DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

NONRESIDENTTRAININGCOURSE

March 1991

Aviation StructuralMechanic E 1 & CNAVEDTRA 14019

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

Although the words “he,” “him,” and“his” are used sparingly in this course toenhance communication, they are notintended to be gender driven or to affront ordiscriminate against anyone.

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PREFACE

By enrolling in this self-study course, you have demonstrated a desire to improve yourself and the Navy.Remember, however, this self-study course is only one part of the total Navy training program. Practicalexperience, schools, selected reading, and your desire to succeed are also necessary to successfully roundout a fully meaningful training program.

THE COURSE: This self-study course is organized into subject matter areas, each containing learningobjectives to help you determine what you should learn along with text and illustrations to help youunderstand the information. The subject matter reflects day-to-day requirements and experiences ofpersonnel in the rating or skill area. It also reflects guidance provided by Enlisted Community Managers(ECMs) and other senior personnel, technical references, instructions, etc., and either the occupational ornaval standards, which are listed in the Manual of Navy Enlisted Manpower Personnel Classificationsand Occupational Standards, NAVPERS 18068.

THE QUESTIONS: The questions that appear in this course are designed to help you understand thematerial in the text.

VALUE: In completing this course, you will improve your military and professional knowledge.Importantly, it can also help you study for the Navy-wide advancement in rate examination. If you arestudying and discover a reference in the text to another publication for further information, look it up.

1991 Edition Prepared byAMEC William H. Odom

Published byNAVAL EDUCATION AND TRAINING

PROFESSIONAL DEVELOPMENTAND TECHNOLOGY CENTER

NAVSUP Logistics Tracking Number0504-LP-026-6960

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Sailor’s Creed

“I am a United States Sailor.

I will support and defend theConstitution of the United States ofAmerica and I will obey the ordersof those appointed over me.

I represent the fighting spirit of theNavy and those who have gonebefore me to defend freedom anddemocracy around the world.

I proudly serve my country’s Navycombat team with honor, courageand commitment.

I am committed to excellence andthe fair treatment of all.”

CONTENTS

CHAPTER Page

1. Management Safety and Supervision . . . . . . . . . . . . . . . . . 1-1

2. Electrically Operated Canopy System . . . . . . . . . . . . . . . . . 2-1

3. Utility Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

4. Air-Conditioning Systems, . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

5, Navy Aircrew Common Ejection Seat (NACES) . . . . . . . 5-1

APPENDIX

I. Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AI-1

II. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AII-1

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .INDEX-1

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INSTRUCTIONS FOR TAKING THE COURSE

ASSIGNMENTS

The text pages that you are to study are listed atthe beginning of each assignment. Study thesepages carefully before attempting to answer thequestions. Pay close attention to tables andillustrations and read the learning objectives.The learning objectives state what you should beable to do after studying the material. Answeringthe questions correctly helps you accomplish theobjectives.

SELECTING YOUR ANSWERS

Read each question carefully, then select theBEST answer. You may refer freely to the text.The answers must be the result of your ownwork and decisions. You are prohibited fromreferring to or copying the answers of others andfrom giving answers to anyone else taking thecourse.

SUBMITTING YOUR ASSIGNMENTS

To have your assignments graded, you must beenrolled in the course with the NonresidentTraining Course Administration Branch at theNaval Education and Training ProfessionalDevelopment and Technology Center(NETPDTC). Following enrollment, there aretwo ways of having your assignments graded:(1) use the Internet to submit your assignmentsas you complete them, or (2) send all theassignments at one time by mail to NETPDTC.

Grading on the Internet: Advantages toInternet grading are:

• you may submit your answers as soon asyou complete an assignment, and

• you get your results faster; usually by thenext working day (approximately 24 hours).

