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Aviation Machinist's Mate R 1 and C: Rate TrainingManual.Naval Education and Training Command, Pensacola,Fla.NAVEDTRA 10344-B74215p.Superintendent of Documents, U. S. GovernmentPrinting Office, Washington, D. C. 20402 (StockNumber 0502-LP-051-7210)

NF-S0.76 HC-S10.78 PLUS POSTAGE*Aviation Mechanics; *Aviation Technology; CourseContent; Engines; *Equipment Maintenance;Instructional Materials; *Job Training; *Manuals;Military Personnel; Military Training;' Promotion(Occupational); Skill Development

ABSTRACTThe profusely illustrated rate training manual is one

of a series of training manuals prepared for enlisted personnel ofthe Navy and Naval Reserve who are studying for advancement in theAviation Machinist's Mate R rating (ADR 1 and ADRC). Chapter oneprovides information helpful for use in advancement. Chapters twothrough ten consist of units on aviation supply, work centersupervision and administration, reciprocating engine systems,reciprocating engine troubleshooting, engine analyzers, reciprocatingengine removal and installation, fuel system maintenance, propelleroperation and maintenance, and helicopter maintenance. A subjectindex is included. (Author/BP)

U S DEPARTMENTOfHEALTH.

EDUCATION A WELFARENATIONAL INSTITUTE Of

EDUCATIONTHIS DOCUMENT HAS BEEN REPROOuCED EXACTLY AS RECEIVED PROMTHE PERSON ORORGANIZATION ORIGINATING IT POINTS

OP VIEW OR OPINIONSS ATED 00 NOTNECESSARILY REFIRESENT OFFICIAL

NATIONAL INSTITUTE OFFOUCATION POSITION OR POLICY

NAVAL EDUCATION AND TRAINING COMMANDRATE TRAINING MANUAL_ NAVEDTRA 10344-6

PREFACE

This Rate Training Manual is one of a series of training manualsprepared for enlisted personnel of the Navy and Naval Reserve who arestudying for advancement in the Aviation Machinist's Mate R rating.As indicated by the title, the manual is based on the professionalqualifications for the rates of ADM and ADRC, as set forth in theManual of Qualifications for Advancement, NavPers 18068 (Series).

....

This training manual was prepared by the Naval Education andTraining Program Development Center, Pensacola, Florida, for the -Chief of Naval Education and Training Support. Technical review ofthe manuscript was provided by the personnel of the Aviation Machin-ist's Mate School, NATTC, Naval Air Station Memphis, Millincton,Tennessee. Technical assistance was also provided by the Naval AirSystems Command.

1974 Edition

Published by

NAVAL EDUCATION AND TRAINING SUPPORT COMMAND

Stock Ordering No.

0502-LP-051-7210

UNITED STATESGOVERNMENT PRINTING OFFICE

WASIINGTON, D.C.: 1974

i

THE UNITED STATES NAVY

GUARDIAN OF OUR COUNTRYThe United States Navy is responsible for maintaining control of the seaand is a ready force on watch at home and overseas, capable of strongaction to preserve the peace or of instant offensive action to win in war.

It is upon the maintenance of this control that our country's gloriousfuture depends; the United States Navy exists to make it so.

WE SERVE WITH HONOR

Tradition, valor, and victory are the Navy's heritage from the past. Tothese may be added dedication, discipline, and vigilance as the watchwordsof the present and the future.

At home or on distant stations we serve with pride, confident in the respectof our country, our shipmates, and our families.

Our responsibilities sober us; our adversities strengthen us.

Service to God and Country is our special privilege. We serve with honor,

THE FUTURE OF THE NAVY

The Navy will always employ new weapons, new techniques, andgreater power to protect and defend the United States on the sea, underthe sea, and in the air.

Now and in the future, control of the sea gives the United States hergreatest advantage for the maintenance of peace and for victory in war.

Mobility, surprise, dispersal, and offensive power are the keynotes ofthe new Navy. The roots of the Navy lie in a strong belief in thefuture, in continued dedication to our tasks, and in reflection on ourheritage from the past.

Never have our opportunities and our responsibilities been greater.

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CONTENTS

Chapter Page

1. Aviation Machinist's Mate R rating 1

2. Aviation supply 13

3. Work center supervision and administration 33

4. Reciprocating engine systems 73

5. Reciprocating engine troubleshooting 102

6. Engine analyzers 120

7. Reciprocating engine removal and installation 142

8. Fuel system maintenance 162

9. Propeller operation and maintenance 169

10. Helicopter maintenance 194

Index 208

5iii

CHAPTER 1

AVIATION MACHINIST'S MATE R RATING

This training manual is designed to aid theADR2 in preparing for advancement to ADR1and the ADR1 in preparing for advancement toADRC. It is based primarily on the professionalrequirements or qualifications for ADR1 andADRC, as specified in the current edition of theManual of Qualifications for Advancement, Nav-Pers 18068. In preparing for advancementexaminations, this manual should be studied inconjunction with Military Requirements forPetty Officer 1 & C, NavPers 10057 (Series).

In preparing this training manual, every efforthas been made to cover professional mattersadequately and yet within reasonable bounds. Ithas been designed to give the prospective ADR1and ADRC a good working knowledge of allsubjects covered by the professional qualifica-tions for advancement. It includes some newmaterial required as a result of new or revisedmaintenance programs and qualificationchanges.

The remainder of this chapter is devoted toinformation which should be helpful inpreparing for advancement. It is strongly recom-mended that this material be studied carefullybefore beginning intensive study of theremainder of the manual.

ENLISTED RATING STRUCTURE

The present enlisted rating structure includestwo types of ratings: general ratings and serviceratings.

GENERAL RATINGS are designed to providepaths of advancement and career development.A general rating identifies a broad occupationalfield of related duties and functions requiringsimilar aptitudes and qualifications. Generalratings provide the primary means used toidentify billet requirements and personnelqualifications. Some general ratings include

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service ratings; others do not. Both RegularNavy and Naval Reserve personnel may holdgeneral ratings.

Subdivisions of certain general ratings areidentified as SERVICE RATINGS. These serviceratings identify areas of specialization within thescope of a general rating. Service ratings areestablished in those general ratings in whichspecialization is essential for efficient utilizationof personnel. Although service ratings can existat any petty officer level, they are most com-mon a?. the P03 and P02 levels. Both RegularNavy and Naval Reserve personnel may holdservice ratings.

THE ADR RATING

The Aviation Machinist's Mate rating iscomposed of two service ratings and one generalrating. The service ratings are AviationMachinist's Mate J (ADJ) and Aviation Machin-ist's Mate R (ADR). The two service ratingsapply to personnel in pay grades E-4 throughE-7. The general rating is known simply as theAviation Machinist's Mate rating and appliesonly to pay grade E-8 (ADCS). At pay grade E-9the AD rating loses its identity and the ADCSadvances, along with the AMCS to Master ChiefAircraft Maintenanceman (AFCM). Figure 1-1illustrates the paths of advancement fromRecruit to Master Chief Aircraft Maintenance-man (AFCM), Warrant Officer (W-4), andLimited Duty Officer.

Shaded areas in figure 1-1 indicate careerstages from which qualified enlisted men mayadvance to Warrant Officer (W-1), and selectedCommissioned Warrant Officers (W-2 and W-3)may advance to Limited Duty Officer.

Aviation Machinist's Mates R maintain air-craft reciprocating engines and their relatedsystems including the fuel, oil, ignition, propel-

AVIATION MACHINIST'S MATE R 1 & C

WARRANTOFFICER

W -I

L DOAV.

MAINT.

CWOW- 4

ADJC AMEC

ADJ2 ADR2E-5

AM H2AMS2

E -5AME2

ADJ3 ADR3E-4

AMH3 AMS3E-4

AME3

*AMEAIRMANE-3 AMEAN

SCHOOL

AIRMANAPPRENTICE

E-2

1.00 INPUT ZONE

AIRMAN * SUCCESSFUL COMPLETION

WARRANT OFFICER INPUT ZONERECRUIT

E-IOF CLASS A SCHOOL IS AMANDATORY REQUIREMENTFOR ADVANCEMENT TO AME 3.

Figure 1-1.--,Paths of advancement.AM.1

Chapter 1AVIATION MACHINIST'S MATE R RATING

ler, and exhaust systems; preflight aircraft;conduct periodic inspections on reciprocatingengines and related systems; test, adjust, remove,replace, preserve, and depreserve engines andengine accessories including carburetors,magnetos, pumps, and other components of theengine and its systems, and supervise reci-procating engine work centers.

In addition to the above listed requirementsthe Chief and First Class Aviation Machinist'sMate R must be qualified to supervise and directperiodic inspections; maintain logs and recordsand prepare reports; order and identify publica-tions; identify and order aircraft parts, tools,and equipment, maintain current shop files ofdirectives and other publications; maintaininventory records; use schematic diagrams, draw-ings, and charts in troubleshooting and correct-ing powerplant system malfunctions; review andevaluate completed inspection forms andreports; analyze reports of discrepancies andmalfunctions and determine corrective action;organize and administer a program of safetyinstructions applicable to aircraft powerplantsand related systems; supervise the man-houraccounting program; interpret directives fromhigher authorities; schedule and assign workload;and maintain quality control of work per-formed.

A wide variety of assignments is available tothe ADR1 and ADRC. In addition to the varioustypes of maintenance activities afloat and ashoreto which ADR personnel are assigned, the ADRIand ADRC are eligible for assignment to instruc-tor duty as well as a numter of other desirableshore billets. Most of these billets are under themanagement control of BuPers and are directlyassociated with training. Others are associatedwith research, testing, or evaluation. Some ofthe more desirable billets to which the ADR1and ADRC may be assigned are described in thefollowing paragraphs.

1. Instructor duty is available to both theADR1 and ADRC at NATTC, Memphis, Ten-nessee, in all of the AD schools. In addition tothe AD schools, the ADR1 and ADRC may beassigned to instructor duty with a unit of theNaval Air- Maintenance Training Group(NAMTG). Units of NAMTG are located atshore stations on both coasts. Personnel assignedto this duty are first sent to Naval Air Main-tenance Training Group Headquarters at

Memphis for a period of indoctrination andinstruction prior to being assigned to one of themany units.

Instructor billets are normally filled on avoluntary basis. Detailed information concerningassignment to instructor duty is contained in theEnlisted Tranifer Manual, NavPers 15909(Series).

2. Chief, Senior Chief, and Master ChiefPetty Officers are eligible for assignment forduty with the Naval Education and TrainingProgram Development Center (NavEdTraPro-DevCen), Pensacola. Florida. NavEdTraProJevCenwas recently established by consolidating thefollowing former activities: Naval ExaminingCenter, Great Lakes, Illinois; Navy 'f gainingPublications Center, Memphis, Tennessee; NavyTraining Publications Detachment, Washington,D.C.; and Naval Correspondence Course Center,Scotia, New York. AD's assigned to NavEd-TraProDevCen assist in the preparation and re-vision of Rate Training Manuals, NonresidentCareer Courses, and Navy-wide AdvancementExaminations for the ADR and ADJ ratings.

3. Recruiting duty billets are available toboth the ADR I and ADRC. These billets arelocated in various towns and cities throughoutthis country and in some possessions.

4. Attache duty is another possibility. Thisduty may be performed at numerous placesthroughout the world.

There are a number of special programs andprojects to which enlisted personnel may beassigned. Some of these involve research, othersmay involve testing or evaluation. An exampleof such an assignment is with the PersonnelResearch Division (PRD), Naval Aviation Inte-grated Logistic Support Center (NAILSC), NASPatuxent River, Maryland. Their mission is todevelop recommended personnel requirementsfor squadrons operating and maintaining thelatest types of weapon systems.

For a listing of other special programs, refer-ence should be made to the Enlisted TransferManual. Others are also announced from time totime in BuPers Notices.

Personnel may indicate their desire for assign-ment to a specific program or proket byindicating it in the "remarks" block of theirRotation Data Card.

As a petty officer you are already aware ofthe importance of the ADR rating to naval

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aviation. Pilots and aircrewmen depend upon theADR for the efficient operation of the aircraft.As aviation progresses, improved powerplantsmust be developed. Thus, the ADR's jobinvolves new and greater responsibilities, and at.all levels he must possess greater technical skillsthan ever before.

When advanced to ADRI and ADRC, evenmore responsibilities are to be yours. As a seniorpetty officer you must possess more thantechnical skills. You must assume greater respon-sibilities not only for your own work, but alsofor the work of others who serve under you.Priefly, the ADR1 and ADRC must be a skilledmechanic, supervisor, inspector, and instructor,as well as an accomplished military leader.Senior Petty officers are therefore vitally con-cerned with the Naval Leadership Program.

As a result of the Naval Leadership Program, aconsiderable amount of material related to navalleadership for the senior petty officer is avail-able. Studying this material will make you awareof your many leadership responsibilities as asenior petty officer and will also be of great helpin developing leadership qualities. It will not initself, however, make you a good leader. Leader-ship principles can be taught, but a good leaderacquires that quality only through hard workand practice.

As you study this material containing leader-ship traits, keep in mind that probably none ofour most successful leaders possessed all of thesetraits to a maximum degree, but a weakness insome traits was more than compensated for bystrength in others. Critical self-evaluation willenable you to realize the traits in which you arestrong, and to capitalize on them. At the sametime you must strive to improve on the traits inwhich you are weak.

Your success as' a leader will be decided, forthe most part, by your achievements in inspiringothers to learn and perform. This is bestaccomplished by personal example.

ADVANCEMENT

By this time, you are probably well aware ofthe personal advantages of advancement higherpay, greater prestige, more interesting andchallenging work, and the satisfaction of getting

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ahead in your chosen career. By this time, alsoyou have probably discovered that one of themost enduring rewards of advancement is thetraining you acquire in the process of preparingfor advancement.

The Navy also profits by your advancement.Highly trained personnel are essential to thefunctioning of the Navy. By advancement, youincrease your value to the Navy in two ways;first, you become more valuable as a technicalspecialist, and thus make far-reaching contribu-tions to the entire Navy; and second, youbecome more valuable as a person who cansupervise, lead, and train others.

Since you are studying for advancement toP01 or CPO, you are probably already familiarwith the requirements and procedures foradvancement. However, you may find it helpfulto read the following sections. The Navy doesnot stand still. It is possible that some of therequirements have changed since the last timeyou went up for advancement. Furthermore,you will be responsible for training others foradvancement; therefore, you will need to knowthe requirements in some detail.

HOW TO QUALIFY FORADVANCEMENT

To qualify for advancement, a person must:1. Have a certain amount of time in grade.2. Complete the required Rate Training

Manuals either by demonstrating a knowledge ofthe material in the manual by passing a locallyprepared and administered test or by passing theNon-Resident Career Course based on the RateTraining Manual.

3. Utilizing an appropriate Personnel Quali-fication Standard (when applicable) as a guide-line, become qualified and demonstrate yourability to perform all the practical requirementsfor advancement by completing the Record ofPractical Factors, NavEdTra 1414/1.

4. Be recommended by his commanding of-ficer, after the petty officers and officers super-vising the work have indicated that theyconsider him capable of performing the duties ofthe next higher rate.

5. Demonstrate KNOWLEDGE by passing awritten examination on (a) military require-ments, and (b) professional qualifications.


Remember that the requirements for advance-ment can change. Check with your educationalservices office to be sure that you know themost recent requirements.

When you are training lower rated personnel,it is a good idea to point out that advancementis not automatic. Meeting all the requirementsmakes a person ELIGIBLE for advancement, butit does not guarantee his advancement. Suchfactors as the score made on the writtenexamination; length of time in service, perform-ance marks, and quotas for the rating enter intothe final determination of who will actually beadvanced.

HOW TO PREPAREFOR ADVANCEMENT

What must you do to prepare for advance-ment? You must study the qualifications foradvancement, work on the practical factors,study the required Rate Training Manuals, andstudy other material that is required. You willneed to be familiar with the following:

1. Manual of Qualifications for Advance-ment, NavPers 18068 (Series).

2. Record of Practical Factors, NavEdTra1414/1.

3. Bibliography for Advancement Study,NavEdTra 10052 (Series).

4. Applicable Rate Training Manuals andtheir companion Nonresident Career Courses.

Collectively, these documents make up anintegrated training package tied together by thequalifications. The following paragraphs describethese materials and give some information onhow each one is related to the others.

"Qua ls" Manual

The Manual of Qualifications for Advance-ment, NavPers 18068 (Series), gives theminimum requirements for advancement to eachrate within each rating. This manual is usuallycalled the "Qua ls" Manual. and the qualifica-tions themselves are often called "quals." Thequalifications are of two general types: (1)military requirements, and (2) professional ortechnical qualifications. Military requirementsapply to all ratings rather than to any one ratingalone. Professional qualifications are technical or

10 5

professional requirements that are directlyrelated to the work of each rating.

Both the military requirements and theprofessional qualifications are divided intosubject matter groups. Then, within each subjectmatter group, they are divided intoPRACTICAL FACTORS and KNOWLEDGEFACTORS.

The qualifications for advancement and abibliography of study materials are available inyour educational services office. The " Quals"Manual is changed more frequently than RateTraining Manuals are revised. By the time youare studying this training manual, the "quals"for your rating may have been changed. Nevertrust any set of "quals" until you have checkedthe change number against an UP-TO-DATEcopy of the "Qua ls" Manual.

In training others for advancement, emphasizethese three points about the "quals";

1. The "quals" are the MINIMUM require-ments for advancement. Personnel who studyMORE than the required minimum will have agreat advantage when they take the writtenexaminations for advancement.

2. Each "qual" has a designated rate levelchief, first class, second class, or third class. Youare responsible for meeting all "quals" specifiedfor the rate level to which you are seekingadvancement AND all "quals" specified forlower rate levels. This manual is written toprovide additional or add-on information to thatcontained in ADR3 & 2, NavPers 1034 2-A, andit is recommended that the material in this 3 & 2manual be reviewed.

3. The written examinations for advancementwill contain questions relating to the practicalfactors AND to the knowledge factors of BOTHthe military requirements and the professionalqualifications.

Record of Practical Factors

Before you can take the Navy-wide examina-tion for advancement, there must be an entry inyour service record to show that you have quali-fied in the practical factors of both the militaryrequirements and the professional qualifications.A special form known as the Record of PracticalFactors, NavEdTra 1414/1 (plus the abbrt.via-tion of the appropriate racing), is used to keep a

AVIATION MACHINIST'S MATE R I & C

record of your practical factor qualifications.The form lists all practical factors, both militaryand professional. As you demonstrate yourability to perform each practical factor, ap-propriate entries arc made in the DATE andINITIALS columns.

As a P01 or CPO, you will often be requiredto check the practical factor performance Oflower rated personnel and to report the resultsto your supervising officer.

As changes are made periodically to the"Qua ls" Manual, new forms of NavEdTra 1414/1are provided when necessary. Extra space isallowed on the Record of Practical Factors forentering additional practical factors as they arepublished in changes to the "Quals" Manual.The Record ,,f Practical Factors also providesspace for recording demonstrated proficiency inskills which are within tne general scope of therating but which are not identified as minimumqualifications for advancement. Keep this inmind when you are training and supervisingother personnel. If a person demonstratesproficiency in some skill which is not listed inthe "quals" but which is within the generalscope of the rating, report this fact to thesupervising officer so that an appropriate entrycan be made in the Record of Practical Factors.

When you are transferred, the Record ofPractical Factors should be forwarded with yourservice record to your next duty station. It is agood idea to check and be sure that this form isactually inserted in your service record beforeyou are transferred. If the form is not in yourrecord, you may be required to start all overagain and reivalify in practical factors that havealready been checked off. You should also takesome responsibility for helping lower ratedpersonnel keep track of their practical factorrecords when they arc transferred.

A second copy of the Record of Practicalractors should be made available to each man inpay grades E-2 through E-8 for his personalrecord and guidance.

The importance of NavEdTra 1414/1 cannot beoveremphasized. It serves as a record to indicateto the petty officers and officers supervisingyour work that you have demonstrated profi-ciency in the performance of the indicatedpractical factors and is part of the criteriautilized by your commanding officer when he

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considers recommending you for advancement.In addition, the proficient demonstration of theapplicable practical factors listed on this formcan aid you in preparing for the examination foradvancement. Remember that the knowledgeaspects of the practical factors arc covered in theexamination for advancement. Certain knowl-edge is required to demonstrate these practicalfactors and additional knowledge can beacquired during the demonstration. Knowledgefactors pertain to that knowledge which isrequired to perform a certain job. In otherwords, the knowiedge factors required for acertain rating depend upon the jobs (practicalfactors) that must be performed by personnel ofthat rating. Therefore, the knowledge requiredto proficiently demonstrate these practicalfactors will definitely aid you in preparing forthe examination for advancement.

Personnel Qualification Standards

Personnel Qualification Standards (PQS) arepresently being developed to provide guidelinesin preparing for advancement and qualificationto operate specific equipment and systems. Theyarc designed to support the advancementrequirements as stated in the "Quals" Manual.

The "Quals" and Record of Practical Factorsare stated in broad terms. Each PQS is muchmore specific in its questions that lead toqualification. It provides an analysis of specificequipment and duties, assignments, or respon-sibilities which an individual or group ofindividuals (within the same rating) may becalled upon to carry out. In other words, eachPQS provides an analysis of the complete knowl-edge and skills required of that rating tied to aspecific weapon system (aircraft and/or individ-ual systems or components).

Each qualification standard has four mainsubdivisions in addition to an introduction and aglossary of PQS terms. They are as follows:

100 SeriesTheory200 SeriesSystems300 SeriesWat:tstations (duties, assign-

ments, or responsibilities).400 SeriesQualifications cards.The introduction explains the complete use of

the qualification standard in terms of what itwill mean to the user as well as how to use it.

Chapter 1 AVIATION MACHINIST'S MATE R RATING

The Theory (100 Series) section specifies thetheory b..:kground required as a prerequisite tothe commencement of study in the specificequipment or system for which the PQS waswritten. These fundamentals are normally taughtin the formal schools (Preparatory, Fundamen-tals, and Class A) phase of an individual'straining. However, if the individual lu s not beento school, the requirements are outlined andreferenced to provide guidelines for a self-studyprogram.

The Systems (200 Series) section breaks downthe equipment or systems being studied intofunctional sections. PQS items ar: essentiallyquestions asked in clear, concise statement(question) form and arranged in a standardformat. The answers to the questions must beextracted from the various maintenance manualscovering the equipment or systems for which thePQS was written. This section asks the user toexplain the function of the system, to draw asimplified version of the system from memory,and to use this drawn schematic or theschematic provided in the maintenance manualwhile studying the system or equipment.Emphasis is Oven to such areas as maintenancemanagement procedures. components, compo-nent parts. principies of operation, system inter-relations, numerical values considered necessaryto operation and maintenance, and safety pre-cautions.

The Watchstation (300 Series) section includesquestions regarding the procedures the individ-ual must know to operate and maintain theequipment or system. A study of the items inthe 200 series section provides the individualwith the required information concerning whatthe system or equipment does, how it does it,and other pertinent aspects of operation. In the300 series section, the questions advance thequalification process by requiring answers ordemonstrations of ability to put this knowledgeto use or to cope with maintaining of the systemor equipment. Areas covered include normaloperation; abnormal or emergency operation;emergency procedures which could limit damageand/or casualties associated with a particularoperation; operations that occur too infrequent-ly to be considered mandatory performuceitems; and maintenance procedures/instructionssuch as checks, tests, repair, replacement, etc.

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The 400 series section consists of the qualifi-cation cards. These cards are the accountingdocuments utilized to record the individual'ssatisfactory completion of items necessary forbecoming qualified in duties ae.igned. Where theindividual starts in completing a standard willdepend on his assignment within an activity. Thecomplete PQS is given to the individual beingqualified so that he can utilize it at everyopportunity to become fully qualified in allareas of his rating and the equipment or systemfor which the PQS was written. Upon transier toa different activity, each individual must re-qualify: The answers to the questions asked inthe qualification standards may be given orallyor in writing to the supervisor, the branch ordivision officer, and maintenance officer asrequired to certify proper qualification. Thecompletion of part or all of the PQS provides abasis for the supervising petty officer and officerto certify completion of Practical Factors forAdvancemen t.

NavEdTra 10052

Bibliography for Advancement Study, NavEdTra10052 (Series) is a very important publicationfor anyone preparing for advancement. Thispublication/bibliopaphy lists required andrecommended Rate Training Manuals and otherreference material to be used by personnelworking for advancement. NavEdTra 10052(Series) is revised and issued once each year bythe Naval Training Corriiand. Each revisededition is identified by a letter following theNavEdTra number; be sure 7ou have the mostrecent edition.

The required and recommended references arelisted by rate level in NavEdTra 10052 (Series). Itis important to remember that you are respon-sible for all references at lower rate levels, aswell as those listed for the rate to which you areseeking advancement.

Rate Training Manuals that are marked withan asterisk (*) in NavEdTra 10052 (Series) areMANDATORY at the indicated rate levels. Amandatory training manual may be completedby (1) passing the appropriate NonresidentCareer Course that is based on the manda-tory training manual; (2) passing locallyprepared tests based on the information given in


the mandatory training manual; or (3) in somecases, successfully completing an appropriateNavy School.

When training personnel for advancement, do--not overlook the section of Naval Tr4 10052

(Series) which lists the required and recom-mended references relating to the militaryrequirements for advancement. All personnelmust complete the mandatory military require-ments training manual for the appropriate ratelevel before they can be eligible to advance.Also, make sure that personnel working foradvancement study the references listed asrecommended but not mandatory in NavTra10052 (Series). It is important to remember thatALL references listed in NavTra 10052 (Series)may be used as source material for the writtenexaminations, at the appropriate levels.

Rate Training Manuals

There are two general types of Rate TrainingManuals. Rate Training Manuals (such as thisone) are prepared for most enlisted rates andratings, giving information that is directlyrelated to the professional qualifications foradvancement. Subject matter manuals give in-formation that applies to more than one rating.

Rate Training Manuals are produced by fieldactivities under the management control of theNaval Training Command. Manuals are revisedfrom time to time to keep them up to datetechnically. The numbering system is beingchanged from NavPers to NavTra. The revisionof a Rate Training Manual is identified by aletter following the NavPers or NavTra number.You can tell whether any particular copy of aRate Training Manua! is the latest edition bychecking the number in the most recent editionof List of Training Manuals and CorrespondenceCourses, NavTra 10061 (Series). NavTra 10061is actually a catalog that lists current trainingmanuals and courses; you will find this cataloguseful in planning your study program.

Rate Training Manuals are designed for thespecial purpose of helping naval personnel pre-pare for advancement. By this time, you haveprobably developed your own way of studyingthese manuals. Some of the personnel you train,hot:. :, may need guidance in the use of Rate

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Training Manuals. Although there is no single"best" way to study a training manual, thefollowing suggestions have proved useful formany people:

F. Study the military requirement and theprofessional qualifications for your rate beforeyou study the training manual, and refer to the"quals" frequently as you study. Remember,you are studying the training manual primarilyto meet these "quals."

2. Set up a regular study plan, if possible,schedule your studying for a time of day whenyou will not have too many interruptions ordistractions.

3. Before you begin to study any part of thetraining manual intensively, get acquainted withthe entire manual. Read the preface and thetable of contents. Check through the index.Thumb through the manual without any par-ticular plan, looking at the illustrations andreading bits here and there as you see things thatinterest you.

4. Look at the training manual in moredetail, to see how it is organized. Look at thetable of contents again. Then, chapter bychapter, read the introduction, the headings, andthe subheadings. This will give you a clearpicture of the scope and content of the manual.

5. When you have a general idea of what is inthe training manual and how it is organized, fillin the details by intensive study. In each studyperiod, try to cover a complete unitit may be achapter, a section of a chapter, or a subsection.The amount of material you can cover at onetime will vary. If you know the subject well, orif the material is easy, you can cover quite a lotat one time. Difficult or unfamiliar material willrequire more study time.

6. In studying each unit, write down ques-tions as they occur to you. Many people find ithelpful to make a written outline of the unit asthey study, or at least to write down the mostimportant ideas.

7. As you study, relate the information in thetraining manual to the knowledge you alreadyhave. When you read about a process, a skill, ora situation, ask yourself some questions. Doesthis information tie in with past experience? Oris this something new and different? How doesthis information relate to the qualifications foradvancement?


8. When you have finished studying a unit,take time out to see what you have learned.Look back over your notes and questions.Maybesomeofyour- questions have been-answered, but perhaps you still have some thatare not answered. Without referring to thetraining manual, write down the main ideas youhave learned from studying this unit. Do not justquote the manual. If you cannot give these ideasin your own words, the chances are that youhave not really mastered the information.

9. Use Nonresident Career Courses when-ever you can. These courses are based on RateTraining Manuals or other appropriate texts. Asmentioned before, completion of a mandatoryRate Training Manual can be accomplished bypassing a Nonresident Career Course based onthe training manual. You will probably fmd ithelpful to take other courses, as well as thosebased on mandatory training manuals. Taking acourse helps you to master the informationgiven in the training manual, and also gives youan idea of how much you have learned.

10. You should note that occasionally- refer-ence is made in the Rate Training Manual topublications which contain information relativeto the rating, but which are not listed in NavTra10052 (Series). These are known as secondaryreferences and should be reviewed in conjunc-tion with your study of the Rate TrainingManual to better prepare yourself for advance-ment.

INCREASED RESPONSIBILITIES

When you assumed the duties of a P03, youbegan to accept a certain amount of respon-sibility for the work of others. With eachadvancement, you accept an increasing re-sponsibility in military matters and in mattersrelating to the professional work of your rate.When you advance to P01 or CPO, you will finda noticeable increase in your responsibilities forleadership, supervision, training, working withothers, and keeping up with new developments.

As your responsibilities increase, your abilityto communicate clearly and effectively mustalso increase. The simplest and most directmeans of communication is a common language.The basic requirement for effective communica-tion is therefore a knowledge of your own

language. Use correct language in speaking andin writing. Remember that the basic purpose ofall communication is understanding. To lead,supervise,- and train others, you must be able tospeak and write in such a way that others canunderstand exactly what you mean.

9

Leadership and Supervision

As a P01 or CPO, you will be regarded as aleader and supervisor. Both officers and enlistedpersonnel will expect you to translate thegeneral orders given by officers into detailed,practical, on-the-job language that can be under-stood and followed by relatively inexperiencedpersonnel. In dealing with your juniors, it is upto you to see that they perform their jobscorrectly. At the same time, you must be able toexplain to officers any important problems orneeds of enlisted personnel. In all military andprofessional matters, your responsibilities willextend both upward and downward.

Along with your increased responsibilities,you will also have increased authority. Officersand petty officers have POSITIONAL au-thoritythat is, their authority over others liesin their positions. If your CO is relieved, forexample, he no longer has the degree ofauthority over you that he had while he wasyour CO, although he still retains the militaryauthority that ali seniors have over subordinates.As a P01, you will have some degree ofpositional authority; as a CPO, you will haveeven more. When exercising your authority,remember that it is positionalit is the rate youhave, rather than the person you are, that givesyou this authority.

A Petty Officer conscientiously and proudlyexercises his authority to carry out the respon-sibilities he is given. He takes a personal interestin the success of both sides of the chain ofcommand . . . authority and responsibility.For it is true that the Petty Officer who doesnot seek out and accept responsibility, loses hisauthority and then the responsibility he thinkshe deserves. He must be sure, by his exampleand by his instruction, that the Petty Officersunder him also accept responsibility. In short, hemust be the leader his titlePetty Officersayshe is.


Training

As a POI or CPO. you will have regular andcontinuing responsibilities for training others.Even if you are lucky enough to have a group ofsubordinates who are all highly skilled and welltrained, you will still find that training isnecessary. For example, you will always beresponsible for training lower rated personnelfor advancement. Also, some of your bestworkers may be transferred; and inexperiencedor poorly trained personnel may be assigned toyou. A particular job may ^all for skills thatnone of your personnel have. These and similarproblems require that you be a trainingspecialist-one who can conduct formal andinformal training programs to qualify personnelfor advancement, and one who can train individ-uals and groups in the effective execution ofassigned tasks.

In using this training manual, study theinformation from two points of view. First,what do you yourself need to learn from it? Andsecond, how would you go about teaching thisinformation to others?

Training goes on all the time. Every time aperson does a particular piece of work, somelearning is taking place. As a supervisor and as atraining expert, one of your biggest jobs is to seethat your personnel learn the RIGHT thingsabout each job so that they will not form badwork habits. An error that is repeated a fewtimes is well on its way to becoming a bad habit.You will have to learn the difference betweenoversupervising and not supervising enough. Noone can do his best work with a supervisorconstantly supervising. On the other hand, youcannot turn an entire job over to an in-experienced person and expect him to do itcorrectly without any help or supervision.

In training lower rated personnel emphasizethe importance of learning and using correctterminology. A command of the technicallanguages of your occupational field (rating)enables you to receive and convey informationaccurately and to exchange ideas with others. Aperson who does not understand the precisemeaning of terms used in connection with thework of his rating is definitely at a disadvantagewhen t tries to read official publicationsrelating to his work. He is also at a great

disadvantage when he takes the examinations foradvancement. To train others in the correct useof technical terms, you will need to be verycareful in your own use of words. Use correctterminology and insist that personnel you aresupervising use it too.

You will find the Record of Practical Factors.NavEdTra 1414/1, a useful guide in planning andcarrying out training programs. From thisrecord, you can tell which practical factors havebeen checked off and which ones have not yetbeen done. Use this information to plan atraining program that will fit the needs of thepersonnel you are training.

On-the-job training is usually controlledthrough daily and weekly work assignments.When you are working on a tight schedule, youwill generally want to assign each person to thepart of the job that you know he can do best. Inthe long run, however, you will gain more byassigning personnel to a variety of jobs so thateach person can acquire broad experience. Bygiving people t, chance to do carefully supervisedwork in areas in which they arc relativelyinexperienced, you will increase the range ofskills of each person and thus improve theflexibility of your working group.

Working With Others

As you advance to PO1 or CPO, you will findthat many of your plans and decisions affect alarge number of people, some of whom are noteven in your own occupational field (rating), Itbecomes increasingly important, therefore, foryou to understand the duties and the respon-sibilities of personnel in other ratings. EveryPetty Officer in the Navy is a technical specialistin his own field. Learn as much as you can aboutthe work of others, and plan your own work sothat it will fit into the overall mission of theorganization.

Keeping Up With New Developments

Practically everything in the Navy-policies,procedures, publications, equipment, systems-issubject to change and development. As a PO1 orCPO, you must keep yourself informed aboutchanges and new developments that affect youor your work in any way.

10

Jc-


Some changes will be called directly to yourattention, but others will be harder to find. Tryto develop a special kind of alertness for newinformation. When you hear about anything newin the Navy, find out whether there is any wayin which it might affect the work of your rating.If so, find out more about it.

SOURCES OF INFORMATION

As a P01 or CPO, you must have an extensiveknowledge of the references to consult foraccurate, authoritative, up-to-date informationon all subjects related to the military andprofessional requirements for advancement.

Publications mentioned in this chapter aresubject to change or revision from time totimesome at regular intervals, others as theneed arises. When using any publication that issubject to revision, make sure that yOu have thelatest edition. When using any publication that iskept current by means of changes, be sure youhave a copy in which all official changes havebeen made.

There are training manuals and publicationsthat offer other additional background material.The educational services officer will alwayshave the most up-to-date information and train-ing manuals applicable to your rating.

In addition to training manuals and publica-tions, training films furnish a valuable source ofsupplemeri:ary information. Films that may behelpful are listed in the U.S. Navy Film Catalog,Nav Air 10-1-777.

ADVANCEMENT OPPORTUNITIES FORPETTY OFFICERS

Making Chief Petty Officer is not the end ofthe line as far as advancement is concerned.Proficiency pay, advancement to Senior (E-8)and Master (E-9) Chief, and advancement toWarrant Officer and Commissioned Officer areamong the opportunities that are available toqualified petty officers. These special paths ofadvancement are open to personnel who havedemonstrated outstanding professional ability,the highest order of leadership and military

responsibility, and unquestionable moralintegrity.

PROFICIENCY PAY

The Career Compensation Act of 1949, asamended, provides for the award of proficiencypay to designated military specialities. Profi-ciency pay is given in addition to regular payand allowances and any special or incentive payto which you are entitled. Certain enlistedpersonnel in pay grades E-4 through E-9 areeligible for proficiency pay. Proficiency pay isawarded in two categories: (1) Specialitypayto designated ratings and NEC's, and (2)Superior performance payfor superior per-formance of duty in certain specialities notcovered by speciality pay. The eligibility require-ments for proficiency pay are subject to change.In general, however, you must be recommendedby your commanding officer, have a certainlength of time on continuous active duty, and becareer designated.

ADVANCEMENT TO SENIORAND MASTER CHIEF

Chief Petty Officers may qualify for theadvanced grades of Senior and Master ChiefPetty Officer which are now provided in theenlisted pay structure. These advanced gradesprovide for substantial increases in pay, togetherwith increased responsibilities and additionalprestige. The requirements for advancement toSenior and Master Chief Petty Officers aresubject to change but, in general, include acertain length of time in grade, a certain lengthof time in the naval service, a recommendationby the commanding officer, and a sufficientlyhigh mark on the Navy-wide examination. Thefinal selection for Senior and Master Chief PettyOfficer is made by a regularly convened selec-tion board.

Examination Subjects

Qualifications for advancement to SeniorChief Petty Officer and Master Chief PettyOfficer have been developed and published inthe Manual of Qualifications for Advancement,NavPers 18068 (Series). They officially establish


minimum military and professional qualifica-tions for Senior and Master Chief Petty Officers.

Bibliography for Advancement Study, NavEdTra10052 (Series) contains a list of study referenceswhich may be used to study for both militaryand professional requirements.

ADVANCEMENT TO WARRANTAND COMMISSIONED OFFICER

The Warrant Officer program provides oppor-tunity for advancement to warrant rank for E-6

12

17

and above enlisted personnel. E-6's, to beeligible, must have passed an E-7 rating examprior to selection.

The LDO program provides a path of advance-ment from warrant officer to commissionedofficer. LDO's are limited, as are warrants, intheir duty, to the broad technical fields associ-ated with their former rating.

If interested in becoming a warrant or com-missioned officer, ask your educational servicesofficer for the latest requirements that apply toyour particular case.

CHAPTER 2

AVIATION SUPPLY

A Chief or First Class Aviation Machinist'sMate R, especially if in a supervisory billet, willfind .himself increasingly involved in the detailsof supporting the man on the job. One of theseareas is in the field of aviation supply.

Aviation supply personnel are vital membersof the aircraft maintenance team; and the ADRas well as personnel in the other aviationmaintenance ratings, must work in closeharmony with them if successful teamwork is tobe achieved. The team must work so that a flowof parts is maintained from the manufacturer tothe man on the jobquite possibly an ADRdoing repair work on the other side of theworld. A correct concept of supply's relation-ship to the entire organization is essential in thesupervision of aircraft maintenance functions.

ORGANIZATION AND FUNCTIONOF NAVAL SUPPLY

The command exercising management controlover the policies and procedures of the aviationsupply organization is the Naval Supply SystemsCommand. The Commander, Naval SupplySystems Command is usually a rear Admiral whois appointed by the President with the adviceand consent of the Senate. He works with thedelegated authority of the Secretary of theNavy, and all policies and procedures of theaviation supply organization emanating fromhim have the full force and effect of SecNavorders.

To better understand the relationship of theNaval Supply Systems Command to the aviationsupply system, it might be well to quicklyreview the development of the Navy supplysystem.

Prior to 1842 the commanding officers ofships and stations were responsible for theprocurement of their own supplies. They were

13

furnished funds for this purpose by the NavyDepartment and were required to account for allexpenditures. In addition to creating an in-tolerable burden of paperwork on the NavyDepartment, this procedure had the effect offorcing prices upward, especially when twocommanding officers were bidding for somescarce commodity.

In 1842 Congress approved the establishmentof a Bureau of the Navy to take cognizance overall matters of naval supply. The primary respon-sibilities of this infant supply bureau were theprocurement, maintenance of custody, andissuance of naval material. They are the primaryresponsibilities of the Naval Supply SystemsCommand today. Every function of the NavalSupply Systems Command is directly related toone or more of these responsibility areas.

In the early years of naval aviation when theNavy had few aircraft, the procurement of spareparts was much like the old system wherebycommanding officers dealt with the sellers to fillthe needs of each command. The pioneer navalaviation project directors had to deal directlywith the manufacturers as parts were required.

By 1917 the Naval Aircraft Factory (NAF) inPhiladelphia had come into existence and wasassigned responsibility for the procuring ofaircraft and spare parts. Other responsibilitiesassumed by NAF included the repair of aircraft,the manufacture of some spare parts, andeventually the manufacture of complete aircraft.There may still be a few aviators around todaywho earned their Navy wings in the old N3N,built by NAF.

In 1921 the Bureau of Aeronautics (BuAer)came into being and assumed the responsibilityof procuring aircraft and aircraft engines. Theresponsibility for procuring spare parts andother aeronautical material remained with NAF,which until 1941 was the aviation supply centerof the Navy.


The Aviation Supply Office (ASO) was estab-lished in 1941 under the technical control ofBuAer and the management control of theBureau of Supplies and Accounts. The functionof ASO was the procurement, custody, andissuance of aeronautical spare parts and tech-nical material. This is essentially the function ofASO today under the technical control of theNaval Air Systems Command. Management con-trol of ASO is exercised by the Naval SupplySystems Command.

RESPONSIBILITIES OF THENAVAL MATERIAL COMMAND

The Naval Aviation Maintenance Program issponsored and directed by the Chief of NavalOperations (CNO). It is administered throughthe operating chain of command and is providedmaterial and technical support by the NavalMaterial Command under the direction of theChief of Naval Material (CNM). The NavalMaterial Command was established in 1966 withthe cognizance over six systems commands. Thecognizant system commands are listed below:

Naval Air Systems CommandNaval Electronic Systems CommandNaval Sea Systems CommandNaval Supply Systems CommandNaval Facilities Engineering Command

The Naval Supply Systems and Naval AirSystems Commands are the two systems com-mands of most interest to the AD personnel.Listed below are some of the important func-tions of the Naval Supply Systems Commandand the relationship to the Naval Air SystemsCommand:

1. Supervises the procurement, receipt,custody, warehousing, and issuance of Navysupplies and materials, exclusive of ammunition,projectiles, mines, explosives, and medical sup-plies.

2. Supervises and directs the operation ofthe supply phases of the Navy supply systemand administers the redistribution program ofexcess personal property within the Departmentof Defense and the sale of Navy surplus proper-ty.

14

3. Authorizes and supervises the transporta-tion of Navy property.

4. Prepares budget estimates and ad-ministers funds for the supply distribution sys-tem.

5. Renders an annual report to the Congressof money value of supplies on hand at thevarious stations at the beginning of each fiscalyear, the disposition thereof, purchase andexpenditure of supplies for the year, and balanceon hand.

6. Coordinates the compilation and arrangesfor the printing of the Catalogs of Navy Mate-rial.

Some additional functions of the NavySupply Systems Command that are of interest toAD personnel are the general functions of ASO;these include the following:

1. Responsibility for overall determinationof requirements, procurement, and distributionof standard aeronautical materials. (Certainmaterials excepted; such as complete aircraftand engines, complete electronic equipment,major photo equipment, nonstandard andexperimental aerological equipment, and itemsof naval weapons ordnance equipment.)

2. Maintenance of a complete file of ASOand Naval Air Systems Command contracts,letters of intent, amendments, extensions, andchange orders, and distribution of all (necessarycopies of documents to Navy field) activities.

3. Stock control of aeronautical materials atall aviation supply facilities, including control ofpacking, preservation and distribution of mate-rial under ASO cognizance to, from, and be-tween aviation supply facilities and major supplypoints.

4. Maintenance of complete records ofmaterial on order and followup procedure neces-sary to effect timely deliveries of all materialunder ASO cognizance.

5. Maintenance of up -to -date records ofexisting storage facilities at depots, major supplypoints, and operating stations for aeronauticalmaterials, and control of influx of materials inaviation supply channels so as not to exceedexisting storage facilities.

6. Determination and disposition ofobsolete and excess aeronautical material underNavAirSysCom cognizance.

Chapter 2AVIATION SUPPLY

7. Preparation and distribution of the NavyStock List of ASO, including interchangeabilitydata.

8. Compilation and distribution of someallowance lists subject to approval by Nav-AirSysCom.

9. Compilation of lists of spare parts to besalvaged from surveyed aircraft.

10. Followup on delivery, stock recording,reallocating as necessary, and distributing changematerial promulgated by NavAirSysCom.

11. Establishment and maintenance of astatistical unit which assembles, compiles, andanalyzes usage data.

12. Maintenance of a representative at eachaircraft manufacturer's plant who keeps ASOfully informed, as requested, as to all changeswhich affect spare parts under procurement.

13. Establishment of an inspection servicewhich inspects aviation supply activities withinestablished naval districts.

APPROPRIATIONS

At one time or another, almost everyone hashad the frustrating experience of not being ableto draw from supply some item needed im-mediately; the usual reason given being "We donot have any money left." It takes only a shorttime to realize that the Navy does not operatewith unlimited funds. This section and thefollowing section, titled "Operating Budgets,"are presented to further an understanding of thesystem whereby funds are made available at theuser activity level for operating expenses.

The main money pool of the govemment isthe General Fund of the Treasury. Funds comeinto the General Fund from such sources asincome taxes, excise taxes, import-export taxes,etc. The only way for money to be expendedfrom the General Fund is by congressionalaction, which has to be approved by thePresident. A bill passed by Congress whichincludes the expenditure of funds from theGeneral Fund is called an appropriation.

An estimate of the amount of money requiredfor the operation of the Defense Departmentduring a given fiscal year is prepared by Depart-ment of Defense fiscal experts well in advanceofthe beginning of the fiscal year. The Congressstudies the proposed budget in the light of world

ts

affairs, the current domestic economy, and suchother considerations as they see fit, then actsupon it. Congress may increase the- amountrequested, decrease it, or pass it as is. Afterpresidential action is completed, the money ismade available to the Department of Defense tobe spent during a specified year. This is knownas an "annual" or "one-year" appropriation.

Congress and the President may also approve"no-year" appropriations for special projectssuch as large construction programs over anunspecified length of time.

Another form of appropriation is the"multiple-year" appropriation for projectswhich will be completed in a predictable lengthof time. An example of the use of this type ofappropriation is the money appropriated tocover the expenses of the NROTC collegeprograms for the next 4 years.

The appropriation by which the AD is mostaffected is the "current-year" appropriation.After the appropriation or expenditure au-thorization is received in the Department ofDefense, it is prorated among the services as apercentage of their previously submitted budgetestimates. The Navy's share is prorated amongthe various systems commands and bureaus inessentially the same manner; that is, as apercentage of their estimated requirements forthe coming fiscal year. The money to be spentfor naval aviation is made available to Nav-AirSysCom. Here, part of the money is allocatedto ASO for the purchase of aircraft spare partsand related equipment in quantities which pastusage data has indicated will probably be suf-ficient for the coming year. These spare parts arefurnished to the operating activities at no cost,since their usage has been anticipated and theitems paid for in advance. The account fromwhich money was spent to buy these items isknown as the Appropriation Purchase Account(APA). Material received in the user activitiesfrom this account is known as APA material.

Another part of NavAirSysCom funds is madeavailable to the operating activities in the formof operating budgets.

OPERATING BUDGETS

Funds available within an appropriation ac-count for commitments, obligations, and


expenditures are administered through theissuance of operating budgets. An approvedoperating budget is an authorization granted forthe purpose of incurring commitments, obliga-tions, and expenditures to accomplish themission of an activity. Therefore, an approvedoperating budget is a subdivision of an ap-propriation which provides the funding au-thority for an official to accomplish a specificfunction or mission.

Approved operating budgets concerning navalaviation are authorizations by NavAirSysCom tothe user activities to spend a certain amount ofmoney during a given length of time forspecified purposes. User activities are shorecommanders.

Operating f unds for stations, reworkactivities, etc., concerned with the operation andmaintenance of aircraft and related equipmentare allotted to them by the NavAirSysCom as anoperating budget. Departments within theseorganizations normally submit their departmentbudget to the station comptroller who reviewsand combines the different department budgetsinto a recommended station budget. Senior A.D'smay be calied upon to assist in furnishing arealistic estimate of division operating expensesand future needs which the department headmay use in formulating the department budget.

Since there is a relatively long period betweenbudget submission and the subsequent receipt offunds, the necessity of accurate estimates offuture requirements and strict management ofmaterials for which allotted funds are expendedcannot be overemphasized.

Operating Targets

Funds to finance the operation of aircraft areallotted by the NavAirSysCom to the air typecommanders. Operating funds for squadrons andunits are apportioned to them by their cognizantair type commander as an operating target(OPTAR). An OPTAR is a planned estimatewhich the air type commander allocates for thefinancing of aircraft operating costs during agiven period of time. OPTAR's are issued on aquarterly basis and unused funds from thepreviously issued OPTAR revert to the controlof the type commander as each new OPTAR isauthorized. Type commanders provide OPTAR's

16

t

to squadrons, units, and ships under theiroperational control, whether or not the useractivity is based ashore.

There are several different types of OPTAR'sissued by air type commanders for aviationpurposes. Two that are of interest to ADpersonnel are flight operations and aircraftmaintenance funds. These are discussed in thefollowing paragraphs.

Flight operation funds are used primarily forthe purpose of financing actual flight operations;therefore, they have application at the Or-ganizational level. These funds finance thefollowing:

1. Aviation fuels and lubricants consumed inaircraft.

2. Liquid oxygen.3. Aerial film for use in aircraft cameras.4. Flight clothing and operational equipment

authorized in NavAirSysCom Allowance List(NavAir 00-3SQH-2).

S. Flight deck safety shoes.6. Squadron administrative consumable

office supplies.7. Unit identification marks (shoulder

patches) for initial issue to newly reportedpersonnel.

8. Material and services required whenlocated at an activity without Navy or MarineCorps Intermediate maintenance capability.

Aircraft maintenance funds are provided toOrganizational and Intermediate maintenanceactivities to finance the cost of various suppliesand materials consumed in the performance ofaviation maintenance. These funds finance thefollowing:

1. Repair parts, common hardware,lubricants, cleaning agents, cutting compounds,metals, and other materials incorporated into orexpended in the performance of aviation main-tenance of aircraft, engines, aeronautical com-ponents and subassemblies, and Navy main-tenance of aviation maintenance support equip-ment.

2. Fuels and lubricants consumed by aircraftengines in the performance of complete sectionrepairs.

3. Pre-expended, consumable maintenancematerial.

4. Replacement of expendable or consumableallowance list items with material accountability


codes B and C. (Allowance list and materialaccountability codes are discussed later in thischapter.)

MATERIAL IDENTIFICATIONIn addition to the task of supervising lower

rated AD personnel in the performance ofroutine duties, senior AD's may be assignedmaintenance supervisor duties. In some cases,these duties will encompass the task of assistingin the procurement of material and parts usedby production personnel. One important area ofmaterial procurement is the correct identifica-tion of the material and parts required. Since atpay grade E-9, AD's compress with other main-tenance ratings and become Master Chief Air-craft Maintenancemen, it is important thatsenior AD's be familiar with some of themethods of identifying material.

There may be times when a part or sometechnical material is needed and the stocknumber is unknown. At other times somematerial may be on hand and its identity notpositively known. A knowledge of the variousmethods of identifying_ material other than bystock number will often help speed thecompletion of a maintenance task. Certain datamay be available which do not identify an itembut which may lead to positive identification.The following sections discuss some methods ofidentifying material.

FEDERAL STOCK NUMBERING SYSTEM

NOTE: At the time of printing this RateTraining Manual, the Federal Stock Number(FSN) is being replaced by a National StockNumber(NSN). The NSN is the same as an FSNexcept for the addition of a two-character codeidentifying the country having cognizance ofthe item, i.e., 1234-00-123-4567 (00 denotesUnited States). The FSN will still appear innumerous publications and manuals; therefore,the FSN is explained in the following paragraphs.

The Defense Cataloging Standardization Act,passed by Congress in 1952, provided for auniform system of identification, classification,and stock numbering throughout the Depart-ment of Defense. Prior to this time there weremany stock numbering systems within theDepartment of Defense and within the Navyitself. It was possible for the same item to be

17

22

stocked under different stock numbers as Navygeneral stores, Navy aviation stores, Air Forcestores, Army quartermaster stores, and manyothers. There was no cross-reference systemwhereby an agency could determine if its excessmaterial was the same as that which was in shortsupply in another agency.

The federal cataloging system eliminated thissituation by placing all like items under a federalstock number bearing a common official govern-ment name. This system was made applicable toall agencies within the Department of Defense.

Under the federal cataloging system, federalstock numbers are required for all items that aresubject to central inventory management withinthe Department of Defense. Each Navy item tobe stocked under centralized nivel:tory controlis assigned a federal stock number which is usedin all supply management functions. This federalstock is listed in supply publications in whichthe item is referenced.

The following paragraphs discuss the variousparts of a coded FSN and frequent reference tofigure 2-1 will assist in understanding thecomposition of coded FSN's.

A cognizance symbol consists of a 2-digitcode prefixed to an FSN to identify anddesignate the systems command office, agency,or Navy inventory manager that exercisesmanagement control over specific categories ofmaterial. Although the cognizance symbol of-ficially consists of two digits, 3t will be observedthat publications and requisitioning proceduresfrequently drop the first digit for APA material,thus 2R is referred to as R, etc.

Listed in table 2-1 are some of the morecommon cognizance symbols, together with thetype material controlled and the name of thecognizant command or office.

The Federal Stock Numbering System wasintended to create and improve standardizationof items of military supply in servicewide useand reduce excess inventories which, for themost part, were caused by the lack of stand-ardization. Also, the reduction of excessinventories eliminates substantial financial lossdue to material obsolescence.

Federal Stock Number (FSN)

The FSN is an 11-digit number whichfurnishes positive identification of virtually all


items of supply from purchase to final disposi-tion. The 11 digits are uniformly arranged ingroups of 4, 3, and 4 digits, with groupsseparated by hyphens. The 11 digits are made upof a 4digit federal supply class (FSC) and a7-digit federal item identification number(FIIN). In addition to the 11-digit number, theNavy supply system utilizes certain codeprefixes and suffixes to aid in the performanceof various management functions. These codesare of significance only within the Navy and arenot used during interservice transactions. Whenthe prefixes and suffixes are used, the FSN isknown as a coded FSN.

Figure 2-1 describes the format of a codedFSN, including applicable management codes foran item of supply under the cognizance of ASO.

Material control codes divide inventories intosegments reflecting similar demand, repair-ability, or other characteristics. For example,some material control codes reflect either fast or

2R H F 1630 - 123-4567 - BF

Cognizance II

symbol

Materialcontrolcode

Material

conditioncode

Federalgroup

Federal

supplyclassification

Federalitemidentificationnumber

Special

materialidentificationcode

T

AD.213Figure 2.1. Breakdown of coded federal stock number.

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slow moving demand characteristics, whileothers denote whether the item is to be repairedby Intamediate or Depot level maintenanceactivitizs.

Material condition codes classify material interms of readiness for issue and use, or toidentify action underway to change the status ofmaterial. For example, one material conditioncode is used to indicate that a particular item isserviceable and ready for issue. If, after issuefrom the supply system and through use thisitem becomes unserviceable, its material condi-tion code would be changed to reflect therequirement for rework, repair, etc. Naturally,upon completion of rework or repair the mate-rial condition code would be changed to showthat the item is serviceable and ready for issue.Therefore, this code changes from time to timeon a particular item depending on the conditionof the material.

The federal supply classification (FSC) _lass isthe first four digits of the FSN and is used togroup related commodities together. Each itemof supply is classified in one, and only one,4-digit FSC. The first two digits denote thegroup or major division of commodities, and thelast two digits denote the class or subdivision ofcommodities within a group. Aircraft com-ponents and accessories are in group 16; there-fore, in the FSC 1630, the 16 denotes an aircraftcomponent or accessory and the 30 indicates aparticular class within this group, which isaircraft wheel and, brake systems. Other classesin group 16 are indicated as 1610propellers,1620landing gear components, etc.

The federal item identification number (FIIN)consists of the last seven digits of the FSN. Itserves to differentiate each individual item ofsupply from all other items of supply. There-fore, each individual item of supply such asbrake, F-4B; brake, P-3A; etc., is assigned aseparate FIIN. The FUN in no way determinesthe position or sequence of the item in relationto other items. A recent change has replaced thefour-character TSMC with a two-letter specialmaterial identification code (SMIC). However,like many areas where changes are made, acertain time element is involved; therefore, theTSMC will still be used for some time on manycoded FSN's. A SMIC is a management codeadded as a suffix to an FSN to indicate a


Table 2 -1. Cognizance symbols.

Symbol

11

01

1R

2R

6R

8R

4V

6V

1W

9G

9Z

Cognizant Activity Material Controlled

Naval Publications and Forms Center,Philadelphia

Naval Publications and Forms Center,Philadelphia

Aviation Supply Office



Naval Air Systems Command

Naval Air Systems Command

Naval Air Systems CommandRepresentatives Atlanticand Pacific

Naval Supply Systems Command

Navy Fleet Material SupportOffice (FMSO)

Navy Fleet Material SupportOffice (FMSO)

Forms

Publications

Consumable Aeronautical material

Repairable Aeronautical material

Aeronautical Support Equipment (IMRL)

Major aeronautical systems andequipment

Aircraft Engines

Technical Directive Compliance(TDC) kits

Bulk and packaged liquid fuel

Navy owned stocks of defensegeneral material

Navy owned stocks of defenseindustrial material

primary weapon support item, specialized mate-rials or general/common material. ASO haspublished a conversion guide which cross refer-ences the SMIC with the TSMC.

Many variations of coded stock numbers willbe encountered in maintenance work. Thesevariations indicate material management respon-sibilities for the item; flag certain, items asrecoverable, consumable, high value, etc.; andidentify the condition of the material if it is notready for issue.

Because the variety of codes is so extensiveand the trend to single service management ofitems has caused so many changes in recentyears, a list of codes that might be prefixedorsuffixed to a stock number would not beappropriate for this course. The primary thingsto keep in mind are that the basic stock number,

19

consisting of three groups of numerals, identifiesthe item from a technical point of view and thatthe other codes identify material managementcharacteristics.

STANDARDIZATION OFITEM NOMENCLATURE

As part of the federal cataloging system, eachitem of supply is assigned an official governmentname. Maintenance personnel frequently refer tomaterial by trade name or terminology otherthan the official government name. Alphabeticalindexes in the various stock catalogs and otherpublications are sequenced by official name. Toeffectively utilize these publications, it is neces-sary to become acquainted with the propernomenclature.


The assignment of names to stock items ispractically as important as the assignment ofFSN's. When items are inducted into the supplysystem, official government nomenclature mustbe assigied. Often this item name plus ad-ditional descriptive data wt.l differ from namesof items previously used. If difficulty is expe-rienced in locating a familiar item in the catalog,it is quite possible that the name has beenchanged to conform to a more general usage. Afew examples will show the importance ofcorrect item nomenclature. It will be found thata "swab" is a small stick with a tiny wad ofcotton on one end, and is used by the MedicalDepartment. In order to clean the decks it willbe necessary to think of another name for"swab." "Mops" will be found listed in thecatalog, together with the correct FSN. Othersamples are as follows: "Ceilometer" becomes"Projector, Cloud Height"; "Zipper" has be-come "Fastener, Slide Interlocking," etc.

NAVAL MATERIAL CATALOGS

Federal and naval material catalogs provideinformation necessary to identify and procureitems of material for operation and maintenanceof activities afloat and ashore. The catalog mostcommonly used by aviation personnel is theFederal Supply Catalog Navy Management DataList.

The Navy Management Data List (NMDL)consists of two separate sections. One section,the Fleet Ballistic Missile Weapons System Sup-plement, has application only to submarineforces and therefore is of little or no use toaviation maintenance personnel.

The other section, titled the ManagementData List, includes basic -management datanecessary for. preparing material requisitions.Also, it is the instrument for publishing datarelative to stock number changes, unit of issue,unit price, shelf life of material. number of itemscontained in a package, and associated informa-tion.

The NMDL is designed to disseminatemanagement type information as it relates to anFSN. It is not designed to act as a comprehen-sive catalog of material in the supply system,identify an item to an FSN, or serve as ashopping guide. Therefore. in order to get the

20

.

necessary FSN or other needed information formaking effective use of the NMDL, additionalpublications must be used in conjunction withthe NMDL. These include the Deleted andSuperseded FUN List, the Consolidated Repair-able Item List, and the Federal Supply CatalogNavy Master Cross Reference List.

The Deleted and Superseded FIIN Listprovides historical data of stock number dele-tions and supersessions. It should be remem-bered that the FIIN taken from this list isreferred back to the NMDL for the requisition-ing data.

The Consolidated Repairable Item Listcontains a listing of Navy managed mandatoryturn-in repairable items. It is prepared to assistin identifying Navy managed mandatory turn-inrepairable items and pertinent movementpriority designators. Some repairable itemsunder the cognizance of ASO and the NavAir-SysCom are not included in this publication.These are listed in the ASO Master Repair List.

The Federal Supply Catalog Navy MasterCross Reference List provides the means ofidentifying an item from a reference number(part number, drawing number, etc.) to an FSN.The FSN found in this publication should bereferenced back to the NMDL for all pertinentinformation required in requisitioning material.

IDENTIFICATION SOURCE DATA

As previously stated, positive identification ofan item of supply has been accomplished whenit is identified to its applicable FSN. For themost part, the FSN is not marked on material;however, most material has some type of dataaffixed to it that can be used for identificationpurposes. Certain data which do not identify anitem but which aid in obtaining positive iden-tification are discussed in the following para-graphs.

Manufacturer's Part Number

Normally, the manufacturers of parts stamp,etch, paint, or otherwise affix a part andmanufacturer's code (vendor code) numbers oneach item manufactured. The use of thesenumbers, part and code, and the knowledge ofthe part's application (that is, on what equip-


ment it is used) normally lead to positiveidentification of the part's nomenclature andFSN. Due to the possible duplication of partnumbers by manufacturers the manufacturer'scode (VENDOR) will be used with the partnumber. The part number and vendor code canusually be found on the part, and/or IPB for theitem needed. The vendor's code is a five-digitcode. If a vendor code cannot be firmlyestablished in the master file, a code of 99999will be inserted. As the vendor codes areestablished, the file will be updated and subse-quent issues of the index will reflect the assignedvendor code. After ascertaining the correct partand code number the FSN may be obtained byreference to the appropriate Federal and NavalMaterial Catalogs.

Drawing Number

A drawing number consists of letters,numbers, or a combination of both which areassigned to a particular drawing fcr iden-tification purposes. The activity controlling thedrawing (normally the manufacturer) assigns thenumber in conformance with their drawingnumber system. One drawing may apply toseveral items; thus other distinguishing data maybe necessary to identify the item on the draw-ing.

Drawing numbers may be used to identify themicrofilm available in some technical libraries.Some large assemblies are illustrated in theappropriate Illustrated Parts Breakdown but arenot broken down sufficiently to show iden-tifying data for their component parts. Byobtaining the drawing number of the larger itemand cross-referencing it to the applicable micro-film, sufficient identifying information for thecomponent part may be obtained.

Nameplates

Some aeronautical materials have nameplatesattached which provide such information as themanufacturer's name or code, make or modelnumber, serial number, size, voltage, phase, etc.Identification data taken from the nameplate ofthe old part can be very helpful in identifyingand procuring a replacement. Nameplate data isparticularly useful when requesting nonstandard

material which is not subject to the federalcataloging system.

Markings and Measurements

Special coded markings, other than partnumbers, and measurements often aid in theidentification of some materials. For instance,compressed gas cylinders are color coved toidentify the contents of the cylinders. Sheetmetal is stamped with a significant identifyingsymbol which is repeated at intervals throughoutthe length of the sheet. This symbol includes thecomposition, temper, thickness, etc.

Flexible rubber hose is marked with a symbolwhich is repeated at intervals throughout thelength of the hose. Bare wire is separatedaccording to diameter. Tubing has two types ofmeasurementsoutside diameter, given ininches; and thickness of the wall, given inthousandths of an inch. Female fittings such ascrosses, tees, and couplings are measured acrossthe inside diameter of the threaded opening. Themale fittings are measured across the outsidediameter of the male threads.

Source Codes

Item Source Codes are symbols whichindicate to a consumer a source of supply for anitem required to maintain or repair aeronauticalarticles. Specifically, these codes indicatewhether the item is to be requisitioned from thesupply ::vstem; to be manufactured; to beobtained from salvage; not to he replaced sincethe next higher assembly is to be installed; or,due to failure, is in need of complete overhaul orretirement of the assembly or equipment fromservice.

Source codes are assigned to material at thetime of provisioning. Known or anticipatedusage is the primary factor in the assignment ofsource codes. The ability to manufacture anitem within a naval activity is considered to beof secondary importance. In other words, itemsare normally source coded for purchase andstocking in the Navy supply system if usage isknown or anticipated. Source codes for individ-ual items may be revised as experience and usagedevelop.

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Source codes are published as a column of thenumerical index of the Illustrated Parts Break-down, and in other publications as directed bythe NavAirSysCom.

Source codes are provided in six seriesP, M,A, N, X, and U.

Source code P series applies to items ofsupply system stock which are purchased in viewof known or anticipated usage.

Source code M series applies to items whichare not purchased but are capable of beingmanufactured at Navy fleet or overhaul activi-ties. These items are normally manufacturedupon demand and are not stock numbered.

Source code A series applies to assemblieswhich are not purchased.

Source code N series applies to items (nuts,bolts, screws, etc.) which do not meet estab-lished criteria for stocking and which are readilyavailable from commercial sources. These itemsare purchased on demand.

Source code X series applies to items notprocured and not practical for storage, main-tenance, or manufacture.

Source code U applies to items which are notof supply or maintenance stocking significance.

Within each of the source code series, thereare one or more subcodes identified by a letteror number appended to the basic code number.These subcodes provide detailed informationconcerning the procurement or manufacture ofvarious parts within the scope of the particularcode series. The applicable Illustrated PartsBreakdown provides ready reference for each ofthe codes and subcodes as required.

The preceding sections have emphasized someof the many things that may be used to identifyor aid in procurement or use of material. Thesenior AD who is familiar with the methods ofidentifying material is an asset to a maintenanceorganization, especially in performing main-tenance supervisory duties.

AERONAUTICAL ALLOWANCE LISTS

This title is inclusive of publications identifiedas Allowance Lists (except advanced base lists),Initial Outfitting Lists, and Tables of BasicAllowances.

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Naval Air Systems Command Allowance Lists,Initial Outfitting Lists, and Tables of BasicAllowances are prepared by the NavAirSysComor the Aviation Supply Office. In nearly allinstances ASO has the responsibility for prepara-tion, but in all cases these lists are published bythe direction of and approved by the NavAir-SysCom. These lists contain the following:

1. The equipment and material (bothconsumable and nonconsumable) necessary tooutfit and maintain units of the aeronauticalorganization in a condition of material readiness.

