 62057. "Opening C h a r a c t e r i s t i c s of t h e C11A Cargo Parachute" with conclusions concerning the operation of s i n g l e G-11A parachutes and make recommendations concerning the t e s t i n g of G-11A parachutes , with i n t e r n a l canopies , in c l u s t e r c o n f i g u r a t i o n s .

I I . OBJECTIVES - The o b j e c t i v e s of the Phase I , S i n g l e G-11A parachute, t e s t program were t o determine:

a . The f e a s i b i l i t y of d e l i v e r i n g cargo loads a t reduced a l t i t u d e s , as low a s 5 f e e t above the ground, with minimum changes to the parachute system.

b . The s i z e , t y p e , and l o c a t i o n of the i n t e r n a l canopy and a method of r i g g i n g the canopy, and

c . An optimum r e e f i n g l i n e l e n g t h .

I I I . INTRODUCTION

An appl ied research program conducted by the U n i v e r s i t y of Minnesota under A i r Force Contract No. AF33(616)-6372 showed t h a t ' a small canopy pos i t ioned in the mouth of a much l a r g e r canopy forced a more rapid f i l l i n g of the l a r g e canopy with l i t t l e or no increase in maximum canooy opening f o r c e s . The Parachute Branch of the Systems Engineering Group" proposed a program t o the U. s . Army Natick Laborator ies to eva luate t h i s technique with standard G-11A parachutes t o determine i f i t would provide a s i g n i f i c a n t reduct ion in a l t i t u d e required f o r heavy equipment a i r droos. The Phase I program was e s t a b l i s h e d t o evaluate s o l i d f l a t and r i b l e s s guide s u r f a c e canopies of 10, 13 and 16 f o o t diameters a t 1 . 7 5 , 3 - 5 and I) .5 f e e t i n s i d e and above the G- l lA canopy s k i r t , Methods of r i g g i n g the i n t e r n a l canopy ( s i n g l e conf luence point and mult ip le l i n e connection) and various r e e f i n g l i n e lengths (none, 20, 40, and 60 foot ) were a l s o planned. However, due to funding l i m i t a t i o n s the program was s u b j e c t e d to continuous reduct ions in the number of t e s t s which could be conducted and t h e r e f o r e the number of c o n f i g u r a t i o n s which could be e v a l u a t e d . As a r e s u l t of FTLGM-TM-63-IO4A a conference among 6511th TG(?). U.S. Army and Parachute Branch personnel was held a t E l Centro. I t was agreed that a consol idated report inc luding 6511th and Yuma t e s t d a t a , data r e d u c t i o n s , and adding conclusion and recommendations should be prepared by the Parachute Branch.

IV. DISCUSSION

The d e s c r i p t i o n of the t e s t i tems, t e s t equipment and t e s t procedures and the tabulated t e s t r e s u l t s have been extracted from FTLGM-TM-63-lOijA r e f e r e n c e 1 and are included as Appendix I of t h i s r e p o r t .

Technica l Memorandum SEM-TM-64-7

1

I V . DISCUSSION ( C o n t ' d )

The Yuma T e s t S t a t i o n d a t a on the C-,-llA p a r a c h u t e have been e x t r a c t e d from r e f e r e n c e 2 ana are i n c l u d e d a s Appendix I I . The Yuma T e s t d a t a i s a v a l u a b l e a s s e t and s e r v e s as a b a s i s of comparison f o r the i n t e r n a l p a r a -chute t e s t s . The u n r e e f e d t e s t s conducted by Yuma are of acedemic v a l u e s i n c e based upon e x p e r i e n c e t h e c l u s t e r c o n f i g u r a t i o n s cannot be r e l i a b l y d e p l o y e d w i t h o u t r e e f i n g . Ihe s t a n d a r d G-11A has a 20 f o o t l o n g r e e f i n g l i n e and i s r e e f e d f o r t w o s e c o n d s .

Because o f f u n d i n g l i m i t a t i o n s t e s t s were o n l y conducted w i t h 13 and l 6 f o o t d i a m e t e r f l a t c i r c u l a r i n t e r n a l c a n o p i e s . The m a j o r i t y of t e s t s were w i t h a s k i r t s e p a r a t i o n d i s t a n c e o f 3 - 5 f e e t w h i l e a minimum number o f t e s t s were a l s o conducted a t 1 . 7 5 and b>5 f o o t l o c a t i o n s above t h e G-11A canopy s k i r t .