In addition to receiving grade results for eachassignment, you will receive course completionconfirmation once you have completed all the

assignments. To submit your assignmentanswers via the Internet, go to:

http://courses.cnet.navy.mil

Grading by Mail: When you submit answersheets by mail, send all of your assignments atone time. Do NOT submit individual answersheets for grading. Mail all of your assignmentsin an envelope, which you either provideyourself or obtain from your nearest EducationalServices Officer (ESO). Submit answer sheetsto:

COMMANDING OFFICERNETPDTC N3316490 SAUFLEY FIELD ROADPENSACOLA FL 32559-5000

Answer Sheets: All courses include one“scannable” answer sheet for each assignment.These answer sheets are preprinted with yourSSN, name, assignment number, and coursenumber. Explanations for completing the answersheets are on the answer sheet.

Do not use answer sheet reproductions: Useonly the original answer sheets that weprovide— reproductions will not work with ourscanning equipment and cannot be processed.

Follow the instructions for marking youranswers on the answer sheet. Be sure that blocks1, 2, and 3 are filled in correctly. Thisinformation is necessary for your course to beproperly processed and for you to receive creditfor your work.

COMPLETION TIME

Courses must be completed within 12 monthsfrom the date of enrollment. This includes timerequired to resubmit failed assignments.

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PASS/FAIL ASSIGNMENT PROCEDURES

If your overall course score is 3.2 or higher, youwill pass the course and will not be required toresubmit assignments. Once your assignmentshave been graded you will receive coursecompletion confirmation.

If you receive less than a 3.2 on any assignmentand your overall course score is below 3.2, youwill be given the opportunity to resubmit failedassignments. You may resubmit failedassignments only once. Internet students willreceive notification when they have failed anassignment--they may then resubmit failedassignments on the web site. Internet studentsmay view and print results for failedassignments from the web site. Students whosubmit by mail will receive a failing result letterand a new answer sheet for resubmission of eachfailed assignment.

COMPLETION CONFIRMATION

After successfully completing this course, youwill receive a letter of completion.

ERRATA

Errata are used to correct minor errors or deleteobsolete information in a course. Errata mayalso be used to provide instructions to thestudent. If a course has an errata, it will beincluded as the first page(s) after the front cover.Errata for all courses can be accessed andviewed/downloaded at:

http:/ /www.advancement.cnet.navy.mil

STUDENT FEEDBACK QUESTIONS

We value your suggestions, questions, andcriticisms on our courses. If you would like tocommunicate with us regarding this course, weencourage you, if possible, to use e-mail. If youwrite or fax, please use a copy of the StudentComment form that follows this page.

For subject matter questions:

E-mail: n315.products@cnet.navy.milPhone: Comm: (850) 452-1001, Ext. 1713

DSN: 922-1001, Ext. 1713FAX: (850) 452-1370(Do not fax answer sheets.)

Address: COMMANDING OFFICERNETPDTC (CODE N315)6490 SAUFLEY FIELD ROADPENSACOLA FL 32509-5237

For enrollment, shipping, grading, orcompletion letter questions

E-mail: fleetservices@cnet.navy.milPhone: Toll Free: 877-264-8583

Comm: (850) 452-1511/1181/1859DSN: 922-1511/1181/1859FAX: (850) 452-1370(Do not fax answer sheets.)

Address: COMMANDING OFFICERNETPDTC (CODE N331)6490 SAUFLEY FIELD ROADPENSACOLA FL 32559-5000

NAVAL RESERVE RETIREMENT CREDIT

If you are a member of the Naval Reserve, youwill receive retirement points if you areauthorized to receive them under currentdirectives governing retirement of NavalReserve personnel. For Naval Reserveretirement, this course is evaluated at 6 points.(Refer to Administrative Procedures for NavalReservists on Inactive Duty, BUPERSINST1001.39, for more information about retirementpoints.)

COURSE OBJECTIVES

In completing this nonresident training course,you will demonstrate a knowledge of the subjectmatter by correctly answering questions on thefollowing: management safety and supervision;electrically operated canopy systems; utilitysystems; air-conditioning systems; and the Navyaircrew common ejection seat (NACES).

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Student Comments

Course Title: Aviation Structural Mechanic E 1 & C

NAVEDTRA: 14019 Date:

We need some information about you:

Rate/Rank and Name: SSN: Command/Unit

Street Address: City: State/FPO: Zip

Your comments, suggestions, etc.:

Privacy Act Statement: Under authority of Title 5, USC 301, information regarding your military status isrequested in processing your comments and in preparing a reply. This information will not be divulged withoutwritten authorization to anyone other than those within DOD for official use in determining performance.