2. Substantially all items used with sufficientfrequency to justify their issuance to all activi-ties maintaining aircraft or equipment for whichthe lists are designed.

3. Information concerning stock number,nomenclature, interchangeability, and superse-dures.

4. A set of detailed instructions for theapplication and utilization of the publication.

5. A table of logistic data showing the totalweight and cube of all material contained in thelist.

In the final analysis, the equipment and spareparts listed in these publications are madeavailable to aircraft operating and maintenanceactivities in accordance with assigned opera-tional maintenance and logistics responsibilitiesthrough appropriate application of allowancelists and outfitting actions. The Aviation SupplyOffice has the responsibility for continuallyreviewing and updating allowance lists.

INITIAL OUTFITTING LISTS

Initial Outfitting Lists are publications whichindicate the range and quantities of maintenancespare parts considered necessary to supportvarious aeronautical end items. These listscontain repair parts. such as airframe parts,electronic parts, engine parts, and general aero-nautical equipment. The material covered byInitial Outfitting Lists is normally retained insupply department stocks until required forissue. This allowance of material is provided toships or activities and is firm only at the time ofinitial outfitting. Increases and decreases in bothrange and/or quantities of material are basedupon usage data of each activity concerned.Each series list is designed to support an aircraft,

Chapter 2AN, iATION SUPPLY

electronic equipment, or some other aero-nautical article.

ALLOWANCE LISTS

These are publications which indicate therange and quantities of equipment and materialconsidered necessary for maintenance support ofassigned and/or supported aircraft. Generally,these items are inuse items required for daily orcontinual use, such as aircraft jacks, air com-pressors, and avionics test equipment.

Publications listing equipment and materialrequired by activities for performance of as-signed mission are known as Tables of BasicAllowance. They contain both shop equipmentand common supporting spare parts. They coverallowances of tools and equipment required foruse by such activities as Fleet Marine Forcesquadrons and target pilotless aircraft activities.

A complete listing of Aeronautical AllowanceLists, Initial Outfitting Lists, and Tables of BasicAllowance, with NavAirSysCom publicationnumbers and their effective dates, is containedin Nav Sup Publication 2002, Section VIII, PartC.

IDENTIFICATION AND TYPESOF ALLOWANCE LISTS

Allowance Lists and Initial Outfitting Listsare identified by the NavAirSysCom publicationnumber 00-35Q (Series), while Tables of BasicAllowance are identified by the NavAirSysCompublication number 00-35T (Series). The follow-ing paragraphs discuss some of the varioussections of allowance lists.

Section A, StandardAeronautical Material andNaval Stock Account Material

Section A covers general material such asnuts, bolts, tubing, hose, paint, and other itemscommon to the operation of all aircraft models.Both equipage and consumable supplies areshown in the Section A.

Section B, AircraftMaintenance Parts

Section B contains airframe, engine, andaccessories maintenance parts peculiar to eachtype of aircraft. A separate section B is issuedfor each model of aircraft.

Section C, Office Furnitureand Laborsaving Devices

Section C lists the items and quantities ofoffice furniture and laborsaving devices for theadministrative support of deployable fleet airactivities only.

Section G, General SupportEquipment For All Types,Classes, and Models of Aircraft

Section G (Series) lists the quantities, ofhandtools, handling and servicing equipment,and material which are made available formaintenance support of aircraft as may beassigned or supported.

Section H, FlightOperational Material

Section H is .applicable to air task groupcommanders and all Navy and Marine squadronsoperating aircraft or having aircraft assigned. Itcontains items and quantities of flight opera-tional material considered necessary to maintainthe concerned activities in a continual conditionof operational readiness.

Section K, Naval AeronauticalPublications and Forms

Section K outlines the general types andclasses of aeronautical technical and trainingpublications and forms which are provided as acommissioning allowance, for various Navy andMarine Corps aviation activities. It lists thosepublications and forms which are issued by theDeputy Chief of Naval Operations (Air) and bythe Naval Air Systems Command, but does notinclude publications provided to aviation activi-ties by other Navy Department systems com-


mands and bureaus, by fleet commands, or bynon-Navy offices.

Section R, Aeronautical Electronics Material

Section R comprises Allowance Lists andInitial Outfitting Lists of electronic equipmentand material required for the test and main-tenance of aeronautical electronic equipmentswithin the Naval Establishment.

Section Z, Special Equipmentand Spare Parts

Section Z includes mobile electric powerplantspare parts and equipment and spare partssupport for aircraft support equipment.

The foregoing section list breakdown includesonly those sections of professional interest tothe AD. The complete list includes allowancelists for arresting gear and catapults, photo-graphic, aerological, etc.

ACCOUNTABILITY CODES

The accountability codes used in allowancelists and most Illustrated Parts Breakdowns areknown as Material Accountability Recover-ability Codes (MARC). MARC's are assignedonly to aeronautical provisioned items to reflectthe accountability, recoverability, and repairpolicy determined for an item of equipment ormaterial required for the maintenance, repair, orrework of an end item. MARC is a systemwhereby a letter of the alphabet is used as aguidepost by personnel working with aviationmaterial. This system helps personnel to deter-mine the proper method of the following:

1. Requisitioning material with regard toinventory control and fiscal accounting proce-dures.

2. Accounting for material while in use.3. Turn-in or disposition of material.4. Repair or overhaul.

The following list defines the various materialaccountability codes.

BExchange Consumables

Code B is applied to items which are con-sumable or expendable but normally require

24

item-for-item exchange for issue after the initialoutfitting. Such items may contain preciousmetals, may be highly pilferable, or may be highcost items.

CConsumables

Code C is applied to all other consumable orexpendable items which do not require item-for-item exchange for replacement.

DEquipage, Support Type

Code D is applied to end items of supportequipment which are economical and practicalto repair on a scheduled basis through a majorrework activity. Code D items are maintained ona custodial signature basis and must be surveyedwhen lost or missing or when beyond eco-nomical repair. After initial outfitting, Code Ditems require item-for-item exchange for replace-ment. Every effort should be made to repairCode D items locally or through fleet supportactivities prior to turning in the item to thesupply system as non-RFI material.

EEquipage, LocallyRepairable, Support Type

Code E is applied to end items of supportequipment which are to be repaired locally bythe using or fleet support activity within theirassigned maintenance responsibility. Code Eitems are maintained on a custodial signaturebasis when in use, require item-for-item ex-change for replacement, and require surveyingwhen lost or missing. The cognizant NavAir-SysComRep may authorize repair of E itemsthrough customer service from a major reworkactivity in order to meet operational commit-ments.

R Equipage

Code R is applied to repairable (except enditems of support equipment) items which areeconomical and practical to repair on a pro-grammed basis through a major rework activity.Code R items are repaired by local activitieswhen the extent of the required repair fallswithin the maintenance capability of the activi-


ty. After initial outfitting, these items are issuedonly on an exchange basis or when necessary toreplace an item expended by approved survey.

LEquipage, Locally Repairable

Code L is assigned to repairable items (exceptend items of support equipment) which can berepaired by deployable squadrons within theirassigned maintenance responsibility upon con-sideration of the following factors:

1. Manhours and skills required to performthe repair.

2. Total cost of providing necessary supportequipment to perform the repair.

3. Total cost of providing necessary parts toperform the repair.

Items coded L are scrapped when economicalrepair is beyond local activity capabilities. Afterinitial .outfitting, issues of Code L items aremade only when exchange procedures providefor turn-in of the replaced items or whennecessary to replace an item expended byapproved survey.

DEVIATIONS FROM ALLOWANCELIST*REQUIREMENTS

It is the policy of the NavAirSysCom to makeavailable to each Navy activity the authorizedequipment and repair parts necessary to insureoperational readiness. Allowance list require-ments are not mandatory and deviations areapproved as pointed out in the following para-graphs.

Type, Force, and major operating com-manders, or their subordinate logistics com-manders, may authorize deviations from allow-ance list requirements. This includes one-timein-excess issue of equipment for a requirementnot considered generally applicable to otheractivities of the same type, or for independentoperations of detached activities.

Organizational and Intermediate maintenanceactivities often have requirements for equipmentwhich does not appear on existing allowancelists. In some cases the equipment is requestedbecause it is considered superior to existingequipment or it may be the result of an entirelynew requirement: that is, for rework of a

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component or to perform repairs or services forwhich no previous capability existed.

In order to assure that each request fordeviation is properly reviewed and evaluated forvalidity and possible application to other main-tenance activities, the originating activityshould submit an official request to the NavalAir Systems Command Headquarters, via thechain of command (including the cognizantNavAirSysComRep). The following generalprocedures are followed in approval or rejectionfor a new piece of support equipment where noprevioqs-elgbility or need existed.

The request, together with complete justifica-tion, should be forwarded via the chain ofcommand to the NavAirSysComHq. The requestshould not be made through supply systemchannels. The type commander normally iden-tifies, on the forwarding endorsement, the Inter-mediate maintenance activity which will per-form the equipment evaluation if different fromthe requesting activity.

The NavAirSysComRep normally investigatesthe request and indicates on the followingendorsement the availability of the requestedequipment from existing resources. Upon reviewand approval, the NavAirSysComHq providesthe activity concerned with the equipment. Thisequipment is considered a prototype and is forevaluation. No additional equipment is normallyprocured until the validity of the need can bedetermined. During the evaluation, the typecommander and cognizant NavAirSysComRepperforms monitoring actions and provides ad-ditional assistance as required.

The completed documentation of the evalua-tion is forwarded via the chain of command tothe NavAirSysComHq. In the forwardingendorsement, the type commander normallySuggests a criteria for allocation of equipment toother activities. Upon review of the evaluationreport, the NavAirSysComHq notifies all con-cerned of the action taken. In case of approval,this includes ASO so appropriate action may betaken to insure updating allowance lists.

AIRCRAFT MAINTENANCE MATERIALREADINESS LIST (AMMRL) PROGRAM

This program has provided for the develop-ment of data and documentation needed to


determine and establish firm support equipmentrequirements and inventory control of aircraftmaintenance support equipment. It provides forthe construction of an Individual MaterialReadiness List (IMRL) for each aircraft main-tenance activity, by name, prescribing items andquantities of aircraft maintenance materialrequired for material readiness of that specificactivity to which the list applies. This programalso provides for the construction of materialreadiness lists to indicate the total quantities ofeach item authorized within stations, logisticareas, and major operating command areas.

Within the AMMRL program there are severalmaterial readiness lists; however, only two arediscussed here.

The Application Data Material Readiness List(ADMRL) is used to specify the requirementsfor each item of aircraft maintenance supportequipment against each level of maintenance andselected ranges of each aircraft, engine, propel-ler, and system for which each item is needed.Through the use of electronic data processingmachines this data is used to develop IndividualMaterial Readiness Lists.

The IMRL specifies items and quantities ofaircraft maintenance support equipmentrequired for material readiness of the aircraftmaintenance activity to which the list applies.As previously stated, this list applies to anactivity by name. The NavAirSysComRep isresponsible for the preparation of the IMRL foreach activity in his cognizant area. It is preparedby extracting from the AMMRL those applicableportions which pertain to the specific aircraftand maintenance material assignments of theactivity for which the list is developed.

Maintenance /Material Control personnelmaintain an updated 1MRL to support currentand anticipated changes in aircraft maintenancesupport equipment requirements. Because theIMRL is continually reviewed and updated andapproved by the cognizant command, it is thefirm mandatory material readiness listof theactivity to which the list applies.

SUPPLY ACTIVITY

The mission of the supply activity is tosupport the operational and maintenance efforts

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of the activity/ship. Stocks of aviation orientedmaterial carried are tailored and replenished tothis end. Positioning, replenishment, and controlof stocks of material in maintenance areas arecarried out as a result of joint decisions by theSupply and Maintenance Officers concerned.They determine the range, depth, and relatedprocedures. The Naval Aviation MaintenanceProgram (NAMP) requires that the cost ofmaterial used in maintenance be determined andaccumulated in such manner and detail thatweapons system costing can be measured. Usageis finely defined as to stock number, withincomponent, within system, within equipment/weapon/aircraft, in a particular squadron,located in a specific operational area, at adefinite point in time. These data are used as aninventory management tool to determine geo-graphic and strategic distribution of stocks ofmaterial. In addition, the data will be invaluablein establishing the material portions of workstandards in maintenance.

SUPPLY SUPPORT CENTER (SSC)DIVISION

Maintenance organizations have one point ofcontact with the supporting supply activity. Thissingle contact point is the Supply SupportCenter (SSC), which responds to all materialrequirements of the maintenance organizations.The SSC is an internal organization of the localsupply department at the division level and isresponsible to the supply officer. It is made upof two sectionsthe Supply Response Section(SRS) and the Component Control Section(CCS). In addition to these two sections, there isthe preexpended bin element which may beorganized as a section under the SSC supervisoror as a unit under SRS or CCS.

Supply support is available consistent withthe operating hours of the maintenance activitiessupported. If maintenance is being performed 24hours a day, then supply support is available 24hours a day.

The supply support center maintains rotatablepool material which consists of repairable ready-for-issue items reserved primarily to satisfy therequirements of Organizational level main-tenance. Items maintained in the pool arecapable of being repaired by the local Inter-


mediate maintenance activity, have applicationrelationship to weapon systems supported bylocal Intermediate maintenance activities, andhave an average Organizational maintenancelevel removal rate of at least one per month.Defective components are turned in toIntermediate level maintenance for repair. Thedefective components repaired to an RFI condi-tion are then returned to the rotatable pool toreplace the components previously issued.

Generally, items included in a rotatable poolare repairable items of supply which are underthe issue control of the local supply officer.However, instances may occur when it is desira-ble to position some items or assemblies (such asa pre-soaked carburetor, built-up wheel as-sembly, built-up prop, etc.) in the pool for useby Organizational and Intermediate maintenanceactivities. Pre-positioning of items of this natureis acceptable as long as they aid in decreasingNOR time.

The local supply officer and aircraft main-tenance officers concerned determine the rangeand quantity of each item required in therotatable pool. Two elements used in thisdetermination are the local repair cycle time andthe local removal rate. The local repair cycletime is the average total elapsed time betweenremoval of a component and the complete localrepair of the item into an RFI condition. Thelocal removal rate is the average number ofdefective components removed over a 3-monthperiod, for which replacement RFI componentswere required.

After the components and the quantity ofeach that will be included in the pool have beendetermined, the supply officer publishes anofficial list of pool items. This listing provides aready reference for the components carried inthe pool. RFI rotatable pool items are with-drawn from the pool by the local supply officeronly under the following conditions:.

1. When actual usage indicates the item/quantity can no longer be justified as a reserva-tion, and the aircraft maintenance officer,concurs.

2. When requested by the aircraft main-tenance officer.

3. Only as a last resort to satisfy non-localsystem requirements.

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In order for the rotatable pool to fully serveits intended purpose there must be completecooperation between the maintenance andsu pply organizations. Organizational main-tenance activities must expedite return of defec-tive components to supply so that these com-ponents can be delivered to the Intermediateactivity for repair. The Intermediate activitymust complete repairs in an expeditious mannerso that the repaired components can be returnedto supply to be placed in the rotatable pool.Then, the supply organization is able to offermaximum support in the form of RFI com-ponents to insure maximum aircraft readiness.

Supply Response Section (SRS)

The Supply Response Section (SRS) isresponsible for preparing all necessary requisi-tions (DD Form 1348) and related documentsrequired to obtain material for local main-tenance use in direct support of weapon systemmaintenance. The maintenance organizationverbally notifies the supply organization of theneed of such material. When material is availablelocally, the time frame for processing anddelivery is as follows:

Priority

1-34-89-15

Process/Delivery Time

1 hour NORS/NFE2 hours

24 hours

The SRS is responsible for physical deliveryof RFI material to maintenance organizations,and the pickup of defective components fromthe Organizational maintenance activity andsubsequent delivery to the Intermediate main-tenance activity. Actual maintenance personnelare not involved in the physical movement ofmaterial between organizations.

This section also performs technical researchin regard to completion of requisition docu-ments as well as determining the status ofoutstanding requisitions and relaying this statusto the customer upon request.

The SRS accomplishes these functionsthrough four unitsthe requisition control unit,the technical research unit, the stock locatorunit, and the material delivery unit.

AVIATION MACHINIST'S MATER I & C

Component Control Section (CCS)

The CCS isfunctions:

I. Physicallyrotatable pool.

2. Maintainingrecords.

3. Maintaining aponents issued to customersbasis.

4. Maintaining a suspenseponents in AIMD.

5. Processing all components receivAIMD.

The CCS accomplishes thesethrough four unitsthe document cthe rotatable pool unit, the suppunit, and awaiting parts control uni

responsible for the following

maintaining components in the

rotatable pool supplemental

suspense fileon

file

for all coan excha

for all

Preexpended Bins Section

m-nge

COM-

ed from

functionsontrol unit,ly screening

t.

This section is responsible for establishing andmaintaining stocks, in maintenance areas, ofcommon repair parts that are considered to behigh usage, low in cost, expended from supplydepartment stock records, and expended fromfinancial records.

MATERIAL CONTROL WORK CENTER

The material control work center in a main-tenance activity performs a staff function, andas such provides support and services to theproduction divisions. It exists for the primarypurpose of insuring that maintenance require-ments for parts and materials are made knownto the supply organization in a timely manner inorder to prevent work stoppages and groundingaircraft. Material control insures that parts andmaterials made available to maintenance aresystematically utilized and not allowed to ac-cumulate or to become depleted. It serves as thesingle point of contact within the maintenanceorganization for the conduct of business withthe supply organization.

The material control work center providesmaterial support to their cognizant organization

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by accomplishing the following general func-tions:

1. Pass all requirements for material requiredfor direct support of weapon system main-tenance to the SSC. A material control register ismaintained for these items.

2. Prepare documents for material requiredfor indirect support of weapon system main-tenance. Examplos of materials for which docu-ments are to be prepared are aviation fuels andlube oils, rags, and flight jackets. A separaterequisition record log is maintained for theseitems.

3. Maintain liaison with the supporting SSCon maintenance material to insure that materialneeds of the organization are satisfied.

4. Establish delivery points for all materialand insure that material received is expeditiouslyrouted to the applicable work center.

5. Furnish technical advice and informationto the supply activity on the identity andquantity of supplies, spare parts, and materialsrequired for maintenance actions.

6. Establish procedures to insure the periodicinventory of tools and the adequate ac-countability of material and equipment oncustody to the cognizant organization.

7. Initiate surveys in the event of loss,damage, or destruction of accountable material.

8. Keep the maintenance control work centeradvised of the overall supply situation as itaffects the activity.

9. Perform cost and allotment record ac-counting, charting, and budgeting of cost ap-plicable to the cognizant organization.

10. Monitor the operation of toolrooms andmaintain an updated IMRL.

I I. Maintain inventory control of authorizedallowances of material.

The material control work center i3 respon-sible for the coordination of material ordering,receipt, and delivery. This is done in such amanner as to insure that the correct material isordered and that it reaches the work centerwithin the specified time frame.

The foregoing functions of the material con-trol work center apply to both Organizationaland Intermediate level activities. Some of thefunctions which are applicable to one level onlyare listed in the following paragraphs.


INTERMEDIATE LEVEL

An Administrative Screening Unit has beenestablished in the material control work centerof Intermediate maintenance activities. Thisscreening unit does the following:

1. Positively identifies material and deter-mines if it is within the repair capability of theAIMD.

2. Insures that all required documentation isaffixed to the component (that is, logs, records,MAF, etc.).

3. Notifies maintenance control of thereceipt of defective components for schedulinginto the AIMD.

4. Transfers the defective components to theappropriate work center when directed by main-tenance control.

All components received in the AIMD mate-rial control receive screening to determine if theitem is within the check, test, or repair capa-bility of the AIMD. As a result of this screening,components requiring maintenance within theAIMD capability are reported to maintenancecontrol as ready for induction. Items beyondAIMD capabilities are returned to the SupplySupport Center with appropriate recommenda-tions for disposition. When work on componentsin the AIMD has been completed, the com-ponents, together with required records, arereturned to material control for appropriaterouting back into the supply organization.

ORGANIZATIONAL LEVEL

In addition to the general functions, thematerial control work center in Organizationallevel activities is responsible for the following:

1. Verification of NORS (Not OperationallyReady Supply) requisitions and maintenance ofcurrent NORS status records.

2. Inventory of aircraft upon receipt andtransfer and maintenance of inventory records.

When removed components are generated as aresult of the maintenance effort, material con-trol insures that the SSC is notified to make apickup. These components must be ac-companied by record cards and logs, whenapplicable, plus the number two, three, and fourcopy of the Maintenance Action Form.

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MATERIAL CONTROL REGISTER

The Material. Control Register is used byIntermediate and Organizational level materialcontrol work centers to record all materialrequested from the Supply Support Center indirect support of weapon system maintenance.Space is provided to record essential informationconsidered necessary to monitor operating target(OPTAR) funds. This information includes partnumber priority, quantity, price, date and timeordered, and date and time received. Mainte-nance control uses the time ordered and timereceived to help determine Not OperationallyReady Supply (NORS) time used in fulfillingreadiness reporting requirements.

MATERIAL REQUISITIONING

The Military Standard Requisitioning andIssue Procedure (MILSTRIP) and Uniform Mate-rial Movement and Issue Priority System weredeveloped by Department of Defense to providea common supply language and more effectivesupply system operations within the militaryestablishment. This system standardizes forms,formats, codes, procedures, and the prioritysystem.

MILSTRIP employs two forms for the requisi-tioning and issuing of material. The Single LineItem Requisition Document (Form DD1348) isthe basic request document submitted to theapplicable supply echelon for material require-ments. The issue document is the Single LineItem Release/Receipt document (Form DD1348-1). Form DD 1348 -I is also used to returnRFI material to the supply system. As previous-ly stated, these forms will be prepared by theSupply Response Section of supply for allmaterial requested in direct support of weaponsystem maintenance and by the material controlwork center for material requested in indirectsupport of weapon system maintenance.

Under the MILSTRIP priority system thedecision to be made in assigning priorities is theurgency-of-need. This, combined with the unit'smilitary importance when applied to the prioritynumber chart (table 2-2), indicates the properpriority number.


Table 2 -2.- Priority number chart.

Force/activitydesignator

Urgency-of-need-designator

A B C

Priorities

I 01 04 11II 02 05 12

III 03 06 13IV 07 09 14V 08 10 15

The force/activity designators represent cate-gories of activities in descending order of mili-tary importance, ranging from the combat forcesunder I to the miscellaneous activities under V.Every activity is assigned one of the fiveforce/activity designators according to their mili-tary importance. These designators are as fol-lows:

I - COMBAT-The highest order of militaryimportance. This designator is not used inpeacetime unless approved by the President orthe Joint Chiefs of Staff.

II - POSITIONED-U.S. Forces positionedand maintained in a state of readiness forimmediate combat or direct combat support.

III - READY-U.S. Forces maintained in aState of readiness to deploy foi combat.

IV - RESERVE AND SUPPORT-U.S. activeand selected reserve forces planned for employ-ment in support of approved joint war plans.This category includes training units and units intraining for scheduled deployment.

V - OTHERS-All units not otherwise as-signed.

Force/activity designators (F/AD's) are as-signed by the Joint Chiefs of Staff or by eachDepartment of Defense component service. TheChief 3f Naval Operations has authority todelegate assignment of F/AD's (other than 1):toCommanders-in-Chief of Fleets. Each activity isadvised by the appropriate military commander

a:a:ea

of the assigned designator which governs theprocurement of material for that activity.

The letters across the top of table 2-2represent different degrees of urgency, in de-scending order of need, from an extremelyserious need under A to routine stock replenish-ment under C. The urgency designator is elec-ted by the requesting activity. Definitions of theUrge iicy-of-Need Designators (UND) for aviationunits (including 1MA's) are as illustrated in table2-3.

NOTE 1: Requirements of this nature are ofsuch a consequence as to require a report tohigher authority of a degradation of the requisi-tioning unit's capability in accordance withestablished NORS procedures.

For example, if a squadron or unit has beenassigned force/activity designator HI and a workcenter supervisor determines that a part or some

-material is needed which, if not received, willimpare the capability of the aircraft to performits assigned mission, then the priority k. signedmust be 03, 06, or 13. Referring to table 2-3,item B (2) describes this particular work centersupervisor's situation; therefore, the urgency-of-need designator will be "B" and the prioritymust be 06.

There are allowable exceptions to the force/activity designated governed priority numbersystem. Medical or disaster supplies and essentialclothing may be requisitioned under priorities03 and 06, respectively, by Lny activity regard-less of its force/activity designator.

MATERIAL TURN-IN

There are two main reasons for turning inmaterial-the first and most common is theturning in of a damaged, wornout, or otherwiseinoperative part in exchange for a like RFI item;and second, returning of material for credit,such as excess material or material received inerror.

When it is determined that a needed part is anexchange item, the old part should be cleaned ofgrease and dirt, drained, flushed, or purged asnecessary before turning it in. It is the respon-sibility of the maintenance personnel to attachaircraft equipment condition tags directly to therepairable item. An aircraft equipment conditionlabel is applied to the exterior of the container.

Chapter 2 AVIATION SUPPLY

Table 2-3.Urgency-of-need designators (definitions).

UND Definition

A

B

C

(1) Emergency requirements for primary weapons, equipment, and material for im-mediate use without which the aircraft concerned is unable to perform assignedoperational missions (HORS). (See Note 1.)

(2) Items required for immediate end use in direct support of equipment essential to theoperation of aircraft (e.g., ground support, firefighting, etc.) without which the avia-tion unit is unable to perform its mission. (See Note 1.)

(3) Items required, to eliminate an existing work stoppage at an Intermediate maintenanceactivity modifying or maintaining primary aircraft or aircraft equipment.

(4) Items required to eliminate an existing work stoppage at an Intermediate maintenanceactivity performing repair and maintenance on unserviceable high value/criticalitem repairables.

(5) Items required to effect emergency replacement or repair of essential physical facil-ities of an Intermediate maintenance activity, without which the activity cannot carryout its mission. (See Note 1.)

(6) UND "A" may be used for Not Fully Equipped (NFE) requirement only whenthe item(s) are needed to return mission essential subsystems and equipments tooperational status.

(1) Item(s) required for immediate end use, the lack of which is impairing the opera-tional capability of the aircraft or organizational unit concerned.

(2) Item(s) required for immediate end use to effect repairs to aircraft and aircraft sup-port equipment, without which the operational capability of the aircraft is impairedor effectiveness in accomplishing assigned mission is reduced.

(3) Item(s) required for the replacement of mission essential items on allowance/loadlists where the last item has been issued out of bin to end tiiiie or the quantity re-maining is less than the minimum replacement unit.

(4) Material required for immediate use to repair unservi..able repairable items idel-tified as high value items or critical items by ASO/NAVAIR.

(5) Items required to effect replacement or repair of physical plant facilities in an In-termediate Maintenance Activity without which the effectiveness of the facility isimpaired.

(6) Items required for immediate installation to effect repair or replacement of auxil-iary equiptnent without which the effectiveness of the assigned mission is impaired.

(7) Required to preclude an anticipated work stoppage in performing maintenance onmission essential equipment. The work stoppage is anticipated within 12 days byCONUS activities and 17 days by overseas activities.

(1) Items required to repair or replace administrative .support equipmentor systems notimmediately essential to operational mission of aircraft or organization units.

(2) Items required for routine stock replenishment.(3) Items requii-eti for scheduled maintenance and repair, not immediately required.

3146


All turn-in material should be returned, ifpracticable, in the container in which the newitem was received.

Activities placing items into shippingcontainers are responsible for the accuracy andcompleteness of information on the tag and thelabel, including the necessary obliteration ofprevious markings on the container which no

'longer apply. The primary reason for these tagsand labels is to provide a means of identificationand condition without disruption of packagingor preservation. These tags and labels indicatethe required disposition to those processing thematerial through channels.

When a defective repairable item is turned in,the following forms are required: copies two,three, and four of the multicopy MaintenanceAction Form and the Accessory and ComponentService Record, when applicable. The supplydepartment uses copy two of the MAF forbookkeeping purposes. Copies three and four ofthe MAF accompany the item to the Inter-mediate maintenance activity. When repair iscompleted by the IMA, copy four of the MAF isattached to the RFI item and the item isreturned to the supply system.

If material being turned in is no longerrequired and is RFI, a Single Line Item Release/Receipt Document (DD 1348-1) is submittedwith the item. RFI means ready for issue in allrespectspreservation still intact and item inoriginal or reusable container with seals un-broken.

Parts Kits

Supporting items and material for the main-tenance, repair, and rework of selectedrepairable type items are procured, stocked,requisitioned, accounted for, and used on a kitbasis as a single item. These parts kits should notbe confused with Change Kits which are issuedto perform a one-time modification of an item,nor with Interim Fleet Maintenance SupportKits which consist of a minimum range andquantity of parts and material to support the

items until regular parts kits become available asa result of normal provisioning action.

A repair kit consists of a group of main-tenance or overhaul parts that are bought,packaged, and stocklisted as a single item regard-less of the supply classification of the itemscontained in the kit. Normally, these parts haveeither a very low unit cost or have a highreplacement rate in overhaul or repair of thenext higher assembly. Depending upon thecomplexity of the item to be repaired, there canbe one or more kits needed for its repair. Repairparts kits are designed to serve three separaterequirements as described in the following para-graphs.

C KIT (CURE-DATED OR SOFTGOODS).This kit provides cure-dated itemssuch as diaphragms, packings, and 0-rings. The Ckit may also contain soft goods not subjected toage controls such as gaskets and seals, plusmetallic items such as screws, nuts, and washersrequired to be removed when cure-dated or softgoods type material are replaced. When mixedcategories of cure-dated parts are packaged in asingle container, the.controlling cure-date of thepackage is that of the oldest cure-dated part inthe package. If cure dated kits become overageddue to the expiration of the storage limitations,the kit is administratively disposed of as excessmaterial.

D KIT (OVERHAUL).This kit contains hardgood repair parts required at the time ofoverhaul. This kit does not contain cure-datedparts nor any metallic item which is placed inthe C kits, thus both are required at the timeoverhaul maintenance is being performed.

F KIT (FLEET).This kit provides thoseitems that are required to be replaced atIntermediate and Organizational maintenancelevels. Replacement of F kit items normally doesnot require special tools or equipment. This typekit does not contain cure-dated parts.

Part numbers for repair kits are listed in theapplicable Illustrated Parts Breakdown and, insome cases, the Maintenance InstructionsManual.

CHAPTER 3

WORK CENTER SUPERVISION AND ADMINISTRATION

A Chief or First Class Aviation Machinist'sMate R is likely to be assigned the responsibilityof supervising a work center. The work centercould be at either the Organizational or theIntermediate maintenance level and mightinclude the line division, quality assurancedivision, maintenance control, or powerplants.

The importance of the supervisor to thesuccess of an organic anion cannot be over-emphasized. He is the link between policymaking and policy execution. The supervisor isprimarily concerned with seeing that the job isdone, not necessarily performing the work him-self. His duties consist primarily of planning anddirecting the workload and maintenancemanagement of the manhour accounting systemwithin his work center.

Although this chapter deals primarily with theproblems of the powerplant work center super-visor, the objectives presented, the problemsinvolved, and the methods of dealing with themmay be applied to other supervisory billets towhich the ADR might be assigned.

SUPERVISOR REQUIREMENTS

The AD in a supervisory position sets inmotion the plans, schedules, and policies of hiscqperiors. His primary concern is seeing that the

)t) gets done, rather than performing the workhimself.

To accomplish this end, the supervisor mustknow his men, assign them work within theircapabilities, direct their efforts, and assumeresponsibility for seeing that each job is donecorrectly.

The supervisor's objectives are to operate withmaximum efficiency and safety, to operate withminimum expense and waste, and to operate asmuch as possible free from interruption anddifficulty. These three objectives are amplified

in Military Requirements for Petty Officer I &C, NavPers 10057 (Series).

It is important that an AD assigned super-visory duties keep in mind the importance of hisnew assignment to him personally. It affordshim the opportunity to gain practical experiencefor future promotions. His duties cannot beapproached in a haphazard manner. To makeright decisions, the supervisor must be knowl-edgeable, possess integrity, and utilize commonsense. He should employ the principles of goodleadership in carrying out his assignment. Theinformation provided in Principles and Problemsof Naval Leadership, NavPers 15924 (Series),will prove invaluable to the new supervisor untilhe has gained more experience.

KNOWLEDGE

Effective supervision of a work centerrequires a competent degree of knowledge con-cerning all areas of aircraft maintenance thatcould affect the work center. The senior pettyofficer must keep abreast of new ideas and beaware of the variety of directives and publica-tions that regulate his actions. He must beknowledgeable of the factors that make him amaintenance manager, of the programs thataffect his work area, of his rating, and theweapon system being supported.

Maintenance Management

The Naval Aviation Maintenance Program(NAMP), OpNav 4790.2 (Series), outlines com-mand, administrative, and management relation-ships and establishes policies for assignment ofaviation maintenance tasks. As defined in thisinstruction, the work center supervisor is respon-sible for the following actions:

1. Insuring the accomplishment of all as-signed work.

33

ac.h8


2. Insuring maximum utilization of personneland facilities.

3. Making recommendations concerning workcenter repair capabilities and facility requiie-men ts.

4. Causing all work to be inspected asrequired.

5. Initiating of material requirements tosupport the workload.

6. Screening of all source documents, workrequests, and associated paperwork to insureaccuracy, completeness, and timeliness of sub-mission.

7. Keeping maintenance control informed ofwork status.

8. Reviewing of daily manhour (when ap-plicable) and maintenance data reports for ac-curacy and submission of necessary corrections.

9. Insuring that the maintenance department'training program is properly supported withinthe work center.

The supervisor who endeavors to becomethoroughly familiar with the contents of theNaval Aviation Maintenance F,ogram Manual,volumes 1-4, will be better equipped to handlethe administrative affairs of the work center. Bythe time most petty officers reach E-5 level,they should be totally familiar with the varietyof source documents associated with aircraftmaintenance. Use of these documents is coveredin Military Requirements for Petty Officer 3 &2, NavPers 10056 (Series). Military Require-ments for Petty Officer 1 & (, NavPers 10057(Series), provides coverage on the variousmanhour and maintenance data reports as wellas other pertinent areas of the NAMP.

Special Programs

The senior AD will by necessity becomeinvolved in the variety of special programs thatdirectly or indirectly affect the supervision ofhis work center. OpNav Instruction 4790.2(Series) provides amplifying information on

selected maintenance programs such as thefollowing:

1. Component repair.2. Foreign object damage (FOD) prevention

program.3. Corrosion prevention 'control program.4. Navy Oil analysis program.

5. Aircraft fuel surveillance.6. NavAirSysCom calibration program.Separate chapters provide in-depth informa-

tion concerning Quality Assurance, Unsatisfac-tory Material /Condition (UR) ReportingSystem, Planned Maintenance System, etc.

Rating

The supervisor who has had varied experiencein all aspects of his rating is a definite asset toany command. A complete knowledge of one'srating is not easily achieved. All too often.personnel put in the required training coursesand rely on the information retained from theRate Training Manual to get them by. Study ofthe latest editions of these manuals and theadditional reference material listed in NavEdTra10052 will assist in the never-ending attempt to

stay current. When advancement in rating quali-fications change, the alert petty officer notesthese changes and strives to correct any knowl-edge deficiencies that might exist. Curiosityregarding activity correspondence, changes andbulletins, changes to maintenance publicationsand other maintenance directives, as well aschanges to other sources of information whichaffect the supervisor's work center and/or ratingcan result in increased ability and confidence.

Weapon System Being Supported

The number of aircraft acc,,''snts, groundaccidents, and incidents involving in. tenanceerrors has increased steadily for the past severalfiscal years. As the number of errors increased,the most often repeated errors continue to bethe same from year to year. Some of the errorscause little or no damage and consequently havenot been appropriately advertised. Many main-tenance errors can be attributed to failure of thesupervisor to properly perform his duties.

A knowledge of the weapon system beingsupported is a must requirement. The traininglectures prepared for use in training personnelwithin the work center should be a valuablesource of information regarding the weaponsystem. Study of the appropriate volumes of theMaintenance Instructions Manual and com-pletion of courses on the weapon systemprovided b.v Naval Aircraft Maintenance Train-mg Groups (NAMTG), which have detachments

3411

Chapter 3 WORK CENTER SUPERVISION AND ADMINISTRATION

in the field, will better equip the supervisor tomake decisions reg-rding maintenance of thesystem. Use of the MIM when performingmaintenance applies to both the worker and thesupervisor. The complexity of many of today'saircraft systems requires that step-by-step proce-dures be followed for accomplishing removal,installation, repair, operational testing, etc. It isimpossible to commit these step-by-step proce-dures to memory. Personnel who arc unfamiliarwith a task that is assigned should readily admittheir lack of proper training rather than attemptthe task with questionable results. It is notuncommon for a supervisor to find that asubordinate has greater knowledge of aparticular system than the supervisor. However,the supervisor must make it a habit to verify anydoubtful information and correct any knowl-edge deficiencies on his part, or he may losesome of the respect necessary to maintaincontrol of his men. This is not to imply that heshould be distrustful of his men. Sometimessubordinates feel that information passed on tothem by others is correct without verifying it inthe MIM. In summary, it is better to admit whenyou do not know something and then followthrough by doing something about it im-mediately.

SUPERVISION AND LEADERSHIP

The experienced petty officer will soon learnthat supervision and leadership are very closelyrelated. The supervisor's role requires that he bea leader, a man of common sense, and a manwho earns the respect of others. Many decisionsare difficult to make. To be effective in hisdecision making, the supervisor assemblespertinent facts, policies, and procedures: de-velops a course of action and evaluates possiblealternatives: selects the best course of action.and initiates the required action. When neces-sary, he consults his own superior prior to takingaction. Every supervisor must face problemssquarely and make timely and sound decisions.The supervisor who dodges his responsibilitieswill soon find his control of suboLinates slip-ping away, d iscipline deteriorating, dis-satisfaction with his supervision increasing andeffectiveness of the organization suffering.

35

40

The supervisor who establishes and maintainsa spirit of cooperation within his work centerand in the everyday dealings with other workcenters and maintenance control will find his jobis much easier. Aircraft readiness is the commonpurpose bf the maintenance organization, and allrating should share a common interest inachieving that purpose. A willingness by eachindividual to submerge his personal interest infavor of getting the job done is a necessaryprerequisite to cooperation. If the supervisor'srequests arc reasonable, made well in advance(when possible), were understood, and providedall necessary information, his requests willgenerally induce cooperative action. If coope-a-tion is lacking, check the facts to find outIf subordinates arc at fault, they can be tolddirectly and in e firm manner, taking intoconsideration the basic principles of good leader-ship.

The supervisor's duties involve planning,direction, and control. Careful planning is anessential ingredient to effective supervision and'minimizes other types of supervisory effortswhen carefully executed. Time and effortinvested in the process of careful planning israrely wasted. It can result in job simplificationand increased efficiency.

The effective supervisor initiates the planningprocess by identifying each specific job to bedone by his men. With a routine clearly estab-lished, he can spend his time on the exceptionsthat may arise. He knows the capacities,interests, weaknesses, and potentials of his men.Knowing each man's level of technical skill,motivation, ambitions, and personality charac-teristics will enable the supervisor to (1) assignthe right man to the right job, (2) identify thetraining needed by each man to do a better job,and (3) establish the standard at which each mancan be expected to perform.

Once action has bee!" initiated, the supervisorprovides direction. This function of supervisionis like that ^` a "foreman." He sees that work isstarted and Knows what is going on at all times.This does not mean that he must always bephysically present while the job is being done.Subordinates should be trained to assumeresponsibility for the job in the absence of thesupervisor so that no man is indispensable,includ'ng the supervisor. The supervisor should,


however, be available when his men are working,and they should know how to contact him. Thesupervisor should always be present when hismen are assigned new tasks, when they havetrouble getting a job done, or when othercircumstances dictate the necessity for hispresence. He must be careful not to over-supervise lest he destroy the initiative of hisworkers and subordinate supervisors. He receivessuggestions and reactions from his subordinatesand acts as necessary on them, giving creditwhen and where it is due. Recognition of eachman as an individual is required.

Control of a job refers to the function ofchecking to see that the job is done as planneda comparing of performance with plans. Devia-tions may reflect poor planning. However,procedures should exist whereby changes inplans that could result in improved performancecan be implemented to minimize repetition offaulty performance.

The supervisor will be challenged to allocatesufficient time to be expended on planning,direction, and control. A spirit of firmness,fairness, cooperation, decisiveness, harmony,and mutual respect while seeing that the job isdone will rarely go unrewarded.

Communications

The area of communications as related tosupervision and leadership is singled out herebecause of its importance. Almost withoutexception, problem areas regardless of theirnature can be attributed to the lack of propercommunications. Men like to be kept informedabout all the things that affect them. Keepingthem informed will improve their morale andgenerally make them more responsive to theneeds of the command. The supervisor canimprove morale by keeping his men as wellinformed as possible concerning need-to-knowand nice-to-know information that could affectthem, as long as it is dot classified.

Communications is a two-way process. Thesupervisor must be able to convey his ideas,orders, etc., and pass on information, eitherorally or in writing, in such a manner that it willbe clearly understood. He must also be willing tolisten to and try to understand the ideas ofothers. Subjectivity (that is, looking at things

36

41

only from a personal viewpoint, because of yourposition, rating, pay grade, or any other reason)will hinder communications. Bias and limitedknowledge can limit a supervisor's ability to beobjective, and by recognizing this fact, he canlisten more objectively.

Ridicule, sarcasm, vulgarity, etc., have noplace in good communications. The supervisorwho must get loud and resort to such languageto get his point across or the job done needs torealize how adversely such action affects his ownfeelings of imnortance and respect. When itbecomes necessary to orally reprimand asubordinate, do it in private, keeping in mindthat he is an individual and as a petty officer hemust have the respect of the men under him. If asupervisor reprimands a man in public, both loserespect and are less effective in getting the jobdone.

Professionalism

It is the responsibility of all senior pettyofficers to install a spirit of professionalism intheir subordinates. Aircraft maintenance is areasonably complicated profession that leaveslittle room for error. The maintenance man whogives it less than his undivided attention presentsa potential hazard. Of primary importance arethe ethical attitudes and considerations involvedin performing each maintenance task, the un-spoken but carefully adhered to codes governingeach man's action.

The responsible petty officer sets the examplehe wishes others to follow, doing the right thingin carrying out each assignment, including (andespecially so) when no one is watching.Undiluted professionalism means that there is noroom for ethical lapses or occasional breaches ofintegrity. The worker who even once shortcutsestablished procedures, does not follow main-tenance manual instructions, sacrifices qualityfor speed, or performs any other action whichcould produce a negative judgment towards himlacks the professional integrity demanded inaviation maintenance. The supervisor whocondones such action is equally guilty of a lessthan professional attitude and the results thatsuch actions could cause.

There is no substitute for thorough knowl-edge of your aircraft, your job, and the proce-

Chapter 3WORK CENTER SUPERVISION AND ADMINISTRATION

dures associated therewith. Correct maintenanceprocedures and thorough quality assurance willamost always produce professional results.Aviation safety demands pure, undilutedprofessionalism from all personnel involved inmaintenance.

WORK SIMPLIFICATION

Work simplification is a common sense, sys-tematic method of identifying and analyzingwork problems, developing solutions, andinstalling improvements. In order to achievemaximum efficiency each supervisor must do hispart to improve the work situation and achievemaximum manpower utilization. This impliesthat the greatest possible use of all resourcesavailable be made in order to help accomplish anactivity's mission. Work simplification is a toolwhich can be utilized effectively in the ac-complishment of this goal. Work simplificationmight be considered as human ingenuity appliedto the work situation. It is the organized use ofcommon sense and creative thinking in thesolution of work problems.

If all men had believed that there could be nobetter way of doing things, we might still bethrowing rocks at game for our food andtraveling from place to place on foot. Progress inthese fields was not made in a single step but ina series of improvements. These changes oc-curred slowly over the centuries, growing out ofa multitude of small improvements.

The supervisor who lives day to day, satisfiedthat what he did yesterday is good enough fortomorrow, will, in most cases, leave his job nobetter from having held it. He leaves nothingsignificant for other personnel to follow him inhis job, and he becomes lost in the shuffle ofmen who are content with merely living anddying.

The majority of improvements in our worlddid not come by accident; rather, they came as aresult of man's ingenuity, growing out of hissense of imperfection and his constant search forimprovement. When an improvement is made,no matter how small, it marks its discoverer as aperson of imagination with a real and activeinterest in his work.

The supervisor who believes in and practiceswork simplification procedures can look with

37

pride upon his contributions or those of peoplewho work with him. This means that thesupervisor should never cease to search forimprovement and must encourage his workers totry to improve jobs over which he has control.

The supervisor should always watch for areaswhere work can be simplified. Work siniplifica-tion pays immediate dividends by increasingboth production quality and quantity. It allowsthe supervisor to meet work schedules moreeasily and reduces waste by producing with lesseffort, increases savings in time and manhours,and thus reduces cost of operation. Workmethods improvement aids in establishing stand-ard procedures. These standard procedures aid intraining both old and new workers, since mostworkers are easier to train, and learning is mucheasier if standard practices are used.

It is true that with good leadership personnelcan be encouraged to work to the limit of theirphysical endurance but unless their eft ,rts areused wisely, the most critical resourcesmanpoweris being wasted. In the final analysis,it is not how hard personnel work but howmuch quality work is accomplished that matters.Therefore, to help achieve maximum resultswith minimum expenditure of human effort, thesupervisor should always strive to use establishedwork simplification techniques.

Work simplification permits continuous evalu-ation by analyzing existing methods and proce-dures with a view toward improving them. Thereis always a better way of performing a task byusing streamlined methods, improved tools,better working conditions, or shorter proce-dures. However, these better methods are notalways apparent. Work simplification should bedirected at all work situations where physicaleffort is expended.

Techniques

There are many techniques for improvingwork methods. For the most part, these tech-niques are adaptable to any part of an organiza-tion as well as a whole activity. Five of theprincipal techniques which, have been success-fully applied to work operations are discussedbriefly in the following paragraphs. All of thesetechniques require the construction, completion,


and use of lists, charts, flow diagrams, etc., inorder to study and analyze specific areas.

WORK DISTRIBUTION ANALYSIS.Workdistribution analysis is a technique used toanalyze objectively the division of work in anorganization. In order to obtain the most effective distribution of work, it is necessary forthe supervisor to have an overall view of theorganization and its operations. The supervisormust clearly understand the work that is beingdceie and be able to see the relationship betweenthe overall operation and the individual workunits as well as the contribution that eachperson makes to the work of the whole organiza-tion.

Distribution of work is an important factor inefficient use of manpower. Time and effort aresaved if related duties are performed by thesame person. Thoughtful matching of assign-ments and qualifications is important so thatpersonnel are not struggling with work that istoo hard for them or wasting their time on tasksthat might be performed by a less skilled person.Another consideration is distribution of work-load to avoid inequalities, since these result inbottlenecks and other inefficiencies.

Work distribution analysis requires that aTask List be completed for each person whosework is being studied. This list contains, insimple statements, tasks the worker performsregularly and the average number of hours spenton each task per week. Next, a Function List isprepared which lists each function performed bythe unit. Each task reported on the Task Listmust be related to a specific function. A WorkDistribution Chart is prepared from the datacollected on the Task List and Function List.This chart presents the work performed in theexisting organization under current operatingconditions. The chart is then studied andanalyzed to find answers to questions such asthe following:

I. What functions take the most time?2. Is the.r.! misdirected effort'?3. Are skills being used properly?4. Are personnel doing too many unrelated

tasks?5. Are tasks spread too thinly?6. Is work distributed evenly?A careful study and analysis of the work

distribution chart should assist in achieving thefollowing results:

38

I. Elimination of unnecessary tasks.2. Reduction of time spent on relatively

unimportant functions.3. Elimination of duplication and overlapping

of work.4. Better balance of workloads.5. Combination of related tasks.6. Realistic estimate of personnel needs.7. Better utilization of skills.8. Reallocation of misassigned personnel.WORK COUNT ANALYSIS.Work count

analysis supplements the work distributionanalysis and is a technique for determining thevolume of work in terms of measurable units.Information obtained by counting or measuringthe work provides a basis for improving methodsand procedures, adjusting work assignments,evaluating performance, and eliminating bottle-necks. Such information is useful in assigningand scheduling work to insure that the workloadis equitably distributed among all personnel.

Items of work counted should be definite andcomparable. Items counted should also berepresentative of work usually performed. Onlythose should be counted that clarify methodsemployed. Counting may take place where thework comes into Production Control; where adecision is made or action is taken, where aprocess is completed, or where long storageoccurs.

Work count information can be used toaccomplish the following:

I. Establish how long it takes to do a givenpiece of work.

2. Indicate whether the volume of a certainpiece of work is sufficient to warrant specializa-tion.

3. Show whether work is distributed evenlyamong workers.

4. Point out bottlenecks where work piles up.5. Indicate whether the work center is

adequately manned, overmanned, or under-manned.

6. Stimulate interest of personnel byproviding comparisons of one person's workwith that of another or with his own recordduring a different counting period.

FLOW PROCESS ANALYSIS.Flow processanalysis is a technique for analyzing flow andsequence of operations. The purpose of thisanalysis is to reduce time and distances in aprocess by eliminating, combining, and changing

43


the sequence of steps in the flow of work.The principal tool of this technique is the

construction of a flow process chart whichprovides a clear and detailed picture of the flowof work. Recording each step in a procedurehelps to identify duplication of effort, back-tracking, and other obstacles to the smooth,efficient flow of work.

MOTION ANALYSIS.Motion analysis is atechnique for making maximum use of physicalmotions. It is a method of studying the motionsof individuals in performing their various tasks.

Work distribution and flow process analysesare directed toward improving the division andflow of work. Motion analysis deals with how anindividual performs his tasks. It seeks to learnwhether the workers are doing their work withminimum fatigue, loss of time, and waste ofeffort. Improvements are effected by re-arrangement of materials and work area and byproper use of equipment.

The simplest way of gathering data formotion analysis is for the supervisor to watch hispersonnel at work and note useless motions.Motion analysis should result in the eliminationof wasteful motions and consequent loss ofwork time, reduction of fatigue by lessening theamount of physical effort required to completea task, and increase the efficiency of personnel.

LAYOUT ANALYSIS.Layout analysis is aprocedure designed to lead to better utilizationof space, personnel, and equipment. A study ofthe layout of a working area can provide usefulinformation for improving the work of individ-uals, distribution of the workload, and flow ofwork from one person to another. Its purpose isto determine what space is needed for theoperations to be performed and how theavailable space may be used most effectively.Besides shortening and simplifying motions, itshould produce working conditions that are ascomfortable and personally satisfactory to theworkers as possible consistent with efficient andeconomical operation.

Tir layout chart is the principal tool of thistype of analysis. This chart consists of a floorplan of the work space, showing doors,windows, electrical outlets, etc. All features thatrestrict usable space should be included.

The following principles should be kept inmind when studying a work center layout chart:

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1. Equipment getting the most use should belocated in the most accessible areas.

2. Layout should provide for safe use ofequipment.

3. Arrangement of equipment and facilitiesshould allow for effective supervision.

4. Arrangement of equipment should ac-commodate the necessary flow of personnelutilizing the work area.

5. Maintenance publications should beconveniently accessible to those who use them.

6. Working space allocations should beconsistent with working conditions.

INSTALLATION OF IMPROVEMENTS.Briefly speaking, work simplification meansimproving methods of doing work or finding abetter way. Improved methods usually involveeliminating unnecessary parts of the job,combining and rearranging other parts of thejob, and simplifying the necessary parts of thejob. By improving methods personnel are able todo better work, with less effort, in less time,without hurrying, with greater safety, and withlower cost. The pattern for achieving thebenefits of work simplification is as follows:

1. Select the job to be improved.2. Break down the job in detail.3. Question the job and each detail of the

job.4. Develop the new method.5. Apply and install the new method.The fact that changes are recommended as a

result of a work simplification study does notalways mean that these changes will or can bemade immediately. There are several reasonswhy a change that many regard as an improve-ment may be slow in being adopted.

Most any change will draw objections from acertain number of persons, There are twogeneral types of reasons for these objections.First, many people regard a recommendedchange as a criticism of the way they have beendoing their work and therefore resent it. Most ofthis type of objection can be avoided if thosewho will be affected by the change canparticipate in some degree in the analysis so thatthe whole enterprise becomes a group activity. Ifthis is not possible, at least a clear explanationshould be made regarding reason for the change.Emphasis should be on future advantages ratherthan criticism of old methods. Secondly, most


people have a natural dislike to changingestablished work habits. If advantages of thenew method are clearly explained, this resistancelessens considerably.

Before making any changes it is well toconsider carefully all likely effects, for some-times unforeseen effects may cancel out thebeneficial aspects of the change. It is important,for instance, when new equipment or facilitiesare contemplated, to be sure that advantages ofthe new installations will outweigh cost. Indirecteffects of change upon other equipment orconditions should also be considered.

Effects upon interorganizational relationshipsshould also be taken into account. If workprocedures are speeded up in one phase of anoperation only to create a bottleneck in another,there will be little or no improvement.

PLANNING WORK CENTERARRANGEMENT

The average Chief or First Class AviationMachinist's Mate R may never have the oppor-tunity of planning the layout of the powerplantwork center in a new facility. In almost everycase, the new supervisor will take charge of analready functioning division or else, when hissquadron or unit moves to a new base, he andhis crew will usually be assigned to spacesalready basically equipped for powerplantrepair. In either case, a reevaluation of thelayout should include finding out from theapplicable allowance lists if the equipment al-lowances have been changed in any way. Thereis no use relocating equipments which involverewiring or plumbing work if improved replace-ment models are authorized and available.

PURPOSE OF THE WORK CENTER

A basic consideration in planning a workcenter layout is At purpose. When more thanone space is available, the supervisor must decidewhich space would be most suited for a power-plant work center. Of two spaces identical insize, one may, for example, be completelyunacceptable for powerplants due to thelocation and size of doors or the shape of thearea.

A change in assigned aircraft model designa-tion always calls for a reevaluation of the workcenter arrangement.

The general function of the work center mustbe considered in the allocation of space andequipment. The ideal work center would containenough space to have workbenches, enginestands, engine buildup, parts and tool stowagespace, propeller section (if required), and amplespace for technical publications in a centrallylocated area. Since this is not normally possible,the supervisor must decide what sections of thework center are to be combined and in whatareas of each space the appropriate equipment isto be installed. This decision should be based onfactors of safety, economy, functionalcompatibility, and convenience.

ARRANGEMENT

Following the determination of which workcenter is to occupy which space or area within aspace comes the arrangement of furniture andequipment.

The arrangement of the work center furnish-ingi should be made on the basis of utility ratherthan appearance. Moving an item of equipmentinto an out-of-the-way corner may greatlyimprove the appearance of the work center butat the same time reduce the efficiency of thepersonnel using the equipment and may possiblycreate a safety hazard. A good rule to follow isto locate equipment where it can be safely usedby the greatest number of people with aminimum of effort in the least amount of time.

Worktables and workbenches should be posi-tioned with respect to fixed equipment so thatthe equipment most often used is most quicklyand easily reached. Electrical and compressed airoutlet: should be readily available to the work-benches. Needless delays are caused by having torig unnecessarily long connections from poorlylocated outlets.

Near workbenches where specific andintricate maintenance functions are performed,consideration should be given to installingspecial lighting such as explosion-proof, vapor-proof, or interference-free type lighting. Undercertain conditions, special lighting may alsoinclude floodlights for outside work areas and inhangars when improved lighting is required.

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Utilization of paint in various colors toemphasize portions of intricate machinery forsafety and reflective purposes is known asdynamic painting. Painting in this categoryshould not be utilized for normal buildingmaintenance.

A system of stowing tools must be devised.An intelligent system cannot be set up withoutfirst determining from allowance lists what toolswill be required for satisfactory operation of thework center. The place for all tools should bemarked or otherwise specified, and everythingnot being used should be kept in that place.

The layout should make provisions for abulletin board upon which may be posted safetyposters, maintenance posters, instructiops andnotices, plans-of-the-day, and such other infor-mation as is appropriate from time to time. Thebulletin board should be located in a prominentplace in the work center, preferably near theentrance where everyone assigned will have topass some time or another during the day.Material on the bulletin board should bechanged frequently, expired notices promptlyremoved, the current plan-of-the-day postedearly, and other posters and material rotatedperiodically. If the same material is presented inthe same format every day, it will not be longbefore the men begin to ignore the bulletinboard and purposes for having it are defeated.New arrangements are noticed and interest isstimulated vith variety.

When aviation Organizational level main-tenAnce activities are moved aboard ship, theirworking conditions and accommodations aredrastically affected. The ingenuity of the super-visor will be required to produce a workablearrangement within very limited spaces. Stowageracks for toolboxes and other work centerequipment should be located to accommodatetheir frequency of use. Some equipment used atless frequent intervals may have to be stowed invoids. An inventory listing of such items, show-ing their specific location, will be necessary.Security of material stowed in voids, toolboxes,and other equipment will require more attentionthan when ashore. Gear not properly stowed andafforded appropriate security has a habit ofdisappearing, and during rough sea states, can behazardous to personnel and/or other equipment.

Much of the work done aboard ship will haveto be done under less than ideal conditions.

Confined spaces, reduced lighting during nighttime flight operations, hazardous conditions onthe flight and hangar decks, problems associatedwith respotting of aircraft to accommodatemaintenance, and a variety of conditionspeculiar to ship operations will require modifica-tions of procedures used ashore. The supervisorshould insure that spaces are utilized to theirfullest extent.

Since most Organizational level maintenanceis "on aircraft" type maintenance, the limitedspace of the work center should present only aminor problem concerning the stowage of gearand some personnel congestion during periodswhen personnel are awaiting work. Considera-tion of the factors previously discussed under"Work Simplification," and further discussed inNavPers 18359 (Series), could result in asmoother transition from shore to shipboardfacilities and vice versa.

.SCHEDULING AND ASSIGNMENTOF WORKLOAD

Among the most important factors withwhich the Chief or First Class AviationMachinist's Mate R is concerned as a supervisorare the assignment and accomplishment of thescheduled workload. His objective is the satis-factory completion of assigned tasks in areasonable length of time, utilizing available menand materials as efficiently as possible. In orderto achieve his objective, the supervisor mustbecome skilled in estimating the amount of timeto allow for the completion of each task andestimating the number of workers required. Hemust realize the importance of assigning bothqualified and unqualified men to the jobs,consistent with his training program. The super-visor must allow for planned interruptions andyet not operate on so tight a schedule thatminor, unplanned interruptions completelydisrupt his schedule.

ESTIMATING TIME ANDPERSONNEL REQUIREMENTS

Most maintenance jobs are of such a naturethat the quality and quantity of people assignedto do them directly affect the time that will berequired for completion. For this reason, time

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requirements and personnel requirements arecombined and discussed together in this section.

Probably the most important single aid inestimating time and personnel requirements foraircraft maintenance tasks is the Periodic Main-tenance Requirements Manual with its relatedcards, charts, and forms. Extensive time andmotion studies of the various inspection require-ments have been made and completion times arefurnished in manhours or manminutes. Thesetimes also reflect routine maintenance, adjust-ments, and replacement if required in con-nection with the aircraft inspection. They arecalculated on the basis that the most efficientnumber of men are continuously employed andthat all necessary equipment, tools, and parts areimmediately available. The upervisor mustconsider all these factors from the knowledge ofhis individual personnel, supply, and equipmentsituation, together with an accurate deter-mination of the extent to which the main-tenance task at hand exceeds the inspectionrequirements if he is to reliably predict thecompletion time. While this procedure may seemrather involved at first, the new supervisor willfind that it is based on sound managementprinciples and that, with experience, his abilityto accurately predict time and personnel require-ments will speedily improve.

PERSONNEL WORK ASSIGNMENTS

Work assignments should be rotated so thateach man will have an opportunity to develophis skills in all phases of the ADR work. Whenassignments are rotated, the work becomes moreinteresting for the men. Another good reason forrotating work assignments is that if one highlyskilled man performs all the work of a certaintype, the supervisor and the work center wouldbe at a great disadvantage in the event the man istransferred. Less experienced personnel shouldbe assigned to work with him in order tobecome proficient in his particular skill. Also, inorder to broaden his knowledge of his rate, theexpert on one job should be rotated to othertasks when there is no immediate need for hisparticular skill.

Strikers should be assigned to various tasks sothat they will acquire experience on all kinds ofjobs. A special consideration for the assignment

of strikers to jobs is that they should be assignedprogressively to jobs of ascending levels ofdifficulty. A striker may be a useful assistant ona complicated job, but he may not understandwhat he is doing unless he has worked his wayup from basic tasks.

ALLOWING FOR PLANNEDINTERRUPTIONS

During an average workday, occasions willarise when personnel have to leave their workingspaces for one reason or another, therebydelaying the completion of the scheduled work.Some delays can be anticipated; some cannot.Among the delays which can be anticipated aretraining lectures, immunization schedules, flightschedules, rating examinations, meals, andwatches or other military duties.

Before making personnel work assignmentsthe supervisor should determine what delays canbe anticipated. It may be possible to arrangeassignments so that work interruption is held toa minimum. When estimating the completiontime of a maintenance task, the supervisorshould allow for these predictable delays.

SUPERVISION OF THEUSE OF EQUIPMENT

In order to achieve maximum productionwithin his work center, the supervisor mustclosely supervise the use of equipment used tosupport the production effort. Such equipmentincludes service, maintenance, and test equip-ment.

As the aircraft becomes heavier, faster, andmore expensive, the support vehicles and equip-ment become more numerous, more complex,and more dangerous. Therefore, this area ofsupervision requires more and more attention.Even though the supervisor goes by the standardrules, every command has problems peculiar toits location and mission. This requires that he befamiliar with the directives and instructionspublished in his command.

The supervisor should take full advantage ofall training programs to assure that each workerattached to his work center knows the specificoperating instructions for the particular equip-ment being used. If his work center is engaged in

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aircraft servicing, he must insure that hisworkers know the type of aircraft being servicedand the service procedures for that particularaircraft and that they follow these procedures.

The supervisor must be familiar with all toolsand test equipment that are normally used in thework center for work which cannot be per-formed on the aircraft. He must be familiar withthe calibration program and insure that allequipment is tested and calibrated as specified.

Safety is of paramount importance in the useof any equipment. The supervisor must befamiliar with all safety precautions pertaining tothe use of each piece of equipment and insistthat these safety precautions be observed at alltimes.

Whenever equipment has been used, thesupervisor must insure that the equipment issecured and stowed, if applicable, when thework is completed.

VISUAL INFORMATION DISPLAYSYSTEM

The Visual Information Display System(VIDS) is a time management tool whichprovides a graphic display of vital, up-to-dateinformation on a continuing basis. The systemcorrelates all aircraft status information, particu-larly awaiting parts and flyable discrepancies andassigns a relative importance to each item.Additionally, the system displays the amount oftime anticipated to perform any maintenanceand the number of personnel available andengaged in work. The ability to review theoverall situation and determine what resourcesare available enables the supervisor to moreeffectively and efficiently carry out his duties.This information is displayed on speciallyconfigured cardex type boards.

QUALITY ASSURANCE

Commanding officers are responsible for theinspection and quality of material under theircognizance. In a maintenance department, theprincipal force for securing compliance withquality standards lies NOT in the instruments,instructions, or other facilities for inspection,but in the state of mind of maintenance person-

nel from the commanding officer down to theworkers.

Generating quality in a maintenance organiza-tion necessitates a sincere interest on the part ofcommanding officers, plainly evidenced to theofficers and men in their commands. Qualityfurther requires that each maintenance officerand supervisor understand clearly how the ac-complishment of a quality job contributes to theeffective operation of the organization. Qualityalso requires that each maintenance workerunderstand not merely a set of specificationlimits, but also the intent and the need for theserequirements.

The quality assurance organization is con-cerned with three functional areasqualitymanagement, quality verification, and technicalpublications.

Quality management is monitored byformulating, implementing, and auditing proce-dures, instructions, and operations to assurecompliance with the policies stated or impliedwithin the NAMP Manual. Quality assurancecoordinates their efforts with those of theactivity's data analysis group to provide informa-tion on maintenance practices and results basedon facts gleaned from the various maintenancesource documents and associated reports.

Quality verification assures that all materialprocessed and actions taken by maintenancepersonnel meet prescribed quality requirements.Direct inspection of material and operations asthey are performed is necessary on a continuingbasis to give adequate assurance that all itemsprocessed and maintenance tasks completedmeet the prescribed requirements. These qualityassurance considerations (tests, inspections, etc.)are included in most weapon system Main-tenance Requirements Card decks as well asmost Maintenance Instructions Manuals andOverhaul and Repair Manuals (03). Qualityassurance verification steps are generally calledfor at various steps during repair progress inaddition to verification of the final product.

Since technical information has a directrelationship towards assuring the quality ofwork performed, the quality assurance divisionhas the responsibility of operating a mastertechnical library and monitoring of dispersedlibraries within the various work centers.Dispersed libraries located within the work

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centers are necessary to place technical informa-tion in the hands of the user who is charged withcompliance. The quality assurance divisionmonitors the operation of these dispersedlibraries, providing new publications, revisions,cancellations, and such other information thatmay affect the publications held. A change entrycertification is utilized to insure that all changeand revision material is entered into the direc-tives and manuals of the dispersed librarieswithin a reasonable time.

Since the responsibility area of the supervisoris the middle ground between management andmen, it is incumbent upon him to initiate andadminister a quality assurance program. Hismain objective is to improve the state of trainingof his men until their mental attitude is suchthat top quality workmanship becomes secondnature. How successful he is in achieving thisobje:Aive will be determined by his ability andinsight in the following areas:

1. The assignment of the proper number ofqualified men to do the jobs, plus-on-the-jobtrainees.

2. Making provisions for adequate on-the-jobsupervision and inspection.

3. Allowing adequat time to perform safe,high quality jobs.

4. Assuring himself that current directivesand publications on safety and aircraft modelconcerned are available and complied with.

5. Monitoring the training program withrespect to timeliness and completeness ofcoverage. Eliminating out-of-date training mate-rial promptly and introducing important newmaterial as soon as possible after receipt withoutregard to lesson schedules.

These procedures should result in high qualityworkmanship by powerplants personnel andmeeting of specifications and quality standardsin the work.