In order t o e s t a b l i s h t r e n d s , opening f o r c e d a t a and a l t i t u d e l o s s i/O a c h i e v e e q u i l i b r i u m v e l o c i t y a r e p l o t t e d a g a i n s t G-11A canopy opening t i m e , F i g u r e s 1 and 2 . These p l o t s r e p r e s e n t d a t a g a t h e r e d i n the t e s t s of the 6 5 1 1 t h program and t h e Yuma t e s t s . I t i s noted t h a t the method of r i g g i n g the i n t e r n a l canopy f o r t h e s e t e s t s had no s i g n i f i c a n t e f f e c t on the o v e r a l l o p e n i n g p e r f o r m a n c e .

\

The f o r c e s , F i g u r e I , f o l l o w the normal e x p e c t e d treati and show a minor i n c r e a s e i n opening f o r c e induced by the i n t e r n a l canopy a s compared w i t h t h e l i m i t e d d a t a o b t a i n e d i n the Yuma t e s t s . The a l t i t u d e l o s s e s . F i g u r e 2 , show a t r e n d which i n d i c a t e s t h e f e a s i b i l i t y of c o n d u c t i n g t e s t s a t 50 f e e t above the t e r r a i n w i t h s i n g l e 100 f o o t d i a m e t e r c a n o p i e s (G-11A) .

Based upon P a r a c h u t e Branch e v a l u a t i o n of a v a i l a b l e t ^ s t f i l m s a d d i -t i o n a l comments on s p e c i f i c t e s t s conducted by t h e 6 5 H t h T e s t Group ( P a r a c h u t e s ) a r e a p p r o p r i a t e .

a . Drop No. OO9-F-62 - There a l s o a p p e a r s t o have been a t i e , l i n e t w i s t , or connector l i n k entanglement which may have delayed' o p e n i n g of the canopy. Once the a r e a of the c o n n e c t o r l i n k s ( w h i c h j o i n the G-11A r i s e r s and s u s p e n s i o n l i n e s ) became f r e e , f i l l i n g of the canopy r e t u r n e d t o normal .

b . Drop No. 1282-F-62 - Frame count of f i l m a v a i l a b l e i n d i c a t e s t h e opening time i s more i n t h e o r d e r of 7 . 8 s e c o n d s .

c . Drop N o ' s I998-F-62 and 2 0 5 1 - F - 6 2 , showed d e f i n i t e t w i s t i n g of the s u s p e n s i o n l i n e s which d e l a y e d canopy opening and f i l l i n g .

d . Drop No. OI59-F-62 - The f i l m r e v i e w e d shows t h a t i n t h e a r e a o f t h e G-11A s u s p e n s i o n l i n e c o n n e c t o r l i n k s t h e r e was an entanglement of a l l but two l i n k s and the i n t e r n a l p a r a c h u t e r i s e r .

T e c h n i c a l Memorandum SEM-IM-64-7

2

IV. DISCUSSION (Cont 'd)

Opening time as d iscussed in t h i s report i s the time from load t r a n s f e r , i . e . when the e x t r a c t i o n parachute becomes the p i l o t chute f o r G-11A, t o f u l l i n f l a t i o n of the G-11A canopy,

V. CONCLUSIONS - Although r e l i a b i l i t y cannot be e s t a b l i s h e d based upon the l imited number of t e s t s conducted and the v a r i e t y of parameters tested s e v e r a l v a l i d conclusions m y be drawn.

a . I t i s f e a s i b l e t o reduce the present a i r drop a l t i t u d e of s i n g l e G-11A parachutes s u b s t a n t i a l l y . The 13 and 16 f o o t d i a . i n t e r n a l canopies at 3 . 5 f e e t above and inside the G-11A s k i r t reduce the G-11A opening time with a minor increase in opening f o r c e .

b. The 16 foot d i a . i n t e r n a l canopy shows l e s s v a r i a t i o n in opening time and a l t i t u d e l o s s f o r a l l the l o c a t i o n s above the s k i r t than does the 13 f o o t d i a . canopy. (Where s u b s t a n t i a l l i n e t w i s t s were noted the data was d iscounted. ) D e l i v e r y with the 16 fcot d i a . i n t e r n a l canopy i s f e a s i b l e from an a l t i t u d e of 500 f e e t above the ground.

c . The method of r i n g i n g the i n t e r n a l canopy has l i t t l e s i g n i f i c a n c e on the opening c h a r a c t e r i s t i c s with the except ion that the i n t e r n a l canopy must be held taught or in p o s i t i o n during the long f o l d and stowing process of canopy packing and during deployment.