NETPDTC 1550/41 (Rev 4-00)

CHAPTER 1

MANAGEMENT SAFETY ANDSUPERVISION

Chapter Objective: Upon completion of this chapter, you will have a workingknowledge of the AME work center supervisor’s responsibilities for acontinuous safety program.

The Manual of Navy Enlisted Manpower andPersonnel Classifications and OccupationalStandards, NAVPERS 18068 (series), states thatthe AME is responsible for the maintenance ofmany systems. Some of these systems are coveredin this manual. Other areas that the AME1 andAMEC must be qualified in are maintaining workcenter records, preparing reports, and training andleadership. The training and leadership responsi-bilities are addressed in the Aviation MaintenanceRatings Supervisor, NAVEDTRA 10343-A1,which you should complete along with thistraining manual (TM).

Senior AME personnel, because of the in-herent dangers involved in the duty, must be moreconcerned with personnel and equipment safetythan senior petty officers in other aviation ratings.Because of this concern, management, safety andsupervisory information is presented here as aseparate chapter, as well as in other placesthroughout this training manual.

SAFETY

Learning Objective: Identify safetyprecautions for working with hazardoussubstances and equipment.

In the AME rating there are many ways fora careless or inexperienced worker to hurt himselfor others and damage equipment. In fact, no otheraviation ratings has more potential for loss of lifeor violent destruction of property than the AMErating. Because of the inherent dangers associatedwith survival equipment, AME supervisors mustbe able to recognize and correct dangerousconditions, avoid unsafe acts, and train others torecognize and respect the importance of safety.

Each year Navy personnel operating andmaintaining safety and survival equipment areinvolved in accidents. These accidents result inexcessive repair and/or replacement cost amount-ing to millions of dollars and reduced operationalreadiness. The magnitude of this recurring lossemphasizes the necessity for preventing accidents,and the associated human suffering. Investiga-tions have revealed two major reasons for mostaccidents with and around safety and survivalequipment; (1) lack of effective training, (2) lackof supervision and leadership. The supervision,leadership, and training required for the properoperation and maintenance of safety and survivalequipment are provided by the AME1 and theAMEC.

The term safety, as discussed in this course,is defined as freedom from danger. This definitioncovers both personnel and equipment. It does notmean that hazards will not exist (they will); butit does mean that if the hazards are known, safetyawareness can and will help prevent accidents.

Safety is everybody’s responsibility, and allhands are required to promote and adhere tosafety rules and regulations. This is easy to say,and it is the ultimate aim of all supervisorypersonnel, but it is not easy to achieve.

The AME’s interest in safety is personal. Askanyone about safety and they will agree it’s veryimportant. This means everyone wants to be safe,but may feel that observing safety precautionsslows down their work. Some feel they know thejob so well that they don’t have to be cautious.Still others think “there will be accidents, but tothe other guy, not me.”

It is these attitudes toward safety that placethe burden of responsibility for safety on AMEsupervisory personnel. They must realize thataccidents can happen anywhere, anytime, and

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to anyone. The AME1 and AMEC must, wherepossible, ensure “freedom from danger” for hispersonnel and equipment.

The best method for the supervisor to meethis responsibility for safety is by a continuoussafety program. This program should includeinspection of work areas, equipment, and tools;interpretation of safety directives and precautions;and personal attention to personnel problems anddifferences.

The main objective of this chapter is to discussthe parts of a SAFETY PROGRAM that willreduce the human suffering and operationalreadiness losses due to aviation safety and survivalequipment accidents.

ORGANIZATION ANDADMINISTRATION OF A SAFETYPROGRAM

Many supervisors feel that it is only necessaryto provide safeguards, and safety will take careof itself. Safeguards are a step in the rightdirection, but they alone will not get good results.To establish a good safety record requires theestablishment of a good safety program. Navydirectives require all organizations to have anactive safety training program. The safetyprogram discussed in this manual is builtaround EDUCATION, ENVIRONMENT, andENFORCEMENT.