PLANNING FOR ADVANCED BASE ORFORWARD AREA OPERATIONS

A Chief Aviation Machinist's Mate must beable to prepare for advanced base or forwardarea operations by estimating aircraft spare partsand supplies, equipment, and manpower require-ments for powerplant repairs. In determining

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requirements for forward area or advanced baseoperations, it is necessary to consider the follow-ing:

1. Mission.2. Environment.3. Operating factors.4. Availability of existing facilities.A knowledge of the material and manpower

requirements as listed in the Advanced BaseInitial Outfitting Lists of Functional Com-ponents will be very helpful. The functionalcomponent is one of more than 300 stand-ardized units of the system which the Navy hasdeveloped to enable it to build and operate itsadvanced bases in the least possible time andwith a minimum expenditure of planning andlogistic effort.

A functional component is a list of therequirements for the performance of a specifictask at an advanced base, and consists of acarefully balanced combination of materialequipment, and/or personnel.

Each functional component is classified ac-cording to its primary function into 1 of 11major groups, including aviation. Each majorgrouping is identified by letter designation andtitle; the functional components contained ineach are identified by a combination letter,number, and title designation. The major groupletter for aviation is H.

H components are designed to provide formaintenance, support, and operation of aircraftin an advanced area under combat conditions,and may be combined with other functionalcomponents to form several types of air stations.

Complete information and data are given inthe abridged and the detailed outfitting lists forfunctional components.

It should be apparent to the ADRC that theadvanced base requirements may not be exactlyas they appear in the Advanced Base InitialOutfitting Lists. In order to use these lists asguides, it will be necessary in most cases to alteror tailor them to fit the individual needs of theunit about to deploy.

Other necessary repair parts, supplies, andequipment may be determined from the out-fitting and allowance lists for the aircraft orother weapons system to be supported.

It is quite likely that the powerplants super-visor will be required to advise the personnel


office in the assignment of individuals toadvanced base or forward area operating units. Itwould seem logical that the number of ADR'sassigned to deploy be in the same ratio as thepercentage of supported aircraft scheduled todeploy. This may be true if the proposed flighthours per aircraft of the detachment exactlyequal the planned utilization of the remainingaircraft and if there are no significant environ-mental problems to be overcome. The list ofpersonnel assigned to deploy should represent across section of the skill levels available unlessspecial maintenance factors indicate otherwise.The selection of personnel should be made asobjectively as possible so that the deployed unitmay function efficiently without working ahardship on the home group.

SAFETY

Operational readiness of a maximum numberof aircraft is necessary if naval aviation is tosuccessfully perform its mission. Keeping itsaircraft in top operating condition is theprincipal function of naval aviation maintenancepersonnel. It is essential that maintenance workbe performed with a minimum of injury topersonnel and damage to equipment and air-craft.

Aircraft maintenance is, to some extent,naturally hazardous due to the nature of thework, the equipment and tools involved, and thevariety of materials required to perform manyrepairs and maintenance functions. Factorswhich can function to increase or decrease thesehazards are (1) the experience levels and mentalattitudes of assigned personnel and (2) thequality of supervision of the maintenance tasks.Thorough indoctrination of all personnel is themost important single step in maintaining safeworking conditions.

The concept of aircraft maintenance safetyshould extend beyond concern for injury topersonnel and damage to equipment andaircraft. Safe work habits go hand-in-hand withflying safety. Tools left in aircraft, impropertorquing of fasteners, and poor housekeepingaround aircraft can cause conditions which mayclaim the lives of flying personnel as well ascause strike damage to aircraft. Safety on the

ground is equally as important as safety in theair.

A recent type commander letter states in part,"While the increased complexity of our modernaircraft is a factor, it is noted that a largenumber of maintenance-error caused accidentsanc4 incidents are due, not to complexity ofequipment, but to lack of supervision andtechnical knowledge. Many mistakes are simpleones in routine maintenance."

Safety in aircraft maintenance depends largelyupon the supervisory personnel. The standardsof quality which they establish are directlyreflected in the quality of the aircraft main-tenance. The primary duty of the senior pettyofficers is to supervise and instruct others ratherthan to become totally engrossed in actualproduction. Attempts to perform both functionsinvariably result in inadequate supervision andgreater chance of error. Supervisors mustexercise mature judgment when assigningpersonnel to maintenance jobs. Considerationmust be given to each man's experience, train-ing, and ability.

Sometimes overlooked in a maintenance pro-gram are the considerations generally groupedunder the term "human factors." These factorsare important in that they determine if anindividual is ready and physically able to dowork safely and with quality. Supervisorypersonnel should be constantly aware of condi-tions such as general health, physical and mentalfatigue, unit and individual morale, training andexperience levels of personnel, and otherconditions which can contribute in varyingdegrees to unsafe work. Not only is it importantthat proper tools and protective clothing andequipment are available for use, but also theinsistence by maintenance supervisors that theyare used is of increasing importance withmodern high-performance aircraft. For example,maintenance personnel are sometimes negligentin the wearing of protective hearing devices inhigh noise areas.

Technical knowledge also plays a large part ina good maintenance safety program. Thecomplexity of our modern equipment demandsthe attention of well-informed and expert main-tenance personnel; otherwise, our weaponssystems cannot be operated and maintained.

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Technical knowledge is a function of educationand training which, incidentally, does not endwith graduation from Class A school. Gradua-tion is only the beginning. An ADR worthy ofthe rating is continually training and learningthrough self-study and application, and througha personal desire for proficiency and self-betterment. But technical knowledge by itself isnot sufficient unless it is coupled with anold - fashioned craftmanship that receivesgratification and keen satisfaction in doing anyjob well. The ADR who wishes to contribute tosafety and reliability improvement must knowhis job and must develop professional pride inthe quality of his work

It is a continuing duty of every personconnected with aircraft maintenance to try todiscover and eliminate unsafe work practices.Accidents which are caused by such practicesmay not take place until a much later date andtheir severity cannot be predicted. The conse-quences may range from simple material failureto a major accident resulting in serious injuriesor fatalities.

There are several areas in which the supervisorcan effectively work to minimize accidentsincident to aircraft maintenance. Among theseare continuing inspections of work areas, tools,and equipment; organization and administrationof safety programs; correct interpretation ofsafety directives and precautions; and energeticand imaginative enforcement of them.

INSPECTION OF WORK AREAS.TOOLS. AND EQUIPMENT

Most accidents which occur in noncombatoperations can be prevented if the full coopera-tion of personnel is gained and vigilance isexercised to eliminate unsafe acts. The power-plants supervisor should diligently inspect workareas, tools, and equipment to detect potentiallyhazardous and unsafe conditions and take ap-propriate corrective action. The ADR may beworking in the shop, in the hangar, or on theline, ant.: all these areas should be included in thesupervisor's inspection. He should check forexplosion or inhalation hazards due to improperventilation of working spaces or carelesshandling of materials.

Fire hazards present another serious problem."No Smoking" rules should be strictly enforced.

Ground wires should be installed on everyaircraft during maintenance to eliminate danger-ous static electric buildups. Spilled oil, grease,and chemicals should be wiped up promptly,and all rags used should be disposed of incovered metal containers.

Handtools should be in good shape, of theproper type, and used only for the purpose forwhich they were designed.

Insure that equipment is operated only byqualified personnel, and that all safety devicesand guards are installed and in good condition.The equipment should also be inspected forbroken or damaged components. Check to seethat periodic maintenance, servicing, and/orcalibration are up to date for those equipmentsrequiring it. Details on the Naval Air SystemsCommand calibration policy are contained inNavAir instruction 4355.4 (Series).

ORGANIZATION AND ADMINISTRATIONOF SAFETY PROGRAMS

In accordance with the Navy policy ofconserving manpower and material, all navalactivities are required to conduct effective andcontinuous accident prevention programs. Theorganization and aufninistration of a safetyprogram applicable to powerplant work centersare part of the requirements of the powerplantsupervisor. The safety program must be inaccordance with applicable instructions. Workmethods must be adopted which do not exposepersonnel unnecessarily to injury or occupa-tional health hazards. Instructions in appropriatesafety precautions are required to be given anddisciplinary action taken in case of willfulviolations.

The safety program will generally involvethree areas of attentionthe posting of the mostimportant safety precautions in appropriateplaces, the incorporation of safety lessons in theformal trianing program, and frequent checksfor understanding during the day-to-day super-vision of work.

Posted safety precautions are more effective ifthey are easily complied with. For example, asign on a tool grinder reads "goggles required,"so one or more pairs of safety goggles should behanging within reach at the machine. Similarly,the protective clothing poster in the welding

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shop should be backed up with readily availableaprons, gloves, shields, etc.

Fixed posters ;Ind signs should be renewedfrequently and not allowed to become rusty,faded, or covered with dust and dirt. Generalsafety posters on bulletin boards and otherplaces should be rotated often to stimulateinterest. Appropriate safety posters may beobtained from the squadron or unit safetyofficer.

The formal safety training sessions shouldutilize films, books, visual aids, or any othersuitable technical material. The men should betold more than just what or what not to do.Each safety subject should be explained indetail. The result of unsafe acts are usually themost dramatic and easiest remembered. Causesof accidents and contributing factors should bereviewed and analyzed. Many good ideas foraccident prevention have been developed intraining sessions.

An extensive series of lessons may bedeveloped over a period of time as latent hazardsare recognized; this will aid in keeping thesessions interesting while avoiding frequentrepetition.

It may be well to mention the new man in thework center at this point.. A separate safetyindoctrination lesson which covers all the majorhazards of the work center should be given thenew man as soon as he reports for work. Nosupervisor with an effective safety program andan excellent work center safety record wants totake the chance that the new man will be hurtbefore attending the complete series of safetylessons.

In the third area of safety program adminis-trationfollowupthe supervisor will do well todelegate authority to his subordinate pettyofficers to assist him in monitoring the program.Also included in the followup area is a respon-sibility of the supervisor to inquire as quicklyand thoroughly as possible into the circum-stances of accidents and reports of unsafepractices and take action or make recommenda-tions.INTERPRETATION OF SAFETYDIRECTIVES AND PRECAUTIONS

The safety precautions in Department of theNavy Safety Precautions for Shore Activities are

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designed to cover usual conditions in shoreactivities. Commanding officers and others inauthority are authorized to issue special pre-cautions to their command to cover local condi-tions and unusual circumstances. The supervisorwill have to apply both sets of rules in theadministration of his safety program.

Safety directives and precautions should befollowed to the letter in their specific applica-tion. Should any occasion arise in which anydoubt exists as to the application of a particulardirective or precaution, the measures to be takenare those which will achieve maximum safety.

When new safety posters or precautions areposted, it is the responsibility of the supervisorto correctly interpret their application to hismen. In this way he will be able to achieve aunity of thought and action in the observance ofthe required safety rule.

The organization's safety officer is availableto assist in interpreting and suggesting ways ofimplementing various safety directives and pre-cautions. Current directives require that a safetyofficer or safety engineer be assigned as head ofthe safety department, division, branch, orsection, whichever is applicable, at all shorestations.

In most instances the hazards involved andthe applicable precautions for a given type ofwork are the same whether the work is doneafloat or ashore.

POWERPLANT INSPECTIONS

The supervisor should insure that for eachmaintenance action, qualified personnel are as-signed, proper tools are available, and propertechniques are employed. The supervisor mustalso conduct an effective training program forpersonnel assigned. During most calendar inspec-tions, the powerplant is removed from theaircraft and taken to a centrally located space toaccomplish the inspection. This enables thesupervisor to closely monitor the check himselfor with collateral duty inspectors. It also affordsthe supervisor an opportunity to initiate on-the-job training.

Maintenance Requirements Cards (MRC's) areused for periodic inspections. The MRC'sprovide the maintenance man a ready referenceto perform the scheduled maintenance on the


powerplant. Each MRC contains one or moredetailed maintenance requirements. Illustrations,clearances, tolerances, charts, and part numberare included when required. All minimumrequirements for the accomplishment of anyparticular periodic maintenance task arecontained in a set of these cards.

Frequent and thorough inspections are neces-sary to attain efficiency and safety. Workingspaces should be checked for cleanliness. Byconducting an effective training program andinsisting on keeping the working spaces cleanand orderly, the supervisor is encouragingorderly thought and systematic work habitswhich will be directly reflected in high qualityworkmanship.

Work priorities are centrally controlled byMaintenance Control. Supervisors at every levelmust know which job is to be given emphasis;thus, work assignments can be controlled andproduction effort applied to desired projects.Each job is assigned one of the followingpriorities: Priority I, Immediate Action; Priority2, Urgent Action; or Priority 3, Routine Action.Work priorities may vary hourly or daily,depending on the flight schedule and the un-scheduled maintenance workload. The super-visor must insure that maintenance control iscontinually informed of the status of assignedwork. He must also insure that quality assuranceinspections are performed as required.

TECHNICAL SPECIFICATIONS

The powerplant inspection refers to an inspec-tion to determine the quality and completenessof work performed and material condition. Thecontrol of quality is the duty of each divisionand each individual. It is the task of the qualityassurance division to aid the various workcenters in the maintenance department in per-forming this duty. The supervisor must recom-mend only the best qualified men in this workcenter to be designated collateral duty inspec-tors to insure that all weapons systems aremaintained to the maximum extent possible.

The responsibility of the supervisor has in-creased iii difficulty with the ever increasingcomplexity, of the aircraft. More and moretechnical specifications and requirements mustbe met. It is almost impossible for the supervisor

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to remember all the technical requirements withwhich his work center must comply. This can beaccomplished, by a thorough training programand designating a competent rated man theresponsibility of maintaining the publicationssection of the work center.

WORKMANSHIP STANDARDS

The main goal of the Navy is to be ready atany given moment to perform any missionassigned. To achieve this goal, all weaponssystems must be maintained to the maximumextent possible to perform 100 percent of thefunctions for which they were designed.

Nonavailability of aircraft due to materialdeficiencies and poor workmanship are majorproblems. Therefore, good workmanship stand-ards are necessary to pinpoint troubles beforethey have a chance to cause serious difficulty. Asystem that includes inspectors who are skilledin the AD rating and trained in good workman-ship standards a vital necessity. This systemshould include compiling records and informa-tion from various sources to gain information onwhere the greatest difficulty lies and why it isthere. The final function of this system is toanalyze 'these facts and point them out toothers. It is difficult to find a yardstick tomeasure the degree of dependability attained.One of the best indications readily at hand isaircraft availability.

PROCURING AND CUSTODYOF MATERIAL

The supervisor is responsible for orderingaircraft maintenance spare parts and material,tools, and other equipment necessary for theaccomplishment of assigned maintenance tasks.Necessarily related to this responsibility arerequirements for 'controlling the use of con-sumable materials, maintaining and accountingfor toots and material held on a custodysignature basis, and, when required, the prepara-tion and submission of evaluation reports.

AIRCRAFT PARTS

Aircraft parts are generally ordered for tworeasons, the first being replacement for parts


which are removed from service on a scheduledbasis. These are usually parts which by theirfailure may cause disastrous consequences. Theother general need for aircraft parts results fromfailure, damage, or unsatisfactory operation ofan aircraft component. As can be seen, parts inthe former category may be ordered in advanceso they can be on hand when required, but thelatter category may not, as their usage isgenerally unforeseen. In either event, the order-ing procedure is the same.

NOTE: Prior to ordering a replacement for afailed part, the supervisor should alwaysccnsider his responsibility and capability toeffect the repair of the old part. If this ca-pability exists (and is permissible) at his leveland the repair is accomplished, it will preventthe expenditure of a great amount of time,trouble, and money required to process suchmaterial through higher levels of maintenance.

The first step in ordering is the identificationof the desired part. After the item is identified,the supervisor must contact maintenance controland have a ':-.iority assigned the needed part.The supervisor will then notify material controlof the item needed, the priority assigned, andthe delivery point. Material control does notprepare supply documents for material requiredin threct support of weapons system main-tenvice. (Normally, material is considered to berequired in direct support of weapons systemmaintenance when the material is to be utilizedin completing a maintenance action which hasbeen assigned a Production or Job ControlNumber.) Such documents are prepared by theSupply Support Center. Material controlverbally rotifies the supply organization of theneed for such material. The local supplyorganization is responsible for the physicaldelivery of RFI material to the maintenanceorganization and pickup of the defective mate-rial.

In a more or less predictable length of time,consistent with the priority, the part will bedelivered to the shop. Prior to opening thepackage or breaking the preservation in anymanner, the Federal Stock Number and anyotheridentifying data on the package should I,:double checked against the shop order file toinsure that they match. Upon depackaging,

49

another check similar to the foregoing should bemade to positively identify the part.

If either inspection reveals any inconsistenciesof identification data, it may be that the supplyoffice has substituted an interchangeable item. Ifso, the substitute item should be checked in theIllustrated Parts Breakdown, Section B Allow-ance list, or the Interchangeable List for ASOand Nav Air Cognizance Repairable Assemblies.If possible, an actual comparison with the oldpart should be made prior to installation asfurther check for suitability.

TOOLS

Ordering of tools is accomplished in much thesame manner as in the past. After the tool isidentified, a filled-in, rough copy of the requisi-tion form is forwarded to material control orunit supply office. This form may be either aDD 1348, or a locally issued form whichprovides spaces for the required information. Inthe material control office or supply office, asmooth copy is prepared, the necessary account-ing data added, signed, and forwarded to themain supply activity.

The need for a tool should develop during aperiodic tool inventory, when all tools should becleaned and inspected, and repaired or replacedas necessary.

Unlike aircraft parts, which should be stockedin the work center, the section G allowance listsprovide for each Organizational maintenanceactivity to have on hand a certain quantity oftools. The applicable allowance lists should becross checked with a current tool inventory andany deficiencies made up as soon as possible. Insome cases, it may be determined that sometools on the allowance lists are not needed orthat the allowed quantity exceeds actual require-ments. In such cases, those tools should not beordered just to have them collect dust on thetoolroom shelves. In addition, excess tools serveto complicate the periodic inventories as well asposing a transportation problem when thesquadron deploys.


GROUND SUPPORT EQUIPMENT

Items of ground support equipment (GSE)used for servicing and maintaining aeronauticalequipment consists of equipment furnished asorganizational property and equipmentfurnished on subcustody from the supportingservice. The Individual Material Readiness Listthat was discussed in chapter 2 of this manualprovides an authorized allowance listing for GSEwhich may be procured or obtained on sub-custody by the supported activity.

Work centers charged with the custody ofGSE must insure that proper care is exercised inits daily maintenance, upkeep, and operation.Preoperational/ or Daily Maintenance Require-ments Cards are available for use in maintainingmost larger items of support equipment. Itemson subcustody from the supporting activity arenormally recalled to the supporting AIMD forperiodic maintenance inspections.

The supporting activity licenses qualifiedoperators and provides GSE training, in additionto that which may be given as part of the workcenter's training syllabus. All operators ofground support equipment must be qualifiedand licensed. The license should be carried at alltimes when operating GSE.

GSE on subcustody to squadrons or otheractivities remains the responsibility of thereporting custodians. Personnel designated asbeing responsible for GSE, within the activityhaving subcustody: must compile utilization onthe appropriate GSE card and forward it to thereporting custodian on the last day of thereporting period. Reporting procedures areprovided in detail in volume III of the NavalAviation Maintenance Program, 'OpNav 4790.2(Series).

INVENTORY AND RECORDS

iWhen the shop is first set up and the initial

allowance of tools and equipment is drawn,inventory cards should be made up on eachitem. These cards should include the name ofthe item. quantity, manufacturer, model, stocknumber, date of acquisition, cost, and dates andnature of repairs and replacement parts.

Some items should be kept in the work centertoolroom or special cabinet, others placed in

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individual toolboxes and issued to the workers.A toolbox inventory record should be preparedin duplicate with the original filed in the workcenter tiles and the duplicate copy placed in thetoolbox, preferably in an oil and grease resistantenvelope.

While each toolbox should be adequatelystocked, it shoulu not contain tools in excess ofactual requirements. Maintenance personnelmust utilize some method of tool accountabilityfollowing each maintenance action to preventtools being left adrift. Tools should be etched ormarked in some manner that will identify themto a specific work center and toolbox. This actsas a deterent to leaving tools adrift and providesthe additional benefit of cutting down on theamount of tool pilferage.

A monthly inventory should be conductedbeginning with the toolboxes and ending withthe toolroom count. The periodic inventoryshould be more than just an item count. Sinceeach item is sighted, it provides an opportunityto ascertain if the tools in actual use are beingmaintained in good repair. If they show evidenceof damage or improper use, appropriate correc-tive action should be taken. The men should beencouraged to make good use of delay time bytool maintenance and equipment servicing.

Aircraft Inventory

In the past, there has always been a problemin maintaining custodial control and locationin formation on command-controlled aero-nautical components and aircraft related equip-ments. In order to maintain an unbroken chainof custodial responsibility incident to the trans-fer and acceptance of naval aircraft, the Stand-ard Inventory Log was developed by the Navy tobe used as an instrument of transfer. In theinterest of standardization among the armedservices, the Aircraft Inventory Record has beendesigned by the Department of Defense for thispurpose. Records (instead of Logs) are nowbeing prepared by the Navy for new productionaircraft and when old Logs are revised.

With remote exceptions, no aircraft may nowbe transferred or accepted without an InventoryLog or Record. On these occasions, an inventoryof the aircraft and its equipment must beaccomplished, based on the items of equipment


and material contained in the applicable Log orRecord.

Although the Log and Record serve the samepurpose, there are some minor differences intheir format and categorical listings. In general,the determination as to whether items are, or arenot, subject to listing in these publicationswithout regard as to whether they are contractoror government furnished and contractor orservice installed, is governed by the following:

1. Items essential to the execution of thedesignated missions of the aircraft, such asarmament, electronics, photographic equipment(excluding cameras other than for primarymissions), and special instruments, are included.

2. Items of equipment which are rigidly fixedand considered to be a basic or integral part ofthe airframe, such as engines, propellers, wheels,tires, and brakes, are excluded. In the case of theAircraft Inventory Record, standard instrumentsare also excluded.

3. Special equipment items essential to thesafety or comfort of the crew such as bedding,liferafts, Thermos bottles, crash axes, andportable fire extinguishers are included.Comparable items which are personal issue orfurnished on squadron allowances are excluded.

4. Loose equipment delivered with the air-craft, such as covers, mooring kits, and jackpads, for which stowage provisions have beenincorporated in the aircraft, are included.

5. Items subject to pilferage or readilyconvertible to personal use, such as clocks,Thermos jugs, bedding, and first aid kits, areincluded. Comparable items whichare personalissue or furnished on squadron allowances areexcluded.

The Standard Inventory Log is subdividedinto groups of equipment (e.g., instrument andnavigation equipment, armament equipment,and electronic equipment). The components arelisted in alphabetical sequence and according totheir location in the aircraft, with the exceptionof the electronics equipment, in which case allcomponents of an equipment are listed in oneplace regardless of their location in the aircraft.Stock numbers are also supplied for individualitems, and are used for ready reference whenreplacements are required.

The Aircraft Inventory Record includes asectional breakdown diagram of the applicable

51

aircraft. This diagram consists of a side elevationand/or the plan view of a wing, or in the case oftwinboomed or flying wing aircraft, the perspec-tive view.

To facilitate inventorying, the sections of tirediagram are identified by letters, the letter "A"being assigned to the foremost section, "B" tothe next, and so on, generally to the rear of theaircraft. The letter "R" as part of the itemnumber, denotes items mounted on the exteriorof the fuselage, and the letter "F" denotes itemsto which access is gained from the fuselage.Subdivisions of sections may be identified by alower case letter such as "Aa" "Ac" etc.

The equipment list portion of the Record isdivided into sections, each of which lists theitems pertaining to a particular section of theaircraft, as indicated on the sectional breakdowndiagram. Within each section, individual itemsare numbered as nearly as possible in thesequence of their physical location in the air-craft without regard to their relation to specificequipment. Stock numbers are not supplied aspart of the equipment listing in InventoryRecords.

One Standard Inventory Log in general isissued as applicable to one aircraft model anddesignates material and equipment peculiaramong the various applicable versions andbureau numbers. The Aircraft Inventory Recordis issued as applicable to one aircraft for aspecific bureau number.

Blank columns are provided on the inventorypages of the Log and Record, in order thattransferring and receiving activities may jointlyinventory and indicate the quantity of each itemascertained to be on board the aircraft at thetime of transfer. A RECEIPT ENDORSEMENTLOG in the Standard Inventory Log, and aCERTIFICATE AND RECORD OF TRANS-FER in the Aircraft Inventory Record areprovided so that transferring and receivingactivities may sign, indicating by column ap-plicability, the items on board the aircraft.

Upon the transfer of an aircraft, representa-tives from the transferring and receiving activi-ties jointly inventory and record, in the ap-propriate column, the quantity of each itemwhich is ascertained to be on board the aircraftat the time of transfer. When a ferry pilot, or anaval vessel is involved in the transfer, two


inventories are made, one prior to the ferryflight or embarkation, and one upon com-pletion.

A Report of Inventory Form supplied withthe Standard Inventory Log, or the ShortagesForm (DD780-2) in the Aircraft InventoryRecord, is generally prepared in triplicate, listingmissing items with appropriate remarks. Theoriginal is retained by the transferring activityand is filed as a permanent record of transfer.

The first carbon copy of the form is left inthe Standard inventory Log or Aircraft Inven-tory Record, as the case may be, and is deliveredalong with the Log or Record to the activityreceiving the aircraft.

The second carbon copy of the report orshortages form is forwarded to the cognizantmajor operating command (controllingcustodian) of the transferring activity for infor-mation and any appropriate action deemednecessary.

In the case of missing items, the transferringactivity makes every effort to locate the missingitems or to withdraw from store the replacementitems necessary to complete the inventory. If itis impossible to locate or supply the missingitems, the notation "Missing items are notavailable" is placed in the Report of InventoryForm in the Standard Inventory Log or theShortages Form in the Aircraft InventoryRecord. An explanatory statement signed by thetransferring representative is placed with thisform, indicating the authority for these short-ages. On the basis of this statement, thereceiving activity may fill the shortages fromstock and account for them in the normalmanner.

When the aircraft is abandoned or disposed ofby scrapping, the Inventory Log or Record maybe destroyed by the activity disposii g of theaircraft. When the aircraft is transferred to otherU.S. agencies, the Log or Record is also trans-ferred. When the iaircraft is sold to a privateparty, the Inventory Log or Record is forwardedto the Naval Air Systems Command immediatelyafter consummation of the sale and include thesignatures of the last custodian (seller) and thepurchaser. In order to provide the buyer withinventory information, the Log or Record maybe duplicated, provided that it includes noclassified information.

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Aeronautical EquipmentService Record (AESR)

The AESR is prescribed for use as a servicerecord for aircraft powerplants, auxiliary powerunits (airborne), airborne gun pods, low-levelescape systems, propellers, in-flight refuelingstores/packages, quick engine change kits, andgas turbine compressor engines (ground).

The aircraft logbook is a hard-cover, loose-leafring binder containing separators and page insertforms.

The AESR is initiated by the activity accept-ing the equipment from the Navy, and issubsequently maintained by the activity havingcustody of the equipment at all times. Whenequipment is installed as part of the aircraft, thisrecord is maintained concurrently with andbecomes part of the Aircraft Logbook.

The AESR is maintained similarly to theAircraft Logbook. Since it is in loose-leaf form,the full identification data and serial number areinserted on each page to insure ready identifica-tion when pages are removed for entries or forany other reason.

The following forms make up the completeAESR:

Custody and Transfer Form.Equipment Operating Log.Inspection Record Form.Record of Rework Form.Technical Directives Form.Miscellaneous/History Form.Scheduled Removal Components Form.Scheduled Removal Component Cards.Supplemental forms include the following:Turbine Rotor Disc Assembly Record.Afterburner Service Record.Compressor Rotor Assembly Service Record.For detailed information on these forms as

well as other Aircraft Logbook forms andrecords, reference should be made to chapter 6in volume II of OpNav 4790.2 (Series).

COST CONSCIOUSNESS

The Navy Cost Reduction Program, NavSo2486, strives to create an attitude of total costconsciousness and to encourage the developmentand implementation of cost reducing actions.Maintenance supervisors as well as their


subordinates can play a definite role in reducingcosts. Areas where costs can be reduced shouldbe identified and action taken through the chainof command. Recognition to the individualresponsible for any cost reduction actions willserve to stimulate the cost reduction program.

Personnel involved in procurement of materialand equipment and those charged with custodyof such items should realize that the overall costfor defense material is tremendous. Costs ofweapons systems, associated test equipment/support equipment, and spare parts necessary tosupport the weapon system during its expectedservice life have increased steadily to the pointwhere improved management is necessary. At-tention must be given resources, utilization ofpersonnel, accident prevention, etc.

Improved work habits, elimination of un-necessary maintenance tasks, improvements totest equipment, consolidation of functions,greater use of resources, and increased capabilityfor repair of specific items at the lowest level ofmaintenance are but a few areas that could beevaluated as a means of reducing costs at theworking level. Supervisors should be alert toways of bringing about such improvements andshould encourage and assist their personnel insubmitting factual beneficial suggestions forconsideration and subsequent dissemination.

Materials belonging to the Navy are notprocured for personal use of the individual, yetthousands of dollars are lost annually due topoor control of material resources. Propersecurity of pilferable items will materiallyreduce costs. Ordering only that material whichis actually needed rather than that which"might" be needed is another area that generallycould receive attention. The ways of reducingcosts are limited only by the supervisor'simagination and ingenuity. Waste, whether it isof manpower, money, or material, costs thetaxpayer and therefore affects almost everyone.

EVALUATION REPORTS

The maintenr..,ce of today's high-performanceaircraft requires more and more special tools,shop equipment, and ground-handling equip-ment. Most of this special equipment is designedand manufactured by private contractors. Themanufacturers frequently request individual

53

fleet activities to conduct performance evalua-tions on items which have been purchased bythe Navy and are new to the industry. Thispractice is approved and encouraged, but astandard procedure for conducting performanceevaluations is necessary.

According to current instructions, themanufacturer's request must be approved by thecognizant COMFAIR before it can be acceptedby the fleet activity requested to perform theevaluation. Upon approval, the activity conduct-ing the evaluation will provide the manufacturer,via the COMFAIR, with a report of the evalua-tion findings, citing any defects or recommenda-tions for improvement. The report shouldinclude the manufacturer's name, name ofproduct, model number, size, and/or capacity ofthe product evaluated, and the specific functionfor which the product may have been used.

TECHNICAL PUBLICATIONS

Aeronautical publications are the sources ofinformation for guiding naval personnel in theoperation and maintenance of all aircraft andrelated equipment within the Naval Establish-ment. By proper use of these publications, allaircraft and other aeronautical equipment can beoperated and maintained efficiently anduniformly throughout the Navy.

General information pertaining to the majorpublications of interest to naval aviation main-tenance personnel is contained in AviationMachinist's Mate R 3 & 2, chapter 4, NavPers10342-A, and knowledge of the material in thattext is presumed.

TECHNICAL DIRECTIVES

The Technical Directive System has beenestablished for the control and issue of alltechnical directives. This system standardizes themethod of issuance for such directives and is theauthorized means for directing the accomplish-ment and recording of modifications and one-time inspections of ground support equipmentas well as aircraft and other aeronautical equip-ment. The Technical Directive System is animportant element in the programs designed tomaintain equipment in a safe and current stateof operational and material readiness.

AVIATION MACHINIST'S MATER 1 & C

This system provides for two types oftechnical directives. The types are determinedby the method of dissemination. The two typesare Formal (letter type) and Interim (messagetype). In general terms, they are both consideredas letter type publications. Such directivescontain instructions or information of a tech-nical nature which cannot be disseminated byrevisions or changes to technical manuals. How-ever, the accomplishment of a technical directiveoften necessitates a change or revision to theapplicable technical manual. Technical directivesare issued in the form of Changes, or in the caseof special circumstances, by Interim Changes orInterim Bulletins.

A formal technical directive is issued as aChange, or as an amendment or revision thereto,and, as stated previously, is disseminated byletter. Formal directives are used to direct theaccomplishment and recording of modificationsto support equipment, as well as aircraft andrelated equipment. An interim technical direc-tive is issued as a Change or a Bulletin, or as anamendment or revision thereto, and, in order toinsure prompt delivery to the concerned activi-ties, is disseminated by message. The interimtechnical directive is reserved for those instancesto correct a safety or operational conditionwhenever it is considered too important to riskwaiting for the issuance of a formal directive.

Each interim Change is superseded by a

Formal Change directive which will have thesame number as the interim directive. InterimBulletins are not superseded by formal Bulletinsas was previously the case. NavSup Publication2002. Section VIII, Part D will still have manyformal Bulletins listed until they are eventuallyphased out.

A Change is a document containing instruc-tions and information which directs the ac-complishment and recording of a materialchange, a repositioning, a modification, or analteration in the characteristics of the equipmentto which it applies. A Change is issued to directthat parts be added, removed, or changed fromthe existing configuration or that parts ormaterial be altered, relocated, or repositioned.

A Change may be issued in parts to ac-complish distinct parts of a total directed actionor to accomplish action on different configura-tions of affected equipment.

54

A Bulletin is an interim document comprisedof instructions and information which directs aninitial inspection to determine whether a givencondition exists. It specifies what action is to betaken if a given condition is found or not found.

Sometimes it is found that a Change ornBulletin is not the complete answer to a

problem, and it is determined necessary toamend or revise an outstanding directive. AnAmendment is a document comprised of in-formation which clarifies, corrects, adds to,deletes from, makes minor changes in require-ments to, or cancels an existing directive. It isonly a supplement to the existing directive andnot a complte directive in itself. A maximum ofthree Amendments may be applied to anytechnical directive, each remaining in effect untilrescinded or superseded by a Revision. Arequirement for further amendment actionnecessitates the issuance of a Revision.

A Revision is a completely new edition of anexisting technical directive. It supersedes theoriginal directive and all existing Amendments.

Interim Bulletins are self-rescinding withrescission dates of 30 June and 31 December,whichever is appropriate for the case at hand.Rescission is the process by which a technicaldirective is removed from active files after allrequirements have been incorporated andrecorded. Rescinding dates are also projected forformal changes. Final rescission action of alltechnical directives is directed in Part D, SectionVIII, NavSup Publication 2002. All activitiesmaintaining files of technical directives shouldretain all technical directives until they aredeleted from NavSup Publication 2002.

Changes and Bulletins are issued by technicalpersonnel of the Naval Air Systems Commandand are based on Contractor Service Bulletins,on reports from various Data Services, or lettersof recommendation or proposed modificationsfrom field service activities. They are auto-matically distributed to all activities concernedthrough inclusion on the Mailing List Requestfor Aeronautic Publications, NavAir 5605/3.

Changes and Interim Changes are assignednumbers in a numerical sequence by the Tech-nical Directives Control Center, located at theNaval Air Technical Services Facility (NATSF),Philadelphia, Pa. As stated previously, a FormalChange which supersedes an Interim Change will


have the same number as the Interim Change.Interim Bulletins are numbered similarly inanother number series.

The title of a Change or Bulletin for supportequipment is made up of three parts. Part one isthe term "Support Equipment;" part two, theword or words "Change," "Interim Change," or"Interim Bulletin;" and part three, thesequential number. When applicable, the words"Rev. A," "Amendment 1," etc. follow thebasic directive.

Changes are classified by various "action"categories. Bulletins may also be assigned anaction classification, but it is not mandatory.The assigned action category serves as a priorityfor compliance with the various directives.

The category "Immediate Action" is assignedto directives which are issued to correct safetyconditions, the uncorrected existence of whichwould probably result in fatal or serious injuryto personnel, extensive damage, or destructionof property. Immediate Action directives involvethe discontinued use of the equipment in theoperational employment under which theadverse safety condition exists, until the direc-tive has been complied with. If the use of theequipment will not involve the use of theaffected component or system in either normalor emergency situations, compliance may bedeferred, but should be accomplished no laterthan 120 days from the date of issue. ImmediateAction directives are identified by a border ofred X's, broken at the top center of the page bythe words "IMMEDIATE ACTION," alsoprinted in red.

The category "Urgent Action" is assigned todirectives which are used to correct safetyconditions which, if uncorrected, could result inpersonnel injury or property damage. This cate-gory of directive is identified by the words"URGENT ACTION" printed in red ink at thetop of the first page and a border of reddiagonals around the cover page.

The compliance requirements for UrgentAction directives specify that the incorporationof the instructions must be accomplished notlater than the next regularly scheduled reworkor overhaul or, for equipment not reworked oroverhauled, on a regularly scheduled basis, notlater than 18 months after the date of issuance.

Routine Action directives are issued wherethere are reliability, capability, or maintain-

55

6o

ability deficiencies which could, if uncorrected,become a hazard through prolonged usage orhave an adverse effect on the operational life orgeneral service utilization of equipment. Thecompliance requirement specifies the incorpora-tion of the instructions not later than the nextregularly scheduled overhaul or rework, or forequipment not reworked or overhauled on ascheduled basis, not later than 18 months afterissuance of the directive. If accomplishment ofthe work requires Depot level maintenancecapability, the compliance may be deferred if itwill seriously interfere with operational commit-ments or schedules. Routine Action directivesare identified by the words "ROUTINEACTION" printed in black capital letters at thetop center of the cover page.

Record Purpose category is assigned to atechnical directive when a modification has beencompletely incorporated by the contractorbefore acceptance by the Navy. This category oftechnical directive merely documents the actionfor configuration management purposes.Consequently, compliance information is notapplicable. They are identified by the words"RECORD PURPOSES" printed in black capitalletters at the top center of the cover page.

INSTRUCTIONS AND NOTICES

Instructions and Notices are the two maintypes of directives provided for in the DirectivesIssuance System which was designed for thepurpose of providing a uniform plan of issuingand maintaining directives. Directives mayestablish policy, organization, methods, orprocedures. They may require action to be takenor contain information affecting operations oradministration. All Naval Air Systems Commandlevel (and above) originated directives aredistributed by the Navy Department Administra-tions Office, with certain exceptions. Each levelof co mmand below Naval Air SystemsCommand level has an administration officeresponsible for distributing that level ofcommand directives to its units or addresseesbelow them.

Instructions and Notices are identified byoriginator and subject classification. A typicaldirective identification breakdown follows:

OpNav Instruction 3750.1A. OpNav indicatesthat this instruction originated in the office of


the Chief of Naval Operations. The 4-digitnumber 3750 is the subject classificationnumber. This particular number indicates theseries on Flight Safety. The number 1 indicatesthe number of issues the originating office hasissued on this subject. (Notices do not have thisnumber.) The letter A indicates the number oftimes this Instruction has been revised; i.e., Afor first revision, B for second, etc. If the lettersC or S precedes the subject classificationnumber, it indicates the classification of thesubject. The letter C indicates confidential and Sindicates secret.

There are 13 major subject classificationnumber groups, ranging from the 1000 group tothe 13000 group. The 13000 group is set asidefor aeronautical and astronautical material.

MAINTENANCE INSTRUCTIONS

The Maintenance Instruction Form Op Nav4790/35 is usually prepared by the cognizantdivision; however, it may be drafted by adivision designated by the Maintenance Officer.These forms have been provided for the use ofmaintenance departments as the standard formfor the interpretation and/or amplification oftechnical directives and maintenance require-ments received from higher authority. The formsmay also be used to issue local technicalinstructions.

A review of the draft should be conducted bythe Quality Assurance Division as well as themaintenance/material coordinator prior to theapproval by the Maintenance Officer. The Main-tenance Instruction must be prepared carefully,because it is the instrument the division officeruses to direct his men. Command directives inthe form of messages are often so brief, that tobe understandable at the working level theyneed considerable amplification and backgroundinformation.. On the other hand, lengthy anddetailed directives prepared for all aviationactivities may be received. Only parts of thesedirectives may be applicable locally, and thedirectives need condensation and selection toadapt them to local conditions. The threepurposes that a Maintenance Instruction may beused for are as follows:

1. A SAMI (Single Action MaintenanceInstruction) may be prepared when a directive

or situation dictates that specific work must beperformed on a one-time basis. By their nature,SAMI's have a 'imited period of applicability,and positive acts, -nust be taken to cancelSAMI's which have J. their purpose.

2. A CAMI (Continuing Action MaintenanceInstruction) may be prepared when a directiveor situation dictates that specific work must beperformed at recurring intervals contingent uponelapsed time or upon the occurrence of aparticular condition or incident. When the workordered may be performed on an aircraft orpiece of equipment at recurring intervals, it isproperly the subject of a CAMI. it is importantthat it be clearly stated when the prescribedaction is taken and that positive control beexercised to insure that the work is actuallyperformed. If the aircraft model concerned ismaintained under the calendar inspection sys-tem, using MRC's (Maintenance RequirementsCards), any new maintenance inspection require-ments should be considered for inclusion in theMRC deck rather than as CAMI material. A copyof these requirements, generated by other thanCNO and NavAirSysCom, with reference, shouldbe submitted with an Unsatisfactory Material/Condition Report (Op Nav Form 4790/47) to beconsidered for inclusion in the next revision tothe MRC's.

3. A TIMI (Technical Information Main-tenance Instruction) may be prepared when adirective or situation dictates that technicalinformation must be promulgated within theactivity. When it is necessary to disseminateinformation, such as techniques and local policy,which does not direct the performance ofspecific work at intervals, but which is sustainingin nature, a TIMI may be properly issued; e.g.,information on hydraulic fluid contamination.

MANUAL PUBLICATIONS

To attain a satisfactory state of readiness,technical manuals are developed, published, anddistributed concurrently with the weapon sys-tem or equipment that they cover. Periodicchanges and revisions are issued as necessary toinsure that manuals continually reflect equip-ment changes and current operational and sup-port concepts and procedures. Technicalmanuals released under the authority of the

56

61


Commander, Naval Air Systems Command, areconsidered the only authorized source of theinformation provided, and the instructions theycontain are mandatory.

The variety of manual publications availableto the AD are designed to provide all essentialinformation necessary to understand the opera-tional theory, troubleshoot and service thesystem, and maintain the weapon system and/orits associated components.

General Manuals (00 Series)

As indicated by the title, this series ofmanuals includes information of interest to allnaval aviation personnel. In the final analysis,some publications in this series may not beconsidered as actual technical manuals; howeve ,

they furnish aircraft maintenance activities withvaluable required information. Manuals includedin the general (00) series that are of interest tothe AD are the three parts of the NavalAeronautical Publications Index (00-500A,00-500B, 00-500C.), Initial Outfitting Lists andAllowance Lists, and the Aviation TrainingLiterature.

Aircraft Manuals (01 Series)

The following types of manuals are preparedand issued for each model of aircraft used by theNavy:

NATOPS (Naval Air Training and OperatingProcedures Standardization Program) FlightManual, herein referred to as Flight Manual.

Maintenance Instructions Manual.Structural Repair Manual.Illustrated Parts Breakdown.Periodic Maintenance Requirements Manual,

including related Maintenance RequirementsCards and Sequence Control Charts.

NOTE: The Periodic Maintenance Require-ments Manual (PMRM) is being replaced byPeriodic Maintenance Information Cards.

The NavAirSysCom also provides a series ofGeneral Engineering Manuals, applicable to allaircraft models, and available to aircraft main-tenance activities. These publications are con-cerned with such subjects as Corrosion Control,Aircraft Structural Repair, Aircraft Hardware,and Aircraft Cleaning. As previously stated,

57

these publications are of a general nature and areused in conjunction with the specific aircraftmodel manuals. These general manuals aregrouped at the beginning of the 01 series manuallisting in Nav Sup 2002, Section VIII, Part C.

A maintenance Planning Manual is issued (fornewer models) to serve as the maintenanceofficer's source of information on maintenancemanagement with respect to the particularweapons system. It contains information onwhat the total maintenance plan for theweapons system is, what facilities, equipment,material, space, and personnel will be needed,and what resources, including technical informa-tion, services, training, supply support, etc., areavailable and how to obtain them.

FLIGHT MANUAL.The Flight Manualcontains complete operating instructions for theaircraft and its operational equipment. Emer-gency operating instructions as well as normaloperating instructions are provided. AlthoughFlight Manuals are issued primarily for the useof pilots and aircrewmen, they provide valuableoperational information to maintenance person-nel as well.

Two methods of updating Flight Manuals areby regular change notices and by interim manualchanges. Regular change notices are issuedperiodically and cover routine changes andinstructions. Interim manual changes cover vitaloperating instructions and are issued whenimmediate action is necessary.

Flight Manuals for newer aircraft models areidentified by -I in Part III of the publicationcode. For example, NA 01-85SA-I identifies aFlight Manual for the S-2.

MAINTENANCE INSTRUCTIONSMANUAL. The Maintenance InstructionsManual (MIM) contains most of the essentialinformation required by aircraft maintenancepersonnel for service and maintenance of thecomplete aircraft. It includes the data necessaryfor troubleshooting and maintaining the power-plant, accessories, and all systems and com-ponents of the aircraft.

Instructions in the Maintenance InstructionsManual include such typical service and main-tenance operations as the following:

1. Routine servicing.2. Lubrication requirements.3. Cleaning.


4. Adjustments.5. Minor repairs.

-6. Removal and replacement of components.7. Testing.The Maintenance Instructions Manual for all

current production aircraft is made up involumes, each volume being individually boundand issued separately. This permits each workcenter in an activity to have its own applicablevolume, or volumes at hand for ready reference.

Classified maintenance information is notincluded in the regular volumes of the Main-tenance Instructions Manual. Essential classifiedinformation is contained in separate volumes orsupplements of the Maintenance InstructionsManual which are classified "confidential."These volumes are usually bound in red in orderthat they may be readily identified and shouldbe handled in accordance with the Departmentof the Navy Security Manual for ClassifiedInformation.

The various volumes of the MaintenanceInstructions Manual cover such areas as thefollowing:

General Information and Servicing.Airframe Group.Powerplant and Related Systems.Armament and Photographic Systems.Electrical Systems.Communication and Radio Navigation Sys-

tems.The first volume, usually titled General In-

formation and Servicing, is designated primarilyfor the plane captain; however, this volumecontains a great deal of information importantto all maintenance personnel. It contains ageneral description of the aircraft, all informa-tion pertaining to servicing the aircraft, andnecessary information which is not contained inother specialized volumes.

Each of the specialized system volumes (air-frame, powerplants, electrical, etc.) of theMaintenance Instructions Manual is furtherdivided into four sections, as described in thefollowing paragraphs.

Section I is the same in all volumes of aparticular aircraft Maintenance InstructionsManual. This section provides an introduction tothe manual and usually supplies a list of thechanges applicable to the particular volumeconcerned.

1

Section II describes the system and com-ponents as well as their operation.

Section III provides such maintenancecoverage as removal and installation proceduresand troubleshooting charts for the Organiza-tional level of maintenance.

Section IV provides component repair proce-dures for the Intermediate level of maintenance.

The different aircraft manufacturers maygroup the material in the various volumes of theMaintenance Instructions Manual underdifferent titles. For example, the Survival andEnvironmental Systems MIM for one modelaircraft may be contained in one volume;whereas, another model aircraft may have twoor more volumes to cover the same subjects.

As previously stated, the complete MIM foran aircraft consists of several separately boundvolumes. Each volume is assigned an individualpublication code number for identification pur-poses. The complete MIM is divided into groupsof volumes (categories) containing related dataor related systems.

Maintenance Instructions Manuals are iden-tified by -2 in Part III of the publication code.Additional dash numbers are used to identifythe different groups or categories. Pointnumbers are used to identify subsystems orrelated data to these groups or categories. Forexample, NA 01-75PAA-2-4 is the code numberfor the P-3A MIM for the Powerplant andRelated Systems. NA 0I-75PAA-2-4.1 signifiesthe MIM for Powerplant Buildup for the P-3A.

STRUCTURAL REPAIR MANUAL.Thismanual is prepared primarily for personnel ofthe AM rating and is used as a guide in makingstructural repairs to the airframe. It containsgeneral information such as airframe sealing,control surface rebalancing, general shoppractices, damage evaluation and support ofstructure, and a description of the structurethrough the medium of indexed illustrations andrepair drawings.

The Structural Repair Manual for most newaircraft is published in two volumes. This is notdue to its size but is to suit its usage by differentfacilities. Volume I is for use at all levels ofmaintenance. Volume II supplements volume Iand contains information used only at Depotlevel facilities.

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ILLUSTRATED PARTS BREAKDOWN.This is actually a parts catalog which lists all theparts of the complete aircraft. The purpose ofthe Illustrated Parts Breakdown (IPB) is to assistsupply, maintenance, and overhaul personnel inthe identification, requisitioning, storing, andissuing of parts for the applicable aircraft.

The Illustrated Parts Breakdown for olderaircraft, like the Maintenance InstructionsManual, may be found in one volume. TheIllustrated Parts Breakdown prepared for currentproduction aircraft contains several volumeswhich usually correspond to the volumes in theMaintenance Instructions Manual.

A - 4 in Part III of the publication codeidentities the Illustrated Parts Breakdown. Theindividual volumes are identified by an ad-ditional dash and number. An example of thecode number for an Illustrated Parts Breakdownin current use is NA 0 I-85SAD-4-5. This is thecode number for the Powerplant and RelatedSystems volume of the S2D IPB.

Each volume of the Illustrated Parts Break-down is divided into at least two sections andsometimes threesection I, Introduction;section II, Group Assembly Parts List; andsection III, when used, Numerical Index. SectionI contains detailed instructions for the use of theIllustrated Parts Breakdown. Section II includesillustrations of all parts of the applicable aircraftand its systems, equipment, and special supportequipment subject to separate maintenance.

The latest type Illustrated Parts Breakdownhas a separate volume for the Numerical Index.The Numerical Index contains an alphanumericlisting of all parts in the Illustrated PartsBreakdown or volume. In addition to partnumbers, the Numerical Index contains figureand index numbers and source code data.

Study of the Introduction (section I) willprovide all the necessary information required toproperly use the Illustrated Parts Breakdown.

PERIODIC MAINTENANCE REQUIRE-MENTS MANUAL. This manual contains theplanned scheduled maintenance requirementsfor the particular aircraft concerned and is thecontrolling document for the planning andaccomplishment of related work tasks throughall levels of maintenance. The maintenancerequirements it contas are set 'forth in amanner that specifies the equipment to be

inspected or examined and the conditions to besought in each instance. The Periodic Main-tenance Requirements Manual (PMRM) does notcontain instructions for repair, adjustment, orother means of rectifying defective conditions,nor does it contain instructions for trouble-shooting to determine causes of malfunctions.

The requirements prescribed in the PeriodicMaintenance Requirements Manual are con-sidered to be the minimum necessary under anycondition to assure timely discovery and cor-rection of latent defects and compliance ismandatory. Due to varying operational require-ments, climatic or environmental conditions,cognizant commanders may increase the scopeor frequency of inspections or examinations asrequired to properly and safely support opera-tions.

Like most technical manuals, the PeriodicMaintenance Requirements Manual is dividedinto parts or sections. These parts/sections coversuch areas as Fleet Maintenance Requirement,Progressive Aircraft Rework Requirements,Component Removal/Replacement Schedule,Scheduled Removal Component Card, andFunctional Test Flight Requirements.

The Periodic Maintenance RequirementsManual is updated by periodic change noticesand revisions. This manual is identified by a -6 inPart III of the publication code. An example ofa code number for the S-2 Periodic MaintenanceRequirements Manual is NA 0 I-85SAD-6.

Periodic Maintenance Information Cards(PMIC).These cardi- (which are gradually re-placing the Periodic Maintenance RequirementsManuals) contain the component removal/replacement schedule and SRC card require-ments covering Organizational and Intermediatelevels of maintenance. Items to be replaced areindicated in unit operating hours, calendar timeor cycles as appropriate, and are listed by systemas arranged in the Maintenance InstructionsManual. Only those items that have a forcedremoval interval and those requiring an SRCcard are listed. As with the PMRM, the plannedmaintenance requirements prescribed by thePMIC are considered to be the minimum neces-sary, and compliance is mandatory. In instanceswhere conflict may exist between the require-ments contained in the cards and other main-tenance directives bearing prior dates, the PMICtake preference.

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In addition to the Component Removal/Re-placement schedule and SRC requirements, thePMIC also contains a maintenance referencetable specifying those directives which have beenincorporated in the PMS publications since thelast routine change or revision.

The Periodic Maintenance Information Cardsare updated by Rapid Action Changes. Thesecards are identified by a -6 in Part hi of thepublication code.

Aircraft Components andRelated Equipment Manuals

These manuals are not limited to but includeAccessories Manuals, Instrument Manuals, Arma-ment Manuals, and Electronics Manuals. The 03series manuals cover all types of accessories;Instrument Manuals are covered in the 05 series;the 11 series manuals are concerned with Arma-ment and related equipment; and the 08 and 16series pertain to Electronics Manuals.

The manufacturer of each item of equipment(carburetor, altimeter, bomb rack, radar set,etc.) is required to provide adequate instructionsfor operating the item and maintaining itthroughout its service life. These manuals there-fore contain descriptive data; detailed instruc-tions for installation, operation, inspection,maintenance, and overhaul; and an illustratedparts list. All manuals pertaining to these dif-ferent items of equipment available for issue arelisted in numerical order (by publications num-ber) in the applicable section of Part C, SectionVIII of Nav Sup Publication 2002. They are alsolisted in 00-500A, but in alphanumeric orderaccording to model, type, or part number. In00-500B, these manuals are listed under theaircraft in which the item is installed.

Aircraft coninonents and related equipmentmanuals are used to supplement informationfound in the aircraft Maintenance InstructionsManual. For example, when the MaintenanceInstructions Manual does not give instructionsfor repairing a particular item, reference shouldbe made to the appliz:able item manuals.

If a component or piece of equipment isrelatively simple, all the necessary instructionsmay be contained in a single manual. Morecomplex items may require two or moremanuals. For example, one manual may cover

operation, service, and overhaul instructions,while the parts breakdown is contained in aseparate manual.

Support Equipment Manuals(17 and 19 Series)

The 17 and 19 series of technical manualscover most types of support equipment. Themanufacturer of each item of support equip-ment is required to furnish adequate instructionsfor operating the equipment and maintaining itthroughout its service life. Like aircraft Main-tenance Instructions Manuals, these publica-tions, prepared by the manufacturer, are issuedunder the authority of the NavAirSysCom andare then official Navy publications.

Support Equipment Manuals are stocked,cataloged, listed, and located in the same manneras aircraft components and related equipmentmanuals.

Included in the 17 and 19 series of technicalmanuals are the Maintenance RequirementsCards for various ground support equipment.

UPDATING TECHNICAL MANUALS

The methods for assuring that technicalmanuals are maintained current to the extentnecessary to maintain their validity or removethem from active status include issuing ofChanges, Rapid Action Changes, Revisions, Sup-plements, and Appendices or by recision orreplacement of a complete manual.

Changes, Rapid Action Changes (RAC), andRevisions are used to update a manual byreplacing, adding, or removing changed pages inthe manual.

Supplements are issued when it becomesnecessary to augment or change data in basicmanuals that is not adaptable to the inclusion ofindividual change pages or when the use ofchange pages is not suitable or practicable.Changes and Revisions are normally issuedinstead of Supplements except in emergencycircumstances where Supplements must beutilized because of the critical time element.

Supplements issued for the Naval AeronauticPublications Index provide an example of asituation whete it would be impractical to issueChang,. Pages vice a Supplement. Supplements'

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are issued as separate manuals and may becumulative or noncumulative. CumulativeSupplements include all the data contained inSupplements previously issued and supersede thepreceding Supplement. The supplement will besectioned in a manner appropriate to the manualwhich it supplements and will be identified bythe same manual title and number as the basicmanual with the word "Supplement" printed atthe top of the title page.

Appendices are issued when it becomes neces-sary to include information in a manual that isnot part of the normal sequence outlined in thecontents, such as charts, tables, listing of codes,etc. Such material becomes an integral part ofthe affected manual.

CHANGES.Changes are issued when onlyparts of the existing manual are affected. Thechange pages replace the correspondinglynumbered pages. When the Change is a FormalChange, all replaced pages must be removed anddiscarded. If the Change contains additional datathat cannot be included on the replacementpage, additional pages are issued. The pagenumbers issued to additional pages are thepreceding page number plus capital lettersuffixes in consecutive order or page numberscontinuing in numerical sequence, depending onthe circumstances.

A Formal Change alters a portion of a manualalready in existence and does not constitute alarge enough change to warrant issuance of aRevision. The Formal Change replaces, adds, ordeletes pages and/or illustrations and the changepages are prepared to be collated into themanual without disrupting the manual formatand sequence. The Formal Change is issued toinclude new models of equipment or add newprocedures and to change existing equipmentand procedures which do not create an emer-gency situation.

Manuals consisting of eight pages or less andthose which do not include a title page arereplaced by a complete revision of the manual inlieu of change page insertions.

RAPID ACTION CHANGES.Rapid ActionChanges (RAC's) are manual changes used toexpedite the dissemination and incorporation ofessential and urgent operation and maintenanceinformation to technical manuals. Utilizing aninterim RAC, information impacting safety of

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flight, hazards to personnel, grounding of air-craft, mission capability, equipment damage, ormaintenance capability will be disseminated vianaval message and incorporated into the affectedmanuals immediately.

A Manual Change Page followup will then berequired within 15 days of release of themessage. Information of a less urgent nature ispromulgated by printed Rapid Action ChangePages. This type RAC is subjected to printingwithin 30 days after problem resolution and islimited to 12 pages or less.

The RAC system has phased out the previousInterim Manual Change. However, it does notaffect the procedures for issuing and in-corporating Formal Changes. The RAC merelysupplements the Formal Change procedures toprovide for rapid issue of urgently required datathat was previously held up by the proceduresinvolved in complying with the normal changesystem.

CHANGE ENTRY CERTIFICATION.It isnot feasible for every work center to have acopy of every publication that is used by theparticular work center; however, they shouldhave the publications most often used such asMaintenance Instruction Manuals, IllustratedParts Breakdowns, and certain General Manuals.All publications held by the work center shouldbe checked out (issued) from the activity'stechnical library, which functions as a part ofthe quality assurance division.

The technical library utilizes technicalpublications location cards to account for eachpublication held in the library as well as thoseissued to the various work centers. By using thissystem, the technical library can maintainreasonable control of all work center publica-tions and applicable Revisions, Changes, etc.,can be procured and issued as necessary to keepall publications current.

When Changes for a particular publication arereceived, technical library personnel check thelocation card and issue the Change to all holdersof that publication, utilizing a Change EntryCertification Form. When the Change has beenincorporated, the certification portion of theform is completed by the holder and returned tothe technical library. This provides a record thatthe Change has been incorporated in the ap-plicable publication. Most technical library


systems dictate a maximum time allowed forincorporation of the Change to disc( urage"putting off" incorporation of Changes, whichhave presented a problem on more than oneoccasion. Publications that were not currenthave been used to perform maintenance tasksresulting in situations that are potential flightsafety hazards.

Quality Assurance is charged with the respon-sibility of making periodic spot checks of eachwork center's publications to ascertain that thepublications are updated properly.

NOTE: That portion of the text affected bythe current Change or Revision is normallyindicated by a heavy vertical line in the outermargin of the page.

Conversion Of ManualsTo Microfilm

A relatively new concept in supplying main-tenance activities with certain types of technicaldata has been accomplished by the use ofmicrofilm. As a means of improving updatedmanual availability and reducing storage spacenumerous maintenance manuals and illustratedparts breakdowns are being placed on 16mmmicrofilm. The microfilm is stored in cartridgesand a label on the cartridge indicates thenumbers of the manuals inclosed. In the futureit is intended that microfilm will be issued tousers in lieu of hard copy manuals.

Microfilming is the photographic art of re-production of text or pictures at ratios ofreduction too great for reading or viewingwithout optical assistance. A reader or sometype of projector is required in order to enlargethe microfilm for reading.

There are many different makes and modelsof microfilm readers and reader printers. Somehave printing capabilities while others do not.Those with the printing capability generally willprovide a permanent copy in a matter of a fewseconds. Coverage of the operation of all thevarious models is not appropriate for this train-ing manual. The Filmac 400C modes covered inthis section is widely used in the Navy.

The Filmac 400C cartridge reader printer(Fig. 3-1), manufactured by the MinnesbtaMining and Manufacturing Company, provides afait means of viewing 16mm cartridge microfilm

and also prints a copy of the frame being viewedin a matter of seconds. This particular model ispractically automatic; therefore, very little train-ing is required to properly operate and maintainit. Like any delicate machine, the operatinginstructions provided by the manufacturershould be closely followed and the machineshould not be abused.

The 400C reader printer operates on standard110-volt alternating current. It is controlled byan ON-OFF switch located above the viewingscreen on the front of the machine. This switchcontrols the projection lamp, which illuminatesthe viewing screen and also the cooling blower.

This machine incorporates an automaticmicrofilm threading process; therefore, loadingand threading microfilm is a simple task.Loading a cartridge of microfilm into themachine consists of inserting the cartridge intothe holder with the open end toward the right.The cartridge is then pressed flat against theholder until the cartridge lock clicks. Threadingis accomplished by turning the speed controlknob counterclockwise and depressing thethread lever for approximately 2 seconds, oruntil images appear on the viewing screen.Microfilm advancement is stopped by returningthe speed control knob to the center position.

A counter registers the frames or images asthey advance; therefore, by referring to theindexed cartridge, the approximate location of aframe can be determined and the microfilmrapidly advanced until this frame number cor-responds to the counter reading. Rapid advance-ment of the microfilm is accomplished byturning the speed control knob counterclock-wisethe farther the knob is turned, the fasterthe microfilm advances. The microfilm is woundback into the cartridge by turning the speedcontrol knob clockwise.

Scanning a cartridge of microfilm in search ofa specific frame can be accomplished by twodifferent ways. One way is by the use of thehand wheel located on the right-hand side of thereader printer. The other way is by use of theappropriate scan button An arrow on each ofthe two scan buttons indicates the direction ofmicrofilm travel. Once the desired frame is onthe viewing screen, the focus ring is used tobring the image into sharp focus.

To make a print or copy of the frame ofmicrofilm being viewed is a simple process. First

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PRINTEXIT SLOT

CARTRIDGEHOLDER

..41

Sao,111Iw.1i

Th-----_- _-__

7a i

PRINT_ii

BUTTON

EXPOSURE.,,,e-CONTROL

FOCUSRING

ONOFF SWITCH

VIEWING SCREEN

HANDWHEEL

COUNTER

SCAN BUTTONS

---...cSPEED CONTROL

Figure 31.Microfilm reader printer.

of all, the image on the viewing screen should becentered and in proper focus. This can beaccomplished by use of the handwheel and focusring. Next, the exposure control knob must beset for proper exposure.

NOTE: Lower exposure control knob settingsgive light prints, and higher settings give darkprints. Experience with the reader printer will,for the most part, provide the operator with thesetting to be used on the exposure control knob.

The print button is then pressed momentarilyand the print comes out the print exit slot.

Prior to microfilm cartridge removal, thespeed control knob should be rotated clockwiseuntil all microfilm is wound back into thecartridge. To remove the cartridge, simply push

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AZ.25

back on the cartridge lock and remove thecartridgeTrom the holder.

This reader printer uses a special type of copypaper and will not operate when the supply ofcopy paper is exhausted. It also uses an activatorsolution in the printing process. Under normaluse, a bottle of activator solution is adequate forone roll of copy paper. !t is a good practice toinstall a new bottle of activator solution eachtime a new roll of copy paper is installed. Theoperator's instructions manual provided by themanufacturer gives complete details for loadingboth copy paper and activator solution. Inaddition, this anual gives instructions forroutine cleaning and maintenance that can beperformed by the operator.

GS


PROCUREMENT OF PUBLICATIONS

The publications covered in the previoussection are specifically prepared to assist main-tenance personnel; however, either through alack of knowledge of their existence, the proce-dures for obtaining them, or plain indifferenceby supervisor personnel, the mechanic is oftendeprived of the benefits publications areintended to provide. Since the use of publica-tions in performing maintenance tasks is manda-tory, they must be on hand and used consistent-ly.

Detailed information concerning the avail-ability of aeronautic publications may be foundin the Naval Aeronautic Publications Index. Thecomplete index is made up of five parts, asfollows:

Nav Sup 2002, Section VIII, Parts C andDNumerical Sequence List.

Nav Air 00-500AEquipment ApplicabilityList.

Nav Air 00-500BAircraft Application List.Nav Air 00-500CDirectives Application List.Nav Air 01-700Airborne Weapons/Stores,

Co n vention al/Nudear, Checklists/Stores Re-liability Cards/Manual Index.

NOTE: The latter part is not used by ADRpersonnel and is therefore not covered in thissection.

NavSup 2002, Section VIII, Parts C and D,contains a complete numerical listing of allavailable naval aeronautic publications dis-tributed by NavA.:rSysCom and stocked for issueas of the date of publication. This numericallisting contains all available publications bypublication number, stock number, and title.Publications are subdivided into subject groupsaccording to type of aircraft or equipment, orcomponent thereof.

Part C (manual publications) contains its tableof contents, as well as the instructions for usingboth Parts C and D of NavSup Publication 2002.Included in these instructions are the methodfor procuring aeronautic publications, the formsand procedures required for ordering publica-tions, and explanations of certain codes used inthe Index. Also a listing of canceled publicationsfor Part C is contained in the last pages of PartC.

Part C is divided into subject matter groups,and all publications within a group are then

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listed in numerical order. For example, allmanuals in the 00 series are listed first, thenfollowed by the 01, 02, 03, etc., through the 51series. The listing includes the publication codenumber, stock number, title, date of latest issueor revision, security classification, requisitionrestriction code. and basic or change code.

Part D (letter type directives) contains a tableof contents, a general alphabetical cross-refer-ence listing, and a listing of Air Force-Navy codecross-references. Part D is divided into a numberof subsections. Included among those of interestto the Aviation Machinist's Mate are powerplant,propeller, accessories, and support equipment.Listed in the powerplant section are all General,Turbojet, and Reciprocating Engine Bulletinsand Changes. The accessory section contains alisting of all Accessories.Bulletins and Changes.The support equipment section contains a listingof all Support Equipment Bulletins and Changes.

The Numerical Index must be used tocompletely identify and, therefore, to orderrequired publications. However, the other partsof the Index (discussed in the following para-graphs) must be used to determine what publica-tions are available for a specific item of equip-ment and to check the applicability of publica-tions to specific equipment.

When an applicable publication number isfound in one of the other parts of the NavalAeronautic Publications Index, it can be easilylocated in the Numerical Index. Here, it can bemore completely identified as to title andnomenclature, stock number (for manual typepublications), security classification, and anyrestrictions concerning the requisitioning of thepublication. In addition, the date of the latestissue or revision of the publication is listed. Thisprovides a means whereby the issue and/orrevision dates of the publications on hand in anactivity can be checked against the dates listedin the current issue and supplement (discussedlater) of the Numerical Index, thus assuring thatthe publications are current

Equipment Applicability List

Basically, the Equipment Applicability List,NavAir 00-500A, is a cross-reference indexlisting of Naval Air Systems Command (Nav-AirSysCom) publications (manuals, changes, and

69


bulletins) of aircraft components and relatedequipment according to model, type, or partnumber.

Since this index contains several thousandentries, one volume would be very cumbersometo use. For this reason, this index is divided intoseveral volumes. At the time of this writing,there are seven volumes.