V I . RLCOM-jEIffiATIONS

a . I t i s recommended that the I n t e r n a l Parachute Study be continued i n t o a phase I I drop t e s t program t o determine the f e a s i b i l i t y of reducing canopy opening time and a l t i t u d e toss when used in c l u s t e r s . Proposed program i s contained in Appendix I I I and has been coordinated with U . S . Army Nat ick Laborator ies and the AFFTC (6511th TG(P).

b. I t i s recommended that a survey of twis ted l i n e s occurr ing in a i r drop programs be accomplished. The U . S . Army and the 6511th are con-t i n u a l l y making a i r drops and should seek t o provide data on G-11A and G-12 l i n e t w i s t occurrances . I t i s f u r t h e r recommended the parachute packing procedures be examined and changes made as required to assure t h a t t w i s t s w i l l not be packed-in and t h a t temporary l i n e t i e s cannot be l e f t in a packed parachute .

Technica l Memorandum S E M - W i - 6 4 - 7

REFERENCES

(1) FILGM-TM-63-IOJ4A, T i t l e d " I n t e r n a l Parachute Study", Gene E. Hamman, Captain, HoAF and Robert P . Hast ings , Captain, UuAF.

(2) Yuma Test S t a t i o n Report of DAT P r o j e c t No. ATA 62057, T i t l e d "Opening C h a r a c t e r i s t i c s of the G-11A Cargo P a r a c h u t e " , D i r e c t o r a t e of Air T e s t i n g , Yuma Test S t a t i o n , Yuma, Arizona.

(3) WABD TH-6O-67I, T i t l e d "A Method To Reduce ? a r a c ' - S I n f l a t i o n Time with A Minor Increase of Opening Force" , Helmut G. r leinrich and Ronald J. Nieeum.

Technical Memorandum SEM-TM-64-7 6

I

APPENDIX I

Extracts^ from T e c h n i c a l Memorandum No. FTLGM-TM-63-IO4A

TEST H 5 M S '

Non-standard f l a t - c i r o u l a r 1 5 ? 5 - f t . nominal d i a m e t e r (D 0 ) and l 6 - f t . DQ c a n o p i e s were the i n t e r n a l p a r a c h u t e s . Standard s t o c k l i s t e d G - 1 1 A , 1 0 0 - f t . D0 p a r a c h u t e s were the e x t e r n a l p a r a c h u t e s . v .

TEST E'-^UIPHlKT

1 . T e s t A i r c r a f t

The t e s t s were conducted u s i n g C-I3OA c a r g o t y p e a i r c r a f t .

> . T e s t Loads

A s t a n d a r d J-1A p l a t f o r m was b a l l a s t e d t o o b t a i n the d e s i r e d w e i g h t of 37OO pounds f o r the t e s t l o a d s .

3 . I n s t r u m e n t a t i o n

Two-channel t e l e m e t r i c equipment was u s e d . One channel 1 a s used t o measure t h e i n t e r n a l p a r a c h u t e f o r c e and t h e o t h e r used t o measure the t o t a l f o r c e .

As a back-up f o r c i n e t h e o d o l i t e c o v e r a g e , a 3 0 0 - f t . drop l,ine w i t h a 1 0 - s e c o n d t i m e - d e l a y was a t t a c h e d t o the l o a d s t o o b t a i n the r a t e of d e s c e n t o f t h e load j u s t p r i o r t o impact-, Hand o p e r a t e d s t o p w a t c h e s were used t o measure f u l l open, drop l i n e and down t i m e s .

2). P h o t o g r a p h i c Coverage

a . C i n e t h e o d o l i t e C o v e r a g e .