ENVIRONMENTAL CONDITIONS

Environment, as it applies to safety, can bedefined as the improvement or redesign ofequipment, machinery, work area, or procedures.The objective of the environment is the elimina-tion of hazards or providing adequate safeguardsto prevent accidents. The objectives are theresponsibilities of the supervisor. Briefly, theobjectives of supervision are as follows:

1.

2.

3.

To operate with maximum efficiency andsafetyTo operate with minimum efficiency andwasteTo operate free from interruption anddifficulty

While these are the primary objectives ofsupervision, it is important for you to rememberthat your new assignment is important to youpersonally. It gives you an excellent opportunityto gain practical experience toward eventualpromotions to AMCS and AFCM.

WORK AREAS

Supervisory personnel should be especiallyaware of shop cleanliness. A cluttered, dirty shopmay cause personnel to become careless andinefficient. Look for spilled grease and oil. Anotherwise “heads-up” man could become a “tails-up” man if spilled grease and oil is not cleanedup promptly. Notice rag storage. Oily rags shouldbe kept in a closed metal container. Noticeobstructions protruding from work benches andlying on decks, or items stowed on top of lockers.These are obvious dangers.

Less obvious hazards are poor work habits.Are the proper tools used for the tasks assigned?Are the established safety rules and regulationsbeing followed? Is the shop lighting andventilation adequate?

The hazardous conditions noticed by the AMEduring inspections should be corrected now, eitherby immediate action or training. General workcenter safety is covered more in the AviationMaintenance Ratings Supervisor manual.

TOOLS

The inspection of tools should include type,condition, and use. As a general precaution, besure that all tools conform to navy standards ofquality and type. Remember that each tool hasa place and should be in use or in that place. Eachtool has a purpose and should be used only forthat purpose.

If hand tools are dull, broken, bent, or dirty,corrective action is necessary. Tools that cannotbe repaired should be replaced. Tools should becleaned and kept clean. Portable tools should beinspected prior to each use to ensure they are cleanand in the proper state of repair. The AMEsupervisor should be very critical of the toolswithin the work center. For more information ontools and their uses, refer to the AviationMaintenance Ratings Supervisor manual.

EQUIPMENT

The AME supervisor will have many differentkinds of equipment in his work center. Theinspection of shop equipment should includechecking for posted operational requirements andfor safeguards such as goggles, hearing protectors,and protective clothing. Always check for leaks,frayed electrical cords, proper workingconditions, and general cleanliness.

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The inspection of work areas, tools, andequipment will point up hazards that must becorrected. Some corrections will be made on thespot, and some will have to be worked outthrough job improvements. The inspections willshow the need for and the continuation of a goodsafety program. For more information on shopequipment, refer to the Aviation MaintenanceRatings Supervisor manual.

SAFETY INSPECTIONS

About 98 percent of all accidents can beprevented. This means that accidents can beprevented by educating personnel to the hazardsor by completely eliminating the hazards. It’s withthis idea in mind that you will make yourinspections. During the inspection, look forhazardous conditions that can be eliminated andfor hazardous conditions that can be correctedthrough training. The two percent classified asunpreventable are caused by natural elements,such as wind, lightning, flooding, etc., and somesteps can be taken to lessen these hazards.

Safety inspections should be continuous. Ahabit should be developed for noting everything.Everytime you walk through the shop, line area,around aircraft, or any area where your responsi-bility extends, think safety. When a hazardouscondition is found, correct it. To put it off untillater is to gamble with the safety of your men andequipment. The hard rule is that in matters ofsafety, “corrective action is required NOW.”

SAFETY EDUCATION

Safety education depends on obtaining andpassing out safety-related information. Safetyinformation is gained through inspections,experience from directives, and by performing ananalysis of job requirements. An effective safetyprogram creates interest as well as suppliesinformation.

The following examples point up the differentways safety information may be disseminated.

1. POSTERS—The Navy provides safetyposters that should be posted in appropriate placesto emphasize the safety message.

2. PRINTED MATERIALS—This covers therequired reading list of safety precautionspertaining to safety. Printed material also coversphysically posting operating procedures on theequipment.