With the exception of several small sections inthe first part of Volume 1, the EquipmentApplicability List is one continuous index ofmodel, type, or part numbers in alphanumericalsequence.

In addition to an Introduction, whichexplains the headings at the top of each, page,the other sections in the first part of Volume 1pi.:1-t-a;:i primarily to manuals for aircraft,weapons systems, and aircraft engines. There-fore, the publication numbers are listed accord-Mg to aircraft, aircraft engine, and weaponssystem designation.

The Equipment Applicability List should beused when attempting to determine whatpublications (manuals, and technical directives)are available on a particular item of equipment,and the manufacturer and part number of theitem are known.

Aircraft Application List

The Aircraft Application List, NavAir00-500B, contains a listing of all manualsgrouped according to their application to anaircraft. This part of the index does not containlistings of any letter type publications, and allmanuals are listed by publication code numberonly.

A list of basic numbering categories isprovided in the front of the book. This list maybe use,' in determining the general type ofequipment covered in a publication. For deter-mining the specific item of equipment coveredby a publication and the title of the publication,reference should be made to Part C of SectionVIII in NavSup Publication 2002.

The Aircraft Application List is especiallyhandy for determining what manuals are avail-able for a particular model of aircraft. Includedunder each model is a complete listing ofapplicable manuals. This listing includes allallowance lists, aircraft manuals, engine manuals,

accessories manuals, etc., pertaining to thatparticular model of aircraft.

Directives Application ListBy Aircraft Configuration

The Directives Application List by AircraftConfiguration, NavAir 00-500C, contains a list-ing of the active Naval Air Systems Commandletter type technical directives with respect totheir applicability to aircraft. The lists in thisvolume are arranged by aircraft series; i.e.,Attack, Cargo/Transport, Fighter, etc. Withineach series the lists are arranged by technicaldirectives code.

Each List in the Naval Aeronautic Publica-tions Index is updated at regular intervals by theissuance of a new list. In addition, some of theseLists are kept current by the periodic issuance ofsupplements between issues of the Basic List.The dates and intervals of the issuance of newLists and supplements have changed from timeto time in the past.

At the time of this writing, the NumericalIndex (Parts C and D of NavSup Publication2002) is issued annually in September. Sup-plements are issued bimonthly between eachbasic issue. The Equipment Applicability List,NavAir 00-500A, is issued annually in Novem-ber. This List is kept current by the issuance ofquarterly supplements between each basic issue.The Aircraft Application List, NavAir 00-500B,is issued in March and September, and theDirectives Application List by Aircraft Con-nguration, NavAir 00-500C, is issued in Januaryand July of each year. Supplements are notissued for these Lists.

Supplements list all aeronautic publicationsdistributed during the previous period, and thosepublications that have been superseded,canceled, or revised. Supplements are cumula-tive, that is, all material from the precedingsupplement is incorporated in the latest sup-plement; therefore, at any given time, not morethan one supplement is in effect for any List.Naturally, the reissue of a basic List cancels theoutstanding supplement.

Supplements for the Numerical-Index (Parts Cand D of Section VIII of NavSup Publications2002) are identified by the word "supplement"printed near the upper right-hand corner of the

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cover. Supplements to the Nav Air 00-500ASeries publications are identified by the word"supplement" printed in the middle of the coverpage.

Procurement Methods

There are five main methods of procuringpublications relating to naval aircraft main-tenance.

The first method is initial outfitting. TheNaval Air Technical Service Facility will providethe prospective commanding officer of a newlycommissioned or reactivated ship, station, oractivity an outfitting of general aeronauticpublications. Normally this outfitting will befurnished 2 months prior to commissioningunless otherwise requested.

The second method is aeronautic technicalpublication outfitting. An Aeronautic TechnicalPublication Outfitting Allowance consists ofthose publications applicable to a particularmodel of aircraft. Initial distribution is provided

by the Naval Air Technical Services Facility to anewly commissioned or reactivated activity.Upon change in mission or aircraft -ustodywhich requires a different set of publications,the activity must submit a request to the NavalAir Technical Services Facility for an AeronauticTechnical Publication Outfitting Allowance, ap-plicable to the model designation of the aircraftinvolved.

The third method of procuring publications isthrough inclusion on automatic distributionlists. The Naval Air Technical Services Facilitynormally provides for the distribution of certainfuture issues of new and revised publicationsdirectly to affected activities. Activities desiringto receive future issues of new and revisedpublications must submit NavAir Form 5605/3,Mailing List Request for Aeronautic Publica-tions, to the Commanding Officer. Naval AirTechnical Services Facility, 700 RobbinsAvenue., Philadelphia. Pennsylvania 1911 I. Workcenter supervisors desiring to receive particularissues. reissues, and revisions of publicationsshould make their requirements known to themaintenance office and/or the activity's tech-nical publications library so that they may beincluded on the next submission of NavAirForm 5605/3.

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NAVAIR Form 5605/3 consists of fourseparate parts:

Part I contains requirements for GeneralAllowance Lists, Indexes, and General SeriesTechnical Manuals and Directives.

Part II contains requirements for Aircraft/Engine Allowance Lists, and Airframe andPower Plant Technical Manuals and Directives.

Part III contains requirements for AircraftComponent Manuals.

Part IV contains requirements for Ship Instal-lation Technical Manuals and Directives.

Instructions for submission of NAVAIR Form5605/3 are printed on page 1 of each part. Theparts may be submitted separately or as a group,as long as the appropriate block in the instruc-tions is checked to indicate the reason forsubmission. The newly submitted form willplace an activity on the mailing list for FUTUREISSUES of Basic, Revised, or Changed manuals/directives only. It is not used as an order blankfor existing manuals/directives.

The fourth method of procuring publicationsis by ordering individual publications direct. TheSingle Line Item Requisitioning System Docu-ment (DD Form 1348 or DD Form 1348M) isused by activities when requisitioning manualtype publications on a one-time requirement.Letter type publications may be ordered on DDForm 1149 Standard Requisition and Invoice/Shipping Document, on a one-time requirement.The use of DD Form 1348, DD Form 1348M, orDD Form 1149 will not result in being placed onthe distribution list to receive future issues orrevisions of the publication ordered. Unlessotherwise directed, individual publications areordered from the Commanding Officer, (1051),Naval Publications Form Center (NPFC), 5801Tabor Ave., Philadelphia, Pennsylvania 19120.

A limited number of publications may beordered utilizing telephone requisitioning proce-dures. This is accomplished by contacting thecustomer service branch of the Naval Publica-tions Forms Center. The same information aswould be placed on an order form should beobtained prior to placing the telephone call,thereby improving accuracy and expediencyover this communications media.

Although Interim Changes and Bulletins arelisted in NavSup Publication 2002, Section VIII,Part D, they are not available for issue through


the Publications Supply System. They are listedonly for informational purposes.

Operating activities requiring copies ofInterim Technical Directives should submitrequests to the appropriate controlling custo-dian. Other activities requiring copies of ITD's inaddition to the initial Nav Air distribution,should submit requests to the appropriate NavalAir Systems Command Representative.

Instructions issued by Washington head-quarters organizations such as Op Nav, BuPers,Sec Nav, Nav Air, etc., are listed in the Con-solidated Subject Index of Unclassified Instruc-tions, NAVPUBINST 5215 Series. They arerequested on Nav Sup Form 1205 from theSupply and Fiscal Department, Washington,D.C.

Requests for instructions from other thanWashington headquarters organizations may beinitiated on Nav Sup Form 1205 or by submit-ting a letter request in accordance with theoriginating activity's 5215 index of instructions.

NavAir Specifications and Standards andNavAir Standard Drawings are listed in NavAir00-25-544 and NavAir 00-25-543, respectively.The Department of Defense Index of Specifica-tions and Standards (DODISS) and related docu-ments, Part I (alphabetical listing) and Part II(numerical listing) provide a more completelisting of specifications and standards of interestto work center supervisors. Specifications, stand-ards, and drawings are ordered on DD Form1425.

In addition to the NavAirSysCom, othercommands publish a variety of material whichmay be useful. There is no hard and fast rule forprocurement of this material. If the item desiredis not listed in the cognizance symbol I catalog(NavSup 2002) and no other source is known,send the request by letter directly to thepublishing command.

Fleet and type commanders publish a limitedamount of material, normally relating to opera-tional problems in their respective areas. Thismaterial is usually supplied .lutomatically toactivities on the standard mailing list. If otherrequirements exist, a letter request may besubmitted to the applicable fleet or type com-mander.

Situations may arise in both Organizationaland Intermediate levels of maintenance which

67

require the use of engineering drawings. Techni-cal information of this type is normally suppliedto these levels of maintenance in the form ofmicrofilm reproductions of the actual drawings.Engineering drawing reproductions provide allthe necessary information to construct, as-semble, and install a part or an assembly.Aircraft and equipment manufacturers provideNATSF and Naval Air Rework Facilities withengineering drawings for use by engineering andrepair personnel. These activities are also pro-vided with microfilm and Vandyke (blueprint)copies of engineering drawings.

}'or the most part, microfilm copies ofengineering drawings are provided in filmstripan .1 in single frames mounted on aperture cards.Aperture cards are standard size EAM cards andhave printed and keypunched identifying in-formation concerning the frame of microfilmwhich they ccntain. It is conceivable thatreproductions of engineering drawings may, inthe future, be provided in cartridge form for useby the Filmac 400C reader printer previouslydiscussed.

Most aircraft and equipment IPB's containmanufacturer's engineering drawing numbers forvarious components. If microfilm of a particulardrawing is required and the drawing numberunknown, then the aircraft or equipmentcompany technical representative should beconsulted for this information.

In most cases the requirement for microfilmwill be on an as-needed basis; therefore, largestocks will not normally be maintained in thetechnical library of Organizational and Inter-mediate activities. The various work centersupervisors will normally notify the person incharge of the technical library of their require-ment for microfilm.

All requests for complete sets of engineeringdrawings should be forwarded to the Commandinb U.S. Naval Air Technical ServicesFacility (EDD), 700 Robbins Avenue, Phila-delphia, Pennsylvania 19111, on a DD Form1149. When a complete set of drawings for anaircraft or equipment is requested, the individualdrawings need not be listed; however, therequest must be accompanied with a statementof justification. Individual drawings may beobtained either from NATSF or the nearestNA VAIRREWORKFAC, via the cognizant


NAVAIRSYSCOMREP. Requests for classifiedand unclassified drawings must be submitted onseparate forms. Since approximately four and ahalf million drawings are available from NATSF,proper submission of requests for copies of thesedrawings is essential to avoid delay in receipt.

SECURITY OF CLASSIFIEDPUBLICATIONS

The problem of security of classified publica-tions in the work center files is generally limitedto ways and means of stowing, using, accountingfor, and disposing of cuch publications in ac-cordance with existing directives. The basicNavy security directive relative to the safeguard-ing of classified information is the Departmentof the Navy Supplement to the DOD Informa-tion Security Program Regulations, Op NavInstruction 5510.1 (Series). Its provisions applyto all military and civilian personnel and to allactivities of the Naval Establishment. The ap-plication of security measures regarding shopfiles may be further influenced by locally issueddirectives which supplement the basic directive.

All personnel in the Naval Establishment areindividually responsible for assuring that knowl-edge of classified information which theyprepare or handle is made available only topersons who have clearly established a legitimate"need to know." Classified material is procuredfor the work center files because it is neededduring the performance of some related main-tenance function. Use of these publications bypowerplant personnel should be anticipated andsteps taken to procure security clearances forselected personnel most likely to require thein formation.

The supervisor must initiate procedures thatinsure him positive control of all classifiedpublications for which he is custodian. The firstproblem of custqdy is stowage. The NavySecurity Manual discusses stowage containers ofvarying degrees of integrity. Also provided in themanual are specific requirements for safeguard-ing combinations and keys for locks as these, tovarious extent, affect the protective capabilitiesof the different types of containers.

Classified publications that are no longerrequired in the work center should be returnedto the Classified Material Control Officer for

disposition by transfer or destruction, as ap-propriate.

MAINTAINING WORK CENTER FILES

There are two general categories of recordsrequired of all work center supervisors. Theseinclude records required by the activity foroperational purposes and those needed by thework center chief for the efficient managementof his work center. It is advisable to keep thesystem of records as simple as possible and stillmaintain the necessary control. Too few records,however, can lead to uncertainty, encourageguessing, and sometimes lead to embarrassingsituations. In order for records to be of maxi-mum benefit and provide adequate control, it isnecessary that records and publications be filedin the work center in such a manner that theymay be quickly located.

The Navy has adopted a filing system whichprovides a definite place for every piece ofcorrespondence and uniformity in filing systemsthroughout the Naval Establishment. In therelatively few years this system has been in useits merits have greatly exceeded any real oimagined disadvantages. The filing system is aintegral part of the Directives Issuance SystemThe 13 major subject classification groupnumbers are further subdivided into primary,secondary, and sometimes, tertiary breakdowns.Each subject group symbol must have 4 or 5digits to be complete. Example of subjectclassification number breakdown:

13X X X Aeronautical and AstronauticalMaterial.

134XXSystems, Components, and Ac-cessories.

13430Arresting and Launching, Provisionsfor.

13430.1Airplane Arresting Hooks, Inspec-tion and Replacement.

While directives (Instructions and Notices)utilize the standard subject group classificationnumbers and breakdowns of the DirectivesIssuance System, many other types of publica-tions do not. When file materials other thanInstructions and Notices are received in theshop, they should be assigned a file symbolbased on the subject group classification

6873


number. The correct application of file symbolsassures uniformity in filing.

Personnel who have a working knowledge ofthe subject classification system and the mannerin which all records are filed can locate requiredmaterial expeditiously at any activity to whichthey may be assigned.

The most important filing operation is clas-sifying (assigning file symbols) since it deter-mines where papers are to be filed so that theymay be located quickly. Each paper received inthe work center for filing should have the workcenter file symbol assigned regardless of whetheror not a file symbol already appears on it. Theproper coding should be determined by the mostimportant, definite, or concrete §ubjectmentioned; the purpose or general significanceof the document; the manner in which similardocuments are sought; and the file symbol underwhich- other documents of a similar nature arefiled.

The actual filing responsibility should beassigned to one person in the work center. Allmaterial awaiting filing should be placed in onebasket only; and to avoid accumulations, shouldbe filed daily.

When material could be properly filed undertwo or more headings, one or more cross-reference forms should be inserted in the files atthe appropriate places to indicate just where thedocument is filed. The cross-reference shouldindicate the following:

I. Originator of the letter, serial number, filesymbol, and date.

2. Addressor of letter.3. Subject of letter.4. Addressee of letter.5. Where letter is filed.6. Brief of letter or applicable part of text.Extra copies of the basic document may be

used instead of the cross-reference form. Cross-referencing, while serving a useful purpose,should be kept to a minimum to conserve space.

Another handy tool for keeping work centerfiles in good order is the "file out" card. Thismay be a locally prepared form that is insertedinto the files whenever a piece of file material ischarged out to another office, work center, orperson, to help keep track of its whereabouts.All "file outs" should be checked periodically toprevent misplacement of material. Care must be

74 69

taken that records are not released to un-authorized persons.

A ready index should be provided in the workcenter so that material may be more easilylocated. The index should be set up according tothe 13 major subject classifications in theDirectives Issuance System and further sub-divided into categories corresponding to the listof standard subject classification numberscontained in SecNav Instruction P5210.11(Series), Standard Subject Identification Codes.

REQUIRED READING ANDMAINTENANCE INFORMATION RECORD

Certain directives and publications are routedto the various work centers as maintenanceinformation, and copies of such maintenanceinformation must be disseminated and retaineduntil it is no longer applicable. Informationshould be placed in a required reading file that isavailable to all hands in the work center. Whennew material is received, it is placed in the"active" required reading file until it is read andinitialed by each man in the work center. It maybe necessary for the work center supervisor toamplify or clarify some information so that itwill be properly understood.

Once all personnel in the work center haveread and initialed the material, it is placed in the"standing" required reading file for use inindoctrinating new personnel and for periodicreview by those personnel who may require it.Newly assigned personnel should read and initialboth the active and standing files. If copies ofdirectives or publications are not available forrequired reading file, a cross-reference sheetindicating the general content of the subjectmatter and its location is utilized to insure thatpersonnel are thoroughly aware of all informa-tion that could affect their actions.

TRAINING OF PERSONNEL

Training of personnel is a necessary functionand one of the most important responsibilitiesof senior petty officers. A Chief AviationMachinist's Mate and to some extent a FirstClass, will have regular and continuing respon-


sibilities for the training of others. Even if asupervisor is fortunate enough to have a groupof men who are highly skilled and well trained,he will find that training is still necessary. Forexample, the training of strikers and lower ratedmen for advancement examinations is acontinuing, never-ending process. The Navy rota-tion policy being what it is, the best men willeventually be transferred and replacements will.in most instances, require training before theycan be relied on to take their places as effectivemembers of the organization. These and similarproblems require the powerplants supervisor tobe well versed in the several aspects of trainingable to set up as well as conduct an effectivetraining program for assigned personnel.

ORGANIZING A TRAINING PROGRAM

Organizing a training program involves suchconsiderations as planning lessons and job plans,selecting and qualifying instructors, making ar-rangements for classroom space. phasing thetraining program with the scheduled workload,procuring visual and other training aids, anddetermining teaching methods for each lesson orlesson series.

The subject matter areas to be included in thetraining program are (1) material relating tomaintenance of aircraft supported, (2) generalmaterial r.quired by the men for advancementexaminations, and (3) material relating to safety.In most cases lessons will fall under more thanone of the subject area'

Once it has been . ermined what publica-tions will adequately cover the subject areas, thematerial must be divided into lessons, and lessonguides prepared. The lesson guides for eachlecture are prepared in accordance with thestandard format provided in Op Nav Instruction4790.2 (Series). The lectures are numbered toprovide a means of recording each man'srhogress within his individual training folder. Atraining syllabus sheet should be prepared foreach man in the work center to provide a handyindex to the state of training of the work centerpersonnel as a whole.

Whether the supervisor teaches the lesonshimself or assigns other petty officers toconduct them depends on the state of training

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of his first and second class petty officers. Arequirement for advancement for third classpetty officers and nonrated personnel is satis-factory completion of the correspondencecourse based on Military Requirements for PettyOfficer 3 & 2, NavPers 10056 (Series). Thiscourse sets forth some of the basic principles oftraining in general and teaching in particular.

An advancement requirement for second andfirst class petty officers is satisfactory com-pletion of the correspondence course based onMilitary Requirements for Petty Officer 1 & C,NavPers 10057 (Series). The latter courseexpands and amplifies training theory andintroduces job analyses, training aids, and test-ing. For the first time in his career the prospec-tive First Class Aviation Machinist's Mate isrequired to demonstrate his ability to formallyteach, use various training aids, and prepare andadminister written tests. In order to demonstratecorrect instructional techniques, the supervisormay elect to teach certain lessons himself orassign them to a competent instructor for thesame purpose. Later he may assign lessproficient petty officers as instructors so thatthey may acquire the experience- necessary forcompleting their practical factors for advance-ment.

If at all possible, training sessions should beconducted at the same time of day and on aregular schedule. Factors to consider whenscheduling lessons are usual flight schedule, mealhours, watches, availability of classroom, andaircraft inspection schedule.

Some lessons are better suited for one type ofinstructional technique than others. The type ofpresentation for each lesson should be plannedin advance. This will also facilitate the rotationof the lessons among the petty officers whorequire experience in teaching.

The effectivity of aviation technical training isgreatly enhanced by the use of training aids. Thesupervisor should always be on the alert forscrap material that can be converted to trainingaids with minimum expense. He must be awareof the existence of applicable training filmg"and,if they are available, schedule them for showingin conjunction with specific lessons. Thesquadron or unit safety officer or station safetyengineer may usually be depended on to supplytraining aids in support of shop safety presenta-tions.


When planning a training program, the super-visor should decide where the classroom sessionsshould be conducted. The space selected shouldpreferably be in a quiet area or at least one witha minimum of noisy distractions. The areashould be large enough to accommodate theexpected student load and be well lighted.Adequate ventilation will help keep the menawake and interested in the presentation. Con-venience is another factor in the selection ofclassroom space. Some of the desirable spacecharacteristics may, on occasion, have to besacrificed in order to find a classroom nearer tothe working area.

TRAINING PROCEDURES

Training procedures are of two general typesformal and informal.

Formal training is conducted in the classroomthrough lectures, supplemented by requiredreading and implemented by the use of allavailable visual aids. A schedule of training isprepared and published periodically by themaintenance officer. It lists the time of thetraining, the location of the classroom, thenames of the men who are to attend, the subjectof the lesson, and the name of the instructor.

Lesson guides are prepared by the divisionofficer and chief or first class petty officers whoare qualified to do so. The lesson guides shouldcontain the title, objective(s), time to beconsumed in presenting the lesson, list ofinstructional aids, list of references, outline forpresentation, and a summary of the lesson.

When a petty officer has been, assigned toinstnict a given lesson, it is his responsibility toprocure a copy of the lesson guide and from itprepare his lesson plan. Lesson plans areprepared by each individual instructor based onthe lesson guide; and though they may differfrom instructor to instructor, they mustadequately cover the subject.

Informal training is the practical instructionof men in the performance of maintenance tasksby means of demonstration and imitation underpersonal supervision in the work center or onthe operating line. Nearly every maintenancetask that is undertaken presents an opportunityfor on-the-job training. The experienced men of

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the division are utilized as fully as possible indemonstrating and imparting their skills to theless experienced.

Under this system, the trainee has theopportunity to actually do the job under thesupervision of an experienced petty officer. Theonly equipment necessary is the job itself. It isnecessary, of course, that the instructor have aninterest in the job and the skill to do it well. Thestriker or trainee will learn by seeing the jobperformed, and he will gain experience byhaving a chance to participate in the accomplish-ment of the job.

The nature of informal training makes regularscheduling impracticable. Actually, it is done atevery opportunity. A training syllabus isprepared under the guidance of the maintenanceofficer, with content and scope correspondingwith practical factor requirements of the person-nel. On-the-job training is reported by theleading petty officer instructors and supervisorsto the division officers on the training syllabusat regular intervals so that a close watch may bemade on individual progress. The records are forreview by higher authority and will point outthe need for training in special areas as well ascertain practical factors. The degree of success inon-the-job training depends on the degree ofrecognition by each individual of his respon-sibility to his outfit to impart his skill andknowledge to the man who is trying to learn.

TRAINING DOCUMENTATIONAND RECORDKEEPING

Maintenance activities, except those that arespecifically excluded, should comply with themanhour accounting procedures outlined inOpNav Instruction 4790.2 by submittingmanhour accounting cards to reflect the ac-complishment of formal inservice training.Procedures for submitting manhour accountingcards are provided in Military Requirements forPetty Officer 3 & 2, NavPers 10056 (Series) andOpNav Instruction 4790.2.

The individual Training Syllabus Sheetprovides a record of formal lectures attended byeach man in the work center. A report of


practical training (OJT) should be made to thedivision officer at regular intervals. This willindicate to the division officer that a man hasfulfilled a satisfactory level of skill to justifycompleting of the various items listed on theindividual's practical factors for advancement

IIMINIIMMEISINaliffigiamt2TQM201^^3E19.

72

sheet. The formal training syllabus record andthe record of practical training will indicate thatrequired training has been completed in all areasor that a need for special training exists andfurther certifies when the individual may beconsidered qualified for advancement.

CHAPTER 4

RECIPROCATING ENGINE SYSTEMS

The basic engine used for discussion in thischapter is the R3350-32W. The R3350-32Wengine is a turbo-compound, 18-cylinder, air-cooled, radial, reciprocating powerplant. Thisengine incorporates three blowdown turbines forexhaust gas power recovery, a reverse low, flowtorquemeter system, a two-speed supercharger, alow-tension ignition system with automaticspark advance, an impeller ignition system, and awater injection system. When the manual sparkadvance is incorporated on the R3350-32Wengine, its designation becomes R3350-32WA.

The R3350-34 is the same basic engine as the-32W, except it incorporates a manual sparkadvance and a direct fuel injection system.

TORQUE CELL

The torque cell is contained in the frontcrank ase section of the engine. It is connectedto a gage in the cockpit through passages in theengine internally and by an electrical transmitterexternally. The gage will read either BMEP ortorque cell oil pressure depending upon theinstallation. The torque cell is composed of thefollowing units: the stationary reduction gearand adapter, the stationary reduction gearsupport, a support oil ring, a stationary piston,two piston oil seal rings, piston to front sectionoil seal rings, 24 steel balls which are retainedloosely in sockets in the reduction gear supportand the stationary reduction gear and adapter,and the torquemeter boost pump.

The torquemeter boost pump is a gear typepump mounted on the top of the crankcasefront section. It is used to boost the engine oilpressure to the desired pressure needed tooperate the torque cell under all operatingconditions. The torquemeter system is il-lustrated in figure 4-1.

The torque cell is formed by the forward faceof the stationary reduction gear adapter, and the

73

75

rear face of the torquemeter piston and its rearoil seal ring. With the exception of leakagebetween_ the stationary reduction gear adapterand the stationary reduction gear support oilseal ring, all the boost pump oil output iscontinually entering the torque cell through ahole in the piston. Oil leaves the torque cellthrough metering slots in the stationary reduc-tion gear adapter and back to the enginepressure oil system through 18 holes in thepiston.

There is a definite relationship between theposition of the adapter metering slots relative tothe piston rear oil seal ring and the torque celloil pressure. The reduction driving gear turns ina clockwise direction, and, through the reduc-tion gear pinions, tends to turn the stationaryreduction gear and adapter in a counterclock-wise direction. However, rotation of the station-ary reduction gear and adapter is very limitedand is converted to forward movement by meansof the torquemeter balls and ball sockets. (Seefig. 4-2.)

Boost pump oil entering the torque cell tendsto force the adapter to the rear. At any givenpower setting, these two forces are opposingeach other and will attain an equilibrium as theadapter metering slots will regulate the torquecell oil pressure which is transmitted to theBMEP or torque cell pressure gage. In this way,an accurate method of determining actualhorsepower output of the engine at the propellershaft can be assured and a system of cruisecontrol can be set up so that the maximumrange can be obtained. A simplified diagram ofthe torquemeter system is shown in figure 4-3.

The general procedures for checking thetorquemeter system for malfunctions arediscussed here. For more detailed and specificinformation concerning the procedures to beused, consult the appropriate engine publication.If the torquemeter is thought to be giving


TORQUEMETER BOOSTADAPTER

PUMP PRESSURE

CRANKCASE FRONTSECTION

SUPPORT

PINION CARRIER

STATIONARYREDUCTION

GEAR

PINIONOIL PASSAGE

OPEN

OIL PASSAGE CLOSED

FIXED PISTON

TO TORQUE GAGE

DUAL THRUSTBEARING

PROP. SHAFTTORQUE CELL

PROP. OIL SUPPLYTUBE

PROP. OIL CONTROLSLEEVE

PROP. SHAFT ANNULUS

CRANKSHAFT

PROP. SHAFT REDUCTIONDRIVING GEAR

PROP SHAFT FLANGE

AD.352Figure 4-1.Reverse low flow torquemeter system.

improper readings, first check the BMEP gage,its transmitter, and its connecting wires andconnections. When it has been established thatthe trouble is not in the gage or relatedequipment, check the MAP gage, the tachom-eter, flowmeter, and their transmitters andconnections.

When it has been determined that the troubleis definitely not due to faulty instruments, aninternal torquemeter check may be made. Theleakage check is made by attaching adapter,pressure gage, filter, cutoff valve, d handpump to the BMEP gage connection r le nosesection of the engine. Pressure is bui.. p withthe hand pump to the engine manufacturer'sspecifications. Then the cutoff valve is turnedoff. A pressure drop in excess of that recom-

mended by the manufacturer would indicateinternal leakage either in the internal lines or inthe torque cell itself. A further check of theinternal system can be conducted to determinewhich of these two units are at fault. If it isdetermined that the fault is not in these pre-viously named units, a comparison check can bemade between the bad engine and the goodengine(s) on a multiengine aircraft.

SUPERCHARGER CLUTCH SYSTEM

The R3350 engine supercharger is a single-stage, two-speed supercharger. The two-speedimpeller drive has a low speed ratio of 6.46: I,and a high speed ratio of 8.67:1. A cutaway

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79

Chapter 4RECIPROCATING ENGINE SYSTEMS

t PROP

STATIONARY

GEAREARSTATION:RVREDUCTIONGEARSUPPORT

VIEWED FROM TOP

AD.353Figure 4- 2. Action of the torquemeter balls. (A) Torque

applied to the stationary reduction gear; (B) notorque applied to the stationary reduction gear.

GAGE

PRESSUREOIL

OIL SEALRINGS

PISTON(STATIONARY)

DRAINMETERING

SLOT

MOVING

CYLINDER

I FORCE

I OILCELL

iV FORCE

AD.354Figure 4-3.Torquemeter system diagram.

75

8D

view of the impeller drive is shown in figure 4-4.Basically, the two-speed impeller drive consistsof two planetary gear trains (primary andsecondary) in series, an intermediate I:, "r, aroller clutch, and an oil-operated plate clutch.Figure 4-5 illustrates the principle of operationwith the component parts in their relativepositions.

The primary pinion carrier is supported byand splined to the accessory drive and startershaft, and thus turns at crankshaft speed at alltimes. As the primary pinion carrier revolves, thepinions, which are meshed with the stationarygear, rotate on their trunnions and turn theimpeller intermediate drive gear (sun gear) in thedirection of crankshaft rotation approximately2.7 times faster than the crankshaft speed. Theimpeller intermediate drive gear, being driven bythe primary pinions, in turn, drives the sec-ondary outer pinion gears.

The secondary outer pinion gears, along withthe secondary inner pinion gears, are mountedon the secondary pinion carrier, which is splinedto the roller clutch. The secondary outer piniongears transmit the drive to the secondary innerpinion gears, which mesh with the gear at theend of the impeller drive shaft. The outerimpeller shaft is splined to the other end of theinner impeller drive shaft and it in turn has theinducer and impeller splined to it. Thiscompletes the drive line through thesupercharger gearing system to drive the impel-ler.

During operation the secondary pinion carrierrevolves slowly in the same direction as theintermediate gear. If the secondary pinioncarrier is stopped from rotating, the impeller willrevolve at a faster speed. This is how the twospeeds in the impeller are obtained. For highspeed, the secondary pinion carrier is forced toremain stationary. For low speed, the secondarypinion carrier is allowed to rotate, but notfreely. It is held to the crankshaft speed by theroller clutch. A simplified diagram of the sec-ondary gear system is shown in figure 46.

The driving force from the intermediate gear,which is turning at approximately 2.7 timescrankshaft speed, can be transmitted by thesecondary pinions to the impeller shaft. How-ever, the impeller will not rotate if the sec-ondary carrier is allowed to rotate freely. Since


7 3 8 6

1

1.1

1. Primary pinion carrier.2. Clutch rollers.3. Primary pinion gears.4. Stationary gear.5. Intermediate (sun) gear.6. Intermediate (bell) gear.

kik

5 2 Ist

Agratarn

4.`

7 10 3 9

4 12

7. Secondary outer pinion gears.8. Inner impeller shaft9. Secondary pinion carrier.

10. Secondary inner pinion gears.11. Accessory drive shaft12. Impeller stationary gear support

Figure 44. Impeller drive.

8176

AD.355

Chapter 4-RECIPROCATING ENGINE SYSTEMS

CLUTCH PLATES AND DISKS SECONDARY DRIVE 6EAR

SECONDARY PINION CARRIERAND CLUTCH DISK ADAPTERIMPELLER INNER

SHAFT

ECONDARY (MIER AND OUTER PINIONS

MPELLER UTCH PISTON

(PLATE CLUTCH UISLNGAGED, ROLLER CLUTCH ENGAGED

'TRANSMISSION OF POWER IN LOW-BLOWER

PRIMARY PINION CARRIER ACCESSORY DRIVE ANDSTARTER SHAFT

PRIMARY PIR: ROLLER CAM

ROLLERTREK

ENGINE SPEED

INTERMEDIATE GEAR

IMPELLER SPEED

NTERMEDIATE GEAR

SECONDARY OUTER PINION

SECONDARY INNER PINION

MPELLER INNER SHAFT

'i;;tHcM.

Vf_ ROLLER

NtrA*71

9 91!),1%0 0.14.0#,X1' ACCESSORY DRIVE GEAR

(PLATE CLUTCH ENGAGED, ROLLER CLUTCH DISENGAGED)

TRANSMISSION OF POWER IN HIGH-BLOWER

FRONT VIEW

SECONDARY PINION GEAR TRAIN

AD.356Figure 45.Two-speed impeller drive.

8 7


AD.Z57

1. Intermediate bell gear.2 Secondary outer pinion gears.

Seconday inner pinion gears.4. Secondary pinion carrier.5. Accessory drive shaft6. Impeller zhaft (inner and outer).

Figure 4.6.Secondary gear system.

the impeller is under a load of air at all timeswhen it is operating, the driving force wouldsimply spin the secondary pinion carrier whilethe secondary pinions walked around theintermediate bell gear if the rotation of thesecondary pinion carrier were not restricted bysome means. Wher the secondary pinion carrieris slowed down, part of the driving force is usedin rotating the impeller. When the secondarypinion gear is stopped icompletely, all the drivingforce is used in rotating the impeller. If thesecondary pinion carrier is allowed to turnslowly, the impeller will slow down. If thesecondary pinion carrier is stopped, the impellerwill speed up. Thus, high and low speeds of theimpeller are obtained.

For low impeller speed the carrier is allowedto rotate, but not freely. The carrier is held to

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83

crankshaft speed by means of the roller clutch.The action of the roller clutch is shown in figure47. The outer race of the roller clutch is formedby the primary pinion carrier. The inner race issplined to the secondary pinion carrier. Whenthe secondary carrier is allowed to rotate, it islocked to the primary carrier oy automaticaction of the rollers on the ramps as shown infigure 4-7(A). This locking action holds therotation of the secondary carrier to crankshaftspeed. When the secondary carrier is heldstationary, the clutch rollers are automaticallydisengaged as shown in figure 4-7(B).

The secondary carrier is held stationary bythe action of an oil pressure plate clutch. Theplate clutch assembly includes a clutch diskadapter (which is bolted to the secondarycarrier), clutch plates and disks, clutch housing,clutch support, piston, and oil rings. A selectorvalve is provided and mechar7.,:a1ly linked to thecockpit to give the pilot a means of controllingthe action of the clutch.

The clutch has five plates and four disks. Thedisks have splines on their internal diameterwhich are splined to the clutch disk adapter. Theplates have splines on their outer diameter whichare splined to the clutch support. A ringlikepiston fits against the plates. The clutch housingis fastened to the clutch support. The spacebetween the housing and the piston forms achamber into which oil under pressure can beadmitted. Two oil rings provide a seal for thepiston. This clutch assembly is bolted to thecrankcase by the clutch support.

When the clutch control valve is in thelow-blower position, the oil supply to the clutchpiston is shut off.and the five stationary platesare disengaged from the four disks, allowingthem to rotate and in turn permitting thesecondary pinion carrier to rotate in the samedirection as the primary pinion carrier. Thispermits the roller clutch to engage, locking thetwo carriers and allowing them to turn atcrankshaft speed. Since the intermediate gearcannot turn the secondary pinions as fast whiletheir carrier is rotating as when it is stationary,the impeller rotates at only 6.46 times crank-shaft speed while it is in low-blower position.

When the clutch control valve is in thehigh-blower position, oil at 70 plus or minus 5psi. is admitted to the forward side of the clutch


(A)

CARRIER ROTATINGVele FRONT REAR

1. Primary pinion carrier.2 Secondary pinion carrier.

3. Clutch inner race.4. Clutch rollers.

Figure 47.Roller clutch. (A) Engaged; (B) disengaged.

piston. This oil pressure forces the piston to lockthe clutch plates, thus holding the secondarypinion carrier stationary. When the secondarypinion carrier is held stationary, the inter-mediate gear, still turning at approximately 2.7times faster than the crankshaft, turns theimpeller shaft through the secondary pinions ata ratio of 8.67:1.

The operation of the impeller drivemechanism should be checked in accordancewith the appropriate technical publications.Whenever a check is made of the impeller drivemechanism, the supercharger control levershould be always moved smoothly and rapidly.Failure to comply with this precaution mayresult in a warped or frozen clutch and thus anengine change. To check the supercharger opera-tion, proceed as follows: Open the throttle to1,600 rpm, and move the supercharger controllever to the HIGH ratio position. Then advancethe throttle to obtain field barometric pressure(30" MAP), allow the engine to stabilize, andthen shift to LOW ratio. A sudden decrease in

emanifold p ts ure will indicate proper operation

79

84

AD.358

of the superchargcr. If there is no indication ofthe blower shifting, a check should be made ofthe linkage to the engine and of the selectorvalve. The valve may be removed for cleaning orreplacement. Also, a pressure test point isprovided on the engine to check oil pressure tothe oil pressure plate clutch.

POWER RECOVERY TURBINES

The R3350-32W and -34 engine models in-corporate three interchangeable exhaust powerrecovery turbines (PRT's). Figure 4-8 is a cut-away view of the power recovery turbine used incompounding these engines. Each of theseturbines is clamped to adapters that aremounted on the supercharger front housing andspaced 120° apart.

OPERATION

The PRT's utilize the energy of the exhaustgases coming from the cylinders and transmit


3031 32 33 34I 35 36

29

28

25

24

23

20

22

21

711111Pr-

118

19

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.=....nr....---11111114.

8

12 11

14

Figure 48.Power recovery turbine (cutaway view).

80

1

2

3

4

5

6

7

9

10

AD.359

Chapter 4-RECIPROCATING ENGINE SYSTEMS

Nomenclature for figure 4-8.

1. Cooling shield assembly.2. Nozzle solid vane.3. Cooling shield flange ring.4. Nozzle flange.5. Labyrinth seal.6. Inlet pipe retaining bolts, nuts, and washers.7. Inlet pill.-8. Cooline'air duct9. Shaft support

10. Shaft support and adapter packing rings.11. Lower thrust washer.12. Gear coupling.13. Supercharger front housing.14. Shaft gear.15. Mounting pad.16. Clamp.17. Nozzle support and adapter locating pins.18. Shield and seal assembly.

19.20.21.n.23.24.25.26.27.28.

31.32.33.34.35.36.

ShaftVibration damper.Upper thrust washer.Shaft oil seal ring.Cooling air impeller spacer.Nozzle assembly to nozzle support cap screws.Cooling air impeller.Nozzle split vane.Turbine wheeLTurbine wheel buckets.Flight hood locating lug.Wheel retaining nut.Cooling shield supportOuter shield.Intermediate shield.,Pylon supportCooling shield inner flange.Inner shield.

this energy back to the engine crankshaft. Theywill add approximately 150 horsepower perturbine for a total of 450 horsepower to thehorsepower output of the engine at maximumallowable power. Each PRT utilizes the exhaustgases from six cylinders-three front and threerear. (See fig. 4-9.)

The gases enter the turbine at the nozzleassembly and cause the turbine wheel to spin athigh speed. A hollow shaft, splined to theturbine wheel, passes through a support clampedto the adapter on the supercharger fronthousing. A vibration damper assembly, consist-ing of spring-loaded plates and disks, assists indampening the lateral vibration and the whip ofthe turbine shaft. A coupling, splined at eachend, connects the turbine shaft to a bevel drivegear in the supercharger front housing. The drivegear meshes with a larger bevel gear, connectedby a drive shaft to the fluid coupling impeller.The fluid coupling rear half (runner) is con-nected by a splined shaft to a pinion, whichmeshes with the PRT crankshaft drive gearcoupled to the engine crankshaft. Figure 4-10illustrates the transmission of the exhaust gasenergy to the turbine wheel and back to thecrankshaft.

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86

To prevent damaging effects from the hightemperatures of exhaust gases, cooling air isdrawn from a duct between the cylinders andconducted to the turbine assembly. A tube andduct assembly delivers the air between thenozzle support and the cooling air shield. Animpeller is provided to force the cool air throughthe assembly and to discharge it, together withthe exhaust gases, from the outer shield outlet.Cooling air is sealed under the turbine wheel bythe labyrinth seal facing the underside of theimpeller. The seal prevents the mixing of theexhaust gases and cooling air until both aredischarged from the outer shield. Oil from theturbine drive shaft is kept from entering thestream of cooling air by pie bellows-loaded seal,which fits tightly in the turbine shaft oil sealsupport.

Oil under reduced pressure, is brought fromthe pressure control valve located in the super-charger front housing by way of internal pas-sages to the PRT fluid coupling support. Fromthe fluid coupllpg support, oil flows throughpassages in the supercharger front housing to anannulus in the turbine coupling gear shaftbushing and through passages in the support tothe fluid drive shaft. From the coupling gear


TOP OF NGINE BOTTV OF ENGINE

AD.360Figure 49.Exhaust system arrangement

shaft bushing, a passage in the front super-charger housing carries oil to the fluid driveshaft. The oil entering from either end of theshaft lubricates the bushing on the shaft andpasses through a set of holes into the fluidcoupling, supplying the necessary pressure foroperation.

When the engine is being started, before oilpressure is built up in the fluid coupling, theimpeller will not drive the runner. Whensufficient oil pressure is built up in the couplingafter starting, the runner then follow theimpeller with a certain amount of slippageswhich will act to absorb any undesirable amount

4 FWD

Figure 4.10.Transmission of exhaust energy back to the crankshaft

S2

7

EXHAUST AIR

COOLING AIR

AD.361


of vibrational conflict between the crankshaftand the PRT unit. As engine rpm increases, theamount of slippage between the runner and theimpeller decreases. The fluid coupling is a vortextype, giving a swirling action to the oil toprevent sludge formation which might freeze thehalves of the coupling together and nullify theireffect.

PERIODIC INSPECTION

The periodic inspections of the PRT's areperformed at the time intervals specified in theapplicable technical instruction,- Damage fromthe hot exhaust gases usually occurs in threemajor component parts of the PRT's: in thecooling shield assembly, turbine wheel, and theexhaust nozzle assembly.

CARBURETION

The objective of all carburetion is to mix withthe air going into the engine the proper weightof fuel for all operating conditions in accordancewith a predetermined mixture formula. Thebasic requirements of a carburetor are the same,regardless of the type of carburetor employed orthe model engine on which it is installed.Therefore, in the following paragraphs themode! 58-CPB11 carburetor and the modelPR-58S2 master control are covered as typicalcontrols, and the model PR-58T1 injectioncarburetor is covered for comparison.

MODEL 58-CPB11 CARBURETOR

The model 58-CPB11 carburetor is of thedirect metering pressure type. This carburetormeters fuel at the desired fuel/air mixture to suita wide variety of engine operating conditions. Itmaintains the fuel /air ratio automatically,regardless of any changes in the air densitywhich results from changes in pressure ortemperature. Provision is also made to enablethe pilot to manually lean or enrich the fuel/airmixture.

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85

Components

This carburetor breaks down into three majorcomponents. They are the fuel metering unit,the air metering unit, and the main body unit.

1. Fuel Metering Unit. The fuel metering unitis attached to the rear side of the carburetor. Itconsists of the pressure regulator assembly,mixture control assembly, manual mixture con-trol valve, metering jets cover assembly, dis-charge vent line assembly, and the solenoidprimer. The pressure regulator assembly regu-lates the pressure of the fuel being delivered tothe jets by use of a spring and diaphragm-controlled valve. This valve is balanced (double-seated) to neutralize the effect of fuel inletpressure. The movement of the pressure regula-tor valve is controlled by changes in the variousfuel and air pressures applied to the threediaphragms of the pressure regulator assembly:the pressure regulator fuel diaphragm, the airdiaphragm, and the fuel balance diaphragm

The pressure regulator fuel diaphragm isexposed to the pressure of the fuel which haspassed through the pressure regulator valve. Theair diaphragm is the largest of the diaphragmsand is subjected to air pressures applied to bothsurfaces. One side of the diaphragm is connectedto impact pressure (low suction) in the mainventuri; the other side, to the throat (highsuction) of the boost venturi. The fuel balancediaphragm is exposed to the fuel at dischargepressure. This force tends to open the pressureregulator valve. At idling speeds or periods oflow airflow through the carburetor, the positiunof the regulator s alve is determined by a systemof springs..

Vapor traps are located in the top of the fuelmetering unit to eliminate vapors accumulatedin the fuel at the inlet screen and also after thefuel passes through the pressure regulator valve.The fuel vapors are vented back to the mainservice tank or tanks of the aircraft.

The manual mixture control is located on theleft end of the fuel metering unit and controls adisk type selector valve which directs the fuelflow to the proper jets to supply the engine withthe correct amount of fuel for all operatingconditions. This valve is also designed so that themixture strength can be manually leaned forbetter fuel economy. There are three jets located


in the mixture control housing. Jets A, Y 2, andC restrict fuel flow through ports I, 2, and 3,respectively, of the manual mixture controlvalve seat. Jet L restricts fuel flow to thesolenoid primer valve.

The B valve is located in the mixture controlhousing. It is spring loaded and diaphragmactuated. In RICH, port 4 is open, allowingreduced regulated pressure to act on the B valvediaphragm. In NORMAL and MANUAL LEAN;E bleed is open and port 4 is closed. Pressure inthe reduced regulated fuel chamber overcomesspring tension and discharge pressure to controlthe action of the B valve. (See fig. 4-11.)

The idle valve, located in the mixture controlhousing, is operated by the throttle control tometer the fuel flow during idling operation. Asthe throttle is opened, the idle valve will openfurther to permit more fuel flow to the engine.An adjustable stop pin assembly is located onthe left side of the throttle body to provide for

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3 4

adjusting the airflow through the throttle bodyto attain the desired idle rpm. The- idle mixturestrength may also be adjusted here on thethrottle linkage to attain the desired opening ofthe idle valve in relation to the throttle position.

The idle valve also performs the function ofan acceleration pump whenever the throttle israpidly opened. Whenever this occurs, the pistonon the rear of the idle valve causes a momentaryand sudden increase of the pressure in thebalance chamber, which results in an increasedpressure regulator valve opening.

Bleeds E and F are also located in the mixturecontrol valve housing assembly, bleeds G and Hin the pressure regulator body assembly, andbleed K in the main body assembly. Bleed E, inthe mixture control valve seat, governs the fuelflow to the back side of the B valve diaphragmduring normal operation. Bleed F controls thepressure balance between the two sides of the Bvalve diaphragm. Bleed H supplies fuel to the

.TO BLOWERTHROAT

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A JET

DE JET

F BLEED

B VALVE

C JET

PORT 2

PORT I

PORT 3

-PORT 5

PORT 4

BLEEDE

MIXTUR CONTROL

AD.362Figure 4-11.Diagram of the 58CP311 CECO carburetor.

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89


fuel balance diaphragm chamber, while bleed Ggoverns the flow of fuel from the fuel balancediaphragm chamber. Bleed K prevents impactpressure surge to the low-suction side of the airdiaphragm.

The solenoid primer valve is connectedexternally to the fuel balance chamber by aboost line and a fuel boost check valve. Whenthe solenoid primer valve is actuated, it willprovide fuel for positive filling of the fuelbalance diaphragm chamber. Fuel flow to thesolenoid primer valve is limited by jet L andfrom the solenoid primer valve to the fuel boostcheck valve by bleed S.

Valves M and N and jets D and DE are housedin the metering jets cover assembly, which islocated on the mixture control assembly. ValvesM and N are actuated by the diaphragm of thederichment valve assembly; valve M is normallyclosed and valve N is normally open. When waterinjection is applied, valve N is closed to preventflow of fuel through the B valve and the C jet tothe discharge port; and permits a predeterminedrestricted flow from the DE jet through the Djet by opening valve M.

2. Air Metering Unit. The air metering unitconsists of the main and boost venturi and theautomatic mixture control. The main venturi isdivided by a streamlined bar extending acrossthe inside of the main body. The boost venturi islocated in the air metering housing. Theautomatic mixture control is also located in theair metering housing. It is a bellows-controlled,contoured needle valve. The bellows willrespond to changes in the air density and as aresult will cause the needle valve to move up ordown and act as a variable bleed to control thevolume of air flowing through the boost venturi.

3. Main Body Unit. The main body unit is ahollow magnesium casting which houses the airmetering unit. The fuel metering unit is attachedto the rear of the body and has end platesattached to its left and right sides. The fueldischarge port is located at the bottom of thebody at the center of the rear flange. The mainbody unit houses the driver and driven throttleassemblies, which are supported by bearingslocated at the center and at both ends. The mainbody unit also furnishes the foundation uponwhich the necessary linkages, adjustable stops,etc. are mounted.

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Operating Principles

Airflow to the engine is controlled by thethrottle valves and measured by the venturi.When the air passes through the venturi, itincreases in velocity, thereby creating a partialvacuum or suction at the throat of the venturi.As the velocity is determined by the amount ofair flowing, and the suction is in proportion tothe velocity, the suction may be considered ameasurement of the airflow. A boost venturi isused to amplify the main venturi suction. Airflowing into slots in the top of the main venturiis directed through the boost venturi andaltitude valve and is discharged into the throatof the main venturi. The amount of air passingthrough the boost venturi and producing theamplified suction is in proportion to the n,venturi suction or to the amount of air beingused by the engine.

The measurement of airflow, as indicated byventuri suction, is used to control fuel flowthrough the action of the pressure regulatorassembly. The regulator assembly consists of apressure regulator valve and three diaphragmsarranged in series. The valve is actuated throughthe movement of all three diaphragms.

The air diaphragm, which is the largest of thethree diaphragms, is exposed on one side toairscoop pressure (low suction) and to boostventuri suction (high suction) on The other side.This differential pressure across the diaphragm isknown as the metering suction differential(MSD) and is an indication of the amount of airbeing consumed by the engine. As the throttle isbeing opened, the venturi suction increases, andthe resulting increase in MSD causes the fuelpressure regulator valve to move open and allowmore fuel to enter the metering chamber. As therate of flow into the regulated pressure chamberincreases, the pressure on the fuel diaphragmbuilds up. The valve will continue to move openuntil the fuel pressure against the fuel diaphragmbalances both the MSD across the air diaphragmand the discharge fuel pressure on the fuelbalance diaphragm.

Since the MSD is a relatively small force, thefuel pressure applied on the pressure regulatorvalve fuel diaphragm is partially balanced out bythe fuel at discharge nozzle pressure applied tothe fuel balance diaphragm. Any change in


discharge nozzle pressure which would cause anabnormal variance of the metering head (pres-sure differential across the jets) is hydraulicallytransmitted to this diaphragm and results in amovement of the pressure regulator valve, whichwill compensate for the disturbance. Analysiswill show that the pressure difference betweenthese opposed fuel forces is equal to themetering head; thus, the MSD is required only tobalance a force equal to the metering head. Theratio of fuel forces to air forces always remainsconstant: therefore, any change in airflow willresult in a proportionate change in the meteringhead.

The power output of the engine is determinedby the weight of air consumed, but the weightof a given volume of air decreases as altitudeand/or temperature increases. To maintainengine power under these conditions, it isnecessary to maintain the weight of airflow byincreasing its volume. However, an increase inairflow volume will cause an increase in venturisuction which, if communicated to the pressureregulator assembly, would open the pressureregulator valve and cause an undesired enrich-ment of the mixture. The automatic mixturecontrol is designed to correct this condition andinsure satisfactory metering under all conditionsof altitude and temperature.

The automatic mixture control consists of acontoured valve, the position of which is con-trolled by a nitrogen-filled bellows containingsome oil to dampen its motion. The altitudevalve is placed in series with the boost venturiand acts as a throttle to control the amount ofair passing through the boost venturi. Loss of airdensity caused iv, either increased altitude orincreased temperature wijI cause the bellows toexpand and move the attitude valve farther intoits seat thereby restricting the airflow throughthe boost venturi. The contour of the altitudevalve is such that it enables the automaticmixture control to hold the MSD to a predeter-mined value for a given fixed mass airflowregardless of changes in air density.

The 58-CPB11 carburetor uses six jets and apower enrichment valve to create a constantmixture strength for all conditions of operation.See table 41 for listing of jets, bleeds, and theirpurpose. Control of the B valve is effected byvariation of the metering head imposed across

86

the diaphragm. In CRUISE RANGERICH orNORMAL (fig. 4-12 (B), shown in CRUISERANGENORMAL), the control spring plusdischarge fuel pressure overbalances the reducedregulated fuel pressure from the E bleed (port 4in RICH), thus closing the B valve. IN POWERRANGERICH or NORMAL (fig. 4-12 (A),shown in . POWER RANGERICH), theregulated fuel pressure from port 4 (reducedregulated fuel pressure from E bleed inNORMAL), overbalances the spring plus dis-charge pressure, thus opening the B valve.

During periods of low airflow, such as idling,the desired mixture varies from that which canbe obtained from the jet system. The throttle-operated idle valve acts as the metering orificeduring this period. As the throttles are movedinto the idle range, the idle valve is movedprogressively further into the fuel dischargepassage and becomes the metering orifice. Theposition of the valve may be varied in relation tothat of the throttle to obtain desired mixturesby means of an adjusting device in the idleadjustment body. The pressure regulator valveposition at this time is determined mainly by asystem of springs. The desired valve position isobtained by adjusting the force of the opposingsprings by means of an adjusting screw.

The flow of the fuel to the different jets iscontrolled by the manual mixture controlwhich,, in turn, controls a disk type selectorvalve in the mixture control housing. When thisdisk type valve is set in the CUTOFF position,all fuel is shut off. During MANCAL LEAN andin NORMAL position, the nianual mixturecontrol directs fuel to jets A, Y2, E bleed, and Bvalve. In the RICH position, fuel is directed tojets A, Y2, C, port 4, and B valve. The manuallean position may be varied to any desired pointbetween CUTOFF and NORMAL for greatereconomy of fuel consumption in the CRUISERANGE.

The derichment system consists of a spring-loaded diaphragm valve with dual seats. Thevalve N, allowing the fuel flow from B valve andjet C, is normally held open; and the valve M,allowing flow from jet DE, is normally heldclosed by the spring and discharge pressureacting on the diaphragm. As the water injectionsystem is actuated, water pressure applied to thediaphragm causes valve N to close the passage


Table 4-1.Application of jets, bleeds, and B valve

Part Application

A jet

Y2 jet

C jet

D jet

DE jet

B valve

L jet

E bleed

F bleed

C:. bleed

H bleed

K bleed

S bleed

Meters fuel for minimum combustion requirements.

In parallel with jet A, supplements jet A fuel flow duringNORMAL and RICH operation. When the mixture control valveis moved from the NORMAL position toward CUTOFF position,the valve disk tends to restrict the flow of fuel through port 2to the Y2 jet.

C or rich jet supplements NORMAL flow through entire rangewhen mixture control is in RICH and operates in parallelwith jets,A and Y2 and in series with jet D.

In series with the B valve and jets C and DE and parallel withjets A and Y2, limits the amount of fuel that can be added formaximum power operation.

Operates when the derichment valve is actuated by water in-jection to maintain the desired fuel flow to jet D when the Bvalve and jet C are closed off. When valve N closes to blockfuel flow through the B valve and jet C to the discharge port,valve M opens to permit flow from the DE jet.

Diaphragm-actuated B valve (power enrichment valve), in parallelwith jets A and Y2 in NORMAL, with A, Y2 and C in RICH, op-erates from the metering head to enrich the mixture in POWERand TAKEOFF range.

Limits fuerflow to the solenoid primer valve.

Drillk passage located in the mixture cbntrol valve' seat governsthe flInv of fuel to the top side of B valve diaphragm duringnorma\ operation.

Regulates pressure at the B valve diaphragm.

Limits flow in line to discharge from the fuel balance diaphragmchamber.

Supplies a source of fuel to fuel balance diaphragm chamber toremove trapped air and help fill the chamber when empty.

Limits the sudden surging of impact pressure from the mainventuri to the low suction side of the air diaphragm.

Limits the fuel flow from the solenoid primer valve to the fuelbalance diaphragm.

i

87

9;


IA VALVE

N VALVE

WATER

INLET Nif

TAKEOFF (WET)

ACCELERATOR PISTONIDLE VALVE

Y2 JET

0 JET

A JET

11111151

DE JET

F BLEED

B VALVE

C JET

PORT 2

PORT I

PORT .3

PORT 5

PORT 4

BLEED E

REGULATED PRESSURE MIXTURE CONTROL

DISCHARGE PRESSURE

REDUCED REGULATED PRESSURE

WATER PRESSURE

ACCELERATOR PISTONIDLE VALVE

\-DISCHARGE VENT LINE

M VALVE

N VALVE

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C JET

MIXTURE CONTROL

NORMAL

PORT 2

PORT 1

PORT 3

PORT 5

PORT 4

BLEED E

DISCHARGE VENT LINE

AD.363Figure 412.Power enrichment valve, B valve, schematic diagram.

88

993


from the jet C and the B valve and to open thepassage from jet DE, thus deriching the mixtureto the desired strength.

During rapid acceleration, the reaction of thefuel metering system is slower than the increaseof airflow to the engine. If this lag is notcorrected, a momentary lean mixture wouldresult. To enrich the mixture, the back of theidle valve is used as a piston, and under suddenthrottle opening, forces a fuel charge into thedischarge pressure balance chamber. As theoutlets of the discharge pressure balance line arerestricted at bleeds G and H, the fuel chargefrom the idle piston momentarily raises thepressure in the discharge pressure fuel balancediaphragm, which in turn opens the fuelregulator valve, providing the additional fuelnecessary during acceleration.

For instructions concerning adjusting of the58-CPB 11 model carburetor idle mixture, idlerpm, and troubleshooting procedures, refer tothe applicable Maintenance Instructions Manual,Flight Manual, and/or local maintenance instruc-tions.

DIRECT FUEL INJECTION

The model PR-58S2 injection carburetor(master control) is a downdraft unit employing aproven method of metering fuel through fixedjets, proportional to mass airflow. (See fig.4-1-3.) This mass airflow is controlled, measured,and converted into a working force to supplyfuel. Therefore, any increase in mass airflowprovides an automatic increase in fuel.

By sensing changes in air pressure andtemperature, automatic adjustment of themetering force provides fuel metering during allconditions of engine operation. Using directinjection pumps to supply metered fuel to theengine, ice formation caused by fuel evaporationwithin the maser control is eliminated andpositive fuel metering during all maneuvers andaerobatics is assured. The master controlprovides a manual means for selecting the fuelrequirements of the engine for all operatingconditions, regardless of engine speed, propellerload, or throttle position.

Understanding of the construction, inspec-tion, and overhaul of the master control is madeeasier since it is subdivided into the following

89

basic assemblies, each of which has an individualfunction:

1. Throttle body assembly.2. Pressure regulator assembly.3. Fuel control assembly.4. Automatic mixture control assembly.5. Electric primer valve assembly and alter-

nate fuel source solenoid.

Operating Principles

The throttle body assembly controls airflowto the engines by use of throttle valves. Measure-ment of mass airflow is accomplished by sensingpressure differential. Design features create thedifferential, while impact tubes and boostventuri tubes sense the pressures. Thesepressures are applied to either side of the airdiaphragm in the regulator assembly to provideair metering force (metering suction). Thismetering suction is the means of measuring massairflow to the engine. (Corrections for changesin air pressure and temperature are accomplishedby the automatic mixture control assembly.)

The pressure regulator assembly is operatedby air and fuel pressure differentials. Regulatedimpact air pressure and boost venturi suctionestablish an air pressur?, differential (meteringsuction). Unmetered and metered fuel create afuel pressure differential (metering head). An airdiaphragm, fuel diaphragm, and suitable sealingdiaphragms, mechanically connected by a singlestem to the poppet valve, provide a means forbalancing the differential pressures. Thus thepressure regulator assembly automaticallysupplies fuel to the fuel control assembly inproportion to the mass airflow through thethrottle body assembly. To prevent vapor fromaffecting positive metering, two vapor separatorsare provided, one each in the top of chambers Dand E. Foreign particles that may cause mastercontrol malfunction are removed from inlet fuelby the regulator fuel strainer.

The fuel control assembly contains meteringjets, power enrichment valve, idle meteringvalve, and the manual mixture control. The fuelcontrol attaches directly to the regulator as-sembly, fram which it receives unmetered fuel.The idle metering valve is mechanically con-nected to the throttle shaft and controls fuelmetering throughout the lower range of engine

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operation. The diaphragm-operated powerenrichment valve provides fuel enrichmentproportional to mass airflow through the throt-tled body assembly. A manual means for select-ing the proper amount of fuel for various engineoperations is provided by the manual mixturecontrol.

The purpose of the automatic mixture controlassembly is to correct fuel flow in response tochanges in air pressure and temperature. Usingtwo sealed metallic bellows, the automatic con-trol, assembly is able to sense air density changescaused by changes in altitude or temperature.Movement of either bellows repositions acontoured needle in its orifice to alter impact airpressure applied to the regulator assembly.

The PR-58S2 master control uses two elec*ricprimer valve assemblies. One primer valve as-sembly introduces fuel at engine pump pressureinto the airstream. The second primer valveassembly (alternate fuel source solenoid)provides an alternate fuel source in the event ofmaster control malfunction. The coils permitcontinuous operation of either unit withoutexcessive temperature rise. Satisfactory positivegrounding of the primers can be accomplishedonly when shielded cables, or grounding straps,are used for direct connection to the aircraftframe.

Injection Pumps

Metered fuel from the master control isdirected through a fuel flow divider to the twoinjection pumps. Each of the pumps receives anequal- amount of the fuel from the mastercontrol. An adapter which is timed to the engineprovides for the mounting of each pump. Thesplined drive shaft of the pump has a masterspline, so that the pump can be mounted on theadapter in only one position. The pump adaptersare timed to the engine crankshaft, so that thecylinder receives the fuel charge at the correctmoment in relation to piston position and theignition event.

A simple schematic diagram of the direct fuelinjection system is shown in.figure 4-14. In thesectional view of the injection pump, note boththe wobble plate on the orive shaft and thespring on each hollow plunger that hold the

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86

plungers against the wobble plate. As the driveshaft is rotated, the plungers move in andoutforced to the right by the wobble plate andreturned by the action of the springs. This is thepumping action which forces the fuel receivedfrom the master control into the lines leading tothe discharge nozzle mounted in each cylinderof the engine. Each plunger furnishes fuel forone cylinder (nine plungers, nine cylinders toeach pump).

Each plunger works inside of a fixed plungerbushing. The bushing has a passage through theside which acts as a relief port to end theeffective pumping stroke. The end of the ef-fective pumping stroke occurs at the sameposition all the time, and the length of plungertravel is the same at all times. It is the beginningof the erective pumping stroke that varies at thedifferent power settings.

Around the outside of each plunger there is abypass sleeve which determines where the ef-fective pumping stroke begins. The bypass sleeveis attached to a bypass control plate. Theeffective pumping stroke starts when a lowerport in the plunger is covered by the bypasssleeve. When the control plate is moved to theleft (fig. 4-14), the effective pumping stroke islengthened, sending more fuel to the cylinders.When the control plate is moved to the right(fig. 4-14), the effective pumping stroke isshortened, sending less fuel to the cylinders.

On the return stroke of the plunger, fuel istrapped in the line to the discharge nozzle by acheck valve. There is an individual check valvefor each plunger.

The bypass plate is positioned automaticallyby metered fuel pressure and boost venturisuction. (Se ^ fig. 4-14.) The metered fuelpressure an. boost venturi suction, which varyat different power settings, are applied to thepump control diaphragm, which works againstthe tension of the bypass control spring. (Seefig. 4-14.) The metered fuel pressure and boostventuri suction are strongest at the higher powersettings. This moves the bypass control plate tothe left, lengthening the effective pumpingstroke and increasing the fuel flow to thedischarge nozzles in the cylinders. At the lowerpower settings, the bypass control spring,opposed by a weaker metered fuel ssure andventuri suction, moves the contrcnlate to the

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.BYPASSCONTROL SPRING VAPOR

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UNMETEREDFUEL PRESSURE

4 IMPACPRESSUT RE

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PUMPPRESSURE

BYPASSCONTROLPLATE

LOWER PORT

PUMP CONTROLDIAPHRAGM

PLUNGER BUSHING

Figure 414.Schematic diagram of the direct fuel injection system.

right. This shortens the effective pumpingstroke, sending less fuel to the cylinders.

When the mixture control of the mastercontrol is placed in the IDLE CUTOFF positionthe fuel flow to the injection pumps is stopped.This reduces the fuel pressure on the pumpcontrol diaphragm and allows the bypass controlspring to move the control plate fully to theright. (See fig. 4-14.) In this position the spillport remains uncovered and the dischargenozzles in the cylidders will remain closed dueto insufficient fuel pressure. A similar action willtake place if a fuel tank is run dry during flight.The control plate will move to the IDLECUTOFF position and stop the flow of fuel tothe engine. Fuel will remain in the pump bodyto provide the necessary lubrication of theplunger mechanism as the pumps are rotated bythe windmilling of the engine. The wobble plate

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AD.365

mechanism is lubricated by engine oil and theplungers are lubricated by the fuel.

Vapor elimination is provided in each pumpby vapor separators which are similar to those inthe master control. They vent and return vaporsto the master control, which in turn returnvapors to the service tanks of the aircraft.

Fuel is delivered from the injection pumps toeach individual discharge nozzle via the fuelinjection lines. Each individual plunger builds upsufficient pressure to overcome the force of thecheck valve spring, causing the check valve toopen, allowing the fuel to enter the injectionlines. Further movement of the plunger buildsup the pressure sufficiently then to open thedischarge nozzle located in the cylinder headand spray the fuel into the cylinder at theproper time in relation to ignition timing andposition of the piston in the cylinder. When the


spray pattern is poor, co.nbustion in thatcylinder will result in engine instability andpossible power loss.

STROMBERG INJECTION CARBURETORS

The PR-58T1 Stromberg injection carburetoris identical to the PR-58S2 master control, andthe principles of operation are the same exceptfor the following:

A constant effort spring, located in chamberA, tends to open the poppet valve with aconstant force and provides a smooth transferfrom idle' to low power cruise operation. Thisspring is in operation through the entire fix'flow range and increases the metering head afixed amount.

All fuel delivered by the power enrichmentvalve and automatic rich metering jet must passthrough the power enrichment jet in parallelwith the derichment jet. After the power enrich-ment valve opens to a predetermined point, thecombined jet area of the power enrichment valveand the automatic rich jet becomes greater thanthe jet area of the power enrichment andderichment jets; at this point the power enrich-ment and derichment jets take over the meter-ing.

The derichment valve is operated by adiaphragm exposed to water pressure on oneside and metered fuel pressure on the other.When the water pressure is applied, the derich-ment valve closes, stopping the fuel supplythrough the derichment jet.