A s k a n i a c i n e t h e o d o l i t e s were used f o r space p o s i t i o n i n g t o determine t h e t r a j e c t o r y from which the late of d e s c e n t and a l t i t u d e change from r e l e a s e t o f u l l open were computed. The t ime of day i n b i n a r y code was r e c o r d e d on A s k a n i a f i l m f o r t ime c o r r e l a t i o n o f e v e n t s .

b . Motion P i c t u r e Coverage

S i x t e e n - m i l l i m e t e r motion p i c t u r e coverage r a n g i n g from 100 t o 200 frames per seconds was o b t a i n e d . One camera was l o c a t e d i n a photo chase a i r c r a f t t o photograph the e x t r a c t i o n , deployment and opening of the p a r a -c h u t e s . Two cameras were l o c a t e d a t the d r o p zone t o photograph the e x t r a c t i o n , deployment , o p e n i n g , d e s c e n t and i m p a c t . One camera was l o c a t e d i n the drop a i r c r a f t t o photograph the e x t r a c t i o n o f t h e l o a d s . One f i x e d camera was l o c a t e d i n an instrumented c l e v i s a t the c o n f l u e n c e p o i n t of the G-11A parachute t o photograph the deployment and opening o f the p a r a c n u t e s .

c . S t i l l Coverage

A s e v e n t y - m i l l i m e t e r sequence s t i l l camera l o c a t e d a t the drop zone was used t o photograph the e n t i r e drop sequence a t ten frames per s e c o n d .

T e c h n i c a l Memorandum SEM-TM-6/,-7.

7

t

o. S t i l l Coverage (Cont 'd)

l o a d s . * 5 " used t o obtain photographs of the r igged

TEST PHOCaDHfiKS

1 - " i g g i n ^ Procedures

J igg ing methoa A and r i g g i n c method "B

. the J - m l S ^ t l t t l t a i w a s T t e d of ' t e n s i l e s trength ( T . S . ) ano a S u S . s ! n y o n ^ b b i n a

l i n e served as a connection between the apex of th ? S ^ S 0 0 0 " " -apex of the G-11A canopy. This qOOO-^ b ! ? l n t e r n a l Parachute and the which were incorporated in the i l * . n a d ' one- foot break loops during deployment. Each b r e ^ loon t l + ^ T * ' ^ t h e S t r e t o h i n ^ o p y parachute w m one turn of 8 ^ 1 b L t t o n taoe l 0 P f t h e ^ the suspension l i n e conf luence ooint o? t h ^ \ K l e 1 6 o o - l b - l i n e connected l i n e confluence point of the G-IIA parachute P A R F C H " T E a n d ^ E suspension the 6000-lb. l i n e to measure t h e o p e ^ n g f o ^ e of t h ^ " ^ T i c c a t e d in-ment of the s k i r t separat ion dis tance ^ lu l n t e r n a l Parachute. Adjust

r n r r x i r ^ - s r

vere attached t o ' t h e G-11A parachute w i t h t o o o I T V ^ ^ k able r i s e r s . The a d j u s t a b l e internal ^ I w b r a i d e < 3 a d j u s t -G-11A parachute w i t h ' a u x i n L y S e c t o r 1 i ^ t S r i / T 0 I l n e 0 t e d ' a t G-11A r i s e r s ( 1 - 1 0 ) . ( s i - f o ) f A ? / T V o f S ' ,8) W h l 0 h w e r e i n s t a l l e d d i s t a n c e S was a d j u s t by p a s s i n i the nt ' separat ion a u x i l i a r y connector l i n k s on the S f l S ^ f ^ 1 p a r a c h u t e r i ^ s through the center core s e c t i o n of the braided i ^ o f r i S r f o l ^ T - ^ O h or so c a l l e d "Chinese f i n g e r " . The i f a s e l f - l o c k i n g device secured by tack ing with Not 5 cot ton threadt ^ u s t a b l e r i s e r was then

v a r i S ^ u r i n g ^ h ^ t e s t ^ p r o g r a m t l & ^ T S i E -d is tance was _ e d w i^th ^ K ^ S S . Z E ^

r ,

c u t t e r s . w t v o SO-IOOE two-second r e e f i n g l i n e

2 - A e r i a l Drop Tests

T h e s e ^ t e s t s ^ e r e Z l ^ V l l t i Z l l T ^ l * the t e r r a i n . droos were a c c o m n l i h f i f f ^ f T f t " t o ^ above rmtely 130 knots except f o r two t e s t s l n d i c a t e d a i r s p e e d of approxi-indicated a i r s p e e d . h l 0 h W e r e i n d u c t e d a t 110 knots