3. GROUP DISCUSSIONS—Group discus-sions are usually conducted when the informationis applicable to all hands. Safety movies fall intothis category.

4. INDIVIDUAL INSTRUCTION—Indi-vidual instruction is normally given when theproblem involves individual work habits or aparticular hazard is pointed out to an individualduring the work process.

ENFORCEMENT

Enforcement as it applies to safety is definedas the formulation of rules and regulations anda safety policy that will be followed by all hands.Enforcement includes reprimanding violators ofsafety rules, frequent inspections to determineadherence to rules, and continuous follow-upprocedures to determine WHY THERE AREVIOLATORS. Supervisors must enforce safetyrules without fear or favor. Safety consciousnessand the will of the worker to aid in preventingaccidents lies with the supervisors. Supervisorsmust not jeopardize cooperation in safety byinconsistency in enforcement.

PLANNING FOR ADVANCED BASEOR FORWARD AREA OPERATIONS

AME Chiefs must be able to prepare foradvanced base or forward area operations withoutsacrificing the safety program. They must estimateaircraft spare parts and supplies, equipment, andmanpower requirements for aviation structuralrepair. In determining requirements for forwardor advance base operations, consider thefollowing:

1. Safety2. Mission3. Environment4. Operating Factors5. The availability of existing facilities

A knowledge of the material and manpowerrequirements listed in the Advanced Base InitialOutfitting Lists of Functional Components willbe very helpful. The functional component is oneof more than 300 standardized units of the systemthat the Navy has developed to enable it to buildand operate its advanced bases in the least possibletime and with minimum expenditure of planningand logistic effort.

A functional component is a list of therequirements for the performance of a specific

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task at an advanced base. It is a carefully balancedcombination of material, equipment, and/orpersonnel.

Each functional component is groupedaccording to its primary function into 1 of 11major groups, including aviation. Each majorgroup is identified by letter designation and title.The functional components contained in each areidentified by a combination letter, number, andits title designation. The major group designationfor aviation is “H.”

“H” components are designed to providemaintenance, support, and operation of aircraftin an advanced area under combat conditions.“H” components may be combined with otherfunctional components to form several types ofair stations.

Complete information and data are given inthe abridged and the detailed outfitting lists forfunctional components. It should be apparent tothe AMEC that the advanced base requirementsmay not be exactly as they appear in the AdvancedBase Initial Outfitting Lists. 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 outfittinglists for the aircraft or other weapon systems tobe supported.

It is quite likely that the AMEC will berequired to advise the personnel office in makingassignments of individuals to advance base orforward area operating units. It would seemlogical that the number of AMEs assigned todeploy be in the same ratio as the percentage ofsupported aircraft scheduled to deploy. This maybe true if the proposed flight hours per aircraftof the detachment exactly equalled the plannedutilization of the remaining aircraft. There mustalso be no significant environmental problems tobe overcome (i.e., excessive heat or excessive coldconditions, depending on the location ofdeployment). The list of personnel assigned todeploy should represent a cross section of the skilllevels available unless special maintenance factorsindicate otherwise. The selection of personnelshould be made as objectively as possible so thedeployed unit can function as safely andefficiently as possible.

SAFETY PRECAUTIONS FORHAZARDOUS SUBSTANCES

Learning Objective: Identify safetyprecautions for working with hazardoussubstances and equipment.

There are many ways for a careless orinexperienced worker to hurt themselves or otherson the job. This section discusses safetyprecautions in three hazardous work areas: liquidoxygen, gaseous oxygen, and high pressure air.Other specific safety precautions are discussed inOPNAVINST 5100.19 (series).

It has been said that every safety precautionhas been originally written in blood. There is noroom for complacency in the performance ofAME tasks. Every job must be performed in a“heads-up” manner to ensure maximum safetyawareness is maintained. Anything less can andwill be disastrous.

LIQUID OXYGEN

Aviators breathing oxygen (ABO) comes inboth gaseous (type 1) and liquid (type 11) states.Liquid oxygen (LOX) is converted to a gas beforeits delivered to the aircrew. LOX requires frequentmonitoring to prevent contamination and toensure safe use. A surveillance program is theprimary method of ensuring that each operationin the LOX supply system is carried out in strictcompliance with established procedures. Surveil-lance begins with procurement or generation ofLOX and continues throughout storage, handling,transfer, and servicing of aircraft.