The acceleration pump, mounted on thethrottle body assembly, is used to compensatefor the inherent lag in fuel flow during rapid orsudden acceleration. The throttle-actuated ac-celeration pump, which unbalances the poppetvalve momentarily, consists mainly of a throttle-actuated piston operating in a cylinder. An inletcheck valve allows fuel to enter the pumpcylinder when the piston is retarded. The pistontravels into the cylinder as the throttle isopened, forcing the pump fuel through achannel to the balance chamber in the regulatorassembly. This increase in the balance chamberpressure opens the poppet valve momentarily,increasing the fuel flow to the discharge nozzle.The duration of the increased discharge iscontrolled by the two bleeds located in the

93

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channels leading to and from the balancechamber at the front of the pressure regulatorassembly.

The metered fuel from the fuel controlassembly flows through a fuel transfer tube tothe throttle body assembly. From the throttlebody assembly the fuel flows to the enginenozzle, which has an opening pressure of ap-proximately 14 pounds.

A thermal expansion vent is provided to Cchamber for the purpose of bleeding off staticmetered fuel pressure when the mixture controllever is placed in IDLE CUT-OFF. Thiseliminated the possibility of fuel leakage pastthe nozzle due to thermal expansion of meteredfuel after the engine is shut down.

WATER INJECTION SYSTEM

The R3350-32W engine is equipped with acomplete wafer injection system through whichantidetonant fluid (usually called water) may beintroduced into the engine induction systemalong with the fuel mixture. With the engineoperating at high power and high manifoldpressure, such as during takeoff or duringcombat emergency, water added to the fuelserves to prevent detonation.

The fluid used in the water injection systemshould be a mixture of 50!50 percent AMS30064 water injection fluid, type I, above -49°F; 60/40 percent AMS 3006A water injectionfluid, type IV, below -49° F. Distilled watershould be used, but tap or drinking water isgenerally suitable for use in the system. Saltwater or dirty water must not be used under anycircumstances, and water with high mineralconcentratior should not be used regularly.

NOTE: Water injection fluid is a deadlypoison for which there is no antidote. Thevapors of the fluid, if inhaled in sufficientquantity, will have the same effect as if the fluidwas taken internally.

COMPONENTS

The water injection system used on theR3350-32W engine consists of two water injec-tion discharge valves, a water power controlunit, and water injection pressure tubes. Thewater injection system provides, automatically,


combat power in both low and high super-charger ratio for "wet" operation..

OPERATING PRINCIPLES

The water injection system is energized by anelectric pump which supplies fluid underpressure up to the control unit. Moving thethrottle beyond 40 inches MAP compresses themetering valve bellows in the power control unitand opens the valve, allowing the injection fluidto flow into the injection valves to be dischargedjust below the carburetor.

During its operation, the fluid cools theburning in the cylinders, allowing a higher MAPand a leaner fuel mixture without detonation orhigher cylinder head temperatures.

If the entitle is operated until the injectionfluid is exhausted, the loss of fluid pressures atthe derichment valve will allow the carburetor toenrich the fuel-air mixture automatically.Manifold pressure is manually adjusted.

IGNITION

HIGH-TENSION IGNITION

The high-tension ignition system consists of amagneto. distributors, the ignition harness, andthe individual spark plug leads. The distributor

i."MAGNETO

SWITCH

CAPACITOR

PRIMARY

may or may not be integral with the magneto. Inthe high-tension system, the coils, breakerpoints, and capacitors are located in themagneto housing. Figure 4-15 shows a simpleschematic of a high-tension ignition system.

The magnetic circuit consists of a rotatingpermanent magnet, pole shoes, pole shoeextensions, and coil core. The pole shoes,extensions, and coil core are made of laminatedsoft iron. The poles of the magnet are arrangedso that the direction of flux through the softiron core revers1s as the rotating magnet isturned. On this type of magneto, the number offlux reversals during one completed revolutionof the rotating magnet is equal to the number ofpoles on the rotating magnet.

The primary coil is wound around the softiron core, one end of the coil being grounded,the other being connected to ground throughthe breaker points. The changing magnetic fieldin the coil core induces a current flow in theprimary circuit when the breaker points areclosed.

When the primary circuit is opened by thebreaker points, current flow stops in the primarycoil and the magnetic field surrounding itcollapses. This action allows the flux of thepermanent magnet to reverse very rapidly,producing a very high voltage in the secondarycoil. The amount of voltage generated isdependent upon the strength of the magnet, the

SECONDARY

COILCORE

PERMANENT MAGNET

SPARKPLUG -s-.

DISTRIBUTOR

Figure 415.Simple schematic of a high-tension ignition system.

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number of turns in the secondary coil, the speedof the flux reversal, and the resistance of thesecondary ignition circuit.

The breaker points are spring loaded to closeand are opened by the lobes on the cam when itis rotated. Because of the reversal of flux in theprimary coil, the direction of current flow acrossthe breaker points changes, thus minimizing thetransfer of metal from one breaker point to theother.

A capacitor connected in parallel with thebreaker points absorbs the current flow at thetime of breaker point opening. In this way thecapacitor aids in the interruption of primarycurrent flow, which results in a higher voltageoutput from the magneto. In addition, arcingacross the breaker points is held to a minimumwhen they are just opening.

The magneto ground wire is connected to theprimary circuit. When the ground wire isgrounded by the ignition switch, opening of thebreaker points does not interrupt the primarycircuit: hence, no high voltage is generated in thesecondary. The potential voltage available oncurrently used magnetos is approximately15,000 to 20,000 volts.

The distributor is the point where the highvoltage generated by the magneto is distributedthrough the ignition harness and leads to thespark plugs at the proper time. and in the firingsequence of the engine. It consists of a rotorwhich rotates at one-half crankshaft speed andwhich is connected to the high-tension wirefrom the secondary coil of the magneto, andelectrodes located radially around the distribu-tor finger and spaced the proper number ofdegrees apart, as required for the engine and thenumber of cylinders involved, and in the firingorder of the engine.

The ignition harness consists of a manifoldwhich contains the wires leading from theindividual electrodes in the distributors to thespark plugs. This manifold shields the wires andgrounds out the electrical disturbances whichwould be picked up by the radio equipment inthe aircraft. For this reason the metal portion ofthe ignition harness must be kept in goodcondition, with no breaks or openings in theharness from the shielded distributor to thepoint where the electrical spark is transmitted tothe insulated core in the spark plug.

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LOW-TENSION IGNITION SYSTEM

Electrically, the difference between the low-tension ignition system and the high-tensionignition system is quite pronounced. Comparethe schematic of the high-tension system (fig.415) with the schematic of the low-tensionignition system in figure 4-16. The high-tensionsystem generates high voltage at the magnetoand then transmits this high voltage through thedistributors to the spark plugs. The low-tensionsystem, however, generates only low-voltagecurrent at the magneto. In the low-tensionsystem the electrical energy is maintained at alow voltage until it is transformed to a highvoltage by the use of transformer coils locatedon each cylinder. By transformer action, themagneto generator primary voltage is greatlyincreased by the secondary coil of the trans-former, and builds to a voltage value sufficientto create a current flow at the spark plug gap.

The low-tension system has many advantagesover the high-tension system. In principle, thissystem isolates the secondary winding of theconventional high-t 'nsion coil from the magnetoand locates it as closely as possible to the sparkplug. Thus, the magneto generates a relativelylow voltage, thereby reducing the electricalstresses in the wiring and reducing the possibilityof flashover at high altitude.

The short high-tension leads also decrease thecapacitance in the system, thereby lowering thevoltage losses which result in lower peak energyto fire the spark plug. This also greatly reducesthe spark plug erosion rate, an item which hasbecome increasingly important because ofcompression chamber pressures and temperatureincrease. The confinement of the high voltage toa relatively short lead has sharply decreased themaintenance problems that insulation gives athigh altitudes.

Since a separate transformer is used with eachspark plug, a carbon brush type distributor canbe, and is, used to distribute the primary outputvoltage of the magneto generator. Thiseliminates the flashover characteristics of thehigh-tension distributor. A complete typicallow-tension ignition system is illustrated infigure 4-17.

The distributor rotor and breaker cam mustboth be driven at one-half engine speed, making


INDUCTION COIL

MAGNETO

SWITCHCOILCORE

CAPACITORL

POINTS DISTRIBUTOR

LEFT OiSTRIBuTOR

Salt, SEGMENT ISNEKT TO FIREWILL FIRE NO 2Cm REAR PLUG

CAR I

Figure 4-16.Simple schematic of the low-tension ignition system.

REAR

CTL N09REAR ROW

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REAR

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FRONT

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RADIO SHIELEHNG MANIFOLD

AD.367

FIFTH SEGMENT NOWCARRYING CURRENTTO NO 9 CALINDERFRONT PLUG

CAP 2

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ADVANCE

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Figure 4-17.Low-tension ignition system.

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NOTE DISTRIBUTOR INNER RING CONNECTSTO OUTER SEGMENTS OUTER RING CONNECTSTO INN R SEGMENTS

COIL WIRE OISTRIB PLUG CYLINDER

R, A RIGHT FRONT REAR

RK B RIGHT FRONT FRONTLI C LEFT REAR REARLi 0 LEFT REAR FRONT

AD.368

Chapter 4 RECIPROCATING ENGINE SYSTEMS

it advantageous to put the breaker cam on thedistributor shaft. The distributor unit containsthe breaker points, capacitors, distributor rotors,and carbon brushes. Low-tension leads carry thecurrent from the distributor to the transformerprimary coil. Basically, the coil is a transformercontaining two primary and two secondarywindings; each unit supplies the high voltagerequired for the two spark plugs of the cylinderupon which the coil is mounted.

The low-tension system contains at least twoof every component except for the magnetogenerator drive shaft. This provides for twocompletely identical systemsRIGHT andLEFT. The RIGHT system, or right magneto,includes magneto coils RI and R2, rightdistributor, one primary and one secondary coilin each transformer unit, and the front sparkplug in each cylinder. The left magneto systemduplicates the right magneto system andincludes coils LI and L2 and all of the rear sparkplugs, plus one primary and one secondary coilin each transformer unit. The function of the

magneto coils can be further isolated, in that LIand RI coils fire the spark plugs in all of theodd-numbered cylinders and L2 and R2 coilsfire all the spark plugs in all of theeven-numbered cylinders.

Spark Advance

The type of spark advance in common usagetoday is the manually controlled system, whichrequires selection of the desired spark setting bya switch in the cockpit. Figure 4-18 shows aschematic of the manual spark advance systemon the R3350-34 series engine. 1 he ignitiontiming is advanced by electrically energizing arelay located in the distributor which deactivatesthe retard points and allows the advance pointsto interrupt the circuit.

A brief description of the theory of sparkadvance and the factors that determine ignitiontiming is as follows. if the fuel/air remainsconstant, the length of time required for theflame to progress across the cylinder remains

ADVANCE TIMINGRELAY ENERGIZED

RELAY POINTS ARE UNGROUNDED. SPARK OCCURS WHEN ADVANCE BREAKER POINTS

OPEN AT 30° B.T.G.DISTRIBUTOR

ADVANCEBREAKER

MAGNETO RETARDBREAKER

....---

STARTER

'IF-11111111

24-VOLT BATTERY

I

_

CONTACTPOINTS

UNGROUNDED

Figure 4-18.Manual spark advance system.

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,RETRSPRING

STRETCHED

-RELAY COILENERGIZED

SPARK ADVANCE-4-- CONTROL SWITCH

CLOSED

AD.369


constant. Therefore, the time at which ignitionoccurs determines the point where the pressurepattern will peak as measured in degrees ofcrankshaft angle. This, of course, assumes therpm remains constant. If the rpm is increased,the flame speed will stay fairly constant and thepressure pattern will peak later hi reference tothe crankshaft angle. To maintain the optimumpressure pattern, it would be necessary to varythe ignition time with each rpm and fuel/aircombination. This is, of course, not practicable.On engines with fixed timing, it is the generalpractice to select an ignition timing that gives adesirable pressure pattern for takeoff with some-thing close to the optimum pattern for cruise.This will insure low basic specific fuel con-sumption for the greater percentage of operatingtime.

If the maximum economy is to be realized onengines that use extremely lean fuel/air ratiosfor cruise, it is necessary to advance the sparkfor this regime of operation. The speed of flamepropagation is a function of mixture strength,with the flame speed reaching its maximum rateat a BEST POWER fuel/air ratio. The leanfuel/air flame speed is compensated byadvancing the spark. Thus, the engine does notrespond to a change in ignition timing within theBEST POWER fuel/air ratio range; but versuslean fuel/air ratios the power dropoff is at afaster rate with the relatively retarded spark.When troubleshooting an engine, this effect offuel/air ratio on engine timing in the lean rangeis a point to remember.

The effects on engine operating temperaturesof using an advanced spark are as follows:

1. Increased cylinder head temperatures forthe following two primary reasons: First, thereis a higher resultant peak temperature in thecylinder when the mixture is ignited earlier; andsecond, the burning combustion gases are incontact with the combustion chamber for alonger period of time. A 10° spark advance willincrease cylinder head temperatures approxi-mately 17° C.

2. A decrease in exhaust gas temperaturzresults primarily from the combustiontemperature reaching its peak earlier in thepower stroke. Earlier peak temperatures result ina more efficient heat balance; that is, a greaterportion of the total available energy is utilized in

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moving the pistons. Therefore, if the engineconverts a greater portion of its heat into work,there will be a corresponding decrease in theamount of energy or heat lost through theexhaust gases. Each degree of spark advance willlower the exhaust gas temperature by approxi-mately 5 1/2° C.

EXHAUST SYSTEM

The exhaust system of the R3350-32W andthe -34 is composed of a system of pipes whichcollect the exhaust gases from the individualcylinders and deliver them to the three powerrecovery turbines. From the turbines the gasesare then discharged to the atmosphere. Theexhaust system arrangement can be seen infigure 4-9. The components of the exhaust mustbe inspected for serviceability at regular intervalsto check for the following:

1. Cracks or holes are not permitted in thepipes, sleeves, and joints.

2. Broken welds are not permitted.3. The total fore and aft movement of the

ball joint ring cannot exceed 0.060 inch.4. Free movement of the ball joint ring is

required.5. Evidence of overheating, leaping, or

chafing which would require further inspectionto determine the cause.

6. Wear of the welded-on antichafe rings orbolted-on antichafe clamps should not exceedone-half of the original thickness.

Figure 4-19 shows the exhaust pipes,antichafe clamps, and the inlet pipe ball joints ofthe power recovery turbine.

LUBRICATION

INTERNAL OIL SYSTEM .

The lubrication system of the R3350-32Wand -34 engines is a pressure, dry sump type. Allmoving parts are lubricated by oil under

_pressure, except the piston rings, piston pins,cylinder walls, intake and exhaust- valves,crankshaft main bearings, and propeller shaftthrust and radial bearings, all of which are eitherlubricated by a splash or jet. For a diagram of


INLET PIPE BALL JOINTS

16-

ANTICHAFECLAMPS

Figure 419. -Inlet pipe ball joints.

.

AD.370

the flow of pressure and scavenge oil throughthe engine, refer to the appropriate maintenanceinstructions.

Oil from an external tank enters the pressurepump in the left side of the rear oil pump andsump body. The pump discharges the oilthrough cored passages in the pump and sumpbody into the inside of the pressure strainer andthen through the outside of the strainer into thestrainer cavity. A strainer bypass valve providesthe engine with lubrication if the oil is too cold,or if the strainer should become clogged. Aspring-loaded check valve at the inlet side of thestrainer prevents the flow of oil under gravitypressure from the tank when the engine is notoperating.

The pressure relief valve in the rear pumpregulates oil pressure to 70 plus or minus 5 psiduring all cruise and high power settings. Thequantity of oil flowing through the valve varieswith engine rpm, engine demand, and the oiltemperature. A pressure control valve in thefront pump and sump housing reduces the oilpressure to 35 plus or minus 5 psi, and anotherpressure control valve in the supercharger fronthousing reduces the pressure through it to 50plus or minus 5 psi.

1494V I

Three pumps collect and return the scavengeoil to the oil tank. Two of these pumps arelocated in the front pump housing and one islocated in the right side of the rear pump andsump body. There is also a scavenge oil strainerand a drain plug in the front pump housing.There are three drain plugs plus a scavengestrainer through and over which the scavenge oilmust pass before it enters the scavenge outletchamber.

EXTERNAL OIL SYSTEM

Each engine installed on an aircraft has itsown complete oil system. The P-2H aircraft willbe used here for discussion purposef, Theexternal oil systems of this aircraft contain thefollowing components: A self-sealing tank andhopper assembly, an oil foam tank, oil coolerdoors and thermostatic control system, manualshutoff valves, a temperature-controlled divertervalve, a capacitance oil quantity system, an oildilution system, and all the necessary plumbing.

In operation, each engine oil system auto-matically maintains normal oil temperatures.Engine oil is supplied through a standpipe in thetank sump; propeller feathering oil is suppliedfrom a point below the engine oil standpipelevel. Oil flowing from the tank makes acomplete cycle through the engine and returnsto the tank. (See fig. 4-20.) The cycle ofoperation is as follows: The oil flows by gravityfeed from the tank to the engine rear oil pump.From there it is routed through the engine andreturned by the oil scavenge pumps to the oiltemperature regulator valve. The regulator valveis attached to the oil cooler and directs the flowof oil according to its temperature either tobypass the cooler, flow over the cooler, or toflow through the cooling tubes. From theregulator valve the oil then flows through athermostatic control unit which senses thetemperature of the oil and varies the position ofthe oil cooler doors to control the amount ofairflow through the oil cooler. Oil then flowsthrough a manual check valve. The next and lastunit the oil goes through on its return to the oiltank is the oil diverter valve.

The oil diverter valve also has a temperaturesensitive element in one end to sense thetemperature of the oil flowing from hopper to

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. Chapter 4RECIPROCATING ENGINE SYSTEMS

the engine, and this determines whether the oilfrom the engine is returned to the main part ofthe tank or to the hopper within the tank. Thepurpose of the hopper is to circulate a smallportion of the oil in the tank for initial warmupof the engine. As the oil gets hotter, the divertervalve begins to close and then diverts the oil intothe main portion of Cie oil tank.

101

106

The emergency shutoff valve for the oil ismanually operated from the cockpit. It isconnected to a motor-driven actuator whichopens or closes the oil shutoff valve. The oneother unit mounted in the oil supply line to theengine is the Y-drain valve, which is used fordraining the oil on periodic inspections orwhenever needed.

CHAPTER 5

RECIPROCATING ENGINE TROUBLESHOOTING

Troubleshooting reciprocating aircraft enginesmay be defined as the systematic and thoroughanalysis of the symptoms of engine malfunction-ing. Proper troubleshooting determines theproper corrective steps to be taken. Generallyspeaking, when irregular ground or flightoperating characteristics are observed in aircraftengines, the cause can be traced to impropermaintenance and/or operation, or to the mal-functioning of engine components.

Efficient maintenance of any mechanism in-variably depends upon the familiarity whichoperators and maintenance personnel have withthe mechanism. The reciprocating engine offersno exception to this rule.

It is essential that Aviation Machinist's Matesknow the engine thoroughly. They should knowwhat it is designed to do and how it fulfills thatfunction. They should be familiar with normaloperating details of the engine, such as oilpressures, temperatures, and consumption, andfuel pressures and fuel flow. All of these shouldbe known for at least three engine operatingconditions: idle, normal rated, and military. Inaddition to these items, personnel should have athorough understanding of the effect of localconditions on the engine; that is, temperature,humidity, field altitude, and wind effect.

If information of the type contained in thischapter is followed, it will be productive of themost efficient maintenance; that is, preventingtrouble before it arises, by recognizingabnormalities of the equipment and tracingth..4n to their sources and making correctionsbefore damage is done. Frequently, severalseemingly unrelated indications of malfunction-ing will eventually be traced to a single source.

It is often unsafe to assume that the engine iscompletely out of danger when some obviouscorrective measure has been taken. Do not behasty in assuming any conclusions. Do notconfuse the significance of cause and effect. For

102

example, low oil pressure, in itself, is nottrouble. It is only an indication that somemalfunctioning exists, the true cause of which isthe trouble.

The preceding puisit is stressed to emphasizethe importance of tracing an abnormal indica-tion to its sour( rather than being satisfied thatrestoration to normal by some obvious adjust-ment, such as changing the oil pressure reliefvalve setting, is all that is required. Invariably,there is a reason for abnormal indication. Besure you know what the reason is and that youhave taken the proper corrective measuresbefore signing out the engine for further service.Proper corrective measure means the use oftime-proven methods, not makeshift FIXES. Forexample, if an accessory fails to perform accord-ing to its specification and no standard repair oradjustment is established to correct the condi-tion, replace with a new part and turn in theoffending part so that it can be properlycorrected at overhaul or scrapped.

Defects resulting from careless engine opera-tion often may be observed best during dis-assembly when the component is covered withoil or carbon (prior to the cleaning process).During disassembly, visually check all com-ponents for signs of scoring, galling, or burning.Look for mechanical defects, deposits of carbon,and caked or coagulated oil. Trace the cause ofthe defects encountered and take the necessaryremedial measures.

NATOPS Flight Manuals contain diagrams,drawings, and charts for use in troubleshooting.Diagrams of the various electric circuits, fuelsystems, lubrication systems, etc., found inService Instructions Manuals are very useful inistklating troubles. Cutaway drawings illustratingthe internal construction of components, andexploded views showing how the various parts ofa c"mponent are put together will often savevaluable time in troubleshooting.

107...}

Chapter S-RECIPROCATING ENGINE TROUBLESHOOTING

Engine troubleshooting in the field may besimplified through the use of various types ofcnarts. A typical ground propeller load curve isshown in figure 5-1. These curves may beconstructed locally by recording the rpm,manifold absolute pressure, BMEP, and the fuelflow at 100rpm intervals from the CLOSEDTHROTTLE position to the field barometricpressure. The propeller should be in full increaserpm (against the low pitch stops) anti the runupshould be made first in AUTO-RICH and then inAUTOLEAN. The shape of the curve for theengines run in the field will usually follow theexample in figure 5-1. However, the curve mayvary in the MAP/RPM relationship due to thedifferences in field altitude, temperature,

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humidity, wind effect, low pitch stop setting,and the carburetor or master control metering.Therefore, it can be seen that a number of thesepropeller, curves should be made in order thatthe troubleshooter can take these variables intoconsideration.

ENGINE DISCREPANCY REPORTS

The accurate analysis of engine discremciesand malfunctions and determining what cor-rective action is to be taken are importantfunctions of the senior ADR's. A knowledge ofwhat may be wrong when traible comes willprovide the best possible clue to the right course

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103

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of action in each instance. Many situations canbe quickly analyzed and timely measures takenif an engine's malfunction symptoms are under-stood. On the other hand, misinterpretation ofapparent abnormal engine operation and sub-sequent improper corrective action may possiblycause a more serious situation than was presentin the first place.

In the event of abnormal engine operation ofany kind, consult the pilot's Naval AircraftRight Record (yellow sheet), diagrams, charts,and all other available sources for any pertinentinformation which might give a clue in locatingthe trouble and effecting a remedy. Wheneverpossible, the engine instrument readings beforeand after the malfunction should be noted.Proper research of engine discrepancies willresult in more positive malfunction analysis andfaster, better corrective maintenance.

GROUND SAFETY PRECAUTIONS

Troubleshooting a reciprocating enginenormally requires the engine to be installed in anaircraft and operating. This broadens the dangerarea for the maintenance man doing the trouble-shooting. Safe working conditions must bemaintained at all times. Therefore, the ADRmust be familiar with and observe all safetyprecautions. The following paragraphs coversome of the ground safety precautions.

Operational readiness of a maximum numberof aircraft is necessary if naval aviation is tosuccessfully perform its mission. Keeping itsaircraft in top operating condition is theprincipal function of naval aviation maintenancepersonnel, and an essential objective should beto perform maintenance work without injury topersonnel and without damage to equipment oraircraft.

Aircraft maintenance is, to some extent,naturally hazardou's due to the nature of thework, the equipment and tools involved, and thevariety of materials required to perform manyrepairs and maintenance functions. Factorswhich can function to increase or decrease thesehazards are (1) the experience levels and mentalattitudes of assigned personnel and (2) thequa' supervision of the maintenance tasks.Tho.ough indoctrination of all personnel is the

most important single step in maintaining safeworking conditions.

The concept of aircraft maintenance safetyshould extend beyond concern for injury topersonnel and damage to equipment and air-craft. Safe work habits go hand-in-hand withflying safety. Tools left in aircraft, impropertorquing of fasteners, and poor housekeepingaround aircraft can cause conditions which mayclaim the lives of flying personnel as well ascause strike damage to aircraft. Safety on theground is equally as important as safety in theair.

A recent type commander letter states in part,"While the increased complexity of our modernaircraft is a factor, it is noted that a largenumber of maintenance-error-caused accidentsand incidents are due, not to complexity ofequipment, but to lack of supervision andtechnical knowledge. Many mistakes are simpleones in routine maintenance."

Safety in aircraft maintenance depends largelyupon the supervisory personnel. The standardsof quality which they establish are directlyreflected in the quality of the aircraft main-tenance. The primary duty of the senior pettyofficers is to supervise and instruct others ratherthan to become totally engrossed in actualproduction. Attempts to perform both functionsinvariably result in inadequate supervision andgreater chance of error. Supervisors mustexercise mature judgment when assigningpersonnel to maintenance jobs. Considerationmust be given to each man's experience, train-ing, and ability.

Sometimes overlooked in a maintenance pro-gram are the considerations generally groupedunder the term "human factors." These factorsare important in that they determine if anindividual is ready and physically able to dowork safely and with quality. Supervisorypersonnel should be constantly aware of condi-tions such as general health, physical and mentalfatigue, unit and individual morale, training andexperience levels of personnel, and other condi-tions which can contribute in varying degrees tounsafe work. Not only is it important thatproper tools and protective clothing and equip-ment be available, but maintenance supervisorsmust insure that these items are properly usedon all occasions requiring their use.

104

109

Chapter 5 --RECIPROCATING ENGINE TROUBLESHOOTING

It is a continui.1,7, duty of every personconnected with aircraft maintenance to try todiscover and eliminate unsafe work practices.Accidents caused by such practices may not takeplace until a later date and their severity cannotbe predicted. The following general safety itemsshould be observed to prevent on-the-jobaccidents.

PROPELLERS

The senior ADR's must continually remindpersonnel working around propeller-driven air-craft that the first general precaution that mustbe observed is to BEWARE OF PROPELEERS.Parking areas and runup areas must be keptclean at all times. During high-power turnups thevelocity of the propeller slipstream may pick upand blow loose dirt, sizable rocks, sand, debris,and even equipment a distance of severalhundred feet. Therefore, due caution should beused in parking an aircraft for runup to avoidpersonnel injury and property or aircraftdamages.

ENGINE NOISES

Reciprocating engines produce noise capableof causing temporary as well as permanent lossof hearing in certain frequency ranges. Thesenior ADR must continually remind personnelworking around operating engines to observe thefollowing precautions:

1. Wear the proper ear protection (earplugsand/or sound attenuators).

2. Do not exceed the time limits on exposureto the various sound intensities.

3. Have periodic checks on hearing ability.More detailed information on these pre-

cautions may be found in Bureau of Medicineand Surgery Instruction 6260.6 (Series).

Engine noise is broadcast from the aircraft inpatterns which vary in direction, distance, andintensity with engine speed. Generally, the mostintense sound areas are in the shape of two lobesextending out and aft from the engine center-line. However, dangerous intensities are alsopresent to the side and forward of the engine.

Damage to hearing occurs when the ear isexposed to high sound intensities for excessiveperiods. The higher the sound intensities, the

105

shorter is the period of exposure which willproduce damage. Above 140 db sound intensity,any exposure without ear protection can causedamage.

NOTE: Sound intensity is measured indecibels (db). A decibel is a number whichrelates a given sound intensity to the smallestintensity that the average person can hear.

The wearing of regulation earplugs or soundattenuators will raise the limits of timeexposure. All personnel working within dangerareas should be familiar with calculated db levels(as specified in the -applicable Maintenancehistructions Manual) and should. wear the neces-sary protective equipment.

Another effect of engine noises that is veryimportant to the supervisor is that they causefatigue. Personnel exposed to high levels of noisefor extended periods of time become overlyfatigued and cease to think properly. This cancause mistakes that may result in serious ac-cidents or at best increase the time required formaintenance. Every effort should be made toprevent overlong exposure to high noise levels.

At the present there are very few noiseabatement devices for reciprocating aircraftengines. Engines equipped with Power RecoveryTurbines and those with collector ring exhaustsystems are substantially quieter than engineswith straight stack exhaust systems. Blastdeflectors are of some help to maintenancepersonnel in that they deflect the engine noisesupward.

AIRCRAFT SURFACES

The radically designed naval aircraft is veryapt to have painted, waxed, and buffed surfaces.As a result, slippery conditions are likely toexist, especially when wet. This possibilityshould always be taken into consideration toavoid slips or falls. Cockpit and maintenanceladders or platforms are furnished to facilitatesafe servicing.

Movable surfaces such as flight control sur-faces, speed brakes, power-operated canopies,and landing gear doors constitute a major hazardto troubleshooting personnel. These units arenormally operated during ground operations andmaintenance. Therefore, care should be taken to

110


insure that all personnel and equipment are clearof the area before operating any movable sur-faces.

FUELS

When working on or around an engine,troubleshooting personnel must guard againstbreathing hydrocarbon (fuel) vapors as they maycause sickness or may even be fatal. Fumes mustrpt be allowed to accumulate; therefore, alwaysuse adequate ventilating measures. Also, avoidgetting fuel on clothes, skin, or in the eyes,because of the high lead content.

After an engine has operated with leaded fuel,it may have yellow residue on parts exposed tothe exhaust gases. These deposits may cause leadpoisoning if inhaled or swallowed. Parts coveredwith the yellow residue should be handled withcaution. Be sure to clean parts showing yellowresidue before reworking them; however, protectopen cuts, eyes, nose, and mouth against entryof any of the material from these deposits whenperforming cleaning operations.

LUBRICATING OILS

Lubricating oils may have an irritating effecton the skin, and the same safety precautions asused with fuel should be followed. In the eventthe clothing becomes saturated with either fuelor oil, the clothing should be removed im-mediately. However, fuel saturated clothingshould be removed in a shower due to thedanger of static electricity igniting the fuelvapors.

CLEANLINESS

Efficient operation of a reciprocating engineis largely dependent upon the cleanliness of thevarious engine components. These componentsmust be kept clean and free from foreign matter.The area in which any adjustment, replacement,or repair is to be done should be kept as clean aspossible. All tools and equipment should be freeof rust, grease, metal shavings, and other foreignmatter.

During assembly, do not remove the wrappingfrom any part until it is ready to be installed. Donot remove the masking tape, seals, or plastic

106

11.1.

plugs from any orifice, passage, or port untilnecessary.

CARBURETION

Some symptoms which are seemingly causedby faulty carburetion are sometimes caused byother malfunctions. Symptoms such as improperidle, poor acceleration, roughness, and lack ofpower, often do not originate in the fuel system.They may be caused by faulty ignition, induc-tion, valve operation, or propeller operation.When it has been 'determined that the fuelsystem is at fault, it is possible to isolate certainparts of the fuel system that may be the troublesource. On the injection carburetor this is doneby checking the fuel system for pressure loss asfollows:

I. Place the fuel selector in the ON position.2. Turn the fuel boost pump ON.3. Move the manual mixture control out of

the IDLE CUTOFF position. (This allows thefuel transfer line between the carburetor and thespinner injection nozzle to be pressurized.)

4. Return the manual mixture control to theIDLE CUTOFF position.

5. Simultaneously turn the fuel selector andfuel boost pump OFF. (Fuel is now trappedbetween the selector valve and the mixturecontrol plates, and between the mixture controlplates and the spinner injection nozzle.) Thereading on the fuel pressure gage (taken fromchamber E as the fuel enters the carburetor)should drop and stabilize at the pressurespecified for the particular system. Thisindicates that there is no pressure loss betweenthe selector valve and the mixture control plates.

If the reading on the fuel pressure gage dropsto zero, there is an external leak between theselector valve and the mixture control plates, orleakage at one of the following points isindicated: vapor vents, primer, selector valve,engine fuel pump diaphragm, balance diaphragm(in chamber A), or oil dilution valve.

If the reading on the fuel pressure gage dropsto the spinner injection nozzle spring pressure (7to 10 psi for a 10-pound spring), leakage isindicated at one of the following points:mixture control plates, regulator fill valve, orfuel diaphragm (between chambers C and D).

Chapter 5 RECIPROCATING ENGINE TROUBLESHOOTING

6. If no pressure loss is indicated in step No.5, move the manual mixture control out of theIDLE CUTOFF position. The fuel pressureshould drop and stabilize at the spinner injectionnozzle spring pressure. If the pressure dropsbelow that of the spinner injection nozzlespring, check for the following: leak in the fueltransfer line, injection nozzle stuck open,ruptured diaphragm between chambers B and Cor a weak spring in the spinner injection nozzle.

Engine backfiring and high cylinder headtemperatures are often indications of a mixturethat is too lean. A lean mixture may be causedby the following: low fuel pressure, vaporseparator stuck closed, boost venturi loose,clogged impact tubes, ruptured air diaphragm(between chambers A and B), defective spinnerinjection nozzle, defective or dirty automaticmixture control unit. or a dirty or collapsedstrainer in the carburetor.

Afterburning and black exhaust smoke areoften indications of a mixture that is too rich. Arich mixture may be caused by the following:excessive inlet fuel pressure, clogged mixturecontrol bleeds, leaking primer, ruptured fueldiaphragm or ruptured balance diaphragm.

DIRECT FUEL INJECTION

When troubleshooting the direct fuel injectionsystem, that part of the fuel system between thefuel selector valve and the mixture control platesof the master control may be checked in thesame manner as for an injection type carburetor.Malfunctions of the master control produce thesame symptoms as similar malfunctions of theinjection carburetor. It is in that portion of thefuel system downstream from the mixture con-trol plates that the master control trouble-shooting procedures differ from that of theconventional injection carburetor. In trouble-shooting the direct fuel injection system, properuse of the primer, tachometer, manifold pressuregage, fuel flowmeter, cylinder head temperaturegage, and BMEP gage are invaluable. The use ofcharts, particularly the accountability chartswhich can be used to check engine performance,part throttle cruise performance charts, and thefull throttle performance curves can be of greathelp to the troubleshooter in his work.

107

FLOW BENCH TESTING

Carburetors and master controls that havebeen removed from service because of defectsmust be overhauled or repaired. When the repairor overhaul has been completed, the carburetoror master control must be tested on a flowbench by qualified personnel. The followingparagraphs cover some of the flow bench testingprocedures.

The carburetor or master control should beset up on a test bench and adjusted to thespecifications that the manufacturer furnishes,which will produce the exact conditions underwhich the unit will operate on the engine. Thebleed check will provide a means for calibratingthe mixture control bleeds, back vent bleeds,and channels in relation to the complete aircircuit. The air circuit test provides a means forcalibrating the automatic mixture control unit inrelation to the fixed variables previouslycalibrated by the bleed check.

After the proper checks and adjustments havebeen made on the flow bench, the carburetor isready for a test flight. Runs or readings areunnecessary on an engine in a test cell. Beforestarting the test on the flow bench, you shouldhave at hand the carburetor setting specifica-tions sheet and the flow test limit sheet, both ofwhich contain the information on the correctsizes of the various parts, settings, and flowlimits for the carburetor or master control as itis applied to a certain engine.

The flow bench is designed for duplicating theeffects of engine operation on the regulator unitand the fuel control unit. The metering pressureacross the jets in the fuel control unit arecontrolled by the regulator unit, which isactuated by the venturi suction and the impactpressure resulting from the airflow through thethrottle body.

The airflow and corresponding venturi suctionand impact pressure are recorded for each engineoperating condition from an actual run on a testengine. These records are placed on a specifica-tion sheet for the engine and carburetor. If theventuri suction and the impact pressure cor-responding to a given airflow are imposed uponthe regulator unit, the volume of fuel flowingfrom the metering jets would be exactly equal tothat which would flow from the metering jets if

1i2


the carburetor were attached to an engine withthe corresponding volume of air flowing throughthe throttle body.

This means that if the same conditions ofsuction and pressure can be imposed on thecarburetor or master control artificially as whenit is in place upon the engine, it can be testedindependently of the engine. This is exactlywhat is done on the flow bench. Instead ofhaving air actually flowing through the throttlebodyas would be the case with the carburetoron the enginethe corresponding values ofsuction and impact pressure, which produce thesame effect as the airflow, are employed in thetest.

It has been explained that the air section ofthe regulator unit is divided by a diaphragm intoa low-pressure chamber and a high-pressurechamber. The pressure difference between thetwo chambers acting upon the air diaphragmproduces the air metering force. To avoid thenecessity of regulating both suction and pressureon the diaphragm during a test on the flowbench, a value of suction alone equal to thedifference in pressure between the two chambersis applied to the suction side of the diaphragm.The other side has a vent open to the outside air,so that it is always at atmospheric pressure.

A carburetor test on the flow bench consistsof applying a value of suction to the regulatorunit corresponding to an airflow for each engineoperating condition and of measuring the result-ing fuel flow from the metering jets. The fuel/airratio is the ratio of the number of pounds of aircorresponding to the value of the suctionapplied to the low-pressure chamber of theregulator unit in relation to the number ofpounds of air flowing from the metering jets.

The flow bench used for testing carburetorsand master controls consists of equipment thatwill supply a source of regulator suction, a fuelsupply that will maintain fuel delivery to theunit being tested at the required pressure,manometers (gages for measuring the pressure ofgases and vapors), and gages for measuring thefuel flow through the carburetor. Through useof the flow bench, a simple, definite, andaccurate check can be obtained on the perform-ance that the carburetor or master control willgive when installed on an engine.

108

IGNITION SYSTEM

The ignition system on the reciprocatingengine, from the standpoint of the ADR per-forming troubleshooting maintenance, isprobably the system with the most discrep-ancies. A clear understanding of the operation ofthe ignition system, the use of various pieces oftesting equipment, the ability to interpret whatthe test equipment shows, and the propermaintenance procedures will improve aircraftavailability, decrease operating costs, and makeeasier the job of maintaining the aircraft enginefor the mechanic.

In troubleshooting the ignition system on areciprocating engine, you will find that the useof certain pieces of equipment will becomeinvaluable. In order to obtain the maximum useof test equipment and to thoroughly understandthe ignition system, it is necessary for themechanic to have an understanding of basicelectricity. The necessary test equipment formaintaining ignition systems will be brieflydiscussed here. Refer to the appropriate tech-nical publications for more detailed informationconcerning these pieces of equipment.

OHMMETER

The ohmmeter is used on the low-tensionignition system to check for continuity, amountof resistance, or for infinity in a circuit, or forpart of. a circuit. The ohmmeter has its ownsource of power; therefore, before using, alwaysinsure that the circuit being tested is not live.This will prevent damage to the ohmmeter. Touse the ohmmeter, first turn the switch on. Theneither set the selector switch to the LOW orHIGH position or place the test leads in theproper sockets in the meter to receive the properreading in ohms. Touch the probes together andadjust the pointer to read "zero" by turning theadjusting knob. For testing, put that part of theCircuit to be tested between the two probes. Aninfinity reading will indicate an open circuit,whereas any reading between zero and infinitywill indicate the number of ohms resistance inthat circuit.

41,


HIGH-VOLTAGE INSULATION TESTER

There are several types of high-voltage insula-tion testers in use. One type is shown in figure5-2. All of these testers are very dangerous ifthey are used improperly. The ground leadMUST always be connected to a definite groundbefore the tester is turned on. When testing alead, the tester must be connected to that leadbefore the test voltage switch is turned on. Asafe procedure is to operate the equipment andsecure the leads with one hand only. Thepositive test voltage lead is connected to theconductor of the part to be tested. The negativetest voltage lead is connected to the insulationof the part to be tested. After getting the properreading, if the lead is good, turn the test voltagerheostat to zero. Allow the voltage to bleed off;then turn the test voltage switch to the OFFposition and hook up to the next lead to betested.

PISTON POSITION INDICATOR

The piston position indicator (the Time-Riteis a common type) is used to accurately deter-

re-

mine the position of the piston, in crankshaftdegrees, relative to top dead center (TDC). Dueto the variations in spark plug position, cylindersize, piston dome shapes, etc., it is necessary touse the proper arm and scale for the engine onwhich you are working.

TIMING LIGHTS

The timing lights are used with the pistonposition indicator to determine the exact instantthe breaker points open and close. There areseveral different types of timing lights in use innaval aviation. On some, the light goes out whenthe points open; on others, the light comes onwhen the points open. Some timing lights alsoincorporate a buzzer to aid in determining pointopening and closing.

COLD CYLINDER INDICATOR

The cold cylinder indicator is a test instru-ment used in determining whether individualcylinders are functioning normally. It consists ofa millivoltmeter, calibrated from 0° to 350° C.It has a wand connected to it by a two-wire

NEGATNETEST VOLTAGE LEAD

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Figure 52.High-voltage insulation tester.

109

114


cable. The wand consists of a contact point, achuck for holding the contact point, three rodsections, and a contact sleeve assembly (handle)containing a switch. A ground wire is equippedwith an alligator clip.

After assembling the wand, check to see thatthe pointer indicates 0°. Adjust if necessary. Theindicator is now ready for use. The procedurefor using the indicator is as follows:

1. Head the aircraft into the wind, start theengine, and warm it up in the normal mannerwith the cowl flaps open until the CHT reaches150°, or until temperature stabilizes at a lowerreading.

2. Then place the ignition switch in theposition in which an excessive magneto dropoffhas been noted. Operate the engine between1,200 and 1,600 rpm to allow the cylinders inwhich the plug or plugs are not firing to cooldown.

3. Stop the engine and immediately performthe cold cylinder check. Starting with No. 1

cylinder, proceed in numerical order around theengine. Check and record the temperaturereading on each individual cylinder, making surethat a good contact is made at the same relativepoint on each cylinder head, preferably near theexhaust port.

This check with the cold cylinder indicatorshould be made within the shortest timepossible. The cylinders which have beenoperating properly will retain their heat and willbe much higher in temperature than the cylinderthat has not been operating. Do not perform thischeck with the cowling removed from theengine:

IDENTIFICATION OF METALPARTICLES

When particles of metal are found in the fuelfilter and oil screens, they may be eithermagnesium, steel cadmium, tin, aluminum,silver, or bronze. In some cases, the type ofmetal may be determined by the color and thehardness of the pieces. When the particlescannot be positively identified by visual inspec-tion and the knowledge of the type of metaldeposits is desired as an aid to troubleshooting, a

110

few simple tests will determine the kind of metalpresent.

The following equipment and chemicals arerequired to make the few simple tests: A sourceof open flame, a permanent magnet, 5 percentsolution of chromic acid, an electric solderingiron, and 2 ounces each of concentrated hydro-chloric acid and concentrated nitric acid.CAUTION: Use extreme care when handling theacids.

For best results, the following test proceduresare recommended for determining the type ofunknown metal particles:

1. Magnesium. A simple test for magnesiumparticles is burning. Magnesium will burn with abright white flash. CAUTION: Never attempt toburn more than a few particles of metalsuspected of being magnesium. Magnesiumpowder or dust is explosive.

2. Steel. The steel particles can be isolated byusing a permanent magnet. Steel or iron isattracted by a magnet.

3. Cadmium. Cadmium particles will dissolvequite rapidly when dropped in a 5 percentsolution of chromic acid.

4. Tin. Tin particles can be distinguished bytheir low melting point. Use a clean solderingiron, heated to 260° C (500° F) and tinned with50-50 solder (50 percent tin and 50 percentlead). A tin particle dropped on the solderingiron will melt and fuse with the solder.

5. Aluminum. When a particle of aluminum isplaced in hydrochloric acid, it will fizz with arapid emission of gas bubbles and graduallydisintegrate, forming a Hack residue (aluminumchloride). Silver and bronze are not noticeablyattacked by hydrochloric acid.

6. Silver. When a silver particle is placed innitric acid, it reacts rather slowly, producing awhitish fog in the acid.

7. Bronze. When a bronze (or copper)particle is placed in nitric acid, it will reactrapidly; a bright bluish green cloud is producedin the acid.

SPECTROMETRICOIL ANALYSIS

The spectrometric method of analyzingengine oil for its metallic content has become anestablished program.

Chapter 5RECIPROCATING ENGINE TROUBLFSHOOTING

To date successes in spectrometric oil analysishave been mainly in analyzing conditions ofreciprocating, turboprop, and turbojet enginesand helicopter transmissions. By this method,impending failures were predicted beforeadvancing to in-flight failures.

Under certain conditions and within certainlimitations, the internal condition of anyenclosed mechanical system can be evaluated bythe spectrometric analysis of lubricating oilsamples from all enclosed, oil-lubricated, aircraftmechanical systems.

Under normal conditions, the rate of wear ofmoving parts will be constant and quite slow,and the wear metal particles will be microscopicor submicroscopic in size so that the particleswill remain in suspension in a recirculatinglubrication system. The spectrometric oilanalysis method is basically applicable only tothose beginning failures which are characterizedby an abnormal increase in the wear metalcontent of the lubricating oil, and whichproceed toward total failure at a slow enoughrate to permit corrective action to be taken bythe operating activity after receipt of adversereports from the laboratory.

The sampling interval is currently establishedas 30 operating hours. Samples should representthe oil circulating in the system. Ordinarily,about 5 hours' operation after oil change isneeded to allow the circulating oil in an aircraftengine to reach equilibrium in regard to metalwear content. Samples taken after oil is added tothe system should be taken only after theaircraft engine has been operated for at least 20minutes.

Complete details of the spectrometric oilanalysis program is contained in NAVMATINST4731.1; titled Navy Oil Analysis Program(NOAP).

CORROSION

Metal corrosion is the deterioration of themetal by chemical or electrochemical attack.The deterioration can take place internally aswell as on the surface. Corrosion can causeeventual structural failure if left unchecked.Therefore, corrosion cannot be overlooked as a

possible cause of trouble when troubleshootingaircraft engines.

A thorough comprehension of the dangers ofcorrosion, the ability to recognize the variousforms of corrosion, and the development of theskills necessary to cope with these dangersshould be included in the objectives of everypowerplants shop training program.

When troubleshooting a reciprocating engine,the entire engine as well as all parts removedshould be cleaned and inspected for evidence ofcorrosion.

The following paragraphs describe some ofthe different types of corrosion and how totreat, prevent, and control them.

COMMON TYPES

Corrosion has been cataloged and typed inmany ways. For descriptive purposes the follow-ing general breakdown is used:

I. Direct surface attack.2. Galvanic or dissimilar metal corrosion.3. Pitting.4. Intergranular attack.5. Crevice attack or concentration cell cor-

rosio n.6. Fretting corrosion.7. Stress corrosion cracking.8. Corrosion fatigue.

Direct Surface Attack

The most common type of general surfacecorrosion results from direct reaction of a metalsurface with oxygen in the air. General attackalso occurs under marine conditions fromexposure of bare aluminum to salt spray orsalt-bearing air. The same type of attack resultswhen engine surfaces are exposed to solidparticles and gases blown from aircraft carrierstacks or when corrosion occurs downstreamfrom engine exhaust areas.

All such direct surface attack results ingeneral etching of the exposed areas. The entirearea becomes anodic and loses electrons directlyto the corrosive material dispersed in the air orspilled upon the surface of the metal.


Galvanic or DissimilarMetal Corrosion

Most corrosion is galvanic in nature, involvingan exchange of electrons between two points orareas, with the destruction of the anodic area.The specific type of attack indicated here is thatwhich occurs whenever two metals or twometallic-areas of different electrical potential arein contact with each other and also connectedby a continuous liquid or gas path, usually saltspray, exhaust gas, or condensate. This is a truechemical cell. Electrons flow, and the anodicarea is destroyed. (See fig. 5-3.) When such acondition develops, either from faulty design orfrom maintenance errors, the most easilyoxidized surface becomes the anode (positivepole) of the galvanic cell and corrodes. The lessactive member of the couple becomes thecathode (negative pole) of the galvanic cell andis protected. The degree of attack depends onthe relative activity of the two surfaces; thegreater the difference in activity, the moresevere the attack.

Pitting attack is a special kind of galvanicreaction, usually localized, with well-definedboundaries. It results from partial protection ofan exposed area. Although pitting may occur inany metal system, it is particularly characteristicof the alloys of aluminum, nickel, andchromium, and is usually a localized breakdownof protection. The point of weakness may be alack of homogeneity in the alloy surface, eitherfrom mechanical working or faulty heat treat-ment. It may result from an inclusion or roughspot in the metal surface or from localizedcontamination that breaks down the surfaceprotection. (See fig. 5-4.)

True pitting takes place at random with noselective attack along grain boundaries. Isolatedareas become anodic to the rest of the surface.Corrosion products formed accentuate theanodic characteristics in the pit area, and deeppenetrating attack develops rather than a generalsurface attack. Aluminum alloy is particularlysusceptible to perforation type pitting when inthe presence of chlorides which are alwayspresent in salt deposits. Maintenance consistschiefly of washing away any concentration of

chlorides and avoiding pockets of stagnant wateron the engine.,

Intergranular Corrosion

Intergranular corrosion is selective attackalong the grain boundaries of metal alloys. (Seefig. 5-5.) It results from lack of uniformity inthe alloy structure. It is particularly charac-teristic of aluminum alloyed with copper or zincand some stainless steels. Aluminum extrusionsand forgings in general may contain nonuniformareas, which in turn may result in galvanic attackalong the grain boundaries. Piano hinges are usedextensively in aircraft engine nacelles and are agood example of extrusions which are extremelysusceptible to such attack.

Similar differences in structure can alsodevelop from localized overheating, such as fromfire damage, in which case the overheated areamay become subject to intergranular attack.Stainless steels and chromium containing alloysin general are subject to intergranular attackwhen overheated.

Intergranular corrosion may exist withoutvisible evidence on exterior surfaces, and seriousstructural weakening may occur before an ap-preciable volume of corrosion products ac-cumulate on the surface. Methods are beingdeveloped to detect intergranular corrosion byuse of ultrasonics and eddy currents. Until theseare fully developed, squadron personnel shouldutilize the services of the nearest NARF mate-rials engineering laboratory when intergranularcorrosion is evident or suspected. When attackhas gone deep enough, the corrosion mayactually delaminate the basic metal layers, be-cause of the increase in volume of the productsover the original metal. This condition of layersof metal peeling off a surface is called "exfolia-tion."

In some cases intergranular corrosion can becontrolled and treated if the attack his notpenetrated too far, and if sufficient structuralstrength still remains. All corrosion products,surface pitting, and fissuring must be completelyremoved to make sure that a true evaluaticin ofremaining structural strength is possible. Thecleaned areas require surface treatment and arenewed protective coating.

Chapter 5RECIPROCATING.ENGINE TROUBLESHOOTING

4+:(-0

'VT 4tt'A'"CP.

Figure &aGalvanic or dissimibr metal corrosion.

113

4

AD.374


AD.375Figure 5.4. Pitting corrosion of steel.

Crevice Attack or ConcentrationCell Corrosion

Concentration cell corrosion is a type ofpitting attack which depends on differences inconcentration of either the dissolved oxygen orthe charged metal particles that may be presentin an entrapped solution. If there are con'entra-tion differences at two different points in anentrapped pool of water or cleaning solution,anodic and cathodic areas may result, and theanodic area will be attacked. This type of attackis generally associated with crevices, scale, sur-face deposits, and stagnant water traps.

If iron is the corroding metal, it combinesdirectly with oxygen to Pam insoluble ferrichydroxide, using up the oxygen and depositingred corrosion products at the point of attack.Around the edge of the corroded area, theoxygen is renewed by direct absorption ofoxygen from the atmosphere.. Underneath thecorrosion deposits, a shortage of oxygen

develops compared to the rest of the watersolution, and the metallic area becomes anodic.Additional metal goes into solution, and achemical cell results with differences in con-centration of charged particle; of iron in thesolution also supplementing the effect of oxygenconcentration differences. As a pit begins toform, the corrosion rate increases, since thebottom of a pit is a perfect spot for an anode todevelop. The small area of the anode, comparedto that of the cathode, accentuates and con-centrates the attack.

Concentration cell corrosion can be con-trolled and prevented by keeping areas clean, byeliminating stagnant pools of water, by avoidingthe creation of crevices during any repairoorkiand by eliminating existing voids which maybecome water traps by use of sealants andcalking materials.

1111101t4a

Fretting Corrosion

Fretting corrosion is a limited type of attackthat develops when two heavily loaded surfacesin contact with each other are subject to slightvibratory motion or oscillations. (See fig. 5-6.)At least one of the surfaces must be metallic.The rubbing contact destroys any protectivefilm that may be present on the metallic surface,and additionally removes small particles of virginmetal from the surface. These particles willusually oxidize to form abrasive materials. Thecontinuing motion of the two surfaces preventsthe formation of any protective oxide films andexposes fresh active metal to the atmosphere.Supplemented by the abrasive effects of thecorrosion products, support areas in generalbecome actively corroded. If the contact areasare small ani sharp, deep grooves resemblingBrinell markings or pressure indentations may beworn in the rubbing surface. As a result, thistype of corrosion has also been called falsebrinelling when developing on bearing surfaces.

Fretting corrosion is evident at an early stageby surface discoloration and the presence ofcorrosion products in any lubricant present. Itfrequently develops when moving heavy equip-ment by truck or from the rhythmic vibration ofa railroad car during long hauls. This type ofcorrosion is limited in its occurrence, but itspresence ruins bearing surfaces, destroys critical

114

119

Chapter 5RECIPROCATING ENGINE TROUBLESHOOTING

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Figure 5-5.-Intergranular attack in aluminum alloy.AD.376

AVIATION mkatiNisrs MATE R 1 & C

AD.377Figure &S.Fretting corrosion of steer.

dimensions, and may be serious enough toeventually cause actual cracking and fatiguefailure. It can be reduced either by controllingrhythmic vibration or by preventing slippage oftwo metal surfaces. Contact surfaces may bebonded together or slippage controlled by in-creasing the contact load. Use of oils, greases, ordry film materials also usually reduces thedegree of fretting corrosion by lubricating theoscillating surfaces.

Stress CorrosionCracking

Stress corrosion is the combined effect ofstatic stresses applied to a surface over a periodof time under corrosive conditions. (See fig.5-7.) Stress corrosion cracking is found in mostmetal systems; however, it is particularly charac-teristic of aluminum, copper, certain stainless

steels, high strength alloy steels, and magnesiumalloys. It usually occurs along lines of %:oldworking and may be transgranular or inter-granular in nature. Aluminum alloy bellcranksemploying pressed-in taper pins, clevis joints,shrink fits, and exposed or overstressed tubing"B" nuts are examples of parts which aresusceptible to stress corrosion cracking.Distorted and stressed metal tends to becomeanodic when in contact with stress-free material,and the galvanic attack occurs along the lines ofstress, which in turn results in rapid failure ofthe part.

Corrosion Fatigue

Corrosion fatigue is a second type of stresscorrosion resulting from cyclic stresses on ametal in corrosive surroundings, rather than the

Figure 5-7.Stress corrosion cracking.AD.378


static loads that cause stress corrosion cracking.The resulting corrosion usually starts at thebottom of an existing shallow pit in the stressedarea (fig. 5-8). Sharp deep pits form, which inturn become the origin of cracks that mayultimately result in failure of the part. This typeof attack is characteristic of any part underregular cyclic stressing. Once attack begins, thecontinuous flexing prevents the repair of protec-tive surface coatings, and additional corrosiontakes place in the area of stress. It is difficult todetect this type of attack in advance except ascracking develops. Frequently, by the time it isnoted, the only solution is the replacement ofthe part.

IDENTIFICATIONAND TREATMENT

When active corrosion is visually apparent, aspecific and immediate program for identifica-tion and treatment is required. In general, anycomplete treatment involves the cleaning andstripping of the corroded area, the removal of asmuch of the corrosion products as practicable,the neutralization of any residual materials thatmay remain in pits and crevices, such restorationof protective surface treatment films as ispracticable, and the earliest replacement of

fr,

FAME ONIIIN

Figure 5.8.Corrosion fatigue.

permanent protective coatings and paintfinishes. Each particular type of corrosion has itsown peculiarities and may require special treat-ment.

One of the most familiar types of corrosion isred iron rust, generally resulting from atmos-pheric oxidation of steel surfaces.

Some metal oxides protect the underlyingbase metal, but red rust is not a protectivecoating in any sense of the word. Its pr....enceactually promotes additional attack by attract-ing moisture from the air and acting as aa talyst in causing additional corrosion to takeplace. As a result, all rust must be removed fromsteel surfaces if complete control of corrosiveattack is to be realized. There is no effectiveinhibitor for its safe control on aircraft surfacesin the installed condition.

Rust first shows on boltheads, holddownnuts, and other unprotected aircraft hardware.Its presence in these areas is generally notdangerous and has no immediate effect on thestructural strength of any major components.However, it is indicative of a general lack ofmaintenance and possible serious attack in morecritical areas. It is also a .factor in the generalappearance of the equipment. When paintfailures occur or mechanical damage exposeshighly stressed steel surfaces to the atmosphere,even the smallest amount of rusting is potential-ly dangerous in these areas and must be removedand controlled.

Magnesium attack is possibly the easiest typeof corrosion to detect in its early stages, sincemagnesium corrosion products occupy severaltimes the volume of the original magnesiummetal destroyed. The beginnings of attack show35 lifting of paint films and white spots on themagnesium surface, which very rapidly developinto snowlike mounds or even white whiskers.Reprotection involves the maximum removal ofcorrosion products, the partial restoration ofsurface coatings by chemical treatment, and areapplication of protective coatings.

AD.379

117

1z

PREVENTIVE MAINTENANCE

Preventive Maintenance is a powerful toolwhich can be used to effectively correct even themost difficult "built-in" corrosion problem.


Such a program can be adjusted by the operatingsquadron to meet the severe environment ofshipboard operations, and then decreased inscope when the aircraft is returned to therelatively mild .conditions of an island shorebase. Much has been done to improve thecorrosion resistance of military aircraft,including improvements in the selection andcombination of materials of construction, inchemical surface treatments, in dissimilar metalinsulation, and in protective paint finishes. Allof these have been aimed at reducing main-tenance effort as well as improving reliability.But in spite of refinements in design andconstruction, corrosion and its control are a veryreal problem that requires a continuous mainte-nance program particularly under marine oper-ating conditions.

Methods

Preventive.. maintenance, as related to cor-rosion control, includes the following specificfunctions:

1. Adequate cleaning program.2. Periodic lubrication.3. Detailed inspection for corrosion and

failure of protective systems.4. Emergency treatment of corrosion as it

occurs.S. Early paint touchup of damaged areas.6. Use of supplementary preservative coat-

ings as necessary.7. Adequate draining of internal cavities by

maintaining drain holes free of obstructions.8. Daily draining of fuel cell sumps to

remove accumulated water and other foreignmatter.

9. Daily wipe down of exposed criticalsurfaces.

10. Sealing of aircraft against water and saltspray during foul weather, and proper ventila-tion of the same aircraft on warm, sunny days.

11. Using all available protective covers onparked aircraft (wing roots, air intakes, enginecovers).

In corrosion control work, the term "clean"means to do the best job possible, using thematerials and facilities available. A wipe downwith a water- or oil-soaked cloth is better than

118

123

no cleaning at all. The importance of frequentcleaning cannot be overemphasized. However,any cleaning procedure used should always bethe mildest method which will produce thedesired results. For example, steam cleaning is avery effective method for removing soils andresidual grease, but it also may erode paint anddamage electrical insulation. The AircraftCleaning and Corrosion Control Manual, NA01-1A-509, covers procedures to be used incleaning aircraft. This manual should be referredto for detailed information on materials,methods, and equipment.

In general, aircraft engines should be cleanedas often as necessary to keep surfaces free ofsalt, soil, and other corrosive deposits. Morespecifically, a thorough cleaning should alwaysbe accomplished as a part of each calendarinspection. Such routine or periodic cleaningshould include the removal of all oil, water, andengine exhaust deposits; the replacement ofcontaminated supplementary preservative coat-ings; and a thorough cleaning of all externalsurfaces.

The amount of cleaning necessary betweenperiodic inspections varies with operating condi-tions, but for ship-based aircraft any period offoul weather should be followed by fresh waterto remove salt deposits. If fresh water is notavailable, waterless cleaner may be used forlimited shipboard cleaning. In any type ofcleaning, make sure that salt solutions andcleaning compounds are not washed intointernal areas and allowed to become trapped.Mask or seal vents and openings necesary toprevent this. Following cleaning, rinse out anddrain exposed cavities to assure that residualcleaning matelals have all been removed.

Engine frontal areas and cooling air vents arebeing constantly abraded with airborne dirt anddust, bits of gravel from runways, and rainerosion, which tend to remove the protectivefinish. In addition, air intake ducts, coolerradiator cores, etc., are not painted. Engineaccessory mounting bases usually have smallareas of unpainted magnesium or aluminum onthe machinN1 mounting surfaces. With moist,salt-laden air constantly flowing over thesesurfaces, they are prime sources of corrosiveattack. Inspection of such areas should alsoinclude all sections in the cooling air path, with

Chapter 5RECIPROCATING ENGINE TROUBLESHOOTING

special attention to obstructions and creviceswhere salt deposits may build up during marineoperations. It is imperative that incipient cor-rosion be inhibited and that paint touchup andhard film preservative coatings be maintainedintact on seaplane and amphibian enginesurfaces at all times.

Equipment

In emergencies where regular waterproofcanvas covers are not available, suitable coveringand shrouding may be accomplished by usingpolyethylene sheet, polyethylene-coated clothor metal foil barrier material. These covers

should be held in place with specification tapesdesigned specifically for- severe outdoor ap-plications. All covers and shrouds should be ,-installed in such a manner that free drainage isassured. Do not create a bathtub which will trapand hold salt water. Shrouds or covers may alsoact as a greenhouse in warm weather and causecollection and condensation of moisture under-neath. They should be loosened or removed andthe aircraft ventilated on warm, sunny days.Where protection from salt spray is requiredaboard carriers, leave covers in place andventilate only in good weather. Fresh watercondensate will do far less damage than en-trapped salt spray.

I 1 9

1124_ .,.......

CHAPTER 6

ENGINE ANALYZERS

As naval aviation progressed new equipmentwas developed to assist maintenance personnelin maintaining and operating the new aircraft.An example of the new equipment developed isthe engine analyzer. The engine analyzer pro-vides continuous visual analysis of the completeaircraft powerplant. It not only detects, but alsolocates and identifies all of the common ignitionmalfunctions and imminent failures that mayoccur during engine operation. The Sperry andBendix engin:, analyzers are covered in thischapter.

FUNCTIONS

The function of the engine analyzer is toprovide the operator with a means for quickdetection, location, and identification of enginemalfunctions in flight or on the ground bymaintenance personnel, and for checking outengines after overhaul or repairs. In flight; itprovides a means for the flight engineer to keepthe engines of the aircraft under constantsurveillance. Should an engine malfunction de-velop, he can evaluate its severity and make theadjustments as required. Further, with the iden-tity and location of the malfunction definitelyestablished while the aircraft is still airborne, theground crew can concentrate on remedying themalfunction immediately on landing without theneed of time and effort to locate and identify it.A further important fact is that the engineanalyzer can detect troubles peculiar to highaltitudes which could not normally be dis-covered during ground checks.

IGNITION ANALYSIS

During ignition analysis the engine analyzerrecords the voltage of the primary coil. In asense the analyzer is a recording voltmeter,

showing every change in voltage that occurs inthe primary coil as the magneto completes a fullcycle (two crankshaft revolutions). By sensing-every change in the voltage of the primary coil,the analyzer scows how the magneto is operat-ing. It shows breaker point operation andmeasures the length of time they are open. Itindicates an improperly operating primary con-denser and shows the condition of the secondarycircuit. To some extent the condition of thespark plugs will reveal to the experienced opera-tor the condition of the cylinders.

120

VIBRATION ANALYSIS

Vibration analysis is accomplished by install-ing vibration pickup units on the cylinders andconnecting the units to the analyzer. These unitsconvert vibrations into voltages which can beseen on the indicator of the analyzer. The use ofvibration analysis can minimize the more costlyengine repairs, such as cylinder changes andengine changes. By inspection of valve actionand combustion characteristics the mechanic cansee evidence of malfunctions before seriousdamage is done. Early detection of such thingsas improper valve clearance, valve bounce orwobble, and detonation may greatly increase thelifespan of the engine.

PORTABLE ANALYZERS

SPERRY PORTABLEENGINE ANALYZERS

The Sperry Portable Engine Analyzer can beused to analyze only one engine at a time. It isuniversal in that it can be used with any typeengine. It can .be used with engines having anynumber of cylinders. The portable analyzerconsists of an indicator, cycle switch, conditionswitch, power switch, signal switch for pattern

125"-

Chapter 6ENGINE ANALYZERS

attenuation, sweep switch, generator rotationswitch, power supply amplifier, inverter, andisolating resistor, mounted in a single cabinet. Asynchronizing generator, a vibration pickup unit,and connecting wires and cables complete theportable engine analyzer. A Sperry PortableEngine Analyzer is shown in figure 6-1.

Components

CATHODE RAY TUBES.The cathode raytube has a phosphorescent screen upon whichvoltages of the ignition primary circuit or of thevibration pickup units are displayed as patterns,which the operator interprets. An electron gunin the cathode ray tube generates an electronbeam and directs it against the screen. Two setsof deflection plates in the cathode ray tubecause this beam 10 move on the face of thescreen. Voltages in the primary circuit of themagneto (or vibration pickup units during vibra--tion analysis) control the vertical deflection ormovement. Changes in these voltages cause theposition, shape, or size of the pattern to vary.

CYLINDERS-PER-ENGINE SWITCH

INDICATOR

CONDITIONSWITCH

o. o POWER SWITCH

.. . GENERATOR. ROTATION SWITCH

SIGNALATTENUATION SWITCH

SWEEP SWITCH eCYCLE SWITCH

® ®

ACCESSPANEL

\A0.380

Figure 6-1.Sperry Portable Engine Analyzer.

121

Voltages from the synchronizing generator con-trol the horizontal deflection of the beam,according to crankshaft position.

CYCLE SWITCH. The cycle switch (fig. 6-2)enables the operator to select the pattern of acertain position of the crankshaft (the pattern ofa certain cylinder). Three removable faceplates,with the firing order of 9- and 18-, 7- and 14-,and 28-cylinder engines, are furnished withthe Sperry engine analyzer. (See fig. 6-3.) A reddot at the base of the pointer of the cycle switchis used as an index mark for vibration analysis.When the red dot is alined with a selectedcylinder number, the exhaust valve closing ofthat cylinder will appear on the left of theviewing screen.

CONDITION SWITCH.A condition switchpermits the operator to select the type ofanalysis desired. One is shown in figure 6-4. Thecondition switch has one index mark which maybe lined up with one of five positions:

L - The pattern of the left magneto is shownon the indicator.

Figure 6Z.Cycle switch (with18-cylinder faceplate installed/.