Technical Memorandum -JoK-Tw-64-7

2 . A e r i a l Drop T e s t s ( c o n t ' d )

A l ^ - f t . D0 r i n g - s l o t e x t r a c t i o n parachute which was permanently r e e f e d wi th a 2 6 0 - i n . r e e f i n g l i n e was used t o e x t r a c t the load and deploy, the G-11A parachute w i t h i t s i n t e r n a l parachute on each t e s t . Force t r a n s f e r was accomplished by u s i n g the standard c o n f i g u r e d e x t r a bar t r a n s f e r d e v i c e on the J-1A p l a t f o r m .

TEST RESULTS

Test r e s u l t s are g i v e n i n Table I .

T e c h n i c a l Memorandum SEM-IM-64-7

9

'tSS'ilXCS OF

S k i r t sepa-Heefing r a t i o n S ( f t )

Test - No.

Drop Wo.

Date Gross

V,eight ( lb)

l i n e length

( f t )

Interna l parachute

and r i g g i n g method

Drop airspeed

(OAS)

1 I650-F-61 22 Deo 61 3500 1+0 1 3 . 5 - f t . FC 3.5 7 150 2 1731+-F-61 1 1 Jan 62 3700 rSo 1 3 . 5 - f t . FC 3.5 B 130 5 1735-F-61 ' 1 1 Jan 62 3700 1+0 1 3 . 5 - f t . FC 7.5 A 150 U 0069-F-62 19 Jan 62 5', 00 None 1 3 . 5 - f t . FC 3 . 5 B 130

5 0070-F-62 19 Jan 62 5 yoo 60 1 3 . 5 - f t . FC 3 . 5 A 131 6 0096-F-62 23 Feb 2 Jvo.. 60 1 3 . 5 - f t . FC 3 . 5 B 130 7 2; Feb 62 : ,'00 1+0 , 1 3 . 5 - f t . FC 3 .5 A 130

C09S-F-62 2 Feb 62 3700 None 1 3 . 5 - f t . re 3.5 A 130 0259-F-62 5 Mar 62 3 , 0 , 20 1 3 . 5 - f t . FC 3.5 B 130

10 0260-F-62 5 Mar 62 5700 20 1 3 . 5 - f t . FC 3-5 A 130 1 1 0320-F-62 28 Mar . 3,oo 1+0 1 3 . 5 - f t . FC 3 .5 B 130 12 0321-F-62 28 Far 2 370!, .0 1 3 . 5 - f t . FC 3 .5 A 330

15 0575-F-62 16 Apr 62 3 yoo Fone 1 3 . 5 - f t . FC 3-5 3 130

H+ 0576-1-62 17 Apr 62 3' 0 20 1 3 . 5 - f t . FC 5 .5 A 131 15 1062-F-62 l-> Jun S ,00 20 1 3 . 5 - f t . FC 1 . 7 5 B 130

1063-- -62 18 Jun 62 3700 None .5-ft. 1'C 1 . 7 5 s 15 J 17 12S1-F-62 1 ) Jul 62 3700 20 1 3 . 5 - f t . FC 1 . 7 5 A 130 IS I- 32-F-62 1..' Jul 62 37CO 20 1 5 . 5 - f t . FC 1 . 7 5 A 13 3 19 135 -F-62 26 Jul 62 3700 20 1 5 . 5 - f t . FC .7.5 A 110 20 1339-F-62 2fc Jul 62 3,00 20 1 3 . 5 - f t . FC 1+.5 A 110

137 F-62 6 Aug 62 3700 20 1 6 - f t . FC 1 . 7 5 A 130 1379-5-62 6 Aug 62 3 00 20 1 6 - f t . FC 1 . 7 5 A 130

23 1I4IL-F-62 9 Aug 62 570' 20 1 6 - f t . FC 3 .5 A 150 3J+15-F-62 9 Aug 62 3700 20 l ( > - f t . FC 3.5 A 150

25 U+56-F-62 11+ Aug 62 3700 20 1 6 - f t . FC 1+.5 A 130 26 H+57-F-62 11+ Aug 62 3700 2

TABLE RESULTS 01

Test No.