The best assurance of personnel safety lies inthe safety education of the people themselves. Thesafety of personnel can be assured only when thereis thorough understanding of potential hazards,the correct procedures and equipment are used,and the equipment is in good working condition.Knowledge of a job situation and appropriatesafety equipment is vital to successful completionof a job. Follow established safety procedures inNAVAIR 06-30-501.

Description and Properties ofLiquid Oxygen

Oxygen can exist as a solid or gas, dependingupon the temperature and pressure under whichit is stored. At atmospheric pressure, oxygen existsas a solid at temperatures below its melting point,– 361°F (–281°C). Solid oxygen turns into a

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liquid at its melting point and remains in this stateuntil the temperature rises to its boiling point,–297°F (–183°C).

At this latter temperature, LOX vaporizes intothe gaseous state. Gaseous oxygen will turn intoliquid at atmospheric pressure by cooling to atemperature below –297°F. By increasing thepressure, gaseous oxygen can be liquified at highertemperatures, up to its critical temperature,– 182°F ( –119°C). Oxygen will not condense toa liquid at temperatures above its criticaltemperature regardless of the pressure applied.The pressure required to liquify oxygen at itscritical temperature is known as its criticalpressure, 736.5 psig. The application of highpressure and ultra-low temperatures to convertgases to their liquid state is known as the scienceand technology of cryogenics. LOX is a cryogenicfluid.

Physical Properties of Liquid Oxygen

Gaseous oxygen is colorless odorless,tasteless, and about 1.1 times as heavy as air. LOXis an extremely cold, pale blue fluid that flowslike water. One gallon of LOX weighs 9.519pounds, which is 1.14 times heavier than theweight of 1 gallon of water. LOX is stored andhandled at atmospheric pressure in well-insulatedcontainers that maintain the liquid at its boilingpoint ( –297°F). Therefore, LOX is boiling as itslowly turns into gaseous oxygen. As theexpanding gas from the boiling liquid increasesin amount, it builds up pressure within thecontainer. Therefore, the expanding gas must bevented to the atmosphere. Confinement of liquidoxygen can be dangerous to personnel, causingsevere injury and death.

This section contains procedures and require-ments for the quality control of LOX that isstored, transferred, handled, and used forbreathing purposes by aircrews. This sectionapplies to AME supervisors who must ensure allsafety procedures and equipment are used duringLOX servicing and handling by qualifiedpersonnel.

Personnel

Personnel selected to perform operations inthe LOX supply system should be trained andhave a thorough knowledge of the characteristicsof LOX, the significance of contamination, andthe dangers involved. Only those personnel whodemonstrate understanding of safety and who

maintain reliable performance should be assignedthe duties and responsibilities of handling LOX.

LOX Contamination

During the handling and transfer of LOX,environmental contaminants must be preventedfrom entering the system. LOX strongly attractsand absorbs atmospheric gases. Contaminantsmake the ABO unusable. Conscientious attentionto correct procedures during handling and transferoperations will prevent contamination and ensuresafety.

The aircraft LOX converter system should besampled and tested for contamination as follows:

Test for odor as soon as possible after a reportof in-flight odors by the pilot or aircrew. Anyabnormal psychological or physiological effectsto an aircrew during or after flight should be causeto suspect possible oxygen contamination.Possible oxygen contamination should also beconsidered in any aircraft mishap when thecircumstances of the mishap are vague orunknown. A sample should be taken and sent toa test site for analysis with supporting details ofthe incident, including history of the supply sourceof LOX. Appropriate reports must be submittedin accordance with OPNAVINST 3750.6. Aninformation copy should be provided to the NavalAir Engineering Center program manager.

Applicable squadrons selected by areacommands must, during each calender month,take a LOX sample from at least one filledconverter and residual LOX from one converter(taken from an aircraft after a flight mission), andforward both to a test site for contaminationchecks.