AD.381


AI

Figure 6-3.Cycle switch faceplates.

AD.383Figure 6.4. Condition switch.

B - The pattern of both magnetos is shownon the indicator.

R - The pattern of the right magneto isshown on the indicator.

AD.382

V - The vibration pattern is shown on theindicator.

S - This position establishes the circuit foranalysis of any other chosen source ofsignal voltage delivered to the analyzerby means of the two posts adjacent tothe condition switch.

POWER SWITCH.The power switch is atwo-position, ON-OFF toggle switch which con -trols the power to the analyzer.

GENERATOR ROTATION SWITCH. Thegenerator rotation switch is a two-positionswitch, clockwise and counterclockwise, whichis provided to reverse the phasing sequence ofthe synchronizing generator. This feature per-mits the use of one cable for generators of eitherclockwise or counterclockwise rotation.

NOTE: The generator rotation switch mustbe placed in the position which will cause thepatterns to move from right to left when thecycle switch is rotated in a clockwise direction.The check for this condition is called thephasing check.

SIGNAL SWITCH.The signal switch is atwo-position switch, attenuated and normal.When this switch is in the NORMAL position,the patterns are of a normal size. In the

122

1f47-v;


ATTENUATED position, the signal voltages arereduced to a lower amplitude, and the patternsappear much smaller.

SWEEP SWITCH.The sweep switch is a two-position toggle switch, slow and fast. In theSLOW SWEEP position, the patterns for 720° ofcrankshaft travel (18 patterns on 18-cylinderengines) appear on the screen. In the FASTSWEEP position, the patterns for 80° of crank-shaft travel (2 patterns on 18-cylinder engines)appear on the screen.

CYLINDERS PER ENGINE SWITCH.Thecyls-per-engine switch is a four-position switchlabeled 18 HT or less, 18 LT, 28 HT, and 28 LT.This switch selects the number of isolatingresistors to be used. It must be set to theposition corresponding to the number of cylin-ders and type ignition system being analyzed.

POWER SUPPLY AMPLIFIER.The powersupply amplifier contains the various circuits,capacitors, transformers, and resistors necessaryto provide the voltage required for the properoperation of the engine analyzer. It provides themeans of making the proper pattern adjust-ments. These are screwdriver adjustments. (Seefig. 6-5.)

L The intensity adjustment screw regulatesthe brightness of the pattern. The adjustmentscrew is turned in one direction or the otheruntil the brilliance desired by the operator isobtained.

2. The focus adjustment screw controls thesharpness of the picture. The desired sharpness isobtained by turning the screw in one directionor the other.

3. The H-centering (horizontal centering) ad-justment controls the start of the trace line fromthe left side of the cathode ray tube. (The traceline, seen on the indicator, is caused by the'electron beam being deflected across the cath-ode ray tube by the horizontal deflectionplates.) The trace line is adjusted to beginone-eighth inch from the left side of the cathoderay tube. Before making the adjustment, thesweep switch must be in the SLOW SWEEPposition, showing the patterns of all the cylin-ders.

4. The length adjustment controls the lengthof the trace line. It should be adjusted to give atrace line 2'/2 inches long. This will normallyextend the right end of the trace line to

AD.384Figure 6.5. Power supply amplifier showing

screwdriver adjustoents.

one-eighth inch from the right edge of thecathode ray tube. The sweep switch must be inthe SLOW SWEEP position for this adjustmentalso.

NOTE: Engine must be at cruise for all traceline adjustments.

5. The gain adjustment is used only forvibration and special analysis. It adjusts thebackground hash or trace line. The amplitude ofthe vibration pattern is dependent upon theshock forces applied to the cylinder.

ISOLATING RESISTOR BOX.Isolating re-sistors are in the circuit between the aircraftengine and the engine analyzer. They preventthe engine magnetos from grounding out in theevent that the engine analyzer develops anunintentional ground. They also reduce thevoltage that is applied to the CRT.

INVERTER.An inverter is used to convertthe 24- to 28-volt, d-c input power to therequired 115-volt, a-c (400-Hz) supply for theengine analyzer.


SYNCHRONIZING GENERATOR.Thesynchronizing generator is mounted on theauxiliary tachometer drive of the aircraft engine.This is the unit that permits timing of theanalyzer to the aircraft engine. It furnishes thevoltages needed for control of the horizontaltrace line. Two types are available to fit either oftwo standard types of mounts with whichaircraft engines are equipped. Each of these twotypes may be fitted with either a straight or anoffset electrical receptacle. Figure 6-6 shows aflange-mounted generator with an offset recepta-cle.

AD.385Figure 6.6. Flange- mounted synchronizing generator

with an offset receptacle.

Figure 6-7 shows a synchronizing generator,mounted by internal threads of the generatorhousing and having a straight electrical receptacle.Flexible drive shafts are provided for someinstallations. However, when a flexible shaft isused, it is possible for undesirable whip action ofthe shaft to have an adverse effect upon thetiming.

VIBRATION PICKUP UNIT.The vibrationpickup unit, containing a coil and a magnet, ismounted on the aircraft engine cylinder head tobe analyzed. The unit is installed either directly

124

AD.386Figure 6-7.Thread-mounted synchronizing generator

with a straight receptacle.

in a tapped hole provided in the cylinder head orin an adapter mounted in the tapped hole,depending on the particular engine. Since theportable engine analyzer is not equipped with avibration selector switch and harness, it ispossible to analyze, for vibration, only onecylinder of an engine. Any vibrations (impactforces) in the cylinder are transmitted to themagnet in the pickup, causing the magnetic fieldto strengthen or weaken, producing voltage. Thevalue of this voltage depends upon the impactforces in the cylinder. A vibration pickup unit isshown in figure 6-8.

Connecting the PortableAnalyzer to the Engine

The portable engine analyzer is usuallymounted in a portable cart assembly, equippedwith a power panel and various cables forconnecting the analyzer to the engine. If it isimpracticable to use the cart assembly at anytime, the engine analyzer may be removed fromit, and power from the aircraft inverter or othersource supplying the required 115-volt, a-cpower may be used. The inverter which nor-mally converts the 28-volt input to 115 voltswould remain with the cart assembly and so is

1:49

Chapter 6-ENGINE ANALYZERS

AD.387Figure 6.8.-Vibration pickup unit.

not used when the analyzer is removed from thecart assembly.

A general coverage of the procedure forconnecting the analyzer to the engine is givenhere. The appropriate technical publication must

ENGINE

FIREWALLRECEPTACLE

1--MAGNETOar LEAD

CYLIN6ERHEAD

1

TACHOMETERPAD

1

t_ _ _ JSYNCHRONIZING GENERATOR

IGNITION .Y.CONNECTER

EXTERNALCABLEPOWERPANEL

be consulted for specific instructions. The gen-eral procedure is as follows:

1. Install the synchronizing generator on theauxiliary tachometer mounting pad, using theproper adapter, if necessary, and the appropriategenerator type.

2. Install the vibration pickup unit on thecylinder head, if vibration analysis is desired.

3. Make the cable connections to the ana-lyzer., as shown in figure 6-9.

BENDIX ENGINE ANALYZER

The Bendix analyzer is similar in manyrespects to the Sperry portable; however, thecontrols are labeled differently, and there aresome additional controls. The following para-graphs explain the functions of the Bendixanalyzer controls and their use. Firare 6-10shows the front panel of the Bendix analyzer.

SPARE - Contains a spare 0.75 amp fuse.PILOT LIGHT - Indicates when power is

applied to the analyzer circuity.

,TO 24-TO 28-VOLT D-CPOWER SOURCE

1:17-1-BRATION

IGNITIONCABLE

PICKUP

1 PICKUP CABLE1 VIBRATION

Y" CONNECTER

VIBRATION PICKUP ANDSYNCHRONIZING GENERATOR CABLE

AD.388Figure 5-9.Portable engine analyzer installation diagram.

125

1.:34


SPARE

VERT. POS

NOR GAIN

DIALREVERSING

SWEEPLENGTHS L

NORPOS

PICKUP GEN

EVEN I

0.75 AMP

1110

ON

or r

rOCUS

INTENSITY

MAGNETOSELECTOR

34

5

2

1/4

SYNSELECTOR

IGN

VERTGAIN

Vls

a RNKR

L vIll 1

INIOFF VIII 2

Figure 610.Bendix analyzer front panel.

126

SIGNALSELECTOR

AD.389


VERTICAL POSITION - Used to either raiseor lower the trace on the cathode ray tube.

HOR GAIN - Horizontal Gain Control, in-creases or decreases the width of the patterns.

DIAL REVERSING - Enables the operatorto parade the patterns across the scope in thesame direction that the EVENT control isrotated. (Same as the Sperry generator rotationswitch.)

SWEEP LENGTH S L - Sweep Length Shortor Long control. In the S (short) position all theignition patterns for one magneto circuit appearon the. analyzer scope. In the L (lonf,) positionthe patterns are spread out enabling them to beobserved one at a time. (Same as the Sperrysweep switch; short is the same as slow sweepand long is the same as fast sweep.)

HOR POS - Horizontal Position Controls.One is a knob control that is used whensynchronizing with a capacitive type pickup inthe long sweep position of the sweep lengthcontrol. The other is a screwdriver control thatis used when a synchronizing generator is in-stalled. It functions in both short and longsweep, and is also used with capacitive pickupsynchronization in the short sweep position.While one control is in use the other is inopera-tive. The screwdriver control used with thesynchronizing generator enables the horizontalbeam to be positioned on short sweep andnormally does not need readjustment. (Same asthe Sperry H centering adjustment.) The pat-terns are moved across the scope by the EVENTcontrol.. Since the EVENT control is not usedwith capacitive pickup synchronization the pat-terns are moved across the scope by use of theHOR POS PICK-UP Knob control.

SYN SELECTOR, PICKUP and GEN - Selectsthe desired type of synchronization. (Eithercapacitive pickup or three-phase generator.)

0.75 AMP -The main line AC power inputfuse.

ON-OFF - The analyzer power control switch.FOCUS - This control varies the sharpness of

the electron beam in the cathode ray tube.(Same as the Sperry focus adjustment.)

INTENSITY - This control varies the bril-liancy of the electron beam in the cathode raytube. (Same as the Sperry intensity adjustment.)

132 127

MAGNETO SELECTOR - Provides selectionof up to seven dual magneto primary circuits foranalysis.

VERT GAIN IGN and VIB - Vertical gaincontrols for Ignition and Vibration. Used to varythe vertical height of the patterns appearing onthe scope.

SIGNAL SELECTOR - Selects the desired sig-nal source for analysis. In the "L" position theleft primary of the magneto previously selectedby the MAGNETO SELECTOR switch will beobserved. '11" position brings both magnetoprimaries (left and right) to the vertical deflec-tion circuits. "R" position is for analyzing theright magneto primary. "MKR" (marker) uses asignal from the capacitive pickup as a timingreference when using a synchronizing generator,the capacitive pickup being installed in a knownlocation, normally the number 1 cylinder. VIB 1and VIB 2 (vibration) positions select thedesired vibration pickup for analysis. (Same asthe Sperry condition switch.)

NOTE: In order to obtain complete ignitionanalysis of an engine with more than twomagneto primary circuits it will be necessary touse both the MAGNETO SELECTOR and SIG.NAL SELECTOR switches. For example, anR3350 engine with low tension ignition wouldbe analyzed in the following manner: MAC-NETO SELECTOR to the number I position,SIGNAL SELECTOR to the "R" position; thiswill allow the operator to analyze R-1 primarycircuit. By placing the SIGNAL SELECTOR tothe "L" position the L-1 primary circuit may beanalyzed. To analyze R-2 and IA primarycircuits the MAGNETO SELECTOR must bepositioned to the number 2 position, and theSIGNAL SELECTOR positioned to "R" for theR-2 primary circuit and then to "L" for the L-2primary circuit.

EVENT - This control varies the point ofsynchronization (sweep initiation) thru a full720 degrees of crankshaft rotation or two enginerevolutions. This means that a pattern disappear-ing on one side of the analyzer scope willreappear on the opposite side thru continuedrotation of the EVENT control; or, in otherwords the sweep may be started at any pointduring the engine cycle. Three reciprocating

AVIATION MACHIN1S1'S MATE R 1 & C

engine firing order sequence plates are securedto the analyzer. These three plates cover the 6,

7, 9, 14, 18, and 28 cylinder engines. The platesare easily changed by removing the four 1/4 turnfasteners. The desired plate is then placed infront and the plates resecured. The degreeindicator is marked in engine degrees and :s readby placing a zero after each indication, forexample 4 is 40, 10 is 100, 36 is 360, and 0 iseither 0 or 720. The dial indicator may berepositioned or set without moving the particu-lar pattern on the analyzer scope. This isaccomplished by holding the dial with one handwhile using the other to locsen the keyed knob1/4 turn. Rotate the dial keeping it out on itsshaft. When positioned, retighten the keyedknob. (The EVENT control performs the samefunction as the Sperry cycle switch.)

PATTERN INTERPRETATION

Cylinders free from malfunctions form pat-terns on the cathode ray tube that are charac-teristic of a specific engine type and of a specificengine ignition system. Malfunctions of theignition system, improper combustion, and me-chanical malfunctions in the cylinder will causedeviations from the normal patterns. The devia-tions may be irregularities in shape, or in therelative size or position of the patterns. Eachtype of malfunction forms a pattern peculiar tothe malfunction. For example, on two enginesof the same type, with the same type ignitionsystems, shorted high-tension leads would formsimilar patterns on the cathode ray tube.

There are several types of ignition systems,each of which produce groups of patternspeculiar to a certain type ignition system. Thetype of spark plugs installed may cause thepatterns to vary slightly. For all of the previ-ously mentioned reasons it is extremely impor-tant that the analyzer operator have a thoroughknowledge of the ignition system and engineprior to attempting analysis or recommendingany corrective action. The patterns of thelow-tension ignition system used on the R3350engine are discussed here. Other engines withlow-tension ignition systems will produce pat-terns somewhat similiar to the patterns picturedin this chapter.

128

133

LOW-TENSION IGNITIONSYSTEM PATTERNS

On the 83350 engine, the magneto arrange-ment is that of two 9-cylinder engines. Eachprimary coil of the magneto fires nine (an oddnumber) spark plugs; thus the successive firing.,of the same spark plugs are of alternate positiveand negative polarity. For example, the firsttime that the front spark plug of No. 1 cylinderfires, the spark will travel from the centerelectrode of the spark plug to one of the outerelectrodes; the next time this same spark plugfires, the spark will travel from one of the outerelectrodes to the center electrode. This polaritychange causes a double pattern to appear on thecathode ray tube. Normal patterns, slow sweep,18-cylinder engine, low-tension ignition system,are shown in figure 6-11. With the sweep switchin the SLOW SWEEP position, crankshaft travelof 720° (all cylinders) appears on the cathoderay tube. The pattern at the left side of thecathode ray tube is the pattern for the cylinderselected by the cycle switch. The pattern secondfrom the left is the pattern of the next cylinderto fire, and so on in the firing order of theengine.

Now place the sweep switch in the FASTSWEEP position. In this position crankshafttravel of only 80° (patterns of two cylinders)

AD.390Figure 6.11. Normal patternslow sweep, l&cylinder

engine, low-tension ignition system.

Chapter 6 ENGINE ANALYZERS

appears on the tube. The pattern on the left isthe pattern of the cylinder selected by the cycleswitch. The right-hand pattern is the pattern ofthe next cylinder to be fired by the samemagneto. Figure 6-12 shows a normal low-tension pattern in the FAST SWEEP position.Both patterns appear above and below the traceline, as successive firings of the same spark plugare alternately positive and negative (positiveabove the trace line, negative below). Thenormal pattern has the following characteristicsas shown in figure 6-12.

I

A0.391Figure 612 Norinal lovrtension pattern fast sweep.

1. Breaker point opening. The instant ofbreaker point opening, shown by the departureof the beam from the horizontal trace line.

2. First excursion. The initial rise and thereturn toward the trace line, indicating the highinitial peak voltage necessary to overcome theresistance in the secondary circuit.

3. Second excursion. Indication of the dis-charge of the condenser.

4. Saddle. Several low frequency waves repre-senting ionization of the spark plug gap.

5. Hook. A slight, though distinct, increase inamplitude before the beam falls to the trace line,indicating combustion.

6. Breaker point closing. The point at whichthe pattern returns to the trace line.

An engine is analyzed by comparing thecharacteristics of abnormal patterns to the

characteristics of a normal pattern. In general amalfunction that causes a higher than normalresistance in the ignition circuit (e.g., a discon-nected spark plug lead) will produce a patternthat has a higher than normal amplitude and ashorter duration of the active portion of thepattern giving a high narrow appearance. Amalfunction causing lower than normal resist-ance (e.g., a shorted spark plug lead) willproduce a pattern with lower than normalamplitude and a longer duration of the activeportion of the pattern giving a long, lowappearance.

A schematic drawing of a low-tension ignitionsystem is shown in figure 6-13. For the purposeof this discussion of abnormal patterns, theschematic drawing is divided into three sections:A, B, and C. The abnormal patterns are alsodivided into three groups. For example, ashorted secondary pattern will indicate troublewith one of the components in section C of theschematic drawing; it is listed with group Cabnormal patterns.

In the following abnormal pattern illustra-tions in which the two patterns appear, theabnormal pattern appears on the left and anormal pattern is shown on the right for acomparison.

Group A Patterns

Groups A patterns are caused by arcingbreaker points, breaker point bounce, breakerpoints out of synchronization, a shorted primarycoil, an open primary coil, or an open connec-tion somewhere between these components.

An arcing breaker points pattern is shown infigure 6-14. An early stage of arcing breakerpoints appears as a bright spot just after thebreaker point opening. Severe arcing is illus-trated. The arc is maintained until the pointshave opened sufficiently to extinguish the arc, atwhich time primary coil current flow ceases,inducing a surge of energy into the high-tensioncoil. The activity in this high-tension coil thenbecomes visible on the tube. Since a largepercentage of the primary coil energy wasdissipated during the arcing, the amplitude ofthe pattern is not as large as normal. Theoscillation in the saddle portion of the patternindicates that the spark plug is firing. All spark

129

1;34)-


IGNITION TRANSFORMERANALYZER PRIMARY COIL

1'TRANSFORMER

--7 SECONDARY COIL

PRIMARY COIL

PRIMARY CONDENSER DISTRIBUTOR (ARial

I PLUG

BREAKER I

POINTS

A 444 B C --PI

Figure 613.Low-tension ignition systemschematic drawing.

b4

AD.393Figure 614.Arcing breaker points pattern

low-tension ignition systo.o.

AD.392

plugs fired by the affected magneto display thispattern. Probable causes are oil on the breakerpoints or a defective (open) or ,.'cconnectedprimary condenser.

A breaker point bounce pattern is shown infigure 6-15. The pattern shown in figure 6-15resembles that for breaker point nonsynchroni-zation (fig. 6-16). The marked difference, how-ever, is the short trace line separating the twoinitial high-amplitude oscillations. Breaker pointbounce may occur before the normal breakerpoint opening and after the normal breakerpoint closing. Probable causes are a weakbreaker point spring or damaged cam with roughspots on it. A weak spring should cause bounceon all spark plug positions of the affectedmagneto; for a damaged cam the bounce shouldoccur on only one spark plug position.

A breaker point nonsynchronization patternis shown in figure 6-16. The breaker point


breaker points are not synchronized, the breakerpoints associated with the patterns appearing tothe left are opening before those associated withthe patterns on the right. By measuring thedistance on the cathode ray tube between thebreaker point openings and allowing 1/32 of aninch to equal 1° of crankshaft rotation, theamount of synchronization error may be de-termined. The breaker point nonsynchronizationcheck should be made on the cylinder to whichthe magnetos are timed.

The foregoing check indicates that one set ofbreaker points is opening before the otlar set,but it does no indicate which breaker points areopening first. By switching the condition switchfrom "B" to "L," then to "R," it can then be

AD.394 determined which set of points is opening first.Figure 6-15.Breaker point bounce pattern but it cannot be determined by this check which

low-tension ignition system. set of points is timed properly.A shorted primary circuit (magneto to distrib-

utor) pattern is shown in figure 6-17. A com-pletely shorted primary circuit in the groundingsystem or between the magneto and distributorproduces no pattern; only the horizontal traceline is seen. Nine very small pips, which areinductive pickups from the other magneto, aresometimes visible. All spark plugs fired by the

AD.396Figure 6.16. Breaker point nonsynchronization

pitternlowension system (condition switch set to"B" position).

synchronization check is made to determine thatboth spark plugs in each cylinder are firedsimultaneously. The condition switch is set to"B" (both magnetos) to display on bre cathoderay tube the patterns from both left and righmagnetos superimposed on each other. If the

131

1.;6"

AD.396Figure 6-17.Shorted primary circuit (magneto to dis-

tributor) patternlowtension ignition system, slowsweep.


affected magneto will display this pattern. Thenine additional patterns are from the othermagneto. Probable causes are faulty magnetoswitch or grounding system, the breaker pointsnot opening, a grounded primary coil or conden-ser, or a ground between the magneto anddistributor.

An open primary circuit (magneto to distribu-tor) pattern is shown in figure 6-18. The ninesmall distorted patterns are caused by the faultycircuit. The nine normal patterns are from theunaffected magneto, but are usually distortedslightly because of the malfunction present onthe one magneto. Probable causes are thebreaker points not closing either mechanically orelectrically because of excessive point clearanceor a foreign substance insulating electrical con-tact between the points. The pattern can also becaused by an open in the distributor.

AD.397Figure 6-18.Open primary circuit (magneto to distribu-

tor) patternlow-tension ignition system, slow sweep.

Group B Patterns

Patterns in group B are caused by trouble inthe component shown in section B of figure6-13.

An open primary circuit (distributor to coil)pattern is shown in figure 6-19. This pattern hasa very high initial voltage and what appears to bea series of loops. Probable causes are an open in

AD.396Figure 6-19.Open primary circuit (distributor to

coil) patternlow-tension ignition system.

the lead from the distributor to the cylinder-mounted coil or an open in the primary windingof this coil.

A shorted primary circuit (distributor to coil)pattern is shown in figure 6-20. No pattern willappear for the selected spark plug (only a splittrace line will be seen), but the pattern for thenext spark plug fired by the selected magneto isdistorted because of the reaction of this mal-function on the system. Probable causes are aground in the primary lead from the distributorto the cylinder-mounted coil or a short in theprimary winding of this coil.

An arcing distributor brush pattern is shownin figure 6-21. This pattern appears normalexcept for the unusual amount of activity in thesloping tail of the pattern between the hook andbreaker point closing. Early stages of arcingappear on isolated cylinders. As the malfunctionprogresses, more cylinders are affected. Theoscillations become larger and cover a greaterportion of the pattern. Severe arcing may causeexcessive activity throughout the entire lengthof the pattern. Probable causes are burned ordirty distributor segments, concaved segmentsurfaces causing the brushes to jump, weakbrush springs, feathered segment edges, or ex-cessive distributor vibration.


AD.399Figure 6.20. Shorted primary circuit (distributor

to coil) patternlow-tension ignition system.

AD.400Figure 6.21. Arcing distributor brush pattern

low-tension ignition system.

Group C Patterns

These patterns indicate a malfunction in thesecondary coil of the transformer coil unit, thehigh-tension lead, or the spark plug itself. (Seefig. 6-13.)

133

These are three different patterns caused byhigh resistance in the secondary circuit. Thedifference in these three patterns depends on theamount of that resistance. The resistance variesfrom first-stage resistance, which permits SOMEspark across the spark plug gap, to an opencircuit, which permits NO spark across ,the sparkplug gap. It is sometimes hard to distinguishbetween the patterns of first -stage resistance andsecond-stage resistance, but since the causes arethe same in both cases, the corrective action isthe same. Second-stage resistance usually beginsas rust-stage resistance and becomes progres-sively worse.

A first -stage high resistance secondary patternis shown in figure 6-22. The initial high peakvoltage is higher than normal, and this firstexcursion returns to a point nearer the zerotrace line. Following this the saddle portion isshorter than normal. Probable causes are largespark plug gap, high resistance within the sparkplug, dirty spark plug contact button or cylin-der-mounted coil contact button, damaged ciga-rette spring at the spark plug or at the cylinder-mounted coil, or any abnormal gap in thesecondary circuit.

AD.401Figure 6-22.First stage high resistance

secondary patternlow-tension ignition system.

A second-stage high resistance pattern isshown in figure 6-23. The initial high peakvoltage is higher than normal, and this firstexcursion returns to a point very near the zero


AD.402Figure 6.23. Second stage high resistance secondary

patternlow-tension ignition system.

trace line. Following this, the saddle portion ismuch shorter than normal. The hook followingthe saddle and the sharp return toward the zerotrace line are not pronounced. The probablecauses are the same as those for first-stage highresistance patterns.

An open secondary pattern is shown in figure6-24. The initial high peak voltage is higher thannormal, and this excursion returns to a pointbelow the zero trace line. This is followed bythree or four excursions with decreasing ampli-tude and a low frequency tail. Since the high-tension circuit is open, the plug is not fired andthe high frequency oscillation normally associ-ated with the energy flow in the high-tensioncircuit is not present. This pattern may occur ononly one or on scattered cylinders. Probablecauses are an open within the spark plug, adisconnected lead, or any open in the high-tension circuit.

An initial fouling of a spark plug pattern isshown in figure 6-25. The height of the initialhigh amplitude oscillation is less than normaland does not return as close to the zero traceline as normal. There is less oscillation .in thesaddle portion of the pattern, and the sharpslope following the saddle is not as pronounced

134

1;41'

AD.403Figure 6-24.Open secondary pattern


AD.404Figure 6.25. Initial fouling of spark plug pattern


as normal. Some combustion is indicated by theoscillation in the saddle portion of the pattern.Probable causes are early stages of spark plugfouling due to a foreign substance (lead orcarbon) on the spark plug electrodes. Thiscondition can generally be cleared up by therecommended plug defouling procedure.

A fouled spark plug pattern is shown in figure6-26. This pattern is similar to the shortedsecondary pattern. However, in contrast to the


AD.405Figure 6-26.Fouled spark plug pattern

!oar-tension ignition system.

steady appearance of the shorted secondarypattern, it represents a changing, claiming appear-ance. Probable causes are spark plug fouling dueto a foreign substance (lead or carbon) on theelectrodes. This condition can sometimes becleared up by using the recommended defoul-ing procedure.

A shorted secondary pattern is shown infigure 6-27. The initial peak voltage amplitude isless than normal. The pattern tail appears as asteady curved line. Probable causes are a badlyfouled spark plug, a short circuit within thespark plug, a short in the high-tension lead orcoil, or a spark plug lead off and shorted toground. If the pattern appears on both sparkplugs of the same cylinder, it usually indicatescylinder failure where metal particles havepeened over the spark plug electrodes. In thiscase the engine should be secured as soon aspossible to prevent further damage.

Miscellaneous Patterns

Two patterns not caused by faulty ignitionare in this group. They are open "P" leadpattern and the no combustion pattern.

AD.406Figure 6.27. Shorted secondary pattern

lowtension ignition system.

An open "P" lead pattern is shown in figure6-28. This pattern can be best described as ninesmall pips and nine normal patterns. The normalpatterns are usually slightly distorted because ofthe malfunction. Probable causes are an open inthe magneto primary lead either in the magnetoor at the AN connecter on the magneto, an openbetween the magneto and grounding switch, oran open in the ignition cable-to the analyzer.This pattern is identical to the shorted primarypattern (fig. 6-17). It does not affect engineoperation; however, it indicates a "hot mag"(cannot be shut off) and is a very hazardoussituation. It must be tagged and repaired imme-diately.

A no combustion pattern is shown in figure6-29. High-amplitude oscillations continuethroughout the pattern. This pattern will appearfor both spark plugs of a cylinder. It indicatesnormal ignition without combustion. Probablecauses are poor carburetion, faulty fuel nozzle,faulty injection pump, leaking fuel line, in-duction system leaks, sticking valves, or anymalfunction causing abnormally lean mixturesresulting in no combustion. Ignition and com-pression must be normal for this pattern toappear.

135

140.

AVIATION MACHINIST'S MATE R i & C

I

I

o

AD.407Figure 628.Open "P" lead pattern

lowtension ignition system.

AD.408Figure 629.-Alo combustion pattern.

VIBRATION ANALYSIS

With the portable analyzer, provisions aremade for the vibration analysis of only onecylinder. With the vibration pickup installed inthe cylinder to be analyzed, and the cable

136

141

connection made from the pickup to the Y-leadof the synchronizing generator (fig. 6-13), thevibration signal is carried to the analyzer by thefive-strand cable that also carries the synchroniz-ing generator signals to the analyzer. The vibra-tion leads are shielded to prevent distortion ofthe pattern by ignition or other outside sourcesof voltage.

The analyzer measures the shock stresses onthe cylinder head as the piston in that cylindercompletes the four strokes of its cycle (720° ofcrankshaft travel). These shocks, or impactforces, which appear as voltages on the cathoderay tube, are the results of exhaust and intakevalve closing, combustion, and scavenging. Anyadditional patterns seen are indicative of enginemalfunction and should be thoroughly investi-gated.

The normal sequence of events taking placeinside the cylinder as the piston completes thefour strokes of a cycle are as follows:

1. Starting with the piston at top center onthe intake stroke, the first event taking place asthe piston travels downward is the exhaust valveclosing.

2. Then, slightly after bottom center, theintake valve closes as the piston travels upwardon the compression stroke.

3. Before the piston reaches top center onthis stroke, ignition occurs, starting the combus-tion of the mixture.

4. As the piston travels downward on thepower stroke, the gases expand until the exhaustvalve opens.

5. The piston passes bottom center and startsupward on the scavenge stroke. Shortly beforetop center the intake valve opens, and the eventsare repeated.

The vibration patterns, as seen on the scopeof the analyzer, are portrayed in vertical pips.Normally only four ) ips are seen on the analyzerscope, representing exhaust valve closing, intakevalve closing, combustion, and scavenge. Thereare two important factors governing accurateinterpretation of these patterns: the time posi-tion and the amplitudes of these pips.

Time Position

The time position, or location of the pipsalong the horizontal trace line, depends on


when, or at what crankshaft position, theseevents causing impact forces occur. The timeposition of the pips indicating exhaust valve andintake valve closing is affected by valve timing,valve clearances, and valve operation. Someallowance must be made for normal variations intime position caused by normal differences invalve clearances, cylinder temperatures, andwear.

Amplitude

The amplitude of the pips representing anevent in the cylinder depends upon the intensityof the impact forces in the cylinder. On engineshaving exhaust and intake valves of the same sizeand weight, such as the R3350, the pips forexhaust closing and intake closing will haveabout the same amplitude. On engines havingexhaust valves which are larger and heavier thanthe intake valve, such as the R2800, the pips forthe exhaust valve dosing will be higher in

EXHAUSTVALVE SEATS

INTAKEVALVE SEATS

amplitude than the pips for the intake closing,because the impact forces created when theheavier valve seats are greater. Exhaust andintake valve opening may or may not cause verysmall pips to appear on the cathode ray tube.The pips representing combustion will vary inamplitude according to the pressures in thecylinder. At high brake mean effective pressuresthe pip will become higher. When detonationoccurs, the amplitude of the pip will be veryhigh. The pips representing scavenge are causedby the vibrations accompanying the discharge ofturbulent gases through the exhaust port. Figure6-30 illustrates the association of engine eventswith the vibration pattern.

In order to obtain a vibration pattern on theportable engine analyzer, place the conditionswitch in the VIBRATION position, place thesweep switch in the SLOW position, and indexthe red dot on the cycle switch to the number ofthe cylinder on which the pickup is mounted. Avibration pattern for 720° of crankshaft rotation

COMBUSTIONSCAVENGE

STROKE

C-720 CRANKSHAFT ROTATION

AD.409Figure 630.Association of the engine events with the vibration pattern.

137

1.42-


will appear on the cathode ray tube. Thebackground hash (the low-amplitude part of thepattern between the events) should be adjustedto about one-fourth inch in height. This is donewith the gain control adjustment on the powersupply amplifier.

A normal vibration pattern is shown in figure6-31. The pip at Pi indicates the exhaust valveopening; the pip at P2 indicates the intake valveopening. These pips may or may not appear on anormal pattern. A normal pattern for an enginehaving the same size valves would have the EC(exhaust close) pip or IC (intake close` pip ofequal amplitude.

Figure 6.31. Normal vibration pattern.

AD.411Figure 6-32.Sticking exhaust valve pattern.

AD.410 AD.412Figure 6.33. Bouncing exhaust valve pattern.

A sticking exhaust valve will produce apattern such as that shown in figure 6-32. TheEC appears to shift back and forth, intermit-tently moving to the right, which indicates thevalve is sticking and closing late. Probable causesare weak valve spring, warped valve stem, carbondeposits on the valve stem, or worn or damagedvalve guide.

A bouncing exhaust valve pattern is shown infigure 6-33. Notice the multiple EC pips. This isusually caused by a weak valve spring.

An improperly seating exhaust valve pattern isshown in figure 6-34. The EC pip will either bemissing or be very small in amplitude. Thecombustion and scavenge pips generally do notappear when this condition exists. The probablecauses are a damaged valve stem or guide,broken valve spring, broken cam follower, swal-

AD.413Figure 6-34. Improperly seating exhaust valve

pattern.

lowed valve, or a foreign substance under thevalve head.

138

143'

Chapter b ENGINE ANALYZERS

The pattern illustrated in figure 6-35 is anormal pattern with foreign pips appearingthroughout the pattern. The four foreign pipsillustrated are evenly spaced, occurring at thetravel limits of the piston, two at the top centerposition of the piston, and two at bottomcenter. This pattern is considered normal whenthe foreign pips are of smaller amplitude thanthe valve closing pips. This pattern is caused bybadly worn piston pins, piston slap, or possiblebearing wear.

'AIM Mill

AD.414Figure 635.Foreign vibrations throughout pattern.

A no combustion vibration pattern is shownin figure 6-36. The valve closing pips are normal,but the combustion pip is missing. Since com-bustion does not occur, the turbulent gases arenot present to cause the scavenge pip. Thispattern is usually due to lack of fuel because ofa bad leak or an obstruction in the inductionsystem. In the case of an engine equipped withfuel injection it may be caused by a faulty fuelinjection nozzle, or a broken or disconnectedfuel line.

A medium detonation pattern is shown infigure 6-37. Detonation vibrations occur at thesame time position as normal combustion vibra-tions, but detonation vibrations are higher inamplitude and may be spasmodic. The ampli-tude varies with the extent of the detonation. Alean mixture is a common cause of detonation.

If any part of a vibration pattern exceeds theEC event in amplitude, it indicates serioustrouble in the engine.

139

144

y..

AD.415Figure 6-36.No combustion vibration pattern.

AD.416Figure 6.37. Medium detonation pattern.

TIMING OF THESYNCHRONIZING GENERATOR

TIMING OF THE PORTABLEANALYZER

The synchronizing generator (fig. 6-38) mustbe properly timed to the engine in order for thehorizontal trace line to represent the propercrankshaft angle. Four methods of timing arediscussed here.

Ignition Pulse Method of Timing

Install an ignition pulse pickup unit betweenany convenient spark plug and spark plug lead.


AD.417Figure 6-38.Synchronizing generator.

An ignition pulse pickup unit is shown in figure6-39. Connect the vibration lead to the ignitionpulse pickup lead and to the analyzer lead.Connect the analyzer to the proper powersource. Start the aircraft engine. Turn theanalyzer power switch to the ON position.Check for proper phasing (patterns should movefrom right to left across the face of the cathoderay tube when the cycle switch is turned in aclockwise direction). If the patterns move fromthe left to the right, change the position of thetwo-position generator rotation switch.

Figure 639.Ignition pulse pickup unit.AD.418

140

Check for proper magneto grounding. This isaccomplished by placing the sweep switch onFAST, the condition switch to LEFT, and themagneto switch to RIGHT, grounding cut theleft magneto. A shorted primary pattern (de-scribed previously in pattern interpretation)should appear on the cathode ray tube. Leavethe sweep switch on FAST, place the conditionswitch to RIGHT, and the magneto switch toLEFT, grounding out the right magneto. Again,a shorted primary pattern should appear. Placethe sweep switch in SLOW SWEEP. This gives aview on the tube of all cylinders. Adjust the gaincontrol to give a distinctively high pip on thetube.

Now place the sweep switch in the FASTSWEEP position. Index the cycle switch to thecylinder number on which the ignition pulsepickup unit is installed. Hold the cycle switchfirmly in this position, and with a screwdriver,rotate the screw in the center of the knob of thecycle switch until the distinctively high pip isapproximately one-half inch from the left end ofthe trace line. The analyzer is now timed to theengine ignition system.

Known-Trouble Method Timing

Disconnect the lead from any convenientspark plug and cap the lead or tie it back whereit cannot make ground contact with the engineor cowling at any place. Start the aircraft engine,connect power to the analyzer, and turn on thepower switch. Check for proper phasing andmagneto grounding. With the condition switch,select the proper magneto (the magneto whichfires the spark plug from which the lead wasremoved). Set the sweep switch to the FASTSWEEP position. Index the cycle switch to thecylinder number on which the spark plug leadwas removed. Hold the cycle switch knob firmlyin this position and, with a screwdriver, rotatethe screw in the center of the knob until theopen secondary pattern (described previously inthis chapter) is approximately one-half inchfrom the left end of the trace line. The analyzeris now timed to the engine. Shut down theengine and replace the spark plug lead beforecontinuing with analysis. When using the known-trouble method of timing, you should be surethat there is not another trouble in the system

145


which would cause a similar pattern to the onewhich you have intentionally introduced.

The disadvantage of the ignition pulse andknown-trouble methods results from the anal-yzer being timed to the ignition system insteadof the engine crankshaft. Too, there is thepossibility that the magneto being used may notbe timed properly.

Pin Timing Method

Install the synchronizing generator on theauxiliary tachometer mounting pad as with theportable analyzer if it is not already installed.Using a piston position indicator, locate, theproper crankshaft position. The appropriatetechnical instructions must be consulted for thisinformation. (For example: Position the crank-shaft at 36° BTC, compression stroke, No. 1

cylinder for R3350-24 engines.) Loosen thecover clamping ring of the syrrhronizing genera-tor (fig. 6-38). Remove the screw from thetiming pin hole. Insert the timing pin in thetiming pin hole. Rotate the housing, !seeping alight pressure on the timing pin. When the

141

146

timing pin falls into the slot of the rotor, thegenerator is timed to the engine. Tighten thecover clamping ring, remove the timing pin, andreplace the screw in the timing pin hole.Connect the cable to the receptacle on thegenerator.

Electrical Timing Method

As with the pin method, locate the propercrankshaft position, install the synchronizinggenerator, and loosen the cover clamping ring.Connect a milliammeter to the receptacle on thegenerator as follows: (1) Negative side of theammeter to "A" pin of the receptacle; (2)positive side of the ammeter to "B" and "C"pins of the receptacle (fig. 6-39). Rotate thestator housing in short jerky movements. Stopthe rotation at the exact position where thedeflection on the ammeter changes from neg,a-five to positive. The synchronizing generator isnow timed to the engine. Secure the coverclamping ring, disconnect the ammeter, andconnect the cable to the receptacle on thegenerator.

CHAPTER 7

RECIPROCATING ENGINE REMOViti AND INSTALLATION

This chapter deals primarily with the generalprocedures involved in reciprocating engine re-moval and installation. The step-by-step proce-dures for removal and installation of a specificengine can be found in the applicable technicalinstructions, which should be used as a guide inthe actual removal and installation procedure.

The first part of this chapter deals withordering, inventorying, and disposal procedures.The second portion covers the removal andinstallation procedures of a powerplant whichencompasses almost all the accessories that willbe encountered by an ADR. Powerplant preser-vation and depreservation are covered in the lastpart of the chapter.

ORDERING, INVENTORYING, ANDACCOUNTING FOR THE QEC

The ADRC must know the procedures forordering, inventorying, and accounting for quickengine change kits (QECK) and spare engines.

Quick engine change kit (QECK) is a kitcontaining all items required for a quick enginechange assembly, less government furnished ac-cessories, engine, and propeller. Quick enginechange assembly (QECA) is a quick enginechange kit completely assembled on a quickengine change stand with the engine and all theaccessories, less the propeller for reciprocatingengine.

The initial requirement for the QECK isdetermined by the Naval Air Systems Command.When such a requirement is established, theQECK is procured from the airframes contractorand allocated in sufficient quantities to meetinitial outfitting requirements. The AviationSupply Office can fill supplement sectionBRAVO requirements for newly formed squad-rons where complements of existing squadronshave been reduced.

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147

Accounting for the QECK is the responsibilityof the supply department, but in some cases theADR is responsible for the inventory of the kit.Reports of quick-change kits, of which theQECK is considered one, are required monthlyfrom all reporting activities. If a supervisor hascustody of a QECK he must make his reports tothe local supply activity on time to insure timelypreparation of the consolidated report to theNaval Air Systems Command.

A QECK should not be uncrated for replace-ment of overage components or incorporation ofapplicable changes. Outstanding changes beyonda using activity's capabilities are installed priorto issue.

NOTE: The powerplants supervisor must takenecessary steps to insure that the QECK in hiscustody is not used for a ready source of spareparts. He can accomplish this by proper indoctri-nation of his workers and proper securitymeasures.

ENGINE DISPOSAL PROCEDURES

ft is the responsibility of the ADR to knowthe procedures for the disposition of aircraftengines removed from service. To know this hemust be familiar with the system used by theNaval Air systems Command. Each model ofaircraft engine is assigned to one of the follow-ing classifications, and by this classification thedisposition of the engine is determined.

CLASSES

Class I and II

These engines are installed in currently oper-ating naval aircraft or scheduled for installationin new aircraft.

Chapter 7-- RECIPROCATING ENGINE REMOVAL AND INSTALLATION

Classes IBA and 111B

These engines are installed in current operat-ing naval aircraft, aircraft held in reserve stockor contingency reserve, and aircraft on bailment,loan, or lease.

Class IV

Class IV engines are obsolete. These enginesare no longer required to support aircraft in thecurrent naval operating program, but are beingretained for training purposes, special projects,cannibalization, or conversion to an acceptableconfiguration.

Class V

These engines are obsolete and excess to therequirements of naval aviation.

DISPOSITION

Serviceable class I, II, HIA. and IIIB enginesare Navy required and should be reported on theaircraft engine accountability report form.

Unserviceable class I and II engines locatedwithin the continental limits of the UnitedStates are disposed of as follows:

1. Engines removed from aircraft due toengine failure or high time, and damaged spareengines should be shipped to the designatedoverhaul activity.

2. Engines installed in aircraft stricken incategories 1, 2, and 4 are to be recovered andshipped to the designated overhaul activityunless the Naval Air Systems Command specifi-cally authorizes disposal simultaneously with theaircraft.

3. All engines referred to must be reportedon form NavAir 13700/2 under the applicablecodes.

4. The overhaul and repair departments mustdetermine the feasibility of overhauling damagedengines or recommend disposal by strike inaccordance with current instructions.

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14S

Unserviceable class 111A engines located with-in the continental limits of the United States areretained at the present location or point ofgeneration pending disposal instructions. En-gines in this classification located at a designatedoverhaul activity can be utilized for support oflimited overhaul requirements as necessary.

Unserviceable class IIIB engines and all class Vengines, both serviceable and unserviceable, lo-cated within the continental limits of the UnitedStates are disposed of as follows:

1. If in reportable condition, engines in thesecategories must be retained at the presentlocation or point of generation, and reported tothe supply department. The supply departmentfurnishes the holding activity an automaticrelease date after which the engine may bedisposed of without further authorization.

2. Engines installed in aircraft stricken maybe retained with the aircraft and reported in theapplicable status code. Upon final disposition ofthe aircraft, the engines may be disposed ofsimultaneously without further authorization.

Unserviceable class II, 111A, and IIIB enginesand all class V engines, both serviceable andunserviceable, located outside the continentallimits of the United States must be disposed ofas excess in accordance with instructions setforth by Navy Property Redistribution andDisposal Regulation No. 1, as amended.

Serviceable and unserviceable class IV engines,both installed and spares, should be retained atthe present location pending disposal instruc-tions from the Naval Air Systems Command.

When an aircraft is stricken because it is lostor missing, or suffers complete destruction, theengines which were installed are expended withthe striking of the aircraft.

Spare engines damaged to the extent ofcomplete destruction are the subject of localsurvey action and subsequently are stricken.

Engines determined as excess in accordancewith current instructions and reported to theproper authority are retained, pending disposalby transfer or donations. No accessory or partshortage is filled or rework accomplished onsuch engines. Engines classified as excess by theNaval Air Systems Command and awaiting dis-position by scrap or salvage do not requirefurther preservation or protection.


ENGINE BUILDUP ANDENGINE CHANGE

Reciprocating engine removal and installationor "engine change" includes the following re-quirements: cowling removal, engine removal,engine installation (including proper hookup andrigging), systems adjustments, and completesystem checkout for flight.

A Chief or First Class Aviation Machinist'sMate R is likely to be assigned the responsibilityof supervising the powerplants work center ateither the Intermediate or Organizational main-tenance level. A. the Intermediate maintenancelevel the powerplants work center is primarilyconcerned with engine buildup, and at theOrganizational maintenance level the power-plants work center is normally concerned withthe engine change. Therefore, the senior ADRmust be capable of supervising and directingboth engine buildup and engine chf rages.

REASONS FOR REMOVAL

The reasons fpir engine removal are as follows:1. High time, The current issue of General

Reciprocating Emine Bulletin (GREB) 86 listsall reciprocating engines and the maximumallowable operating time for each. It also author-izes, under certain conditions, two 10-percentextensions of the maximum allowable operatingtime.

2. Mechanical failures. These include threecategories: internal, external, and unsatisfactoryperformance.

a. External failure. This includes cracks inthe main engine sections, broken studs whichcannot be replaced, and/or damage to a part thatcannot be repaired in the field.

b. Internal failure. This is further brokendown into two groups: determined causes andundetermined causes. Determined causes areknown failures of parts; for instance, a super-charger clutch stuck in high blower, no lowblower action, hydraulic lock, or an impellerthat has been damaged beyond limits. Unde-termined causes are not readily apparent. Exam-ples of these are engine seizures, unusual noises,and met! particles in the sump or strainers.Whenever metal particles are found in the sumpand strair ers, see the current issue of GREB 165

which covers metal contamination of enginesand provides operating activities with compre-hensive procedures for the identification offoreign material, serviceability determination,test, and cleaning of contaminated engines andoil systems. Further, it serves to eliminateunnecessary removals and overhauls of engineswith suspected internal failure.

c. Unsatisfactory performance. Examplesof unsatisfactory performance are high oil con-sumption; low compression (covered by thecurrent issue of GREB 207) caused by broken orworn rings and burned or warped valves; worn,scuffed, or damaged pistons; and internal oilleaks which will cause malfunction of systems orbearing failure.

3. Accidents. Possible engine damage mayoccur whenever the propeller comes into contactwith a foreign object or the ground uponlanding. Whenever this happens, the followingprocedures must be followed to determine theextent of the damage, if any, to the engine.

a. If engine is not operating at impact.(1) Always inspect the propeller shaft

for runout in accordance with the applicableGREB. NOTE: If the propeller has been sub-jected to extensive damage indicating that alarge amount of work will need to be performedto determine the extent of the damage to theengine, the engine should be removed andreturned to the designated overhaul activity formajor inspection and repair.

b. If the engine is rotating at impact.(1) If the propeller strikes a foreign

object or the ground which results in thecomplete stalling of the engine and the bladesare bent or twisted beyond allowable limits, theengine must be removed and sent to the desig-nated overhaul activity for inspection and repair.Whenever blade bending or twisting is notapparent to the naked eye, the propeller trackwill be determined by tracking with the use ofthe correct equipment and the proper proce-dures.

(2) Whenever the propeller strikes a for-eign object or the ground and does not result inthe complete stalling of the engine and does nottwist or bend the blades, but cuts, pits, orgouges are present so that the propeller needs tobe removed, the following procedures must befollowed:

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Chapter 7 RECIPROCATING ENGINE REMOVAL AND 1NSTALLA i ION

(a) The sumps and strainers must beinspected for metal contamination in accordancewith GREB 165 and its latest revision.

(b) Propeller shaft runout must bechecked thoroughly.

(c) Timing of the magneto must bechecked to determine if the engine has beensubjected to gear or shaft damage in the rearsection.

c. All information concerning the rejectingof or continuing in service propellers, rotors, orhelicopter gearboxes is included in the applica-ble publications pertaining to these components.

4. Overspeed. A current GREB covers maxi-mum overspeed and lists engines and the maxi-mum rpm allowed, the rpm at which an inspec-tion is required, and the rpm that requires anengine change.

Engines that have been operated in theinspection-required range must be properly in-spected to determine the status of the engine asfollows:

a. Remove the main oil screen and hispect.b. Check the valve clearances to determine

whether valve stretching has occurred.e. Chezk the compression of all cylinders;

replace any cylinders that show a compressionloss greater than 35 percent.

d. Visually inspect the cylinders for cracksand the tops of the pistons for indications oftwisted articulating rods.

e. Check all valve adjusting screws for thecorrect torque.

f. Check all spark plugs for the correcttorque.

g. Inspect cylinder holddown capscrews forthe correct torque.

h. Functionally check the propeller gov-ernor and other suspected components.

i. Ground check the engine.j. Inspect the strainers and magnetic sump

plugs.k. Conduct postflight inspection of the

strainers and the magnetic sump plugs after thenext three flights following abnormal operation.

5. Excessive corrosion. If this is of a suffi-cient nature, it requires an engine change. Whenpropeller shaft corrosion is present, the areaaffected and the depth of the corrosion ere thecriteria for an engine change. The propeller shaftshould be checked for corrosion as prescribed by

145

the current applicable GREB and whenevex thepropeller is removed for maintenance checks,rework, etc.

Engine modifications are normally accom-plished at engine overhauls. Specific enginebulletins may require an engine to be changedand sent to overhaul for incorporation of modi-fications, but usually is completed at the nextroutine overhaul if not done by the operatingactivity.

SAFETY PRECAUTIONS

x.50,

Prior to removal and installation of a recipro-cating engine the aircraft should be in a cleanworkspace, free from foul weather disturbances.Adequately secure the aircraft with wheelchocks or with tiedown provisions. Turn off allelectrical power to the aircraft. Install protectiveplugs and caps on all openings, lines, andelectrical connectors when disconnected or re-moved. .

Care must be taken when maneuvering work-stands, engine stands, cranes, etc., around theaircraft to prevent damage to the engine andaircraft. Prior to using a hoist or crane to raise orlower an engine, the cable should be checked forfrayed, worn, or broken strands. Check forproper routing of the cable on the drum toprevent cable slippage or jamming during engineremoval and installation. Never leave an engineunattended while it is being supported by ahoist. When lowering an engine, constantlyobserve the engine clearance with the aircraftnacelle to prevent damage to the engine ornacelle.

Cleaning of the engine air inlet and theaircraft nacelle cannot be overemphasized inorder to protect the engine from entr; offoreign materials which will cause seriousdamage to the engine. Account for each nut,bolt, washer, safetywire, etc., used or replacedduring engine maintenance. When transportingengines on trailers or trucks, make certain thatall openings of the engine are covered. If theengine is not to be installed in the aircraft in theimmediate future, install engine closures andcover the -engine with a clean, light canvas; orwrapping paper.

Do not start an engine before accounting forevery tool and all equipment used in the


vicinity, and thoroughly inspect the inlet ductarea and cowling for loose objects. Make certainall personnel and equipment are clear of thepropellers and aircraft control surfaces prior tostarting the engine. Use care when operating anengine on the ground or deck. Use no morepower than necessary.

FOREIGN OBJECT DAMAGE (FOD). AND QUALITY CONTROL

The object of aircraft maintenance is to insurethe highest state of readiness and reliability atthe lowest cost in men, money, and material.Two of the controlling factors in achieving thisgoal are FOD prevention and quality control.

Due to the large area and different workcenters involved in a reciprocating engine re-moval and installation, FOD potential is great.Therefore, the need for good quality control isgreater.

There should be little doubt as to whatconstitutes foreign objects. Actually a foreignobject may be anything that can pass through anintake or find its way into a sump, a fuel tank,or a lube tank with the potentiality of causingdamage to the engine or its components.

Toolboxes are a great source of foreignobjects. Every time something is taken from atoolbox and not returnedimmediately after use,FOD potentialities climb sky high. Engine afterengine has been damaged with stray wrenches,screwdrivers, and flashlights.

Toolboxes must be checked and rechecked.All parts, nuts, bolts, washers, and safetywiremust be kept off the floor, the deck, the turnupareas, and any other place where there is theslightest possibility that they might get into anengine.

Personal belongings must be carefullyguarded, even to the extend of emptying pock-ets before approaching an engine. Nothing mustbe placed near inlets of engines which could beforgotten.

The quality control concept is fundamentallythe prevention of the occurrence of defects. Thisconcept embraces all events from the start of themaintenance operation to its completion.

Prior to the engine installation, a thoroughinspection of the aircraft and engine should be

146

conducted. If any maintenance has been done inthe nacelles which required removal of sealants,insure that all affected areas are resealed prior tothe engine installation.

Inspect the nacelle area, including small open-ings, niches and indentation, for foreign mate-rials. Inspect the engine mount wells and mount-ing brackets. Check all electrical boxes andconduits, fire detector elements, and clips.

Check all lines, hoses, cables, and electricalwiring for correct installation and security. Theyshould be secured with clamps at proper inter-vals to prevent vibration and chafing.

TYPES OF ENGINE CHANGES

Two methods of engine replacement areemployed with reciprocating engine aircraft.They are the QEC (quick engine change) and thesix-point method. The QEC method is the morewidely used and is the one discussed in thischapter. The six-point method, although accept-able, has the disadvantage of consuming toomuch time. The prime requisite in naval aviationis the availability of aircraft or how soon theaircraft can be returned to a flying status.Therefore, the QEC method is the one that isused the most often.

Under some conditions, it is necessary tochange only the engine (six-point method) andtransfer, the necessary parts and accessories tothe new engine. The lack of replacement partsand accessories is the reason for using thismethod and involves either installing the partsand accessories on the engine while it ismounted on an engine stand or after it has beeninstalled on the aircraft.

QEC

The QEC unit consists of the powerplantcomplete with accessories, cowling, the oil cool-er and scoop, etc. The assembly may be de-tached at the firewall and removed intact iffurther disassembly is unnecessary. If the power-plant is being removed for disassembly, it maybe more convenient to first remove the propel-ler, oil scoop, and the cowling panels. Figures7-1, 7-2, and 7-3 show three different conditionsin which the engine may be removed. In some

Chapter 7RECIPROCATING ENGINE REMOVAL AND INSTALLATION

ENGINE HOIST EYE

Figure 7-1.Bare engine removal.

AD.421

AD.419 Figure 7-3.Complete powerplant removal from thefirewall (QEC).

AD.420Figure 7-2.Powerplant and engine mount removal.

147

15.E

cases where a propeller is not immediatelyavailable for the QEC buildup or the propellerstill has a considerable number of hours leftbefore it would ordinarily be changed, it isremoved and reinstalled on the replacementengine. See the current propeller bulletin for theallowable times between overhauls for propellersand propeller system components.

Removal of the Powerplantfrom the Aircraft

Prior to removal, perform an engine preserva-tion run in accordance with Nav Air 15-02-500.

When the powerplant is to be removed fromthe airframe to accomplish other work and beremounted after this work is accomplished, itwill not be necessary to drain the oil. If theremoval is for the purpose of an engine change,certain flushing procedures must be performedin accordance with the latest issue of GREB 165and Accessory Bulletin 42, Series 1964.


If the propeller has been feathered because ofinternal failure of the engine, it must be ascer-tained that there are no metal or foreignparticles present in the propeller featheringsystem. All feathering lines must be flushed. Thegovernor and the feathering pump should beremoved and sent to overhaul. The propellerdome and barrel should be thoroughly flushedand cleaned, and checked for metal contami-nation.

For removal of a typical powerplant from amultiengine aircraft, the following steps are tobe taken:

1. Support the tail of the aircraft with a tailstand.

2. Remove the propeller.3. Drain the engine oil tank, if required; then

close the hydraulic, fuel, oil, and the blast tubeshutoff, utilizing the firewall shutoff lever(emerg.) in the cockpit.

4. Drain the engine oil sumps and the oilcooler and replace the plugs.

5. Disconnect the battery or pull and tag allthe circuit breakers in the powerplant circuit tothe engine being removed.

6. Disconnect the magneto cannon plug atthe firewall recptacle and connect to the ground-ing receptacle.

7. Disconnect all fluid lines at the firewall.(See fig. 7-4.)

NOTE: Cap all lines and fittings as soon asthey are disconnected in order to prevent entryof foreign materials into the various systems.

8. Disconnect all electrical connections at thefirewall.

9. Disconnect the throttle and mixture con-trol rods at the master control and at thefirewall pulleys. Keep these rods with theaircraft.

10. Disconnect the engine supercharger controlrod at the engine rod.

11. Disconnect the cabin supercharger driveshaft disconnect cable at the disconnect lever(outboard engines only).

12. Remove the cabin supercharger drive shaftand disconnect unit (outboard engines only).

13. Remove the generator gearbox drive shaftand disconnect unit (outboard engines only).

14. Disconnect the accessory blast tube actu-ating rod at the valve and at the firewall. Keep itwith the aircraft.

1. Engine oil-in (enginesNos. 1, 2, and 4).

2. Engine oil-out (en-gines Nos. 1, 2, and4).

3. Propeller featheringoil.

4. Electrical connecter.5. Hydraulic pump suc-

tion.6. Oil tank vent.7. Hydraulic case drain

return.8. Hydraulic pump pres-

sure.9. Cabin supercharger

drive shaft discon-nect able (outboardnacelles only).

AD.422

10. Engine superchargercontrol cable.

11. Throttle and mixturecontrol pulleys.

12. Fuel vapor return.13. Oil separator return.14. Deicer suction.15. Deicer pressure.16. Fire extinguisher

supply-17. Master control anti-

icor.18. Propeller anti-icer.19. Fuel supply.20. Engine oil-out (engine

Na 3 only).21. Engine oil-in (engine

No. 3 only).

Figure 7-4.-Discnnnect points at the firewall(view looking aft). .

15. Attach the powerplant hoist sling and thevariable center of gravity beam to the power-plant as shown in figure 7-3.

16. Apply just enough lift to the hoist torelieve the engine attaching bolts of weight.

IP,

153


17. Make a final check to insure that alldisconnections have been made at the firewall.

18. Remove the powerplant attaching nuts,washers, and bolts. Note the combination ofbolts and washers at each point of attachmentfor correct reassembly.

19. Move the powerplant straight forward un-til clear of the nacelle.

NOTE: The assembly should be kept balancedto maintain a horizontal attitude in order toprevent damage to the control brackets andpulleys at the firewall.

20. Mount the powerplant on a workstand.

SHADED PARTS ARETRANSFERREDREPLA

TOCEMENT 3

ENGINE (UNLES3OVERHAUL OF PARTIS REQUIRED)

1. Lower cowl panelsupport cable hook.

2. Side cowl panel sup-port rod bracket

& Engine mount coolingblast tube.

AD.423

4. Upper cowl panelsupport rod bracket

5. Propeller featheringoil line and dips.

6. Fireseal installation.

Figure 7.5. Right side view of the powerplant

Removal of the EngineFrom the Mount

With the powerplant mounted on a work-stand, proceed with the following steps:

1. Remove the oil cooler scoop and allcowling.

SHADED PARTSARE TRAMMEDTO REPLACEMENTENGINE (UNLESS OVERHAULOF PART IS REQUIRED)

1. Propeller anti-icingfluid line and dips.Torquemeter pres-sure line and clips.

& Propeller anti.icerflow regulator.

4. Propeller junctionbox to brush housingconduit

5. Propeller junctionbox.

6. Propeller governorcontrol wiring.

AD.424

7. Cylinder head temp-erature bulb andwiring.

8. Propeller reversingblade switch wiring.

9. Power recovery tur-bine hood (three).

10. Engine mount coolingblast tube.

11. Fireseal installation.

Figure 7.6. Left side view of the powerplant

2. Remove the shroud access panels.3. Remove the three power recovery turbine

hood and tail pipe assemblies and place protec-tive covers over the turbines. (See fig. 7-5.)

4. Disconnect and cap the propeller anti-icing lines at the fireseal fitting.

NOTE: Figures 7-5, 7-6, and 7-7 are threeviews of the engine showing transferable partsand the parts locations.

5. Disconnect the propeller governor wiringharness at the engine left junction box.

6. Disconnect the propeller reversing har-ness at the engine left junction box.

7. Remove the governor and the reversingharness feed-through fitting screws at the fireseal

1.54

AVIATION MACHINISTS MATE R 1 & C

SHADED. PARTS ARE TRANSFERRED TOREPLACEMENT ENGINE (UNLESSOVERHAUL OF PART IS REQUIRED)

1. Power recovery tur-bine hood (three).

2. Power recovery tur-bine hood clamp as-sembly (three sets).

3. Fuel pump balanceline and clips.

4. Manifold pressureline and clips.

5. Engine dynafocalmounts (six).

6. Engine mount ring.7. Cabin supercharger

disconnect bearingtemperature indicatorwires.

ENGINE ASUPERCHARGER BRACKETASSEMBLY AND ROO

AD.425

8. Master control adapterand seal assembly.

9. Master control sealassembly.

10. Mixture control valvelever.

11. Throttle shaft lever.12. Engine supercharger

bracket assembly androd.

13. Master control deiceroil-out line.

14. Master control deiceroil-in line.

15. Torquemeter pressuregage line and clips.

Figure 7-7.-Accessory section of thepowerplant (looking forward).

and pull the harnesses forward for removal withthe engine.

8. Disconnect the temperature indicatorbulb wires for cylinders No. 1 and No. 2, audpull the wires back to remain with the mount.'

9. Disconnect the propeller feathering oilline at the fireseal.

10. Remove both fuel injection pumps.11. Remove the master control and place a

protective cover over the mounting pad.12. Disconnect the oil tank breather line,

engine breather lines, oil-in and oil-out lines, andthe engine oil pressure line at the engine.

13. Disconnect the oil-out temperature bulbwires.

14. Disconnect the inlet, outlet, and pressurebalance lines from the engine-driven fuel pumpand remove the pump.

15. Disconnect the seal drain lines at theengine-driven accessories, and disconnect theblower case drain at the engine.

16. Disconnect the air lines at the air pump.17. Disconnect the lines at the hydraulic

pump.18. Disconnect the manifold pressure line at

the engine.19. Disconnect the electrical terminals at the

magneto, generator, primer solenoid, starter,analyzer signal generator, and tachometer. Dis-connect the starter ground cable.

20. Disconnect the accessory blast tubes.21. Remove all plumbing support clips from

the engine.22. Make a final check to insure that all

disconnections are made.23. Install the hoist sling and variable center-

of-gravity beam as shown in figure 7-1 and applyjust enough lift to support the engine.

24. Remove the engine mount-to-mount ringbolts and bonding links.

25. Move the engine forward and up so thatthe engine rear oil sump will clear the mountring.

Installation of theEngine in the Mount

After an engine has been depreserved andprepared for installatiOn in accordance withcurrent technical publications, the followingsteps are to be taken for installation of theengine:

1. Transfer the engine-driven accessorieswhich are to be. returned to service from theremoved engine to the replacement, or installthe replacement accessories and parts.

NOTE: Each aircraft engine has an inventorylist of those parts and accessories which should

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Chapter 7 RECIPROCATING ENGINE REMOVAL AND INSTALLATION

remain with the engine. If this inventory list isnot available, the current GREB should beconsulted to determine which parts and acces-sories are to remain with the old engine and theones which are to be removed and installed onthe replacement engine.

2. Transfer the propeller governor harnessand propeller reversing harness to the replace-ment engine.

3. Transfer the propeller feathering line tothe replacement engine.

4. Transfer the propeller fairing assembly.5. Transfer the propeller electrical junction

box.6. Transfer the cowling support rod brack-

ets and lower cowl panel support cable hook.7. Install a new or reconditioned set of

engine mounts as follows:a. Clean the parting surfaces of the engine

mounting pads and the mount pedestals.b. Place new insulating pads over the en-

gine mounts.c. Install the six mounts on the engine,

using a washer under each nut. Tighten to thespecified torque.

8. Apply a thin coat of specified lubricantto the mating surfaces of horns, mount ringeyes, and the bolt shanks only. Do NOTlubricate the bolt threads.

9. Move the engine aft to aline mounts withthe mount ring and insert the bolts with theheads forward, using a washer under eachbolthead. Maintain the engine at an attitude thatwill bring the fireseal rings into alinement.

10. Mate the fireseal rings; then continue theaft movement until the engine mounts contactthe mount ring.

11. Install the washers and nuts and tightento the specified torque.

NOTE: If the entire chamfer on the end ofthe bolt does not extend through the lockingportion of the nut, remove the washer fromunder the nut. Do NOT remove the washer fromunder the bolthead. When installing the engine,apply a coating of the approved thread seal to allslip joint surfaces of the asbestos sheet seal,engine fireseal segment assemblies, fireseal re-taining ring assembly, engine fireseal flangeassembly, and engine fireseal retainer segment.Do NOT aline fireseal rings with fingers. Startthe engagement with the proper tool.

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...The remaining steps of installation are in the

reverse order of those given for the removal ofthe engine.

Installation of the Powerplanton the Aircraft

When the replacement powerplant is ready forinstallation on the aircraft, proceed with thefollowing steps:

1. Magnetically inspect the powerplant at-taching bolts.

2. Inspect all the firewall fittings and electri-cal connectors for condition. Make the necessaryreplacements before mating the power plant tothe firewall.

3. Inspect the shroud-to-firewall seal assem-bly and replace it if damaged.

4. Apply a thin coat of approved lubricant tothe mating surfaces of the nacelle and the enginemount aft fitting; to the exposed outer surfacesof the alining bushings; and to the exposed"surface of the shearpins. Do NOT lubricatethreads.

5. Hoist the powerplant package with thevariable center of gravity adjusted to suspendthe package in a horizontal position.

6. Move the assembly straight aft and engagethe shearpins and alining bushings.

7. Install the attachment bolts with the headsforward. Make certain that the washers with thechamfered bores are placed under the heads ofthe bolts.

8. Tighten all bolts evenly; then tighten thetwo upper bolts to the specified torque.

9. Remove the hoisting equipment; thentighten the remaining bolts to the specifiedtorque.

The remainder of the connections can now bemade in_the reverse order of removal.

1

SIX-POINT METHOD

The six-point method of engine change is thetype used to remove the engine from the mountwithout removing the mount from the aircraft.The engine can also be removed with the mountfrom the aircraft, but this will depend on theavailability of equipment such as L stands andengine stands to support the old and the newengines while the necessary work is performed.


This type of engine change is usually, a slowprocess; and when speed of operation is needed,it is not recommended unless the supportequipment is available.