Drop No.

Reefing Gross l i n e Interna l .

Date weight length parachute ( l b ) ( f t )

S k i r t sepa-r a t i o n S ( f t ) and r i g g i n g Drop A1

method airspeed (p ( M S )

29 199S-F-62 6 Dec 62 3700 20

30 1999-F-62 6 Dec (2 3700 20

31 2050-F-62 17 Jan 63 3700 20

32 2051-F-62 17 Jan 63 3700 20

33 0113-F-63 2U Jan 63 3700 20

3U 011i+-F-63 2U Jan 63 3700 20

35 0159-F-63 5 Feb 63 3700 60

36 0160-F-63 5 Feb 63 3700 60

37 Olol-F-63 8 Feb 63 3700 60

33 0162-F-63 3 Feb 63 3700 60 1 6 - f t . FC

1 3 . 5 - f t . FC

1 3 . 5 - f t . FC

1 6 - f t . FC

1 6 - f t . FC

1 6 - f t . FC

l l ^ f t . FC

1 6 - f t . FC

1 6 - f t . FC

1 3 . 5 - f t . FC

3.5 A

3.5 A

3.5 A

3.5 A

3.5 A

3.5 A

3.5 A

3.5 A

3.5 A

130

130

130

130

130

130

130

130

130

130

1

* Not instrumented '

* * Data not obtained

R'^ it'AR KS

(A) The platform tumbled in a p o s i t i v e d i r e c t i o n ( a f t end r o t a t ' n g downward) and the susper,s:

(B) The attachment between the apexes of the i n t e r n a l and G-11A parachutes was e l iminated . Th: canopy during deployment and opening; the i n t e r n a l parachute wrapped around the l i n e s of t platform was destroyed a t impact.

(C) The suspension l i n e s tangled then c l e a r e d producing a slow opening.

(D) The G-11A parachute did not f u l l y open before impact. Time from r e l e a s e to impact was .J

(E) The G-11A parachute experienced a s l i g h t s k i r t r e s t r i c t i o n 0

(F) The C-11A suspension l i n e s twisted during opening r e s u l t i n g in a slow opening.

(G) The suspension l i n e s of the e x t e r n a l parachutes tangled in t h e suspension l i n e attachment parachute was not involved in the entanglement.

TA 12 I (CONTM RESULT.; Of' ATRIAL DROP TESTS

spa-S ( f t ) ;ing Drop

airspeed (KIAS)

irop a l t i t u d e (pressure

( f t )

130 '+30

130 500 130 1500

130 1500

130 700 130 630

130 700

130 700

130 680

130 700

Opening time (sec)

I.U 7.6

..6

9.2

9 .0

3 .0

6.'5 i'-.Jj

1 'U

iaxuium t o t a l f o r c e ( lb)

, 720

9,275

7,U70

3,300

9,1(50 3,610

8,600

7, < oo

t

i aximum i n t e r n a l parachute

f o r c e ( l b )

1,500

1 ,375

3 ,175

,10 2,135

2,313

2,625

2,2.60

A l t i t u d e change

r e l e a s e to f u l l open

( f t )

* *

it 30

Uko 3-30

51(2 451

311+ 503

331+

Rate of descent corrected t o

ICAO standard atmosphere

( f t / s e c )

21 .3

23.0

20.9

1 9 . 2

23.6

1 7 . 5

18.9

1 3 . 5

lie marks

(D)

(S)

(F)

(5)

rd) and the suspension l i n e s between the i n t e r n a l and G-11A parachutes tangled causing a slow opening.

was e l iminated. This al lowed the v e r t i c a l l y unrestrained i n t e r n a l parachute to drop below the s k i r t of the G-11A round the l i n e s of t h e G-11A paraciiute. This r e s u l t e d in a r e s t r i c t e d opening and high r a t e of descent . The J-1A

se to impact was . j seconds. Rate of descent a t impact was approximately I4O f e e t per second,

opening.