Aircraft oxygen and LOX systems, and LOXconverters, must be purged in accordance with theapplicable maintenance instructions manual(MIM) and/or NAVAIR 13-1-6.4, O x y g e nEquipment Manual. Purging is done when thesystem or the converter is left open to theatmosphere, when empty, or whenevercontamination is suspected.

GASEOUS OXYGEN

The supervision of aviators gaseous breathingoxygen requires the same surveillance as for LOX.Adequate and reliable supervisory control ofaviators gaseous breathing oxygen demands thateach operation in the gaseous breathing oxygensupply, and aircraft servicing system, be carried

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out in strict compliance with proceduresestablished to assure safety of flight and missioncompletion.

This section establishes procedures and re-quirements for the quality control of gaseousoxygen that is stored, transferred, and used forbreathing purposes by aircrews. This section isapplicable to all personnel who are responsible forsupervising or performing the operations as-sociated with and servicing of the aircraft withaviators breathing oxygen.

Quality Control Requirements ofGaseous Oxygen

The procurement limits for purity and con-tamination, which include the absence of odor,of aviators gaseous breathing oxygen must meetthe requirements of the current issue of MIL-O-27210.

The on-station monitoring of aviators gaseousbreathing oxygen for contamination is performedby a sniff odor test.

WARNING

The odor test is very hazardous due to thehigh pressure in the cylinder. Do not placeyour face or nose directly into the ventinggas stream and do not take deep breaths.Discontinue “sniffing” any gas at the firstindication of irritation of the nasal pas-sages or at any sign of physical discomfort.Some contaminants are extremely irritat-ing, poisonous, or toxic, and can causephysical injury. The odor test can only beperformed safely if the procedures arefollowed exactly.

NOTE

Persons temporarily unable to detect orclassify odors because of head colds, hayfever, etc., must be excluded from theassignment of inspecting for the presenceof odorous contaminants.

If an odor is detected, discontinue theinspection process. When detected, an attemptshould be made to classify it, such as “acrid,”“sweet, ” “rotten egg,” “glue like,” etc., as thiswill help in the identification of the source of thecontaminate.

Gaseous Oxygen Servicing Trailer

Gaseous oxygen servicing carts must besampled and tested whenever contamination issuspected or after the completion of anymaintenance action performed on the cart. Anodor test must be conducted prior to servicing anyaircraft system. This is accomplished by openingslightly the valve at the terminal end of therecharging hose and smelling the escaping gas inaccordance with the procedures described in theA6-332AO-GYD-000. If an odor is present, theservicing cart will not be used to service theaircraft. Each cylinder must be inspected for thefollowing:

. Proper painting and marking.

l Valves are tightly closed and not leaking.

l Safety caps and safety plugs are secure.

. Hydrostatic test date is current.

. All valves, manifold, servicing hose, andcylinders are clean and free of grease and oil. Thepresence of any grease or oil on the valves orcylinders must be reported to the maintenanceofficer for necessary action, and the servicing cartmust be placed in a contaminated status.

HIGH-PRESSURE AIR

Using high-pressure compressed air safelyrequires knowledge and skills. Despite all thesafety programs and posters regarding this shophazard, reports of fatalities and serious injuryfrom this cause continue to accumulate.

High-pressure compressed air is provided fromone of three sources:

1. A portable high-pressure cylinder2. A cascade-type servicing trailer equipped

with several cylinders3. Direct service from a portable high-pressure

air compressor

Each of these sources is no less dangerous thanthe precautions already discussed for handlingoxygen cylinders. Precautions apply generally aswell for the handling and stowage of compressedair cylinders.

Do not fill any cylinder with a gas other thanthat gas for which the cylinder has beenspecifically designated. Explosive mixtures may

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be formed when cylinders containing residualcombustible gases such as hydrogen, propane, oracetylene are charged with air or oxygen. Thereverse of this procedure is equally hazardous.

Cylinders used for aviators’ breathing oxygen,dry nitrogen, dry argon, dry helium, or dry airthat are found to have open valves and/or apositive internal pressure of less than 25 psi(gauge) should be tagged “Dry Before Refilling.”