The procedure involved in changing an air-craft engine by the six - print method will followalong the same lines as the QEC. All thenecessary disconnections and removal of partswill be the same except that all of this work willtake a longer period of time and usually withinthe same workspace in the hangar and in thevicinity of the aircraft. The length of time thathangar, dock, and shop space will be tied upwhile changing an aircraft engine by the six-point method is an item that will have to beconsidered. Also, the new engine and accessoriesthat need to be changed should be ordered farenough in advance in order that the minimumamount of time will be consumed once theengine change has been started.

RIGGING AND ADJUSTING

This section covers some of the basic inspec-tions and procedures to be used in the riggingand adjusting of throttles, mixture controls, fuelselectors, and firewall shutoff valves. Theseprocedures are given only to acquaint the ADRwith the rigging and adjusting procedures andshould not be used for actually rigging thecontrols on the aircraft.

Inspect all bellcranks, cables, and rod bearingsfor looseness, cracks, and corrosion. Particularattention should be given the rod and bellcrankswhere the bearing is staked. This area is subjectto stress cracking and corrosion. The adjustablerod ends should be inspected for damagedthreads and the number of threads remainingafter final adjustment. The drums should beinspected for wear, and the cable guards shouldbe checked for proper position. If the cableshave been loosened, the tension must be set.

THROTTLE

The throttles are actuated by cable systemswhich extend from the flight station to thefirewall in each nacelle. Levers for each throttlesystem are located on the pilot's control standand the flight engineer's control stand. Thecontrols that are forward of the firewall consist

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of a pulley mounted in a swing bracket sup-ported by the nacelle structure, and two parallelrods extending from the pulley to a double-armed bellcrank on the master control throttleshaft. The swinging bracket will compensate forengine vibration and movement so that thethrottle settings will not be affected. To rig thethrottle control proceed as follows:

1. Install a rigging pin in the firewall pulleyand its bracket.

2. Adjust the push-pull rods between thefirewall pulley and the master control so thatthe throttle shaft is resting firmly against theclosed stops and the pulley shaft center on theswinging bracket is the correct number of inchesfrom the firewall.

3. Then adjust the cable tension in thesystem to the proper tension so that the pilot'sthrottle lever has the correct amount of cushionin the closed position.

4. While maintaining the position of thepilot's lever, adjust the turnbuckles at the flightengineer's control stand so that the flight engi-neer's lever will have the correct amount ofcushion.

5. Recheck the cable tension, the throttleshaft position, and the position of both throttlelevers in the cockpit.

6. Then remove the rigging pin and check thethrottle lever from both positions in the cockpitseveral times to ascertain that there is a fullfreedom of movement.

MIXTURE CONTROL LINKAGE

The mixture control on the master control iscable operated from the flight engineer's controlstand to a pulley mounted on a swinging bracketon the overhead of the nacelle structure forwardof the firewall. The bellcrank on the mixturecontrol rod is connected to this pulley by apush-pull rod. The swinging bracket performsthe same function here as the swinging bracketassembly performs for the throttle.

The rigging of the mixture control is asfollows:

1. Install a rigging pin in the firewall pulleyand bracket.

2. The mixture control lever on the mastercontrol is to be placed in the IDLE CUTOFFposition.

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3. The push-pull rod between the mastercontrol and the swinging bracket on the firewallshould be adjusted until the swinging bracket isthe proper distance from the firewall. When thisis done, slip the bellcrank onto the mixturecontrol and then tighten it down against theserrations.

NOTE: Observe the precautions of adjustingthe rod end assembly so that it has sufficientthread engagement.

. 4. Adjust the cable portion of the linkage sothat the control lever in the cockpit is in theIDLE CUTOFF position. Then tighten thecables to the proper tension.

5. Remove the rigging pin and then dperatethe system through the full range of travelseveral times to insure that the mixture controlplates are in the proper position in relatioh ocothe lever at the flight engineer's panel.

FUEL SELECTOR

The fuel tank selector and shutoff valves arecable operated from the flight engineer's controlstand. To rig them, proceed as follows:

1. Place the flight engineer's control levers inthe CLOSED position for the valves to Nos. 1, 4,and 5. The three-way selector valve controllevers are to be placed in the midtravel position,or in the No. 2 and No. 3 positions, respectively.

2. Adjust the cable tension to the properamount so that the control levers to Nos. 1, 4,and 5 have the proper amount of cushion in theCLOSED position. Remove the rigging pin andcheck for the proper amount of cushion whenthe levers are moved to the OPEN position.While the three-way selector valve control leversare in the MID position, check for the properamount of tension on the cables.

NOTE: All cable tension adjustments shouldbe made in relation to temperature.

3. Recheck all cable tensions, position of thecontrol levers, and the position of the valveactuating levers. Also check for smooihness ofoperation throughout the operating range.

FIREWALL SHUTOFF VALVES

The four emergency fuel shutoff valves arelocated upstream from the engines. These aremanually operated two-way valves and operate

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in conjunction with the blast air, oil, andhydraulic emergency shutoff valves. They arecontrolled from the overhead control panel inthe flight station. The rigging procedure is asfollows:

1. Insert pin in the pulley rigging hole.2. Place valve lever in the OPEN position.3. Place the flight station emergency shutoff

lever in the OPEN position.4. Adjust the push-pull rod to the proper

length and install on the valve lever. Make finaladjustment as necessary to the rod for theproper alinement of the leveri.

5. Operate the flight station lever to theOPEN and the CLOSED position to check theproper operation of the valve.

ENGINE RUN-IN

A carefully controlled run-in of new or newlyoverhauled engines before they are operated athigh power for prolonged periods of use will addgreatly to the service life of the engine. Preoilingis required for model R3350 engines whenstarting a new or newly overhauled engine forthe first time, when depreserving an engine,when an engine is started after having been idlefor longer than 72 hours, and when an oilchange or c Cher operations have been performedwhich would permit air to enter the inlet oil linebetween the supply tank and the pressure pump.

The procedures for preoiling, ground run-in,and flight testing of a newly installed engine arediscussed in the following paragraphs.

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PROCEDURE

The procedure for engine run-in is as follows:1. After insuring that the engine has been

completely depreserved, it is necessary to pre-oilthe engine. The pre-oiling should be accom-plished just before the engine is ready to run.The primary purpose for pre-oiling the engine isto insure that EVERY bearing surface in theengine has an oil cushion on it prior to the initialstarting of the engine. A typical pre-oilingprocedure is as follows:

a. The oil tank is to be filled to a safeoperating level.

b. Remove the engine sump plugs and theengine oil strainers and drain all excess corrosion


preventive compound. Clean the oil strainerswith Stoddard Solvent and reinstall. Providecontainers to catch oil at these points.

c. Remove the rear oil pump and sumppre-oiling vent plug.

d. Open the oil tank shutoff valve andallow approximately 2 gallons of oil to drainfrom the vent to make sure that there are no airpockets in the oil tank supply line. Then replacethe vent plug.

e. Connect the pre-oiling line to the pre-oilconnection in the rear pump and sump housing.

f. Remove a rocker box cover from one ofthe uppermost cylinders.

g. Remove the front spark plug from eachcylinder. This will reduce the load on the starteras the engine is pulled through during thepre-oiling procedure.

h. Use the correct grade of engine oil thatis normally used. The oil used in pre-oilingshould be heated in the range of 71°C to 104°Cand supplied to the engine at 30- to 50-psi oilpressure by the pre-oiling equipment while theengine is being pulled through with the starter.Do not exceed 50 psi at any time duringpre-oiling.

i. Operate the starter and the pre-oilingunit until oil is visible in the rocker box fromwhich the cover has been removed. Do not allowthe starter to become overheated.

j. Secure pre-oiling, install the rocker boxcover, and install all of the spark plugs exceptthose of the bottom cylinders. Install the enginedepreservation plugs in those cylinders for theinitial run of the engine. CAUTION: Insure thatspark plug leads are properly capped to preventthe ignition of the oil and fuel expelled throughthe blowout plugs. The initial run of the engineshould be approximately 30 seconds.

NOTE: Prior to starting the engine, and toprevent loading the manifold absolute pressuretransmitter with preservative mixture and/or oilduring depreservation of model R3350 engines,remove and cap off the MAP line to thetransmitter at the engine rear cover location.Leave this line capped off during the depreserva-tion run, being careful not to exceed 2,200 rpmand to maintain propeller control in full increaserpm settling. Following the depreservation run,remove the cap, blow out the manifold absolutepressure line from the rear case forward, andreconnect the line.

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After insuring that the engine will operate,remove the depreservation plugs (blowout plugs)from the lower cylinders and install the sparkplugs. Then proceed with the normal run -in inaccordance with existing instructions. At alltimes during the run-in there should be adequatefirefighting equipment standing by with snffi-cient checked-out personnel to use if necessary.

2. Ground run. After the initial depreserva-tion run and during the subsequent groundoperating time, the engine is to be operated withthe propeller in the full low pitch position, theaircraft must be headed into the wind in adust-free area, and the engine instruments mustbe under the close scrutiny of a qualifiedmechanic at all times. Personnel standing bywith firefighting equipment should also be onthe lookout for fuel and oil leaks.

After it has been determined that the installa-tion is performing properly, the cowling is to beinstalled to obtain the maximum cooling of theengine for all subsequent ground operation.Upon completion of the depreservation run andthe inspections that are outlined in section 5 ofNavAir 15-02-500, any additional ground oper-ating time can be limited to that required for thefinal adjustments of the oil and fuel pressuresand the propeller governor, and any otheradjustments that may be required to insure thatthe engine performs properly.

3. Test flight. When the above requirementshave been satisfactorily completed, the aircraftmay be released for a 1-hour minimum testflight. The gross weight of the aircraft should bekept to an absolute minimum practicable for theflight (minimum fuel, crew, etc.). The aircraftshould also be flown within gliding distance ofthe field from which the takeoff was made, ifoperationally feasible. Full power should beused for the takeoff, bat the power and the rpmshould be reduced to climb power as soon aspossible to hold the time at maximum power toa minimum. It is also important to hold climbpower to a minimum and to avoid reaching theservice ceiling of the engine. All climbs andhigher power settings must be made in theauto-rich position, and the climb attitude shouldbe such that the maximum cooling of the enginecan be maintained at all times. It is alsonecessary to insure that the specified tempera-tures, manifold pressure, and the BMEP limitsare not exceeded at any time.

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The engine controls should not be movedrapidly at any time during the test flight, butshould be moved with moderation, keepingwatch on the instruments for any unusualindications. When increasing the power settingsabove minimum cruise, it should be done gradu-ally at 100-rpm increments with a duration of 1minute at each increment and returning to lowcruise power and remaining there for a sufficientperiod of time to allow the engine to cool.

The engine may be operated in the auto-leanrange during cruising after at least one-half hourhas elapsed after takeoff. However, all climbsand descents will be made with the mixturecontrol(s) in the auto-rich position.

4. Ground check after test flight. When thetest flight has been satisfactorily completed andupon return to the line, a high-power runup ismade for approximately 1 minute. When this hasbeen done and the engine secured, the strainersare checked and the engine given a thoroughvisual inspection for evidence of fuel and oilleaks, and the security of all hoses, connections,and accessories is checked.

When this procedure has been satisfactorilycompleted, the engine may be released forunrestricted flight.

The procedures that have been listed aboveare the minimum requirements that have beenestablished to insure that the engine has beensatisfactorily installed prior to the release of theengine for normal flight operations. Wheneverany abnormal discrepancies or conditions existduring the ground run or the test flight, thecause of the malfunction must be determined ina sufficiently extended ground run and/or testflight before the engine can be released fornormal flight operations.

PRESERVATION ANDDEPRESERVATION

The Chief and First Class Aviation Machinist'sMate R must know the procedures for preservingand depreserving reciprocating engines and theiraccessories. Corrosion is the result of chemicalor electrochemical action upon metals. (See fig.7-8.) It is greatly accelerated when dissimilarmetals such as magnesium and steel are coupledor when dirt, salt, exhaust gases, etc., are incontact with metal surfaces. Rust on iron or

155

fri

AD.426Figure 74.Example of corrosion.

steel and the white powder on aluminum ormagnesium are the products of corrosion. Theseproducts, along with dirt and salt, pick upmoisture from the air and hold it in contact withthe metal, thereby speeding up the corrosiveaction. When moisture and dirt are permanentlyremoved from metal surfaces, the tendency ofsuch surfaces to corrode is usually eliminated.Therefore, the major problem facing the ADR isto prevent the accumulation of moisture on thesurfaces of the engine and its accessories.

To achieve suitable protection against corro-sion, a continuous barrier must be placed be-tween the metal surface and any possible sourceof moisture. This can be accomplished by one orboth of the following procedures:

1. As a direct oarrier, all the surfaces whoseoperation will not be impaired thereby areprotected against the accumulation of moistureby a coating of a protective surface film. Wherepracticable, this film is an electro-plate, a paint,or a chemical treatment. Examples of these are:cadmium plating on studs and nuts, paint on theengine exteriors, and a permanent resin coatingon the articulating and master rods and manyother nonbearing internal engine surfaces. Sur-faces which cannot be so treated are coveredwith temporary coatings containing special cor-rosion-preventive ingredients. These compoundsare as heavy as it is practicable to apply without


adversely affecting the operating characteristicsof the engine. The protective film is ineffectiveagainst moisture that is trapped between thesurface to be protected and the film at the timeof application. It is essential, therefore, that thesurface to be protected be both dry and cleanwhen the protective film is applied. The coatingmaterial, the air used to apply it, and theatmosphere where the work is being accom-plished must be as moisture free as pot Bible. Forresults of good and poor preservation, see figures7-9 and 7-10, respectively.

2. Additional protection against corrosion isprovided by completely enclosing uninstalledengines and some, of the accessories in a mois-tureproof barrier. The moisture content of thebarrier is reduced by adding dehydrating agents.The amount of the dehydrating agent used issufficient to reduce the relative humidity withinthe barrier to 30 percent or below at alltemperatures normally encountered. It has beenestablished that corrosion will not take place ifthe relative humidity is maintained below 30percent.

NOTE: To be effective, either of these proce-dures must be applied to an engine before therehas been an opportunity for corrosion to start.These procedures are not nearly so effective inretarding existing corrosion as they are in

AD.427Figure 7-9.Results of good preservation.

AD.428Figure 7-10.Results of poor preservation.

preventing it in the first place. Corrosion shouldbe removed before preservation is attempted.

The primary determining factor in selectingthe proper type of preservation is the dispositionof the engine or the accessories after they havebeen preserved. For example, in the preservationof an engine to be reinstalled, longtime storageshutdown procedure should be used to coverany changes in the anticipated installation date.Another factor to be considered is the time thatwill elapse between preservation and reuse oroverhaul. The status of the equipment and themethod by which the equipment will be trans-ported may present still other problems. Prior toapplying a protective coating to a reciprocatingengine refer to the latest amendment to GREW213.

TYPES OF PRESERVATION

Methods used for preserving aircraft enginesvary, depending upon the length of storage timeanticipated, the conditions under which theengine is stored, and the internal preservativematerial used. There are five basic preservationtypes in use for aircraft engines. Maintenanceprocedures and depreservation requirements alsovary, depending on the original preservationapplied.

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16krt,:i


Type I

This type of preservation is used for all en-gines where the length of the storage period isnot known to the activity preparing the engine.Its primary application is for the protection ofnew or newly overhauled engines and for oper-able engines being returned for overhaul or minorrepair. It may also be used for low-time engineswhich are being removed from one aircraft forinstallation in a second, when the period betweenremoval and subsequent ground runup is un-known or is to exceed the period of time an un-installed engine may remain outside a container.This type of preservation must not be appliedsooner than 10 days prior to removal of the en-gine fro4n the aircraft.

Type II

Type II preservation is intended primarily foroperable engines which are stored under cover(indoors or on the hangar deck) for periodswithin the storage limits permitted outsidedehydrated containers. It is used primarily for:

a. Engines which have failed the test standcheck and must be returned to shops for minorrepair and adjustment.

b. Low-time engines being removed from anaircraft and scheduled for installation in asecond aircraft within the permissible storagelimitations for an engine outside a container.

c. An operable low-time engine turned in foroverhaul or minor repair when the activitypreparing the engine knows that the overhaul orminor repair will be undertaken within thestorage limitations for engines outside of con-tainers.

Type III

Type III preservation is intended primarily foroperable engines that are to be stored undercover (indoors or on the hangar deck) forperiods not longer than 14 days. This periodincludes the entire elapsed time from the origi-nal preservation runup or exercising run to theground runup of the engine after it is installedon the aircraft. While Type III usage is limitedcompared to other types of preservation, it canbe used by squadrons and maintenance activitieschanging an engine from one aircraft to another,

or by Depot maintenance activities for protec-tion of engines during progressive aircraftrework or modification. This type preservationfor uninstalled engines may not be renewed.

Type IV

Type preservation is used for the protec-tion of inoperable engines being prepared forstorage and shipment, with the exception ofthose inoperable engines which have been sub-jected to water immersion. An inoperable engineis considered to be an engine that cannot begiven a complete preservation run even wheninstalled on a test stand or in an aircraft.Examples of engines in this category are recipro-cating engines with sudden stoppage damage,stuck superchargers, cracked housings, or brokenaccessory holddown studs. This type of protec-tion may also be used by activities which do nothave runup facilities, or at times when improp-erly preserved or corroded engines are found instorage, and it is known that the disposition ofthe engine is overhaul or minor repair.

Type V

All aircraft engines which have been immersedin water (either salt or fresh), or which havebeen involved in fires or aircraft accidents,where the engine has been exposed to Foamite,or other firefighting chemicals must be preservedwith Type V preservation.

PREPARATION FOR PRESERVATION

To accomplish satisfactory preservation, thesurfaces must be thoroughly cleaned whereverpracticable before application of the preserva-tion compound. Not only is any surface contam-ination capable of picking up moisture from thesurrounding air, but also it may be of such acomposition as to result in direct chemicalattack. New or newly overhauled engines mayusually be externally cleaned by removing greaseand oil from the surfaces. Particular care mustbe taken to clean the protruding portion of apropeller shaft. For cleaning of this nature,usually accomplished between the preservationrun and final preservation, an approved dry-cleaning solvent is recommended. If it is not

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available, kerosene may be used. However, kero-sene is not considered as useful as drycleaningsolvent because of_the evaporation time. Sur-faces must be both clean and dry prior toapplication of the preservative compounds.

For engines being returned for overhaul orminor repair, a proper balance should be main-tained between cleaning and leaving satisfactorypreservative compounds in place. No general rulecan be made except that corrosion-preventivecompounds allowed to remain should be free ofdirt. Steam cleaning with the proper steamcleaning compound usually removes most soils.If the engine is excessively oily, greasy, orcoated with old preservative compounds, apresoak for approximately 15 minutes with aspray-applied mixture of six parts of keroseneand one part of grease cleaning compound,should provide sufficient softening to permitsteam cleaning to function. If the engine is notexcessively coated with foreign matter, the useof kerosene alone may give satisfactory results.Again, great care must be used to insure propercleaning.

PRESERVATION OFRECIPROCATING ENGINES

The preservation of a reciprocating engine isaccomplished after the engine lubricating systemhas been filled with the required preservative.

During the preservation run, the engine isoperated for the minimum period of 15 minuteswith the specified corrosion-preventive mixturein the lubrication system, which varies with theparticular type of preservation that is beingaccomplished. The engine must be operated sothat the oil inlet temperature of the engine ismaintained within a temperature range of 95°Cto 120°C for the entire preservation run of theengine. The oil cooler inlets may be blanked offif the desired temperature of the oil cannot bereached. During the preservation run of theengine, care should be taken not to exceed thecylinder head temperature limits.

At the completion of the preservation run'inject the atomized corrosion-preventive mixtureinto the induction system. The mixture shouldbe applied at a rate of approximately 40 to 50gallons per hour so that full coverage of the

complete induction system will be attained.Injection of the mixture is made at the base ofthe carburetor instead of the top so that theimpact tubes of the carburetor will not becomeclogged.

Four basic factors control the quantity of themixture as it is injected:

I. The size and the number of the outletorifices in the injection nozzle.

2. The pressure of the compound at the timeof injection.

3. The engine rpm.4. The temperature of the compound at the

injection nozzle.NOTE: Preservation of Aircraft Engines, Nav-

Air 15-02-500, illustrates a typical corrosion-preventive compound injection nozzle.

Actual injection of the preservative mixtureinto the induction system is accomplished in thefollowing manner:

1. Adjust the engine rpm so that it is oper-ating in the range of 1,200 to 1,600 rpm.

2. Begin injecting the compound.3. As soon as steady smoking is observed

from all the exhausts of the engine, move themixture control to the IDLE CUTOFF position.Do not close the throttle.

4. When the engine stops rotating, shut offthe ignition.

5. Cut off the supply of injection compoundto the engine.

6. When the engine has come to a completestop and the ignition is turned off, turn on thefuel boost pump and open the mixture controlto the AUTO-RICH position and allow the fuelto drain from the supercharger drain valve. Whenpreservative-free fuel is observed running fromthe supercharger drain valve, close the throttleand mixture control, and shut off the fuel boostpump.

Immediately upon shutdown of the engineand while it is still hot, place the propeller ortest club blades in the proper position so thatremoval can be accomplished without rotatingthe engine.

As soon as possible after the preservation runand while the engine is still hot, drain theexcessive corrosion-pre. z,ntive compound fromthe oil tank, engine sumps, crankcase, and oilscreen or filter chambers. Check for metalcontamination. If none is found, clean the oil


screens or filters, coat them with the compound,and reinstall them in the engine. Install dehy-drator plugs in all sump plug openings, andsecure the sump plugs to the engine structurewith 4- wire.

During or after the draining of the corrosion-preventive compound from the engine and assoon as practicable, remove the air intake ducts,exhaust stacks, and other equipment that willnot be shipped with the engine. Also remove theaccessory drive covers that are not pressurelubricated.

Depending upon the type of preservationbeing used, an even coating of hot compoundmust be sprayed int.) and over all internalsurfaces of each cylinder through the spark plugopenings. DO NOT ROTATE THE CRANK-SHAFT DURING OR AFTER THIS OPERA-TION.

NOTE: Do not apply excessive Amounts ofpreservative. All that is necessary is a uniformthin coating on all surfaces. Excessive amountsof preservative do not contribute to the effec-tiveness of the preservation; but they do causedifficulty whenever the engine is depreservedand increase the possibility of hydraulic lock.The personnel whom you designate to do thecylinder spraying should be thoroughly trainedin the proper procedure of applying the com-pound to the inside of the individual cylinders.

The general procedure for spraying the in-ternal area of the cylinder is as follows:

1. Place the cylinder preservation mixture inthe reervoir, heat the mixture to the correcttemperature, and mix thoroughly. Premixingand preheating the compound prior to placing itin the reservoir will be a timesaver.

2. Close the vessel and connect the gun andlines.

3. Discharge the gun into a clean containeruntil a fine uniform spray is produced at thenozzle. This mixture discharged from the guncan be retained for future use.

4. Insert the discharge tube of the gun intothe cylinder and determine the position of thepiston. Use the free hand to mark the distancethe gun will travel into the cylinder to a pointjust short of the piston. Withdraw the gun untilthe nozzle is at the spark plug opening.

5. Start spraying. As soon as the trigger isdepressed and the mixture begins to discharge

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into the cylinder, move the run slowly into thecylinder. Do not touch the piston. Then movethe gun back to the spark plug opening andcease spraying.

6. Proceed at orce to spray each cylinder inthe same manner. Do not allow the gun tobecome idle for more than I minute; otherwise,the mixture will thicken and an even spray willnot develop.

The thickness of the coating can be deter-mined by spraying the mixture into a glass jarand experimenting to obtain the minimumcoating. Do not rotate the crankihaft during orafter the internal spraying of the cylinders.

After completion of the cylinder spraying, allthe spark plugs or solid plugs must be installedin the engine. If the engine is going to be placedin a metal container for shipment or storage, thespark plug openings must be sealed with theproper type dehydrator plugs.

The spark plug leads should be cleaned withan approved dryclean!ng compound, and driedwith a lint-free cloth. Insert the insulating andsealing compound in the terminal lead protectorand install the protector on the terminal sleeve.Then snap it on the dehydrator plug nipple.

The fuel feed valve cover plate and the fuelfeed valve are removed. Coat the fuel feed valvewith the preservative compound and reinstall. Besure there is no fuel remaining in the fuel feedvalve recess.

The exhaust ports must be sealed with a bagof desiccant properly anchored within each one.All external openings of the engine are to besealed in accordance with the existing preserva-tion instructions. When bags of desiccant areplaced in the blower throat, a tag indicating thenumber of bags of the desiccant used should beattached to the cover plate. The accessory drivesalso should be sprayed with the mixture thatwas used for the engine runup. Reinstall thecover plates; or if the accessory is to be shippedinstalled on the engine, install the accessory,using all related attaching parts.

Close the breather openings. For engines thatare to be placed in metal containers, usescreened plugs or one thickness of a moisture-proof and vaporproof barrier material secured inplace with tape. Seal the oil inlet and outlet withoil and me:4 ture resistant blank caps. Usegaskets under 411 metal blank-off plates. Remove


the thrust bearing cover plate, and coat thethrust bearing thoroughly with the engine runuppreservative compound.

The propeller shaft should be thoroughlycleaned and then coated with a soft-film corro-sion- preventive compound. After it has set, thesurface of the shaft should be wrapped with theproper type paper and secured with tape. Instal-lation of the shipping cap for the propeller shaftshould be delayed until after the engine has beeninstalled in the shipping container.

NOTE: A durable type tag should be at-tached to the propeller shaft with the followinginformation on it:

TYPE (indicate type) PRESERVATIONNAME OF ACTIVITYDATE OF PRESERVATIONThe preceding section of this chapter contains

some of the general procedures for preservingthe aircraft reciprocating engine. For additionalinformation refer to the appropriate technicalpublication listing reference material concerningthe preservation of reciprocating engines.

The supervision of the preservation process ofaircraft engines and their associated accessoriescannot be stressed too much due to the highcost of repairing or replacing all or part of themwhen corrosion has set in because of inadequatepreservation or the failure to follow the properprocedures.

Aircraft engines are also preserved and leftmounted on the airframe. Under these circum-stances the engine is preserved in accordancewith the type of preservation used on theaircraft.

Type A preservation is applied to aircraft thatfall within the following categories: awaitingoverhaul (AOH), awaiting modification (AMO),completed service life (CSL). Only overhaulactivities perform type A preservation.

Type B preservation is generally applied toserviceable and modernized aircraft that areessentially sound and in flight condition at thetime of preservation. Such aircraft may bestored under maintained type B preservation forperiods of 6 months duration. Type B preserva-tion is applied only by Depot maintenanceactivities.

Type C preservation is mandatory for allaircraft that are to be shipped by a surface vesselthat does not have the facilities or the personnel

available for en route maintenance of type Dpreservation.

Type D preservation must be applied to anyaircraft that is not flown at least once in every14 days. Aircraft in this category may be main-tained in a type D preserved status indefinitely,provided all discrepancies are corrected immedi-ately after a test flight which is made once every30 days and the preservation is completelyrenewed at this time.

Type E preservation procedures must befollowed for all aircraft that have crashed in saltwater or have been subjected to the applicationof firefighting foam or chemicals. These preser-vation procedures must be started immediatelyupon the removal of the aircraft from the wateror as soon as the rue is extinguished, dependingon the release of the aircraft from the board ofinquiry.

For definite information pertaining to' thepreservation of aircraft and engines, the ADRshould consult Preservation of Aircraft Engines,NA 15-02-500.

Preservation of uninstalled engines must bemaintained throughout the storage period.. Itwill be necessary to maintain the air within thestorage container at the recommended 30 per-cent relative humidity or below. The corrosion-preventive mixture which was applied duringpreservation prevents corrosion for only a shortperiod of time whenever high humidity condi-tions are permitted to enter the container.Corrosion will sometimes be encountered whenthe relative humidity of the container is belowthe required 30 percent, but this will be due tothe improper removal of corrosion that waspresent before the engine was placed in thecontainer, or delaying too long in the replace-ment of dehydrating agents. Carefully followingthe specified maintenance procedures is equallyas important as the initial preservation treat-ment. When both of these are adhered tothroughout, there can be assurance that theengine will be protected throughout its storageperiod.

Engines that are placed in metal shippingcontainers are pressurized when they are placedwithin the container, and this pressure ischecked upon receipt of the container. It is alsochecked before shipment and at least once every30 days after the initial preservation. Pressure

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may be checked with a pressure gage or amanometer. If the pressure within the containeris too low to measure, the condition of theinternal indicator should be determined. If a safecondition is indicated, the container should berepressurized with dry air. If the indicator doesnot indicate a dry condition, the container willhave to be opened and the engine checked forevidence of corrosion.

DEPRESERVATION OFRECIPROCATING ENGINES

The procedures that are followed when de-preserving an engine vary in accordance with thetype of preservation with which the engine waspreselved and whether the engine is installed oruninstalled. The general depreservation proce-dures are discussed here.

The pressure_ of the metal container must berelieved before the holddown bolts are takenout. After the top portion of the container hasbeen removed,_ take all bags of desiccant and thehumidity indicator from the engine. Remove allthe protective paper, if any, from around theengine. Remove any accessories and theirmounting board and hold them for futureinstallation when the engine is ready for them.Remove the engine from the bottom half of thecontainer and install it in a suitable engine stand.Accessories that were attached to the engineshould not be depreserved until less than 10days before the initial runup. The shippingcontainer will be disposed of in accordance withlocal directives.

When the engine has been mounted in thestand, remove the sump plugs and dehydrator orscreen plugs and allow the excess preservativematerial to drain from the engine. If the job isbeing i zrformed in cold weather, it may be bestto ',cc a preheater and heat the engine so thatthe maximum amount of preservative can bedrained from the engine. While the engine is in anosedown position, rotate the crankshaft so thatthe pistons will force the excess preservative' out

of the spark plug holes. Inspect each cylinderinternally for evidence of corrosion and excesspreservative material. If excess preservative ma-terial is present, pump it out with a suctionpump. Replace all drain plugs, but do notlockwire at this time.

Inspect the engine exterior for evidence ofcorrosion. After the drainage of the excesspreservation material has been accomplished(assuming that the engine will be installed on anairframe as soon as it is ready), install the sparkplugs in the cylinders. Continue with the normalengine buildup procedure. Do not disturb anybreather seals, seals, or anything that is notnecessary to be disturbed. Do not depreserve thepropeller shaft until immediately prior to theinstallation of the propeller.

After the engine has been built up and theaccessories depreserved and installed, mount theengine on the airframe and complete the neces-sary connections. Remove the preservative com-pound from the propeller shaft, using a dry-cleaning solvent, and dry with a lint=fits.e, cloth.Install the propeller, complying with ai sicialinginstructions to prevent corrosion of the propel-ler shaft.

As soon as the engine is ready to operate forthe first time, all inspections have been compliedwith in regard to depreservation, and the instal-lation of the ace ssories and the engine in themount has been accomplished, prepare theengine for pre-oiling prior to initial start. Pre-oiling procedures have been discussed previouslyin this chapter.

The procedures for depreserving an installedengine are not discussed here, as the procedure isessentially the same as for an uninstalled engine.The procedures, of course, vary somewhat withthe type of preservation that has been applied tothe engine. Consult the appropriate technicalpublications, including all local publications anddirectives, for the proper procedures to follow atall times when preserving and depreserving air-craft reciprocating engines and associated acces-sories.

CHAPTER 8

FUEL SYSTEM MAINTENANCE

The aircraft fuel system begins with the tanksand ends at the carburetor inlet. The onlycontrol required between these points is fuelpressure. It must be capable of delivering fuel tothe carburetor at the required pressure and in§ufficient volume to meet the demand of theengine(s). The senior ADR must maintain andservice the aircraft fuel system. Therefore, hemust be familiar with fuel transfer and pressurefueling, construction of fuel cells, and proce-dures for removal and installation of bladder andself-sealing fuel cells. (The repair of bladder andself-sealing fuel cells is performed by personnelof the AM rating.)

The first part of this chapter is devoted tocomponents and operation of typical fuel trans-fer and pressure fueling systems. This is f^llowedby a section on the removal and instauationprocedures for bladder and self-sealing fuel cells.It should be emphasized that this is generalinformation and should not be used for actualfuel cell removal and installation. Identificationof foreign matter found in fuel systems iscovered at the end of the chapter.

FUEL TRANSFER AND PRESSUREFUELING

Fuel transfer and pressure fueling systemsprovide a controlled means of receiving fuelfrom external sources and supplying the fuelfrom tanks and cells within the aircraft to theengine(s).

NOTE: Since the fuel system of the P-2Hencompasses the components used in mostreciprocating engine aircraft, it is used in discuss-ing the components and operation of fueltransfer systems.

The P-2H fuel system includes six outer wingpanel cells and eight center section cells. Alsoincluded are two bomb bay and two wingtip

tanks which are optional loading. Control of thefuel system is accomplished by two engine-driven fuel pumps, a maximum of seven electricauxiliary booster and transfer pumps, fuel quan-tity gages, and all necessary plumbing andcontrols.

Under normal conditions, fuel in the wingtiptanks, bomb bay tanks, and center section tanksis transferred to the main tanks (outer wingpanel tanks) before being supplied to the en-gines. Fuel in the bomb bay tanks is firsttransferred to the center section tanks beforebeing transferred to the main tanks. Float valvesin the center section and main tanks, togetherwith the transfer boost pumps, automaticallyaccomplish fuel transfer, provided the fuel con-trol panel is placed in normal.

COMPONENT DESCRIPTION

Fuel Cells and Tanks (P-2H)

The aircraft fuel system consists of thefollowing fuel cells and tanks: Outer wing tanks,center section tanks, wingtip tanks, and bombbay tanks.

The outer wing tanks include three fuel tanksinstalled in each outer wing panel between wingstations 204 and 420. (Each tan's is composed oftwo interlaced cells.) The cells are constructedof lightweight, bladder type, nonself-sealing, orsemirigid, self-sealing cells, depending on themanufacture date of the aircraft.

The center section fuel cells are lightweightbladder type cells and are not of self-sealingconstruction. They consist of eight cells installedin line in the wing center section, four on eachside of the centerline of the fuselage. The fourcells on the left are interconnected and act as asingle tank, and the four on the right aresimilarly interconnected.

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Chapter 8FUEL SYSTEM MAINTENANCE

The wingtip tanks are an integral part of thecenter mounted, circular nacelles installed ateach wingtip. Each tip tank is a self-contdinedunit; the filler neck, drain valve, and transferpump are all easily accessible, and do not requireremoval of any other structure. Quick-releaseplumbing and electrical fittings make it possibleto jettison the tanks if desired.

Provisions are incorporated in the bomb bayfor two lightweight self-sealing cells. The cellsoccupy the full length of the bomb bay and aremounted side by side. When both cells are used,they are plumbed together to act as one bombbay tank. The cells may be jettisoned, if desired,as all connections are of the quick-release type.

Fuel Transfer (P-2H)

Control of the fuel system is accomplishedfrom the pilot's overhead control panel. Controlknobs on the panel actuate electric motors,accessible within the fuselage, which in turn arecable-connected to the individual fuel selectorand crossfeed valves, located aft of each enginenacelle. The individual actuators, which positionthe fuel valves, can also be positioned manuallyin case of electrical failure.

In normal use, fuel is supplied to the enginesfrom the outer wing tanks. As the outer wingtank fuel level drops, float valves automaticallyallow transfer of fuel in sequence from thewingtip tanks, the center section tank, and thebomb bay tank. In case of an emergency, fuelcan be transferred from the center section tanksto the engines.

OPERATION

Fuel Transfer

Normal fuel transfer is accomplished in tilefollowing sequence:

1. When the fuel level in the main tank dropsto 3,600 pounds (600 gallons) the float valve inthe number 3 cell opens, alLtwing fuel in thewingtip tank to be transferred to the main tank.

2. When the fuel level in the main tank dropsto 2,880 pounds (480 gallons) the float valve inthe number 1 cell opens, allowing fuel in thecenter section tank to be transferred to the maintank.

3. When the fuel level in the center sectiontank drops to 3,600 pounds (600 gallons) thefloat valve in the number 1 cell opens, allowingfuel in the bomb bay tank to be transferred tothe center section tank.

NOTE: The fuel control panel incorporates afuel flow diagram. By positioning the tankselector valve controls and fuel flow valvecontrols to obtain unbroken lines, the course ofthe fuel flow obtained under various selectoivalve settings is clearly indicated.

u..Aliary Fuel Transfer

! the event that fuel fails to transfer fromthe tenter section tanks to the main tanks, fuelremaining in the center section tanks can beobtained by selecting the center section tanks asthe engine feed tanks.

Fuel in tanks on one side of the aircraft canbe transferred through the crossfeed line totanks on the opposite side, according to thesettings of the fuel tanks selector valves. Thetransfer-boost pump in the tank receiving fuelmust be OFF, the transfer-boost pump in thetank yielding fuel ON, and the boost pumphigh-low selector switch in the HIGH position.

Engine Supply

Fuel from either outer wing tank or centersection tank can feed direr to one or bothengines. In' normal use, however, fuel is suppliedonly through the outer wing tanks. The transferboost pumps in either the center section tanksor the outer wing panel tanks are capable ofmaintaining fuel pressure to an engine in casethe engine-driven fuel pump fails (provided thejet engines are not operating). Fuel crossfeed isavailable in the P-2H and is used when an enginefailure occurs or when necessary to equalize fuellevels in the left and right wing tanks.

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16.8

Refueling

Normal refueling of most models of the P-2Haircraft is by gravity fueling through the fillerunits located in each tank. The aircraft shouldbe fueled in the following sequence; main tanks,center section tanks, wingtip tanks, and thebomb bay tanks.


NOTE: Although the aircraft is normallyequipped with circular 200 U.S. gallon wingtiptanks, the elliptical 350 U.S. gallon wingtiptanks are interchangeable. If the aircraft isequipped with the elliptical tanks, fuel loadingmust be limited to 180 U.S. gallons in each tank.

Some naval aircraft are equipped with fea-tures that allow pressure (single-point) refueling.Pressure fueling is accomplished by connectingan outside fuel supply to the pressure fuelingconnector. The flow of fuel to all tanks or anycombination of tanks is controlled by electric-ally operated pressure fueling valves. Thesevalves are controlled by switches on the pressurefueling control panel.

The primary fuel level control valve (floattype) in each tank will act 0 shut off the fuelinlet at the tank when it becomes full. If aprimary valve fails to close when the fuelquantity reaches the proper level, a float-operated secondary shutoff switch (one at eachtank) will actuate. The secondary shutoff switchwill cause the corresponding tank fueling valveto close and a corresponding indicator light, onthe pressure fueling control panel, to go on. Thislight indicates that the primary fueling floatvalve has failed and that the fuel quantity forthe corresponding tank is above the normal fuellevel.

The d-c power must be connected and allappropriate circuit breakers IN to energize thesecondary fuel shutoff system at all times duringfueling operations.

NOTE: Because of escaping fumes aroundfuel tank vents and the pressure fueling compart-ment, operation of lights and electrical equip-ment nonessential to refueling must be avoided.Always have power off when disconnecting orreconnecting electrical plugs from remotelyoperated fuel valves when manually overridingthe valves.

Defueling

The P-2H is defueled through the defuelvalves (fuel drain valves). The valves - aremounted over the landing gear trunnion, justforward of the bulkhead, below the rear beamon the inboard side of the nacelles, and at theaft end of the lower electronic compartment.The defuel valves are two-position valves which

can be operated only at the valves. When thevalves are opened, fuel drains from the systemthrough the drain port in the valve.

Defueling aircraft with pressure refuelingcapabilities is accomplished through the pressurefueling manifold. Defueling consists of defuelingany or all tanks by connecting a fuel line fromthe fuel manifold connector, through a suctionpump to an outside storage tank or suitablereceptacle. Selection of the tank or tanks to bedefueled is accomplished at the pressure fuelingcontrol panel.

FUEL CELLS

Included among the various types of internalfuel cells used in naval aircraft are bladdertypecells, self-sealing cells, and integral cells. Bladdertype cells and self-sealing type cells are construc-ted of rubber and fabric and are removable fromthe aircraft. Integral cells form a part of theaircraft structure and are therefore not remov-able. If trouble develops within an integral cellitself, AMS personnel will handle the repairs.

Since the ADR is concerned with removal,installation, and handling of bladder and self-sealing fuel cells, it is imperative that he befamiliar with the construction features of thesecells and have a clear understanding of theremoval, installation, and handling proceduresfor each type.

During the process of removal and installationof a fuel cell, the fuel cell and aircraft will beopen to tools, parts, and foreign objects. Checkthe cell and aircraft structure before installing anew or repaired fuel cell and, before completingan installation, account for all tools and spareparts. It would take only a small inexpensivepart or tool left in a fuel cell to cause millions ofdollars in damage and possible loss of life.

SELF-SEALING FUEL CELLS

A self-sealing cell is a fuel container whichautomatically seals holek or injuries causedduring combat operatioit A self-sealing cell isnot bulletproof, but is merely puncture sealing.As the bullet passes through the cell wall intothe cell, the sealant springs together quickly andcloses the hole. At this time some of the fuel in

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the tank comes in contact with the sealant andmakes it swell, completing the seal. In thisapplication, science has used the natural sticki-ness of rubber and the basic conflict of rubberand petroleum tv sea! the hole. This sealingaction reduces the fire hazard brought about byleaking fuel or oil and keeps the aircraft's fuel oroil intact so that the aircraft may continueoperating and return to its base. (See fig. 8-I.)

There are several different types of self-sealingcells currently used in naval aircraft. The mostcommonly used types are the standard six-plycell, the combination bladder and self-sealingcell, and the non-metallic plioform cell.

The bladder and self-sealing cell is the. mostcommon type.

The combination bladder and self-sealing cellis made up of two parts. One part is made ofbladder type rubber, and the other part is madeof six-ply self-sealing construction. This type cellis also semiflexible.

The nonmetallic plioform cell is of six-plyconstruction with additional supporting layers.The addition of the supporting layers makes thistype cell n on flexible.

.....1

Figure 8-1.Bullet sealing action.

BLADDER TYPE FUEL CELLS

IlLs"---------

AD.429

Bladder type cells are used when self-sealingproperties are not required. These cells areusually made of very thin gage material in order

165

to give minimum possible weight. They requirecomplete support from a smooth cavity.

Bladder type cells are fabricated in the samemanner as self-sealing cells in that they have aliner, nylon barrier, and a retainer ply. Thesealant layers are omitted. All three plies areplaced on the building form as one material inthis orderliner, barrier, and retainer.

The liner is made of Buna N rubber, thebarrier is nylon, and the retainer is a specialfabric impregnated with Buna N rubber. Theoutside is finished with colored Buna Vinylitelacquer. (See fig. 8-2.)

LINING

AD.430Figure 8-2Primary fuel cell materials.

The major fittings are similar to those used inself-sealing fuel cells except that they have onlyone flange on the inside (liner side). The cell ismade slightly larger than the cavity of theaircraft so the weight of internal pressure of thefuel is borne by the aircraft structure.

REMOVAL AND INSTALLATION

Most fuel cell damage occurs during Theremoval and installation process. The correctprocedure to be used varies for each type ofaircraft; therefore, reference should always bemade to the Maintenance Instructions Manualfor the aircraft concerned. There are, however,


some general removal and installation proce-dures, as described in the paragraphs following.

Removal Procedure

The steps outlined below are generally fol-lowed when removing a fuel cell from anaircraft.

Defueling of the fuel cell is the first step andshould be conducted in a designated area. Checkto make certain that all the aircraft's electricalswitches are in the OFF position. Ground theaircraft and container by approved methods. Ifno means of grounding is available attach acopper wire to the aircraft structure and securethe other end to a metal stake or pipe driveninto the earth approximately 4 feet.

Make certain that firefighting equipment is onhand in the proper working order with qualifiedpersonnel for its operation. Completely drainthe fuel from the cell.

Purge the fuel cell to remove residual fuel,and explosive and toxic fumes. The use of air forpurging is the most efficient and effective meansof removing the explosive and toxic fumespresent in empty fuel cells. Carbon dioxide mayalso be used for temporary displacement ofexplosive mixtures from the interior of fuelcells.

CAUTION: Water is never used on rubbertype cells as a purging agent, as it may causefailure of cell stiffeners and baffles.

The cell must be purged until all odors of fuelare removed, or tested with the explosion meterto a nonexplosive mixture content. The mostthorough job of purging can be accomplishedafter the cell has a removed from theaircraft.

Remove any necessary parts of the structureor accessories to gain access to cells. Whennecessary to remove special equipment, such asradio or radar equipment, it should be removedby a technician from the shop concerned,whenever possible. The removal of stressed skinppnels may make it necessary on some aircraftto jack or hoist certain sections to relieve strainand prevent possible structural damage.

Disconnect all fittings and lines leading to thecells as required. Failure to do this may restilt indamaged fittings. The type of fittings to bedisconnected from the cell depends upon the

design of the 'fuel system in the aircraft. Accessfittings on some types of cells may have to beremoved. This is essential because other fittingsmay have to be removed from inside the fuelcell.

Tape or protect sharp edges and corners of allcavity openings to eliminate chafing.

If necessary, collapse the cell and strap it in afolded position, being careful that the bends donot occur at any of the fittings. Cells whichrequire collapsing should never be removed byany other method.

Carefully remove the cell, observing the fol-lowing precautions:

1. Do not pull the cell by its fittings.2. Carefully guide the protruding fittings past

all obstructions.3. If the cell binds while removing it, do not

force it. Stop to determine the cause of thetrouble and remedy it before continuing. Sprin-kle the cell with talc or other suitable powder ifit becomcs necessary to squeeze the cell aroundor between structural members.

4. Do not pry on rubber fittings or on thecell with sharp instruments; use large woodenpaddles..

Handling Precautions

Always carry or haul fuel cells. The purposeof carrying or hauling fuel cells is to protect theoutside (retainer ply) wall, which serves tosupport the shape of the cell and protect the--self-sealing (sealant) layer underneath it fromgasoline spillage; therefore, its cord constructionand lacquer coating must be cautiously safe-guarded.

Never jostle or carry cells around by theirfittings. Such handling may distort or break themetallic ring arour.d the fitting, causing com-plete failure of the fuel cell. Do not flex coldcells since this will crack the stiffened syntheticrubber. Cells exposed to cold temperature (be-low 65°F) should be warmed to room tempera-ture before being handled excessively.

Remove cells from shipping containers care-fully. Before removing, be sure to detach allcarrier straps and hanger fittings. Sufficientmanpower should be available to carefully re-move the cell from its container.

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Never leave a semicollapsible cell without itsstiffeners or internal braces for a period beyond30 minutes. A longer time under such treatmentwill cause the cell to assume a permanent set orremain partially collapsed.

NOTE: Bladder type fuel and oil cells andnylon pliocels are much more delicate thanself-sealing cells and require extremely carefulhandling; otherwise the handling precautions arethe same as for self-sealing Cells.

Installation Procedure

The steps outlined below are generally fol-lowed when installing a fuel cell in an aircraft.

Check the cells to make certain that it is theproper one for the cavity. Tape all cell openings.Inspect the fuel cell cavity for cleanliness, andloose bolts, nuts, etc., and. make certain thereare no sharp metal or protruding edges whichmay damage the cell during or after the installa-tion of the fuel cell. Tape or otherwise protectthe edges of the fuel cell if necessary.

Apply talc or other suitable powder to theouter surface of the cell and the cell cavity, asdesired, to make it easier to move the cell intoposition.

If necessary, collapse or fold the .cell asrequired and secure it with webbed straps. Thecell should be warmed to room temperature; andwhen applying straps, place them and thebuckles so they are easily accessible after the cellis installed.

Guide the fuel cell into the cavity, makingsure it is installed in the right direction. Woodenpaddles with rounded edges may be used toguide the cell into the cavity; never use toolswith sharp edges or points. If any bindingoccurs, determine the trouble and remedy itbefore damage is caused to the fuel cell. Be verycareful that protruding fittings are not damaged.

Remove straps if cell was collapsed; thencheck the interior of the cell to make certainthat no tools or foreign materials were leftinside. .

Install and torque all fittings as required.,Tighten and torque bolts in such a sequence thatno undue stress will be placed at any oneparticular point. Lockwire all bolts and screws asnecessary and attach all bonding wires.

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17'2

NOTE: The use of any sealing compounds onrubber fuel cell fittings is prohibited. Sealingcompounds may be used only on connectionswhen the adjoining surfaces are metal.

Check the entire system for leaks. The airpressure method is recommended. Cells may bechecked by filling with fuel; however, leaks maynot occur for 24 hours when using this method.

Torque Requirements

One of the main causes of fuel leaks can beattributed to improper torquing of bolts used tosecure fittings, door cover plates, and attach-ments. Overtorquing causes excessive rubbercold flow, warps fitting plates, and in somecases, breaks the metal insects in fittings. Im-proper torquing sequence results in fuel leaks;therefore, it is important that a set sequence befollowed. Prior to installation, check the propertechnical instructions for torque sequences andtechniques.

TESTING

When a new or repaired fuel cell is installed inan aircraft, it should be tested for possible leaksbefore it is filled with fuel. The air pressuretest is the best method of determining if anyleaks exist. This test consists of applying airpressure to a sealed cell and checking for theexistence of leaks with a mercury, ,manometer.

IDENTIFICATION OF FOREIGNMATTER IN FUEL SYSTEMS

The identification of foreign matter in thefuel system of an aircraft is important in thatthe carburetor can perform properly only whenuncontaminated fuel is delivered to it. For thisreason, a system of filters, sumps, drains, andscreens are installed in the fuel system to insurethat only uncontaminated fuel is delivered tothe carburetor. Every precaution must be takento keep the fuel from being contaminated: fromthe gas farm, to the gas truck or pit, and throughto the final delivery to the aircraft.

The proper daily and preflight inspectionprocedures and maintenance checks should be


rigidly adhered to. The sumps and strainersshould be drained after every fueling operation,after allowing time for foreign matter or waterto settle to the bottom of the system. Thestrainers should be taken apart and visuallychecked at every inspection period and when-ever a malfunction is suspected within thesystem. Pieces of the lining in the tanks or hoselines may be found occasionally in the strainers,and the necessary steps should be taken to

locate the source and to repair or replace theitem immediately. Material such as dust and dirtmay be introduced into the system through thefiller necks of the tanks or whenever repairs aremade to the system. Cleanliness is of primeimportance in all aircraft fuel systems, and anyforeign material found anywhere in the systemmust be identified and its source located as soonas possible.

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CHAPTER 9

PROPELLER OPERATION AND MAINTENANCE

The Chief and First Class Aviation Machinist'sMee R are required to troubleshoot and correctpropeller system malfunctions and to rig andadjust propeller control mechanisms. In order toaccomplish this, they must know the operatingprocedures for constant-speed propellers, includ-ing procedures for propeller disassembly andassembly. In addition, the Chief Aviation Ma-chinist's Mate R must know the procedures forbalancing propeller assemblies.

The purpose of this chapter is to provide ageneralized picture of the maintenance andtroubleshooting of the constant-speed propellersystem. The 43E60 and 24260 propellers areused as typical propellers. When actuallytroubleshooting a system or performing actualmaintenance, reference must be made to theappropriate technical publications.

OPERATING PRINCIPLES(43E60 AND 24260)

The Hamilton Standard Reversing Hydro-matic propeller permits constant-speed opera-tion within the limits of the pitch changingmechanism, feathering of the propeller in flight,and reverse pitch operation which greatly im-proves the ground handling characteristics ofmultiengine aircraft. The two types of propellersdiscussed in this chapter are the 43E60 and24260 models, and the model 5U18 double-acting constant-speed control, which is the samefor both propellers except for minor modifica-tions. (See fig. 9-1.)

Instead of the two-slope cams used in thenonreversing type, three-slope cams are used inthe reversing model, the third slope beingutilized for reverse-pitch operation. A reverse-pitch stop ring limits the blade angle in reversepitch on the 43E60 and 24260. The low bladeangle is limited by a low-pitch stop lever

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assembly. (An oil transfer housing is used todirect oil to and from the propeller.) Oil fromthe constant-speed control is directed to eitherthe inboard or outboard side of the pistonthrough the oil transfer housing.

A cam assembly on the No. 1 blade shankactuates a blade control switch on the barrelduring unreversing and unfeather operation. Asimilar cam on the No. 2 blade on three-bladedpropellers and on the No. 3 blade on four-bladedpropellers actuates another blade control switchon the barrel during feathering and reversingoperations.

A slipring assembly, which provides a meansof current transmission from a brush blockassembly mounted on the nose section of theengine to the blade control switch on the 43E60propeller, is mounted on the inboard end of thepropeller barrel. The slinger ring is used todistribute anti-icing fluid to the blades and isattached to the slipring assembly. Nozzles directthe fluid' to the propeller blades. The 24260propeller utilizes both face and drum typesliprings for deicing and control of the propellir.Deicing on this model propeller is done electric-ally, using heaters in the leading edge of eachblade.

BARREL ASSEMBLY

The barrel assembly of the 24260 propeller ismachined from a one-piece steel forging incor-porating a cylindrical central bore and fourcylindrical blade arms. The blades are retainedby four races of ball bearings. The inner race forthese bearings is on the blades, the outer race isin the barrel. Each blade is free to turn about itsaxis under control of the dome assembly.

The barrel assembly of the 43E60 propeller ismade in two pieces, and they are machined andbalanced as a pair and kept together for the lifeof the propeller. The barrel halves are held


Figure 9-1.Cutaway view of the 43E60 propeller.

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AD.431

Chapter 9PROPELLER OPERAT;ON AND MAINTENANCE

together by the barrel bolts and nuts. The boltsare hollc and may be filled with lead wool asrequired to achieve final propeller balance.

CONSTANT-SPEED CONTROL

The double-acting constant-speed control di-rects oil to either the inboard or the outboardside of the piston in the dome, changing theblade angle in order to maintain the selectedengine rpm. It is mounted on the nose section ofthe engine. The control is made up of threeassemblies: head, body, and base. The 5U18control utilizes a stepmotor electric head toadjust the position of the speeder rack, which inturn changes the compression on the speederspring. This sets the control to maintain anyselected rpm within the operating range of theconstant-speed control. The stepmotor electrichead may be controlled through a synchronizersystem or by a manually operated toggle switchin the cockpit. The electric head eliminatesmechanical linkage between the cockpit and the.constant-speed control. The constant-speed con-trol also includes flyweights, a gear type pumpwhich produces oil pressure for the operation ofthe propeller, and various valves which controland direct the flow of oil to the propeller.

An electrically driven auxiliary pump is usedas a source of high-pressure oil during the fourauxiliary operations. These are the feathering,unfeathering, unreversing, and reversing cycles.The output of the auxiliary pump is led to theconstant-speed control and is automatically di-rected to the proper side of the propeller pistonto produce the desired blade angle change.

PROPELLER OPERATION

The most significant natural force affectingthe angle of the propeller blades is the centrif-ugal twisting moment, which tends to move theblades to a flat or a zero blade angle. This forceis always present when a propeller is rotating.Oil pressure from the constant-speed controlmust overcome the centrifugal twisting momentin order to move the blades to a higher bladeangle when desired. Therefore, higher oil pres-sure is required to increase blade angle.

171

Oil pressure directed to the outboard side ofthe propeller piston causes the blades to movetoward a higher pitch. The constant-speed con-trol permits oil drainage from the inboard sideof the piston when the blade angle is it :eased.When the blade angle is decreased, the cunstant-speed control directs oil to the inboard sidf, ofthe piston and allows drainage front the out-board side of the propeller piston back to theinlet side of the pump in the constant-speedcontrol. Both the pressure oil and the drain oilflow through separate passages in the oil transferhousing, which is screwed into the propellershaft. The propeller piston may move outboarduntil a steel sleeve in the piston rests against thelevers of the low-pitch stop lever assembly.These levers are held outward by a wedge so thatthey will engage the sleeve in the piston as thepropeller blades reach the low-pitch setting.

When reversing operation is desired, oil pres-sure from the governor aided by oil pressurefrom the auxiliary pump actuates the servo unitof the low pitch stop lever allowing the pistonsleeve to cam the stop levers down and moveforward to the reverse position. This allows thelevers to move inward so that the sleeve in thepiston may pass by the levers, allowing theblades to go past the low-pitch limit and intoreverse pitch. The limit of reverse is reachedwhen lugs of the reverse-pitch stop ring on therotating cam come up against lugs on thestationary cam. The No. 2 blade switch, which isactuated by a cam attached to the blade shankof either No. 2 or No. 3 blade, shuts off theauxiliary pump a few degrees before full reverse.Constant-speed control oil pressure then movesthe blades into the full reverse position. In thereverse position, slotted ports in the pistonsleeve are opened to act as a dump valve,permitting the high oil pressure on the inboardside of the piston to dump through the ports tothe outboard side of the piston.

During unreversing, the auxiliary pump fur-nishes high-pressure oil to the constant-speedcontrol, whiCh directs the oil to the outboardside of the piston and allows oil to drain fromthe inboard side of the piston. When the pistonhas moved to a point where the forward end ofthe piston sleeve is well past the levers of thelow-pitch stop lever assembly, the levers areforced outward by spring tension on the wedge

176.


and the auxiliary pump is cut off by the No. 1blade switch. The piston then moves back untilthe sleeve rests against the levers of the low-pitch stop lever assembly.

During feathering, the auxiliary pump fur-nishes high-pressure oil to the constant-speedcontrol, where it is combined with governor oilpressure and is directed to the outboard side ofthe piston and allows drainage from the inboardside of the piston. This moves the piston inboardand the blades to the feather position. Lugs onthe high-pitch stop ring (located on the rotatingcam) contact lugs on the stationary cam to stopthe blades in the feather position.

For unfeathering, high-pressure oil from theauxiliary pump is supplied to the constant-speedcontrol which directs it to the inboard side ofthe piston, moving the piston outboard and theblades to a lower angle. As the propeller beginsto windmill, the governor boost pump starts tooperate and will aid the auxiliary pump to movethe blades out of feather. The auxiliary pump isshut off by releasing the feather button when alow rpm is reached. This terminates the unfeath-ering cycle and allows the constant-speed con-trol to maintain full decrease rpm, which isselected prior to unfeathering.

CONSTANT-SPEEDCONTROL OPERATION

A cutaway view of the constant-speed controlis shown in figure 9-2.

The stepmotor electric head provides a meansof controlling the compression of the speederspring (8). This compression determines the rpmnecessary to hold the flyweights (9) in abalanced or onspeed condition. If compressionon the speeder spring is increased, more rpm isrequired to cause the flyweights to move out-ward to attain the onspeed condition. If com-pression is decreased, less rpm is needed.

Whenever the flyweights move in, the pilotvalve (13) moves down. When the flyweightsmove out, the pilot valves moves up. Theposition of the pilot valve determines whetheroil is directed to the inboard side of the pistonor to the outboard side of the piston. Duringconstant-speed operation, the pilot valve (13) ispositioned by the forces of the flyweights andthe speeder spring. During the four auxiliary

1. Electric head.2. Pump.3. Highprenure and re-

lief valve.4. Shuttle valve.5. Low-pressure relief

valve.6. Pressure cutout switch.7. Drive gear shaft

AD.432

8. Speeder spring.9. Flyweight

10. Solenoid valve.11. Selector valve.12. Auxiliary pressure

check valve.13. Pilot valve.14. Low rpm adjustment.15. High rpm adjustment

Figure 9-2Cutaway view of the 5U18constant-speed control.

conditions, it is positioned by oil pressure in theupper or lower positioning chamber. If thegreater force is on the top of the positioningland, the pilot valve will move down. If thegreater force is on the bottom of the positioningland, the pilot valve will move up.

The pump (2) boosts engine oil pressure tothe pressure required to operate the propellerduring constant-speed operation. This does notinclude the four auxiliary conditions mentionedpreviously.

The high-pressure relief valve (3) limits themaximum oil pressure for operation of the

172

177

i.

Chapter 9-PROPELLER OPERATION AND MAINTENANCE

propeller except when correcting for a normalunderspeed condition.

The selector valve directs high-pressure oil toback up the spring side of the low-pressure reliefvalve during the feathering, unfeathering, revers-ing, unreversing, and normal overspeed opera-tions. The low-pressure relief valve preventspressure from building up sufficiently to actuatethe servo unit of the low pitch stop lever duringground operation.

During all conditions except normal under-speed, high-pressure oil is directed to the springside of the low-pressure relief valve by theselector valve, increasing the amount of pressurenecessary to open the low-pressure relief.,valve.and allowing ressure to build up until itis relieved by the high-pressure relief valve.By controlling the pressure during a normalunderspeed condition, the low-pressure reliefvalve prevents an inadvertent reversal duringground operation.

The shuttle valve (4) is used to direct high-pressure oil to the plunger side of the pressurecutout switch (16) and return oil to the springside of the pressure cutout switch. The pressurecutout switch is used on some models to releasethe feather button after the blades reach the fullfeather position.

The auxiliary pressure cheek valve (12) per-mits the entry of high-pressure auxiliary pumpoil into the constant-speed control during thefour auxiliary conditions and allows for positivepositioning of the pilot valve. It also directs oilto the following places whenever it is in opera-tion: The pressure chamber of the pilot valve,the solenoid valve, and the lower positioningchamber of the pilot valve to create an artificialoverspeed for feather and unreverse. It preventsoil from the pump of the constant-speed controlfrom pressurizing the auxiliary pump line duringconstant-speed operation. It also has a smallbleed hole for winterization, which allows aslight amount of control oil to enter theauxiliary line during constant-speed operation.This will prevent oil congealing in this lineduring cold weather.

The solenoid valve (10), is energized duringunfeathering and reversing. It directs oil pressureto the upper positioning chamber causing thepilot valve to move downward, thus creating anartificial underspeed condition.

The low rpm adjustment (14) provides ameans of setting the minimum governing rpm bylimiting the upward travel of the speeder springrack.

The high rpm adjustment (15) provides ameans of setting the maximum governing rpmby limiting the downward travel of the speederspring rack.

CONSTANT-SPEED OPERATION

During constant-speed operation the gearpump of the constant-speed control boostsengine oil pressure to that required for theoperation of the propeller.

UnderspeedAn underspeed condition is shown in figure

9-3. The force on the speeder spring has over-come the centrifugal force of the flyweights andthe pilot valve has moved down. The pilot valvein this position directs oil pressure to theinboard side of the propeller piston and allowsoil to drain from the outboard side of thepiston. The oil pressure on the inboard -- ;de ofthe piston moves the piston outboard, movingthe blades to a lower angle. As the blades moveto the lower angle, engine rpm increases. Theincreased centrifugal force on the flyweightscauses the flyweights to move outward, raisingthe pilot valve. When the force of the speederspring becomes balanced by the centrifugal forceon the flyweights, the pilot valve will be inposition to restrict the pressure and drain ports,and the pitch will stop changing. This is theonspeed condition.

Ov.rspeedWhen the engine rpm exceeds that selected by

the pilot, the centrifugal force of the flyweightswill overcome the force of the speeder springand the flyweights will move outward. Thisraises the pilot valve, directing oil pressure to theoutboard side of the piston, allowing drainagefrom the inboard side of the piston and movingthe blades to a higher blade angle. As the bladeangle is increased, the rpm is decreased, whichlessens the centrifugal force exerted by theflyweights. The flyweights move inward. Whenthe selected rpm is attained, the flyweightsbalance the force of the speeder spring. The

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178

ELECTRIC HEAD

PILOT VALVE


HIGH-PRESSURE

RELIEFVALVE

SOLENOIvAITE

BLADEROTATING

CANCAM

ROLLER-,PISTON

LOW-PRESSURERELIEF VALVE

FEATHERINGPUMP a MOTOR

BRUSHES SIGNAL CONTROLSWITCH SWITCH

CONSTANT SPEEDUNDERSPEED

BLEED OIL f DRAIN WI

HIGH-PRESSURE L I ENGINE OR RETURNOIL OIL

LOW-PITCH SERVO PISTONSTOP ;T ASV,

LEVER

Figure 9-3.Propeller system operating diagramconstant speed.

pilot valve restricts oil flow to and from thepiston, and the onspeed condition is againreached.

During all conditions of constant-speed opera-tion, the wedge is forcing the levers of thelow-pitch stop lever assembly outward, holdingthe levers in position to engage the sleeve of thepiston, thus limiting the low blade angle. Withthe auxiliary pump off and no pressure in theline from the auxiliary pump to the constant-speed control, the auxiliary pressure check valveprevents oil from the pump in the constant-speed control from pressurizing the auxiliarypump line. Except during normal underspeed,the selector valve is in the position which allowsoutboard oil pressure to reach the spring side ofthe low-pressure relief valve. This allows thehigh-pressure relief valve to control the pressuregoing to the propeller piston except during anormal underspeed condition.

174

OPERATION DURINGAUXILIARY CONDITIONS

-SERVOPISTONVALVE

AD.433

Reversing

The operation of the propeller during revers-ing is shown in figure 9-4. For reversing, anartificial underspeed condition is set up in theconstani-speed control. (Notice that the fly-weights are inward, in the same position as for anormal underspeed condition.)

The artificial underspeed condition is accom-plished in the following manner. An electricalcircuit is completed when the throttles aremoved back onto the reverse position. A switchon the landing gear prevents this circuit frontbeing completed unless the weight of the aircraftis on the ground. This also prevents accidentalreversing during flight. The completion of thecircuit turns on the auxiliary pump, which

199

Chapter 9PROPELLER OPERATION AND MAINTENANCE

ELECTRQ HEAD

PILOT VALVE.

HIGH -PRESSUP:

REUEFVALVE


FEATHERING PUMP& MOTOR

BLADEROTAT

CAMING

BRUSHES LsSIGNALSWITCH

ROLLER

0 4-

PISTON

LOW -PITCH SERVO SERVOCONTROL STOP PISTON PISTON

SWITCH LEVER SHAFT VALVEY

REVERSING

AUXILIARY OIL

HIGH-PRESSUREOIL

IDRAIN OIL

ENGINE OR RETURN

Figure 9-4.Propeller system operating diagramreversing.

furnishes high-pressure oil to the governor toassist in reversing the propeller. This high-pressure oil is delivered through the auxiliarypressure check valve to the solenoid valve, whichis energized by the completion of the circuit sothat the high-pressure oil may enter the upperpositioning chamber to the top of the pilotvalve. The force of this oil mows the pilot valvedown into the underspeed condition. The selec-tor valve allows the oil from the solenoid valveto back up the spring side of the low-pressurerelief valve, thus raising the pressure permittedin the system. The underspeed position of thepilot valve directs oil pressure to the inboardside of the piston, moving the piston forwardand the blades to reverse pitch.