i.on l i n o att-achme ; l i n k area and the recovery parac. ute did not f u l l y open. The suspension r i s e r of the i n t e r n a l

1 1

APPENDIX I I

E x t r a c t s from Yuma Test S t a t i o n Report of DAT P r o j e c t No. ATA 62057

PART I - General

A. D e s c r i p t i o n of M a t e r i e l ; The G-11A cargo parachute packed wi th and without r e e f i n g l i n e .

B. Test O b j e c t i v e s : The o b j e c t i v e i s t o determine the opening c h a r a c t e r -i s t i c s of the G-11A parachute canopy with and without r e e f i n g l i n e during a i r drop of a 3,500-pound load from a C-I30 a i r c r a f t f l y i n g at 1,500 f e e t absolute a l t i t u d e and 130 knots i n d i c a t e d a i r speed.

C. Findings : The performance c h a r a c t e r i s t i c s of the G - l l A cargo parachute packed wi th a r e e f i n g l i n e i s comparable in regard t o snatch and opening f o r c e s to the G- l lA packed without a r e e f i n g l i n e . The G- l lA cargo parachute packed without r e e f i n g l i n e opened a t an average of 2.8 seconds f a s t e r with an average r e d u c t i o n in a l t i t u d e l o s s of 272 f e e t as compared with the r e e f e d G - l l A cargo parachute . See Table in Part I I , s e c t i o n B1 and Annex B, Table I .

D. Conclus ions: I t i s concluded t h a t :

a . The unreefed G - l l A cargo parachute i s capable of a i r d e l i v e r y of a 3,500-pound load with f a s t e r opening time and l e s s a l t i t u d e l o s s than the r e e f e d G- l lA cargo parachute .

b . There i s no s i g n i f i c a n t d i f f e r e n c e in magnitude of snatch and opening f o r c e s between the r e e f e d and unreefed G- l lA cargo parachute in a i r d e l i v e r y ' o f a 3,500-pound l o a d .

PArtT I I - Test Lata

A. M a t e r i e l and Equipment:

1 . Energy D i s s i p a t i n g M a t e r i e l : Paper Honeycomb, 80 (0) 1/2 EDF.

2 . P l a t f o r m : Plat form Assembly, Cargo Air D e l i v e r y , 6,000-pound Load, with B a l l a s t .

3 . P a r a c h u t e s :

a . G - l l A Cargo Parachute

b . 1 5 - f o o t R i n g s l o t E x t r a c t i o n Parachute

Technica l Memorandum SEM-IM-64-7

12

PA/.T I I - Test Data (Cont 'd)

B. Instrumentat ion:

1 . M e t e o r o l o g i c a l : M e t e o r o l o g i c a l data was provided by U . - . Army S i g n a l Corps Meteorologica l Team, Yuma Test S t a t i o n , Ar izona.

2. Tensiometers: S e l f - r e c o r d i n g , photographic .tensiometers v;ere employed to record parachute opening f o r c e d a t a .

3 . C inetheodol i te : Air d e l i v e r y system t r a j e c t o r y data was obtained by use of c i n e t h e o d o l i t e instrumentat ion. P o r t i o n s of the reduced data are contained in Annex B, Table I . Complete t r a j e c t o r y data are a v a i l a b l e from t h i s d i r e c t o r a t e .

!). Motion P i c t u r e Coverage: A i r - t o - a i r and g r o u n d - t o - a i r motion p i c t u r e coverage photographed e x t r a c t i o n , deployment, d e s c e n t , and impact r'icnomena. Photographic coverage of the canopy opening c h a r a c t e r i s t i c s was obtained by use of a gun camera mounted on a 2 - f o o t s l i n g attached below the r i s e r extension confluence p o i n t .

c . Procedures :

Ten a i r drop t e s t s were conducted t o obtain required data f o r determi-nat ion of the opening c h a r a c t e r i s t i c s of the G-11A cargo parachute. Five te.-ts were conducted with the parachute packed in accordance with stanc

D. Data:

. D a t a re

Ul c!

M

.o vo, o cc HvDvo cy h co -4-no c n c ^ n cr

( s q i ) "SOHOi 0MIN3J0 o o o o o o o o o o o o o o O ^ ^ O O O J O l f l p rosac^F-coac^r

d

(B1T ) 30H0,S KOXTOS o * o o o o o o o s o o o o o o u v ^ o o o o ^ ^ i o v n

EH

1 > 1 A

* ( s d j ) ' p ? s ) " M s 3XVH a n i n ' b s

CMCM t^-=tOCMCOC-CT* i^-OJCMCViCMCMCMrHr-CiHCM EH

1 > 1 A insect SLVH anun?-^

cniA vr> rH cno-^ co o t-H CyWCMCNJv'MiMHHCyCM

' ss 0 n E-i 1

( o s s ) H/AOa CM CO CM CO O O J-CO -3"C0 -ic-^ - i o LP, ^r (rv-n UVA c*- u^ i

( o e s ) H O I i W I I i a Y I S \DNO OJ CO cy - ^ o o c o ^ cr^ j^-cr^ -crco co -^ r^ o t>-i4 i1 H t f t CM CO i-H f-'

( o s s ) pNIMsiS J--J-C0 -d" -J J-CO CM o-c>aNco o^o^o^o covo

( s e e ) D j t f t l L i a o o c o CM O O O CO -^ 3" co

a^ ^

( o s s ) l i F W K n a s a ' D^ 4 0 (M -d" f^ H ^ n ^ H H H H H H

( o s s ) TIVJ 50HJ W W 4 C M O O I M O W W o o o c o o o o o o

( o a s / i j ) MIOOIIA C^ -^ OCO CM C*"\ C CM CM CO CM CM -=t r-i CO Al -H COCO J CM CM CM CM CM CM iM iM CM

l i ( w ) ( s q s ) l o n i i n v cr* coco j - c n n - H coci~\-j u^co c^vrSco^o vO co -^ t v> -tfvO I1 (t IIf1

O CO

t

Table I I : Meteorologica l l a t a

SURFACE MLT2.0HGL0GICAL DATA AIRCRAFT ALTITUDE

METEOROLOGICAL DATA

.1 ' 2 '3 4 5 6

7 8 9

10

103.8 9 7 - 3

100.0 109.6 102.3

96.0-9 7 . 4

98.9 96.6 >5.8

16 21 21 20 27 30 26 30 3 4 3 7

29.I1 29. 4 29.4 29.4 29.4 29.4 29.4 29.3 2 9 . 4 2 9 . 4

2.14 2 . 1 6 2 . 1 5 2 . 1 2 2 .14 2 . 1 6 2 . 1 6 2 . 1 5 2 . 1 6 2 . 1 5

8 . 7 4 - 9

P -4 .5 6.0 *ND 3.0 3.0 1 1 . 0 2,0

3.0

220 185 218

ND 165 045 185 235 215

1600 1500 1500 1994

ND L500 1500 1500 1500 1500

4 7 9 0 4500 4490 5 4 0 0

ND 4 3 7 5 4260 4600 4280 4220

9 - 3 6.0 7.0

14.0 ND

8.0 7.0

15.0 4.0

1 1 . 0

4 No Data

16

' f ! I i i I APPENDIX I I I

PROPOSED T-cT PROGRAM G-11A Parachute C l u s t e r s wi th I n t e r n a l Canopies

Mr. of Drops* Nr. tn C l u s t e r s Remarks.

" O Use standard G-11A c o n f i g u r a t i o n wi th 16** f o o t f l a t c i r c u l a r i n t e r n a l canopy.

5 3

3

Standard G-11A except that the r e e f i n g l i n e l e n g t h s h a l l be 60 f e e t .

^ Optimized r e e f i n g l i n e l e n g t h w i l l be used

^ Optimized r e e f i n g l i n e l e n g t h w i l l J be used

Optimized r e e f i n g l i n e l e n g t h w i l l be used

* This i s a reasonable minimum number of t e s t s required t o demonstrate f e a s i -

b i l i t y .

** Based upon s i n g l e canopy performance the 16 f o o t i n t e r n a l canopy l o c a t e d 3 . 5 f e e t above and i n t e r n a l t o the G-11A s k i r t was s e l e c t e e .

Technica l Memorandum SEM-TM-6^-7 17