Since the sleeve of the piston is stopped bythe levers of the low-pitch stop lever assembly,sufficient pressure builds up at this point toactuate the servo unit of the low-pitch stop lever

175

AD.434

to r ove the wedge from underneath the levers.The levers are moved inward by the cammingaction of the piston sleeve releasing the pistonand allowing the blades to move into reversepitch. Before the blades reach the full reverseposition, the cam on the No. 2 or the No. 3blade actuates the switch that cuts off theauxiliary pump. The blades are then held inreverse pitch by pressure from the pump of theconstant-speed control. The reverse stop ringlimits the angle of the blades while in fullreverse.

Unreversing

The operation of the propeller during un-reversing is shown in figure 9-5. To accomplishunreversing, an artificial overspeed condition isset up in the constant-speed control.

1.8D

I

AVIATION MACI-IINIST'S MATE R 1 & C

ELECTRIC HEAD

rPILOT VALVEBLADE

ROTATINGC

CMROLALER

HIGH-PRESSURERELIEFVALVE

SOLENOlilLVE


FEATHERING PUMP8 MO1OR

BRUSHES SIGNALSWITCHSWITCH

RO L

UNREVERSING

AUXIUART OPHIGHPRESSUREOIL

I

ci...-Z t.,

/LOW-PITCH

STOPLEVER

MAIN OILENGINE OR RETURNOIL

Figure 9.5.Propeller system operating diagramunr. ersing.

When the throttle is moved forward (out ofthe reverse position), the unreversing circuit isenergized, thus turning on the auxiliary pump.The solenoid v "e, when deenergized, shuts offthe pressure to the upper positioning chamber,which had been maintaining the artificial under-speed condition, and allows it to drain. Theauxiliary connector check valve directs oil pres-sure that moves the pilot valve up and into theoverspeed condition. Oil pressure is again di-rected by the sele.ctor valve to back up thespring of the low-pressure relief valve, thusallowing high oil pressure into the system. Oil isdirected by the pilot valve to the outboard sideof the piston, which moves the blades toward ahigh angle.

Because of the reduced oil pressure on theinboard side' of the piston, the wedge movesunder the levers of the low-pitch stop leverassembly after the piston sleeve clears them.

176

18x.

Y._

PISTON

/

I ISERVO SERVOPISTON PISTONSHAFTASS'Y

VALVE

AD.435

This forces the levers outward. When the sleeveof the piston passes the levers, the levers returnto their normal constant-speed position. Whenthe blades reach an angle well above the low-pitch position, the cam mounted on the No. 1blade actuates a switch that turns off theauxiliary pump and the propeller returns to alow blade angle.

Feathering

The operation of the propeller during feather-ing is shown in figure 9-6. For feathering, anartificial overspeed condition is set up in theconstant-speed control.

When the feather button is pushed in, theauxiliary pump is started. High-pressure oil isdirected by the auxiliary connector check valveto raise the pilot valve to the overspeed condi-tion. High-pressure oil again backs up.the spring


ELEGIAC HEAD

PILOT VALVE

HIGH-PRESSURE

RELIEFVALVE


BLADEROTATING CAM ROLLER

CAM PISTON

/soireeW LVE

FEATHERING PUMP6 MOTOR

BRUSHES SIGNALSWITCH

CONTROL LOW-PITCH SERVO SERVOSWITCH STOP PISTON PISTON

LEVER SHAFT VALVEASS'Y

FEATHERING

AUXILIARY OILHIGH-PRESSUREOIL

1 4

I I

DRAIN OILENGINE OR RETURNOIL

Figure 9-6.Propeller system operating diagramfeathering.

of the low-pressure relief valve and permits thehigh pressure necessary for moving the blades tothe feather position. Oil is directed by the pilotvalve to the outboard side of the propellerpiston, moving the blades to the feather angle.When the lugs of the feather stop ring on therotating cam contact the lugs of the stationarycam, the blades are in the feather position. Thefeathering operation is terminated by pulling outthe feather button and breaking the circuit, orby a pressure cutout switch or timer whichautomatically releases the feather button, de-pending on the installation used.

Unfeathering

The operation of the propeller during un-feathering is shown in figure 9-7. To accomplish

ita

AD.436

unfeathering, an artificial underspeed conditionis set up in the constant-speed control.

To unfeather, the feather button is momen-tarily held out manually. This turns on theauxiliary pump and positions the solenoid valveto direct auxiliary oil pressure to the upperpositioning chamber to position the pilot valvein an artificial underspeed condition. At thesame time this high-pressure oil from the sole-noid valve is directed through the selector toback up the low - pressure relief valve, allow-ing a high pressure in the system. With the pilotvalve in the underspeed condition, oil is directedto the inboard side of the piston. This forces thepiston forward and moves the blades out of thefeather position to a lower blade angle.

Unfeathering is terminated when the featherbutton is released. If the feather button is heldout too long, the cam on the No. I bladeactuates the switch which cuts out the auxiliary


ELECTRIC HEAD

PILOT VALVE

HIGH-PRESSURERELIEFVALVE


BLADEROTATING CAM ROLLER

C

\PISTON

SOLENOIDVALVE

FEATHERING PUMP& MOTOR

BRUSHES SIGNAL TROL,WITCH SWITCH

UNFEATHERING

LOW-PITCH SERVO SERVOSTOP PISTON PISTON

LEVER SHAFT VALVEA

11 AUXILIARY OIL p i DRAIN OIL

Now HIGH-PRESSURE ENGINE OR RETURNOIL OIL

Figure 9-7.Propeller system operating diagramNeathering.

pump and deenergizes the solenoid valve. Thishappens just before the sleeve in the pistonreaches the low-pitch stop lever and preventsaccidental reverse pitch, since an artificial under-speed condition is required to actuate thelow-pitch stop lever.

iCONSTANT-SPEED CONTROL

INSTALLATION AND REMOVAL

INSTALLATION

A general discussion of installation procedureis given here. The appropriate technical publica-tions should be consulted for specific instruc-tions.

If the constant-speed control is to be installedon a new or overhauled engine, remove themounting pad cover from the engine nose. Makesure that the shipping gasket between this cover

..

178

183

AD.437

and the engine pad is also removed. Failure toremove this gasket would affect the flow ofengine oil to the control and would causemalfunction of the control. Clean the surface ofthe mounting pad and base of the control.Install a new gasket on the mounting pad withthe raised portion of the metal screen of thegasket facing up. Install the control on the studsof the mounting pad. The one proper position ofthe control on the mounting pad is indicated bythe shape of the joining surfaces. Make sure thatthe splines of the control shaft are properlyalined with the internal splines in the engine padand that the circular boss in the base of thecontrol fits properly into the circular recess inthe engine pad. Install the washers and nuts andtighten evenly to the proper torque. Lockwirethe nuts in pairs.

Connect the auxiliary high-pressure oil linefrom the auxiliary pump to the auxiliary con-nector on the control. Make the electrical


connections to the solenoid valve, etc. Aftertune-up, if necessary, make the low-rpm andhigh -rpr' adjustments by first toggling thespeeder spring rack off the stop and thenloosening the self-locking nuts on the adjustingscrews. Remove the lockwire from the screwsand adjust to give the desired rpm settings.Tighten the nuts and lockwire the adjustingscrews to each other.

REMOVAL

The removal of the constant-speed control isthe reverse of the installation procedure. Ifanother control is not installed immediately,install a gasket and cover on the mounting pad.

PROPELLER INSTALLATIONAND REMOVAL

INSTALLATION

Clean the propeller shaft and engine thrustnut thoroughly. Put a light coat or clean engineoil on the propeller shaft. Install the split rearcone on the propeller shaft, making sure that thesurfaces of the cone are dry and clean. Installthe spider shaft spacer on the shaft next to therear cone. Install the 0-ring seal on the shaftnext to the spacer. Make pencil marks on theforward end of the propeller shaft to indicatethe locations of the locking holes of the shaft.This will facilitate the alinement of one of theslots in the retaining nut with a hole in thepropeller shaft.

Place the front cone, propeller retaining nut,and snapring in position in the propeller hub,turning the blades in ti 3 hub enough to allowthese parts to be inserted past the blade gearsegments. As with the rear cone, the surfaces ofthe front cone should be clean and dry. Apply athin coat of thread lubricant to the threads ofthe propeller shaft.

Using a power wrench and sling assembly, liftthe propeller onto the shaft. If the propellershaft has an index spline or an index screw, alinethe blank spline of the propeller hub with it andslide the propeller back on the shaft. As thepropeller is pushed fully into position, tightenthe retaining nut by hand to insure that there isnot binding or cross threading. Tighten the

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184

retaining nut with a short bar until it is snug.Using the power wrench, tighten the retainingnut to the proper torque, and aline one of thelocking slots in the retaining nut with one of thelocking holes in the propeller shaft.

Place the oil transfer housing gasket againstthe plate inside the propeller shaft. Clean thethreads of the oil transfer housing and theinternal threads of the propeller shaft and applya light coat of thread lubricant or engine oil tothem. Carefully screw the oil transfer housinginto the shaft by hand. Tighten the oil transferhousing to the proper torque, alining the splineson the housing with the splines on the inside ofthe retaining nut to receive the lock segment.Install the lock segment and secure with the locksegment lockwire.

NOTE: Never back off the retaining nut toaline a slot with a hole. If necessary, back theretaining nut all the way off and retighten to theproper torque. Insert the propeller retaining nutlock through the hole in the shaft and into theslot in the retaining nut.

Prior to installing the dome, each bladeshould be turned in the barrel to the specifiedfeathering setting and the rotating cam in thedome should be set at the high angle.

NOTE: The dome may be installed with theblades at the low pitch setting with the sameresults; however, it is recommednded that themethod of setting the units at the feather anglebe used. Therefore, this method is described inthe following paragraphs.

Assuming that all correct settings and adjust-ments have been made during assembly oc, thedome, set each blade of foie propeller in thefeathered angle specified. Refer to the bladebutt index and, using the blade turning bar, turnall blades in a manner that will aline the indexline on the barrel with the feathering anglespecified on the butt blade. Using the correcttool on the rotating cam gear, turn the cam untilthe feather stop ring lugs contact the lugs on thebase of the fixed cam. This stop ring should, ofcourse, be checked to assure that it is accuratelylocated.

Install the required number of preload shimsover the fixed cam locating dowels. The totalthickness of shims required is etched on thebarrel shelf. The dash number following theshim number indicates the thickness of the shim


in thousandths of an inch. Do not install thedome-barrel seal at this time.

With the dome lifting handle installed in thedome, lift the dome and aline it with thelocating dowels on the barrel shelf. Because ofthe dowel arrangement, the dome will fit in onlyone position. Just before installing the dome,check that the rotating cam is tightly against thestop lug. After the dome is positioned correctly,tighten the dome retaining nut until it is firmlyseated on the barrel shelf. Aline the hole in oneof the retaining nut lugs with one of the crescentslots in the outboard edge of the barrel. Care-fully mark this location of the retaining nut, andremove the dome..

Install the dome-barrel seal, and again place,the dome in position using the same care asbefore. Tighten it until the previously markedholes are lined up.

NOTE: With the dome assembly properlyseated in the barrel, the front face of the domeretaining nut will be approximately flush withthe outboard edge of the barrel. Failure totighten the dome unit securely in the hub willresult in elongation or failure of the dome shellretaining screws, and oil leakage around thedome retaining nut.

Check the feather angle at the referencestation with a protractor and blade template.

Remove the dome lifting handle and, with theaid of a blade turning device, manually turn theblades to low pitch. Again check the setting withthe protractor. At both feather and low pitch,the blade angles should be within 0.5 degrees ofthe specified settings. Insert the dome retainingnut lock screw and safety it with a cotter pin.Install the dome cap, and lock the cap in placewith a cotter pin or a lock screw and a cotter pinon later assemblies.

NOTE: If for any reason the oil transfer tubeis removed from the dome or the setting of thelow-pitch stop lever assembly is disturbed, thesemust be reset accprding to current propelleroverhaul instructions. This also applies to thereverse- and high-pitch stop rings. Care must betaken not to damage the oil transfer tube duringdome installation and removal.

REMOVAL

The removal procedures are the reverse of theinstallation procedures. While the dome or the

180

135

propeller is removed, special care must be takenthat no electrical circuits are energized from thecockpit. If the auxiliary pump were turned on, astream of oil (often hot) under pressure wouldbe sent out the propeller shaft, causing possiblyserious injury to anyone in front of the propel-ler.

After removal, if another propeller is not tobe installed immediately, clean, oil, and coverthe propeller shaft. If the propeller is to bestored for any length of time, preserve thepropeller in accordance with current instruc-tions.

ASSEMBLY AND DISASSEMBLY

The installation and removal of propellers areusually performed in Organizational mainte-nance activities. The supporting AIMD providesreplacement propellers to the Organizationalactivity in a ready-for-installation condition andreceives the replaced propellers in the conditionthey were removed from aircraft. Therefore, thepreparation of new or overhauled propellers for

'Organizational activities is the responsibility ofthe AIMD. Thereby, propellers received fromOrganizational activities are either repaired orare prepared for shipment to Depot maintenanceby the AIMD. This requires the assembly anddisassembly of the propellers, as appropriate,which, of course, must be accomplished by theADR's assigned to the AIMD.

NOTE: It must be emphasized that the pro-cedures discussed in the following paragraphs arerepresentative of those required for the assemblyand disassembly of different models of propel-lers. Therefore, applicable technical manualsmust be utilized for the assembly and disassem-bly of specific models. Current technical manualsare especially important for obtaining suchinformation as the part numbers of requiredspecial tools, military specifications of cleaningmaterials and lubricants, correct torque valuesand tolerances, etc.

Assembly

The following procedures are those requiredto assemble a new or ovei auled propeller asreceived from supply and to test it prior toinstallation on an aircraft. As received, the


disassembled components are coated with pre-servative and packed in a shipping box.

Remove the barrel from the shipping box andclean it thoroughly with an approved solvent.Place the barrel on the assembly and balancingbushing installed on the post of the assemblytable. Attach the bushing in place with the frontcone and propeller retaining nut. Remove thebarrel bolts and separate the barrel halves usingthe specified puller. Make certain not to let thebottom half of the barrel drop on the table.

Remove the blades from the shipping box andclean with an approved solvent. Do not allowthe cleaning solvent to contact any rubber parts.All plated steel parts should be given a light coatof oil after cleaning.

Remove the various components from theirpacking containers and remove the preservation.It should be noted that the components arenumbered to indicate their location in thepropeller. It is imperative that these parts beinstalled in their correct positions to obtainproper fit and balance of the propeller.

Install the blade packing rings by opening thesplit and sliding onto the blade shank. Makecertain the side with the pins is outboard. Applya light coat of the recommended lubricant to thepackings and spider arm bearing surfaces, andstretch the packings over the bide butts. Applya light coating of the recommended lubricant onthe shim and shim plate and install Them ontotheir respective blade butts. After making cer-tain that the barrel supports are in their pkoperposition, install the blades on the spider arins.inaccordance with the proper numbers. Beforepressing the blades against the spider, make surethat the spider shim plates are correctly fittedover the drive pins.

Line the zero on the beveled washer with thezero on the blade butt. Apply a light coat oflubricant to the thrust bearing retainers andinstall the retainers between the flat surfaces onthe beveled and flat thrust washers on the bladeshank.

While holding the thrust bearing retainers inplace on each shank, and, with the blade packingin place against the thrust washer, raise theinboard barrel half into position so that the arm,identifying numbers on the spider and barrelhalf coincide. With the barrel half properlyalined, carefully drive it into place with a

181

1S6

rawhide or rubber mallet. Lubricate the barrelhalf seals and install them into the groove of therear barrel half.

Match the position numbers of the outboardbarrel half with the inboard half and drive theoutboard half dowr, with a rawhide or rubbermallet until it seats on the barrel supports. Whendriving the barrel halves together, drive theminto place evenly. Do not hammer continuouslyon one side.

The barrel bolt bosses are numbered so thatthey progress in a counterclockwise directionwith numbers 1, 2, 3, and 4 between barrelblade bores 1 and 2, and so number 1 andnumber 12 are at opposite sides of number 1barrel blade bore. The barrel bolts are numberedcorrespondingly. Install the bolts in their respec-tive positions. One washer should be place onthe heads of bolt numbers 2, 6, and 10, and onewasher under the head-and one Fasher under thenut of bolt numbers 3, 7, and 11. One washer isrequired under the head and one under thespinner mounting bolt of bolt numbers 4, 8, and12. No washers are required on bolt numbers 1,5, and 9. Install the nuts on the bolts handtight.Torque in the manner and to the value specifiedin the applicable technical manual.

After it has been assembled thus far, removethe propeller fiarn,the assembly table and installit on the post of a ast rig. Install the front coneand propeller retaining nut, then install the oiltransfer housing. .

Remove the dome from 'the shipping box andclean the exterior surface 'with an approvedsolvent. Install the dome, following the proce-dures similar to those required for installationon the aircraft, discussed previously. Install thedome cap and tighten securely, but do notinstall the lock screw and cotter pin.

An operational and leakage test is performedat this phase of the assembly. To accomplish thistest, open both the pressure and back pressurevalves and start the test rig. Check the propelleroperation to low pitch by opening the inboardpressure valve, closing the outboard pressurevalve, and gradually closing the inboard backpressure valve until a pressure sufficient tounlatch the feather latch is obtained and theblades move to the low pitch position. Manuallymove each blade simultaneously toward lowpitch to remove backlash. Using a protractor and


blade template, measure the blade angle. Themeasured angle should be within 0.5 degree of

"the specified setting.To reverse the propeller blades, increase the

pressure on the inboard side by closing theinboard back pressure valve until the pressure issufficient to move the propeller blades to fullreverse position. Manually move each bladesimultaneously toward full reverse to removebacklash. Measure the blade angle with a pro-tractor and blade template. The measured angleshould b_ e within 0.5 degree of the specifiedsetting.

Feather the propeller by opening the out-board presscre valve and gradually closing theoutboard back pressure valve until the propellermoves to the full feather position. Manuallymove each blade simultaneously toward the fullfeather position to remove backlash. With aprotractor and blade template, measure tileblade angle. The measured angle should bewithin 0.5 degree of the specified setting.

Gradually close both the back pressure valvesuntil a pressure of 90 psi is obtained on bothinboard and outboard pressure gages and holdthis pressure for one minute. There should be noexternal leakage. Repeat this test with 400 psiapplied to both sides of the dome and hold forone minute. There should be no external leak-age.

Remove the doMe cap, flyweight, and oiltransfer tube and then remove the dome assem-bly. Remove the oil transfer housing, the propzi-*ler retaining nut, and the front cone from thetest post.

Attach the required deicing components tothe propeller in accordance with the applicabletechnical manual. After these components areproperly installed, the propeller is mounted on apropeller stand ready for installation on anaircraft.

Disassembly

When a propeller is removed from an aircraftfor shipment to overhaul or to be stored, it mustbe preserved. The following procedures ,arerequired for disassembling the propeller, preserv-

182

1 L)

ing it for shipment or storage, and placing it inshipping boxes.

Immerse the dome assembly less the flyweightassembly and oil transfer tube in a vat of theapproved preservative and let drain on a stand.Remove the lockwire from the drive boltsattaching the slip ring to the barrel. Remove thecontrol switch connectors and then remove thedrive bolts and slip ring assembly.

Remove the propeller retaining nut snap ring,the retaining nut, and the front cone. Place thepropeller on the assembly At and remove thespinner rear bulkhead attaching nuts, then re-move the rear bulkhead. If desired, this may bedone while the propeller is suspended by a hoist.Remove the barrel bolts and the bracket andnozzles. The control may be removed or left onthe rear bulkhead, as desired. Place all smallparts as they are removed in one group so theywill not be lost and can be packed separately forshipment.

Install the barrel puller and lift the outboardbarrel half from the spider. Using a rubber orrawhide mallet, drive the inboard barrel halfdown far enough to remove the blades from thespider arms.

With the blades removed, reinstall the barrelhalves over the spider and install the barrel bolts.Tighten the bolts to a snug position. Immersethe barrel in the preservative and let it drain on astand.

Place the dome in a shipping carton lined withoiled paper and seal tightly. Then, place thebarrel in a shipping carton and seal tightly withoiled paper. The cartons should be marked insuch a way they will not become separated ormixed with other cartons of the same form.Place oiled paper between each blade shank andthrust washer. Cover the thrust washers with anapproved preservative and wrap the washers andblade shank with oiled paper. Place the bladesand the cartons containing the dome and barrelin the shipping box. e

Lubricate all small parts except the slip ringassembly and the spinner rear bulkhead, bracket,and nozzle assemblies. Pack the small parts incontainers and place in the shipping box on topof the dome and barrel cartons. Pack so therewill be no shifting in handling and then seal theshipping box.


TROUBLESHOOTING

Table 9-1 contains a list of troubles, probablecauses, and remedies. The extent to whichcomponents may be disassembled for partsreplacement or repair is governed by one ormore of the following: General or local policy;availability of parts, tools, and equipment; andexperience of personnel. In any case whencorrecting discrepancies, the applicable opera-tion, service, or overhaul instructions should beconsulted. The faulty parts listed in table 9-1may be located by referring to the illustrationsindicated in the table. Refer to figures 9-8, 9-9,9-10, 9-11, 9-12, and 9-13.

RIGGING AND ADJUSTING

Rigging and adjusting of the 43E60 and24260 propellers are primarily concerned withadjusting, as there is little rigging to be donewith these propellers. Adjusting of the low-pitchstop lever assembly and indexing procedures ofthe dome assembly can be accomplished byreferring to the Overhaul Instruction Manualsfor each type propeller.

BALANCING

Since a propeller rotates at a very high rate ofspeed, balance is A propeller out ofbalance could cause s 'ous damage or possibleloss of life. Therefore, is of great importancefor the Chief and First Class Aviation Machin-

ist's Mate R to understand propeller balancing in

183

.15(5

order to recognize this dangerous condition andtake the proper remedial steps.

Three classifications are used when referringto a propeller out of balance. These are static,dynamic and aerodynamic.

STATIC BALANCE

When a propeller's center of gravity does notcoincide with its axis of rotation it is referred toas being out of balance statically. This conditionmust be checked and corrected by the manu-facturer, a Depot maintenance activity, or over-haul activity.

DYNAMIC BALANCE

When similar propeller elements (blades, spin-ners, cuffs, etc.) do not follow the same plane ofrotation the propeller is said to be out ofbalance dynamically. This condition must becorrected at an overhaul or Depot maintenanceactivity.

AERODYNAMIC BALANCE

When the amount of thrust per blade isunequal the propeller is out of balance aerody-namically. This condition usually occurs whenthe improper angle is set on one or more bladesof a propeller. This condition usually happenson installation of a propeller or when the domeassembly has been removed for maintenance andreinstalled. Correction of this condition is ac-complished locally by removing the propellerdome and indexing the blades to the properangle.


Table 9-1.Propeller troubleshooting chart.

Trouble Probable Cause Remedy

PROPELLER LEAKAGE

At dome cap

At dome retainingnut

At barrel blade bore . . .

In rear cone vicinity.. .

Damaged seal (7), fig. 9-8 Replace seal.

Loose cap (3), fig. 9 43 Tighten cap.

Damaged dome-barrel seal Replace seal.(2), fig. 9-8.

Damaged blade packing (21), Replace packing.fig. 9-9.

Improper blade packing Replace packing.

Foreign material under Wipe packing and sealing surfacesblade packing. clean.

Damaged spider-shaft seal Replace seal.(2), fig. 9-9.

Damaged spider-shaft seal Replace spacer.spacer (3), fig. 9-9.

Engine thrust plate seal Consult engine manual.

CONTROL LEAKAGE

Between head andbody

At high-pressureconnector.

Between reliefvalve housingand body.

Damaged head-body seal (14),lig. 9-11.

Loose head- body nutsDamaged connector gasket

Loose attaching nuts.Damaged relief valve gasket

(26), fig. 9-11.

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189

Replace seal.

Tighten nuts.Replace gasket.

Tighten nuts.Replace gasket.


Table 9-1.Propeller troubleshooting chartContinued.

T rouble Probable Cause

CONTROL LEAKAGECONTINUED

Between relief valvehousing and reliefvalve plug.

Between body andbase.

Between base andengine mountingpad.

Remedy

Loose relief valve housing(27), fig. 9 -11.

Damaged relief valve pluggasket (31), fig. 9 -11.

Loose relief valve plug (32),fig. 9-11.

Damaged body-base seal (9),fig. 9-12.

Loose body-base nutsDamaged mounting gasket

(35), fig. 9-12.

Loose attaching nuts

Warped base (36), fig. 9-12Warped engine mounting pad

Tighten housing.

Replace gasket.

Tighten plug.

Replace seal.

Tighten nuts.

Replace gasket.

Tighten nuts.

Lap base.

Consult engine manual.

ROUGHNESS Ignition or carburetion

Engine part failure

Ice on propellerBlade angles vary among blades

Blade out of track

Propeller unbalance


Feather propeller (in flight).

Turn on anti -icing system.

Adjust 11 blades to the properangle, using protractor or indexlines.

If limit is exceeded, replace pro-peller.

Remove and balance propeller.HUNTING OR SURGING Ignition

PROPELLER

Poor carburetion

Excessive internal leakage incontrol.

Excessive leakage in enginenose section.

Sticky control pilot valve (11),fig. 9-11.

Sticky low-pressure reliefvalve (30), fig. 9-12.

Sticky selector valve (22),fig. 9-11.

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190

Check ignition system.

Check induction system and carbu-retor.

Check control on test stand.


Remove and clean, or replace pilotvalve.

Remove and clean, or replacevalve.

Remove and clean, or replaceselector valve.


Table 9.1.- Propeller troubleshooting chart-Continued.

Trouble

HUNTING OR SURG-ING PROPELLER-CONTINUED

Probable Cause Remedy

Faulty tachometer

Air in propeller system

Calibrate or replace tachometer.

Operate controls 2 or 3 times be-tween high and low rpm duringengine runup.

IMPROPER SYNCHRO- Faulty synchronizerNIZATION.

INABILITY TO ATTAINMAXIMUM RPM ATTHE CHOCKS.

Consult synchronizer manual.

Incorrect high rpm setting.... .

Low engine power

Faulty tachometer

Sticky pilot valve (11), fig. 9-11.

Faulty circuits to stepmotorelectric head.

Improper installation of low-pitch stop lever assembly ...

Adjust high rpm setting on controlhead.


Calibrate or replace tachometer.Remove and clean, or replace pilot

valve.

Check circuits.

Reset stop lever assembly in dometo establish low blade anglespecified for the aircraft.

OVERSPEEDING ONTAKEOFF.

INABILITY TO:FEATHER

Incorrect high rpm setting oncontrol head.

To rapid opening of throttitl... .Damaged or incorrect mounting

gasket (35), fig. 9-12.Sticky pilot valve (11),

fig. 9-11.

Sticky low-pressure reliefvalve (30), fig. 9 -12.

Faulty tachometer

Insufficient exercise of pro-peller mechanism.

Damaged shaft gasket (10),fig. 9-13.

*Aircraft batteries low

* Faulty electrical system

*Items also apply to INABILITY TO UNFEATHER.

186

Adjust high rpm setting.

Open throttle slowly and evenly.Install correct new gasket.

Remove and clean, or replace pilotvalve.

Remove and clean, or replace reliefvalve.

Calibrate or replace tachometer.Move control several times

through constant-speedrange with engine running.

Replace gasket.

Charge or replace batteries- andcheck generator system.

Check auxiliary pump circuits.

Chapter 9 PROPELLER OPERATION AND MAINTENANCE

Table 9.1.- Propeller troubleshooting chart-Continued.

Trouble Probable Cause Remedy

INABILITY TOFEATHERCON-TINUED.

*Sheared coupling inauxiliary pump.

*Restricted oil supply toauxiliary pump.

*Damaged oil line fromauxiliary pump to constant-speed control.

High-pressure relief valve (28)

Replace coupling.

Check auxiliary pump inlet linesfor obstruction.

Replace line.

Reset or replace valve.

*Stuck high- or low-pressurerelief valve, selector valve,or pilot valve.

Windmilling of propeller atfeather caused by incorrectsetting of high-pitch stop ring.

Clean or replace valve.

Reset high-pitch stop ring.

INABILITY TO UN-FEATHEIt

(NOTE: See asteriskeditems under INABILITYTO FEATHER)

Faulty solenoid valve (20), fig. Repair circuit or replace solenoid9-11. valve.

Faulty No. 1 blade switch circuit

INABILITY TOREVERSE

Faulty solenoid valve (20),fig. 9-11.

Improver reverse settingLow-pitch stop levers do not

allow piston to pass.Aircraft batteries low

Stuck selector valve, pilotvalve, or high- or low-pressure relief valve.

Check and repair circuit.

Repair circuit or replace solenoidvalve.

Reset reverse stop ring.Replace low-pitch stop lever as-

assembly.Charge or replace batteries and

check generator system.Clean or replace faulty valve.

INABILITY TO UN-REVERSE.

Faulty .:elector valve or solenoidvalve.

Fsulty No. 1 blade switch

Faulty auxiliary pump or circuit.

*Items also apply to INABILITY TO UNFEATHER.

18-

._01,

Repair or replace faulty valve.

Check and repair circuit.

Check and repair circuit or pump.


1. Gear preload shim.2. Dome-barrel seal.3. Cotter pin.4. Dome retaining nut lock screw.5. Stop ring spacer.6. High- and reverse-pitch stop rings.7. Dome cap seal.& Screw9. Dame shell.

10. Screw.

11. Lever sleeve bushing.12. Welch plug.13. Ball.14. Dome retaining nut15. Piston seal.16. Internal retaining ring.17. Cam roller shaft.18. Piston assembly.19. Cam roller assembly.26. Cam roller sleeve.

Figure 9-8.Dome assembly.

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193

AD.43821. Cam roller needle bearing spacer.22. Cam roller needle bearing.23. Cam roller.24. Cam roller thrust washer.25. Colter pin.26. Cam bearing nut.V. Fixed cam.28. Rotating cam.29. Cam outboard bearing.30. Can inboard bearing.

Chapter 9- PROPELLER OPERATION AND MAINTENANCE

13 12 15 10 1 2422

2325

21 30 17 16 10 7 6 4

20

18

14 I I 9 12 26 27 28

1. Retaining nut lock assembly.2. Spider-shaft 0-ring seal.3. Spider and shaft seal spacer.4. Rear cone.5. Reinforcement sleeve.6. Cotter pin.7. Barrel bolt extension.8. Castellated nut9. Washer.

10. Washer.

2931

11. Welch plug.12. Barrel bolt11 Locating dowel.14. Locating dowel.15. Barrel (front half).16. Barrel (rear half).17. Barrel half seal.18. Spider shim plate.19. Spider shim.20. Blade gear segment.

Figure 9-9.-Barrel assembly (43E60).

194 189

8 7 6 5

A0.439

21. Blade packing.22. Barrel support insert.23. Insert pin.24. Barrel support.25. Barrel support shim.26. Hub snapring.27. Propeller retaining nut28. Front cone.29. 0-ring seal.30. Spider ring.31. Spider.


1. Setscrew.2. Blade packing nut3. Blade packing retaining segment.4. Blade packing backup rings.5. Blade packing.6. 0-ring seal.7. Seal retaining segment.8. Blade support ring.9. Micro adjusting rings.

10. 0-ring seal.11. Cotter pin.12. Stop pin.13. Blade segmental gear.14. Shim.15. Unreversing control spacer.16. Snapting.17. Pre loading screw.18. Pre loading screw thrust ring.19. Lock wrench.20. Washer.21. Lock wrench retaining screw.

22.23.24.25.26.27.28.29.30.31.32.33.

AD.440

Blade to barrel arm ball.0-ring seal.Barrel balancing plug.Barrel balancing plug lock screw.Welch plug.Front cone.Propeller retaining nutHub snapring.Propeller retaining nut lockwire assembly.Adjusting pin.Unreversing control plate.Brush and connector assembly.

34. Brush.35. Spring.36. Tab lock washer.37. Barrel.38. Reinforcement sleeve.39. Barrel-shaft 0-ring seal.40. Barrel-shaft seal spacer.41. Rear cone.

Figure 9-11-Barrel assembly 124260).

190

I. 9 5


I 2

IP-- 3231 CI,

29----430

28

26

7 II 14 15 16 17 2533

1. Speeder spring.2. Cotter pin.3. Slotted pilot valve nut.4. Lockwasher.5. Speeder spring collar.6. Pilot valve ball bearing.7. Internal snapring.8. Drive gear shaft bushing.9. Drive gear shaft spring washer.

10. Driver gear shaft washer.11. Pilot valve.12. External snapring.13. Flyweight assembly.14. Head-body seal.15. Clamp insert16. Clamp ring.17. Body.18. Solenoid valve attaching screw.

20

18

19. Washer.20. Solenoid valve.21. Solenoid valve gasket22. Selector valve.23. Internal snapring.24. Dowel.25. High-pressure relief valve 0-ring seal.26. High-pressure relief valve gasket.27. High-pressure relief valve housing.28. High-pressure relief valve.29. High-pressure relief valve spring.30. High-pressure relief valve shim.31. High-pressure relief valve plug gasket32. High-pressure relief valve plug.33. Idler gear.34. Drive gear shaft.35. Coupling snapring.36. Drive coupling.

Figure 111.-Control body assembly.

191

196

AD.441


48 2827

47---__40, 26

22 23 17 154121/

-

1. Internal snapring.2. Output check valve housing.3. Check valve bell.4. Check valve spring.5. Check valve stop.6. Input passage sleeve.7. Body-base stud.8. Auxiliary pressure check valve stud.9. Body-base seal.

10. Castellated nut11. Washer.12. Pressure cutout switch.13. Receptacle attaching screw.14 Lodcwasher.15. Plain washer.16. Receptacle assembly.17. Receptacle flange.18. Receptacle gasket.19. Spring adjustment shim.20. Spring.21. Piston.22. Switch body.23. Dowel.24. Contact.

AD.442

25. Cutout switch gasket.26. Cutout switch gasket27. Cutout switch plate gasket28. Low-pressure relief valve spring.29. Shim.30. Low-pressure relief valve.31. Cutout switch shuttle valve plug.32. Shuttle valve plug base 0-ring -seal.33. Cutout switch shuttle valve.34. Cutout switch attaching stud.35. Mounting gasket.36. Base.37. Castellated nut38. Washer.39. Auxiliary pressure check valve gasket.40. Valve-base 0-ring seal.41. Spring seat42. Shim.43. Auxiliary pressure check valve inner spring.44. Auxiliary pressure check valve outer spring.45. Auxiliary pressure check valve.46. Elbow.47. Fillister head screw.48. Cover plate.

Figure 9-12-Control base assembly.

192

191


1. Cotter pin.2. Screw.3. Dome cap.4. Low-pitch stop lever assembly.5. Dome assembly.6. Segment lockwire.7. Lock segment& 0-ring seal.9. Oil transfer housing.

10. Shaft gasket11. Drive bolt.12. Washer.13. Bolt.14. Bolt.15. Washer.16. Connector support

AD.443

17. Terminal.18. Clamp.19. Insulated wire.20. Tube.21. Coupling.22. Bracket and nozzle assembly.23. Control slip ring assambly.24. Control switch assembly.25. Shim.26. Bolt27. Counterweight (inner).28. Counterweight (outer).29. Blade cam assembly.30. Blade assembly.31. Barrel.

Figure 9.13.- Propeller assembly (43E60).

193

1°8i,,S

CHAPTER 10

HELICOPTER MAINTENANCE

This chapter covers the SH-3A as a typicalhelicopter for the description of helicoptermaintenance. Although all the helicopters in

.active service are powered by jet engines, ADR'Sare still being assigned to helicopter squadronsand should be familiar with transmission androtor systems. The engines will normally bemaintained by ADJ personnel, but ADR'S maybe required to assist them at times. Because ofthis possibility it is recommended that ADRpersonnel read the chapter on turboshaft heli-copter maintenance contained in the ADJ 1 & CRate Training Manual.

SH-3A HELICOPTER

The SH-3A is a twin engine, antisubmarinewarfare (ASW) helicopter,, designed for land andcarrier-based operations. It is also capable ofwater landing and takeoff.

The SH-3A has a hull shaped fuselage andoutrigger sponsons into which the main landinggear retracts. A fixed horizontal stabilizer isinstalled on the upper right side of the pylonand two T58-GE-8B gas turbine engines aremounted side by side above the fuselage forwardof the rotary wing head.

Flight configuration is a five-blade main lift-ing rotary wing head and a five-bladed rotaryrudder. Forward, aft, lateral, and vertical flightare accomplished through the rotary wing head,while the rotary rudder counteracts torque fromthe rotary wing head and provides directionalcontrol.

Power to drive the rotary wing head issupplied through the main gearbox. The rotaryrudder is driven through shafting which extendsaft from the main gearbox, through the discon-nect coupling and intermediate gearbox, andterminates at the tail gearbox. The main gearboxalso incorporates a rotor lockout system which

194

199

permits the use of No. 1 engine to operate thegenerators and hydraulic pumps for groundhandling purposes. .

Three separate hydraulic systems are used inthe SH-3A. The primary and auxiliary hydraulicsystems are used in conjunction with the me-chanical linkage of the flight controls. Theauxiliary hydraulic system is also used in con-junction with the automatic stabilization equip-ment (ASE).

The utility hydraulic system provides powerfor the retractable main landing gear, automaticblade fold system, windshield wiper system, andrescue and sonar hoist systems. It also suppliesfluid to the rotor brake system. Figure 10-1shows the SH-3A helicopter.

POWER TRANSMISSION SYSTEM

The transmission system of the SH-3A con-sists basically of the main gearbox, tail driveshaft, oil cooler and blower, and the pyloninstallation. The latter includes the intermediateand tail gearboxes.

The main gearbox drives the rotary winghead, tail drive shaft, and accessory components.The accessory components, including the maingearbox oil pump, generators, and the hydraulicpumps, are driven whenever the left engine isoperating. The rotor lockout system preventsthe rotary wing head and the rotary rudder fromrotating during ground runup. The tail driveshaft transmits torque to the intermediate gear-box where the drive angle is changed, and on tothe tail gearbox where the drive angle is againchanged and the rpm reduced to drive the rotaryrudder.

The tail drive shaft also drives the transmis-sion oil cooler and blower. Oil from the maingearbox is fed to the oil cooler and blower andreturned to the gearbox for lubrication and

Chapter 10 HELICOPTER MAINTENANCE

eft

010Figure 101.Model SH-3A helicopter.

cooling purposes. The main gearbox also in-dudes freewheel units that balance the inputfrom the engines, assist in rotor lockout, andpermit freewheeling of the rotary wing headduring aut' rotation.

MAIN DRIVE SHAFT

The main drive shaft is a dynamically bal-anced shaft that transmits torque from theengine to the main gearbox. It consists of ahigh-speed shaft, Thomas coupling, engineadapter, match-marked nuts for engine attach-ment, and match-marked bolts and ruts forattachment to the main gearbox coupling. TheThomas coupling and engine adapter are securedto the shaft by special bolts and Hi-Lok collars

195

AD.314

to prevent disasFembly. The shaft is made oftubular steel. It is flanged at both ends forconnection to the Thomas coupling, adapter,and power turbine cooling flange, and to themain gearbox coupling flange. The drive shaft ishoused within and protected by the aft enginesupport. Direction of rotation is clockwise whenviewed from the aft end of the engine. Toremove the main drive shaft, the affected power-plant must be removed. Figure 10-2 shows adetailed view of the main drive shaft.

MAIN GEARBOX

The main gearbox is located on the transmis-sion deck aft of the engines. It drives theaccessories, supports and drives the rotary wing

zoo ...


ENGINE POWER ?URSINE RANEE

SWIM SOO

..-- 141 EOK C011AR MAIN NIA SKATE

SWIM gEkT

SPECIAL NUT

NUT

CROSS SECTIONAL VIEW

EMANATED STEEt DISC (THOMAS COOKING) NEAR SUPPORT ASSENkY --.....

ADAPTER

SECTION A A

Figure 10.2Main drive shaft

196

201

SECTION 8 li

AD.318


head, and provides the power takeoff to drivethe rotary rudder. The accessories, which in-clude two generators, two transmission oilpumps, three hydraulic pumps, and a rotortachometer-generator, are driven through free-wheel units. When the rotary wing head isdisengaged, the accessories are driven by athrough shaft geared to the No. 1 engine.

Torque sensors, incorporated in the inputsection, sense engine input torque indicationswhich are transmitted to the engine torqueindicators, mounted on the instrument panels.Lubrication of the main gearbox is accom-plished by a self-priming wet sump system.The No. I oil pump is mounted on the low-er left side of the rear cover and supplies oilto the oil cooler and lubricating jets. The No. 2oil pump is mounted on the upper right side ofthe rear cover. Each oil pump acts as a backupfor the other in case of failure. Oil lines from thetw ) pumps are connected by a tee fitting, fromwhich oil is routed to the oil cooler and thelubricating jets. An oil level sight gage is locatedon the lower left side of the main gearboxhousing. The oil filler tube is located above thesight gage. A transmitter sends oil pressurereadings to the transmission oil pressure gage inthe cockpit. A temperature bulb located in themain gearbox housing transmits oil temperaturereadings to an indicator in the cockpit. A chipdetector plug in the strainer allows inspection ofthe main gearbox for metal contamination. Thechip detector plug is also connected in serieswith the intermediate and tail gearbox plugs to awarning light in the cockpit. The actuatedfreewheel unit in the main gearbox provides themeans of disengaging the rotary wing head whileproviding power to operate the accessories sec-tion of the main gearbox. In addition, the unitfunctions as a freewheel unit during autorota-tion. Basically, the unit consists of a cam,rollers, a cage, and a housing. In normal flight,the unit is not actuated and the No. 1 enginedrives the cam which forces the rollers againstthe housing. The housing is then mechanicallyconnected to the cam and drives the rotary winghead. Should the housing rotate faster than thecam, as in autorotation, the rollers ride free ofthe cam and permit the housing and cam torotate independently. In accessory drive, theactuator shaft lugs rotate .the cage, holding the

197

rollers free of contact between the cam andhousing. Power is then transmitted to theaccessory section by the through shaft. Figure10-3 shows a schematic view of the maintransmission including the freewheel units. Fig-ure 10-4 shows the component location of theSH-3A transmission system.

Removal

For removal and installation, the main gear-box is handled as a quick change unit, either byitself or with the rotary head installed. Acces-sory components are removed, if necessary, afterthe main gearbox has been removed from thehelicopter.

To facilitate removal of the linear actuator,place the accessory drive switch in the flightposition before removal of the main gearbox.Hinge down the engine and transmission serviceplatforms and remove the engine aft cowling andthe rotary wing fairing halves.

After opening all access doors, remove theaccess panel from the aft rotary wing fairing.Turn off all electrical power, disconnect theelectrical plug at the chip detector, and install adrain fitting. Drain the oil in a suitable con-tainer. After draining the oil, replace the chipdetector. For the step-by-step procedure fordisconnecting the main gearbox, the operationand service instructions manual should be fol-lowed. When all lines and connections aredisconnected, install the engine supports. Dis-connect the input flange from each engine maindrive shaft flange. (Refer to fig. 10-2.)

After disconnecting the engine aft supportsfrom the gimbal rings, remove the first sectionof the tail drive shaft with the flexible steelcouplings. To prevent damage to the maingearbox, accessory components, or the helicop-ter during removal, check to insure that allelectrical wiring and lubrication lines have beendisconnected. Using a sling and a suitable hoistwith a rated capacity of at least 3,500 pounds,remove the main gearbox and lower it onto acart.

Installation

For installation, the reverse procedures areused. When the installation is complete, °ervice

2Q2


FROM #2ENGINE

FREE WHEELUNIT

HELICALGEARS

BEVEL RING GEAR

ACCESSORYDRIVE GEARS

a TAIL ROTOR1.."' DRIVE SHAFT

SPUR GEAR

FROM #IENGINEr

=.,.0001

111111110. THROUGH SHAFT,. .........*

=--- .4.4"HELICALFREE WHEEL GEAR

UNIT

Figure 143 SH3A main transmission schematic.

the hydraulic tanks and check for leaks. Tightenall lubrication lines and service the main gearboxwith oil. Install the engine aft cowlings, rotarywing fairing halves, and the access panel on theaft rotary wing fairing and check for security.After the required flight time, retorque thegearbox mounting bolts in accordance withcurrent instructions.

Troubleshooting

Table 10-1 contains some of the troublesencountered with the main gearbox. It also liststhe probable cause and remedy for each trouble.

MAIN GEARBOX OILCOOLER AND BLOWER

The main gearbox oil-cooler and blower unit(fig. 104) is located in the aft rotary wingfairing. It consists of a cooler (radiator), blower,and duct. The blower is belt driven by the tail

198

203

ACCESSORYDRIVE GEARS

AD.317

drive shaft and forces air through the cooler.Hot oil from the main gearbox is pumpedinto the cooler. If the temperature ofShe oil is less than 70°C the oil is bypassed tothe return line by a thermostatic regulator. Oilreturning from the cooler is forced through thelubricating jets in the main gearbox.

Removal

For removal of :he oil cooler and blower,hinge down the transmission service platformsand remove the rotary wing fairing access panels.Drain the oil from the main gearbox and withall electrical power off disconnect the wiringfrom the fire extinguisher and remove the clipsfrom the blower. Remove the belts from thedriven pulley by lowering the oil cooler andblower. (Do not remove the belts from the drivepulley on the tail drive shaft.) Disconnect thehoses and remove the clamps. Separate the


OIL COOLER 8BLOWER

TAIL GEARBOX

TAIL DRIVESHAFT

INTERMEDIATEGEARBOX

TAIL DRIVESHAFT

( SECTION 3r)

Figure 10-4.SH3A transmission system component location.

blower from the cooler and remove the blower,then remove the cooler.

Installation

For installation, position the cooler and sup-port on the bulkhead with the bolts, but do nottighten the bolts. Attach the blower to thecooler and position the oil cooler and blower on

AD.187

the forward support. Install the bolts, but donot tighten, Install the oil hoses and clamps.Install the pulley belts on the driven pulley andthe driving pulley on the tail drive shaft.Position the oil cooler and blower, using thespecial jack. Adjust and align the pulley beltsand tighten the holddown bolts. Connect thewiring for the fire extinguishers. Service themain gearbox with oil. If the oil cooler has been

199

'A.C4


Table 141.Main gearbox troubleshooting chart.

Trouble Probable cause Remedy

Low oil pressure . . . .

Gradual dropoff ofoil pressure dur-ing flight.

Fluctuating low oilpressure and ex-cessive oil lossthrough breather.

Increase in oil tem-perature.

High oil pressure .

Excessive chips instrainer, or onmagnetic plug.

Excessive externaloil leakage of themain gearbox.

Low oil level in sump

Improper oil

Oil cooler valve stuck open

Clogged strainer

Relief valve stuck open

Excessive leakage in the maingearbox

Clogging of oil cooler

Failure of oil pump

Leakage in oil cooler

Bearing in gearbox running hot

Low oil level

Improper oil

Faulty regulator

Internal leakage of main gearbox

Loose belts on blower drive

Cold oil in system

Relief valve jammed closed

Internal failure of gearbox

Leakage around rear accessoryseals, main shaft seal, or lowerhousing bottom seals.

Service the gearbox

Service gearbox with properoil.

Replace cooler.

Clean strainer.

Repair or replace valve.

Replace gearbox.

Clean or replace oil cooler.

Replace gearbox.

Replace oil cooler.

Replace main gearbox.

Service gearbox.

Service gearbox.

Replace regulator.

Replace main gearbox

Adjust belts.

Allow sufficient time for oilto warm up.

Repair or replace relief valve.

Replace gearbox.

Replace leaking seals.

200

1405

Chapter 10HELICOPTER MAINTENANCE

drained, an additional gallon of oil will berequired for the gearbox. Install the rotary wingfairing access panels and hinge up the transmis-sion service platforms.

Troubleshooting

For troubleshooting the main gearbox oilcooler and blower, refer to table 10-2.

ROTOR BRAKE

The rotor brake system permits application ofthe main rotor brake manually or automatically.It incorporates a master brake cylinder, pressureg age, panel package, rotor brake, accumulator,check valves, and pressure switches. Operationof the system is closely associated with theoperation of the blade fold system.

The rotor brake is located on the input coverof the main gearbox and is hydraulically actu-ated to stop the rotation of the rotary winghead. Actuation is accomplished manually bymeans of the rotor brake master cylinder in the

cockpit, or automatically during blade foldingby the blade positioner control valve. In manualoperation, the rotor brake is capable of stoppingthe rotary wing head in 14 seconds from 157rpm. The rotor brake consists of a rotor brakedisc and housings containing four pistons andfour brake linings.

Removal

To remove the rotor brake, hinge down theengine and transmission service platforms andremove the engine aft cowlings. Disconnect thehydraulic lines and remove the elbows, nuts,gaskets, and rings. Remove the rotor brake fromthe main gearbox by removing the nuts andwashers; the rotor brake disc may now beremoved by removing the six bolts that secure itto the drive.

Installation

Prior to installation check the thickness of thebrake disc. If it is not within the specified limitsit must be replaced.

Table 10-2Main gearbox oil cooler and blower troubleshooting chart


High gearbox oiltemperature withdrop in oilpressure.

Loose belts on blower drive

Improper operation of radiatortemperature regulator.

Clogged radiator

Leakage in radiator

Adjust belts to obtain properdeflection and tension

Unusual vibration andnoise from oilcooler fan.

LBad bearing in fan

Loose belts

Improper alignment

Replace radiator.

Clean and flush or replaceradiator.

Replace radiator.

Replace fan.

Tighten or replace belts.

Align pulleys.

206

201


Loosen all the adjusting pin nuts and push thepistons as far into the housing as possible. Nowposition the rotor brake disc and shims on theinput bevel gear flange and secure with the bolts.Before installing the brake assembly, check therunout of _the disc. If it is within limits, install iton the main gearbox. Adjust the thickness of theshims to center the rotor brake disc in the brakehousings to within 1/32 inch. With the rotorbrake disc secured on the main gearbox, checkthe distance between the edge of the bladepositioner drive unit gear and the edge of therotor disc. If the dimension is not within limits,reshim the positioner drive unit. After obtainingthe proper clearance, install the elbows, nuts,gaskets, and rings. Install the hydraulic lines andbleed the brake system to remove the air.Actuate the rotor brake master cylinder severaltimes and then check the clearance of all brakelining pucks. If the proper clearance cannot beobtained, replace the rotor brake.

Troubleshooting

Refer to table 10-3 for troubleshooting therotor brake system.

TAIL DRIVE SHAFT

The tail drive shaft extends from the tailtakeoff coupling flange at the rear cover of themain gearbox to the disconnect jaw of theintermediate gearbox. The primary purpose ofthe shaft is to transmit engine power to drive therotary rudder. It also provides the drive for themain gearbox oil cooler blower fan. The taildrive shaft is composed of five sections.

Section I consists of a shaft and two Thomascouplings. Section II consists of a flanged shaft,pulley, bearing support housing, and a flange.Section III consists of a shaft, four bearingsupports, and two flexible steel couplings. Sec-tion IV consists of a shaft, four bearing sup-ports, and a disconnect coupling jaw.

Sections I and II are enclosed in the aft mainrotor fairing. Section III is enclosed in the aftmain rotor fairing and in the tail drive shaftaccess fairings. Section IV is enclosed in the taildrive shaft access fairings. Section V is mountedin the pylon and consists of a shaft and twoflexible steel couplings.

Removal

To remove the tail drive shafts, fold the pylopand remove the main rotor fairing screen, hingedown the transmission service platforms andopen the tail drive access fairings. For the stepby step procedures refer to the applicabletechnical manual. The following paragraph givesa brief removal procedure.

To remove section IV, remove the bolts andnuts from the bearing rings and remove therings. Remove the bolts on the right side of thebearing support plates. Remove the lower boltson the left side of the bearing support andloosen the others. Swing the bearing supportplates up and out of the way. Do not remove thebearing support plates, because installation inany position except the original will result inmisalignment and excessive runout. The sameprocedures may be followed for removal of theother shafts except section II. The oil cooler andblower drive belts must be removed from thedriving pulley to remove section II.

Installation

For installation, the reverse procedure is used,but upon completion a shaft runout check isrequired. Any excessive misalignment will causevibrations and damage to the drive shafts. Referto the applicable technical manual for thecorrect procedures and limitations.

Troubleshooting

Refer to table 10-4 for tail drive shafttroubles, probable causes, and remedies.

INTERMEDIATE GEARBOX

The intermediate gearbox (fig. 10-4) is lo-cated forward on the pylon where it joins the aftfuselage. The intermediate gearbox transmitstorque and changes the angle of drive from themain gearbox to the tail gearbox. It consists ofan input housing and gear assembly, with aspring-loaded disconnect jaw, a center housing,and an output housing and gear assembly. Thespring-loaded disconnect jaw provides a meansof folding and unfolding the pylon withoutmanually disconnecting the transmission. When

202207-

Chapter 10HELICOPTER MAINTENANC13

Table 1113.Rotor brake system troubleshooting chart


Brake does nothold,

Low hydraulic fluid level

Leakage in hydraulic lines

Internal or external leakage inmaster brake cylinder.

Internal or external leakage inbrake.

Worn brake lining pucks

Service utility fluid tank withhydraulic fluid.

Check lines for leakage.

Replace master brake cy-linder.

Replace brake.

Replace lining pucks.

Spongy brake. Air in system Bleed system.

Brake disc scored. Uneven brake wear Replace brake disc.

Evidence of brakecontact withrotor brake off.

Blake not disengaging

Insufficient clearance betweenbrake pucks and, disc.

Replace brake assembly.

Check clearance.

the pylon is folded, the pylon transmissioncomponents are locked to prevent the rotarywing from windmilling. When unfolded, the lockautomatically disengages. The input and outputhousings contain bevel gears to change the angleof drive, up along the pylon. The center housingincorporates an oil level sight gage on the leftside, a magnetic drain plug on the bottom, and afiller plug at the top. The gearbox is splashlubricated and air cooled.

Removal

To remove the intermediate gearbox, drainthe oil and remove the fairing from the pylon,and fold the pylon. Insure that all electricalpower is off; then disconnect the electricalwiring ai the pylon terminal block and chipdetector plug. Remove the grommet and clampthat secures the wiring and pull the wiringupward through the bracket. Support the taildrive shaft and disconnect it at the flange of theoutput housing. Support the intermediate gear-

lirk

box, remove the bolts securing it to the bracket,and remove the gearbox. Unbolt and remove thebracket.

Installation

To install the intermediate gearbox, install thebracket and install the gearbox after insuringthat the correct shims are on the studs. Checkthe alignment of the gearbox and position theflexible steel coupling of the tail drive shaft onthe output housing of the gearbox. Position theconvex seat of each coupling washer against thecoupling. Install the shims equally at each ear ofthe flange. Place the unused shims under ,theboltheads and 'washers. Secure this stackup tothe output housing of the intermediate gearbox.Shims should be installed equally at each end ofthe drive shaft sections. Insert the electricalwiring through the bracket and connect it to thechip detector and pylon terminal block. Installthe grommet, secure the clamps, and safety wirethe chip detector plug. Remove the support


Table 10-4.Tail drive shaft troubleshooting chart


High frequency vi-brations inhelicopter causedby the tail driveshaft.

Loose bolts and nuts at attachingflanges.

Drive shaft installed with incor-rect shims.

Bolts loose, sheared, or withimproper torque.

Damaged bearing support bracket.

Drive shaft not bonded to shaft.

Rough bearing

Damaged coupling disc

Damaged flange

Damaged drive shaft

Tighten nuts to specifiedtorque.

Install drive shaft correctly.

Tighten bolts to requiredtorque. Replace bolts ifnecessary.

Replace bracket.

Replace drive shaft section.


Replace damaged part.



Failure of driveshaft.

Fatigue failure

Improperly aligned drive shaft....

Scratch or dent on drive shaft . . .


Realign drive shaft.


from the tail drive shaft and unfold the pylon.Service the gearbox with oil and replace allfairing.

Troubleshooting

Refer to table 10-5 for intermediate gearboxtroubles, probable causes, and remedies.

TAIL GEARBOX

The tail gearbox (fig. 10-4), mounted at thetop of the pylon, serves as the attachment forthe rotary rudder, changes direction of drive 90degrees, and reduces the shaft speed. An actua-tor shaft, controlled by the rotary rudder flight

204

controls, operates the pitch control beam. Thepitch control beam is connected to the sleeve ofeach rotary blade to change the pitch of theblades. The gearbox is splash lubricated. Amagnetic drain plug is installed in the bottom ofthe input housing. Access to the tail gearbox isgained by removing the fairing at the top of thepylon.

Removal

To remove the tail gearbox, first remove therotary rudder, but leave the pitch control beamwith the tail gearbox. Insure that all electricalpower is off; disconnect the fairing and rotarybeacon anticollision light. Disconnect the electri-

Chapter 10HELICOPTER MAINTENANCE

Table 145. Intermediate gearbox troubleshooting chart


Excessive oil leak-age at seals orparting flange.

Deterioration of seals Replace seals or inter-mediate gearbox.

Gearbox running toohot.

Insufficient lubrication

Improper eear tooth clearance . .

Defective beXrings

Service gearbox.

Replace gearbox.

Replace gearbox.

High frequencyvibration inhelicopter struc-ture caused byintermediategearbox.

Gearbox mounting nuts loose

Defective gearbox bearings

Gear teeth damaged

Tighten nuts to requiredtorque.

Replace gearbox.

Replace gearbox.

cal wiring from the chip detector plug and drainthe oil. Disconnect and remove the bellcrankand control rod. Support the upper end of thetail drive shaft and disconnect it at the inputflange. Retain the nuts, bolts, and shims. Installthe lifting eye on the tail gearbox. With tensionon the hoist, remove the bolts, washers, barrelnuts, and shims securing the tail gearbox to thesupport. Now remove the bolts securing the tailgearbox, hoist the tail gearbox from the helicop-ter, and place in a stand. Retain all washers andshims for installation.

Installation

After repairs have been completed, lift thegearbox ir:o position and align it in accordancewith the applicable technical manual. Install andsecure the bolts, washers, barrel nuts, retainers,and shims to the support. Remove the lifting eyeand torque the bolts to the required torque.Connect the tail gearbox to the flexible steelcoupling. Install the coupling shims equally ateach ear. Connect the control rod to thebellcrank and secure it. Install all fairing and therotating beacon anticollision light. Insure that all

205

&di."' 0.

electrical power is off; then connect the wiringto the anticollision light and magnetic chipdetector. Install the rotary rudder faking andservice the gearbox with oil.

Troubleshooting

Refer to table 10-6 for troubleshooting thetail gearbox.

ROTOR HEAD ASSEMBLY

The rotary wing head (fig. 10-5) of the SH-3Ahelicopter is a fully articulated head, splined toand supported by the rotary wing shaft of themain gearbox. The head supports the five rotarywing blades, is rotated by torque from the maingearbox, and provides the means of transmittingthe movement of the flight controls to theblades. Its design permits automatic folding ofthe blades.

The principal components of the head are thehub and swashplate. The hub consists primarilyof a hub plate and lower plate, hinge assemblies(located between each arm of the plates),


Table 10.6.Tail gearbox troubleshooting chart


Seal leakage. Clogged breather

Defective seal

Clean breather.

Replace seal.

High frequency' vi-bration inhelicopter struc-ture caused bytail gearbox.

Tail gearbox mounting bolts loose.

Improper number of shims at themountings.

Defective bearings in tail gearbox.

Gear teeth damaged

Tighten bolts to requiredtorque.

Check the alignment and in-stall the correct numberof shims.

Replace the tail gearbox.


Tail gearbox over-heating.

Insufficient lubrication

Excessive lubrication

Defective bearings

Internal oil system clogged

Improper gear tooth clearances orbearings preloaded. -






Exc-ssive oil leak-.ge at packing

seals or partingflanges.

Deterioration of packing or seals. Replace the input or outputseal, and if leakage stillexists, replace the tailgearbox.

sleeve-spindle assemblies (which are attached tothe hinge assemblies), and five damper-positioners. The swashplate consists of a rotatingand a stationary swashplate.

Other components of the head are the fiveanti-flapping restrainers, five droop restrainers,five adjustable pitch control rods, and therotating and stationary scissors. The swashplateand pitch control rods allow movement of theflight controls to be transmitted to the rotarywing blades. The hinge allows each blade to lead,lag, and flap. The damper-positioners restrictlead and lag motion and position the blades in

preparation for folding. Sleeve-spindles alloweach blade to be rotated on its span-wise axis tochange blade pitch. The antiflapping restrainersand the droop restrainers restrict flapping mo-tion when the rotary wing head is slowing orstopped. The control lock cylinder is unlockedto permit the sleeve, to rotate about the sleeve-spindle axis. The stationary scissors are con-nected to the stationary swashplate and themain gearbox upper housing; the rotating scis-sors are connected to the rotating swashplateand the lower plate of the hub.

206

211


VERTICALHINGE PIN

DAMPERRESERVOIR

BLADE FOLDMANIFOLD

SLEEVE ANDSPINDLE NO.1

UPPERPLATE

/FOLD

HINGE

HORIZONTALHINGE PIN

ANTI-FLAPRESTRAINER

DAMPERPOSITIONER

STATIONARYSWASHPL ATE SCISSORS

PITCHCONTROL ROD

Figure 10.5. Rotor head assembly.

207

1 24

AD.319

A

AD rating, 34Advance, spark, 97-98Advanced base, 44-35Advancement, prepare for, 5Aeronautical Allowance Lists, 22Aeronautical Equipment Service

Record, (AESR), 52Aircraft inventory, 50-52Aircraft Inventory Record, 51Aircraft Maintenance Material Readiness

List (AMMRL), 25-26Aircraft parts, procuring and

custody, 48-49Analysis, 38-39Analysis, oil, 110-111Application Data Material ReadinessList (ADMRL), 26

Appropriation Purchase Account (APA), 15Assurance, quality, 43-44Aviation Supply Office (ASO), 14

B

Backfiring, engine, 107Base, advanced, 44-45Bibliography for Advancement Study,NavEdTra 10052, 7-8

BMEP, 73, 74, 103, 107Breaker points, 95, 129, 130, 14, 132Bulletin, 54

C

Capacitor, 95Carburetion, 106-108Carburetor, 83-93Cathode ray tube, 121, 128, 136Cell, torque, 73Change, 54, 60-62

INDEX

Change assembly, quick engine (QECA), 142Classified publications, security of, 68Clutch, supercharger, 74-79Cognizance symbols, 17, 19Communications, 36Component Control Section (CCS), 28Consolidated Repairable Item List, 20Corrosion, 111-119, 155-156Courses, Nonresidence Career, 9

D

Damage, foreign object (FOD), 146Defueling, 164Detonation, 120Distributors, 94, 95Drawing number, 21

Engine:backfiring, 107change, 146-152run-in, 153-155

Exhaust, 98

E

F

Factors, knowledge and practical, 5Federal stock number (FSN, 17-19Files, 68-69Film Catalog, U.S. Navy, NavAir10-1-777, 11

Foreign object damage, 146Forward area operations, 44-45

G

General Fund of the Treasury, 15General ratings, 1Ground support equipment, procuringand custody, 50

208

",' 213

INDEX

H

Helicopter:intermediate gearbox, 203-204main:drive shaft, 195gearbox, 195-201

power transmission, 194-201rotor:brake, 201-202head assembly, 205-206

tail:drive shaft, 202gearbox, 204-205

Ignition, 94-98Individual Material ReadinessList (IMRL), 26

Initial Outfitting Lists, 22-23Injection, water, 93-94Inspections, 47-48Instruction, maintenance, 56Insulation tester, 109Intensity, sound, 105Inventory, aircraft, 50-52Inverter, 123Item Source Codes, 21-22

K

Kits:parts, 32quick engine change (QECK), 142

Knowledge factors, 5

L

LDO, 12Leadership, 35-37Light, timing, 109List of Training Mnauals andCorrespondence Courses,NavEdTra 10061, 8

Lubrication, 98-101

M

MAF, 32Magneto, 94, 95, 128-129

Maintenance instruction, 56Maintenance Requirements Cards (MRC's),47Manual of Qualifications for Advancement,NavPers 18068, 5, 11

Manuals, 56-60Manufacturer's part number, 20-21Material Accountability RecoverabilityCodes (MARC), 24-25

Material Control Work Center, 28-32Metal testing, 110Microfilm, manuals to, 62-63Military Standard Requisitioning andIssue Procedure (MILSTRIP), 29

N

National stock number (NSN), 17-19NATOPS, 57, 102Naval:Aircraft:

Factory (NAF), 13Flight Record, 104

Air:Maintenance Training Group(NAMTG), 3

Systems Command, 14, 15Aviation Maintenance Program(NAMP), 26, 33-34

Leadership Program, 4Supply Systems Command, 13, 14

Navy Management Data List (NMDL), 20Nonresident Career Courses, 9Not Operationally Ready Supply (NOBS), 29Number:drawing, 21federal item identification(FUN), 17-18

0Ohmmeter, 108-109Oil analysi.r., 110-111Operating target (OPTAR), 16-17, 29Operations, forward area, 44-45

P

Part number, manufacturer's, 20-21Parts kits, 32Personnel Qualification Standards(PQS), 4, 6-7

Point, breaker, 129, 130, 131, 132Power recovery turbines, 79-83

209

t 214


Practical factors, 5Preservation of Aircraft Engines,Nav Air 15-02-500, 158, 160

Principles and Problems of Naval LeadershipNavPers 15924, 33

Printer, reader, 62-63Procuring and custody of tools, 49Professionalism, 36-37Propeller:assembly, 180-182balancing, 183barrel, 180, 189constant speed control, 171, 172-174178-179

disassembly, 182feathering, 176-177installation, 179-180operation, 171-174, 178removal, 180reversing, 174-175troubleshooting, 183unfeathering, 177-178=reversing, 175-176

Publications, procurement of, 64-68

0Quality assurance, 43-44Quick engine change (QEC), 142

R

Rating:AD, 34general, 1service, 1

Reader printer, 62-63Record of Practical Factors, NavEd.Tra1414/1, 5-6, 10

Refueling, 163-164Revision, 54, 60-62

Safety, 45-47. 145-147Scheduling, 41-44

S

Security of classified publications, 68Service rating, 1Simplification of work, 37-40Sound intensity, 105Spark advance, 97-98Standard Inventory Log, 51Supply:

Response Section (SRS), 27Support Center (SSC), 26-28

Supercharger clutch, 74-79Supervision and leadership, 35-37Symbols, cognizance, 17, 19System, weapon, 3435

T

Target, operating (OPTAR), 29Technical Directive System, 53-55Tester, insulation, 109Testing, metal, 110Timing light, 109Tools, procuring and custody, 49Torque cell, 73-74Training, 10Training program, organization of, 70-72Tube, cathode ray, 121, 128, 136Turbines, power recovery, 79-83

V

Visual Information Display System(VIDS), 43

Warrant Officer, 12Water injection, 93-94Weapon system, 31-35Work:center, material control, 28-32simplification, 37-40

Yellow sheet, 104

210

215