When operating the compressed air servicingtrailers, (gaseous oxygen or nitrogen) thefollowing precautions should be observed:

1. Only qualified operators should operate thetrailers while charging. Complete familiarity withthe trailer is a basic prerequisite for safe operation.

2. The servicing hose end and installationconnection fitting should be thoroughly inspectedprior to servicing and any foreign matter removed.

3. Never charge an installation without theproper fusible safety plug and blowout disc in thetrailer charging system.

4. Always know the pressure existing in thesystem to be filled and the pressure in all cylindersto be used in the cascading process before startingcharging operations.

5. A malfunctioning pressure regulator shouldbe disconnected from the line by closing itsassociated shut-off valve. The trailer can then beoperated with the remaining pressure regulator.

6. The charging hose should never bestretched tightly to reach a connection. Positionthe trailer so that the servicing hose is not undertension while charging.

7. Always open all valves slowly. The dangersof rapid cascade charging must be avoided.Compressed air should never be blown towardsanyone, used for cleaning of personal clothing,or as a means of cooling off a person.

SAFETY PRECAUTIONS FOREJECTION SEATS AND EXPLOSIVE

DEVICES

Learning Object ive : Ident i fy theimportance of the ejection seat check-outprogram.

Ejection seats have several inherentlydangerous features that are a definite hazard touninformed and/or careless personnel. Con-sequently, whenever the aircraft is on the ground,all safety pins must be installed and not removeduntil the aircraft is ready for flight. Caution must

be observed at all times during maintenance ofand around the seats to avoid injury and equip-ment damage by explosive devices of the seat.Safety precautions and correct procedures cannotbe overemphasized.

Keep all cartridges away from live circuits.Under no circumstances should any person reachwithin or enter an enclosure for the purpose ofservicing or adjusting equipment without theimmediate presence or assistance of anotherperson capable of rendering aid.

When removing cartridges for inspections orfor safety reasons, they must be marked foridentification so they can be reinstalled in the samedevice from which they were removed. Under noc ircumstances should an unmarked orunidentified cartridge be installed in any cartridge-actuated device.

Cartridges should be handled as little aspracticable to minimize risk of fire, explosion, anddamage from accidental causes. All safety devicesmust be kept in good order and used only asdesignated.

Cartridges must be stored where they will notbe exposed to direct rays of the sun, and they mustbe protected from extremely high temperatures.When in containers, they must be stored in a cool,dry place where they can be readily inspected.

The seat must always be disarmed beforeremoval from the aircraft because firing of theseat may occur. While handling percussion-firedcartridges, you must exercise extreme caution notto drop cartridges because they can fire uponimpact.

The following general precautions shouldalways be kept in mind.

1. Ejection seats must be treated with thesame respect as a loaded gun.

2. Always consider an ejection seat system asloaded and armed.

3. Before you enter a cockpit, know where theejection seat safety pins are located, and makecertain of their installation.

4. Only authorized personnel may work on,remove, or install ejection seats and components,and only in authorized areas.

EJECTION SEAT CHECK-OUTS

The modern, high-performance aircraft usedby todays Navy place extreme demands onemergency escape systems. These systems containhighly explosive devices that are designed for one-time use only. Actuation of these devices could

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result in severe injury or death to personnel anddamage to or destruction of aircraft. Therefore,due to the inherent dangers associated withejection seats and canopy systems, a seat/canopycheck-out procedure is required. The Egress/Environmental Work Center (AME shop) is re-sponsible for indoctrinating all personnel in thehazards and safety precautions associated withthese systems. A thorough seat check-out will begiven, by a qualified Aviation Structural Mechanic(Safety Equipmentman) (AME), to all newlyassigned maintenance personnel prior to theirperforming any aircraft maintenance work on theaircraft, and every 6 months thereafter. Inaddition, any personnel removed from aircraftmaintenance responsibilities for over 90 days mustreceive a seat check-out before performing anyaircraft maintenance. The AME work center andthe other maintenance work centers will maintainrecords of seat check-outs, including date given,date due, and the signature of the AMEperforming the check-out.

The seat check-out program will be establishedby a squadron MI. All personnel due seat check-out requalification will be listed in the monthlymaintenance plan.

EJECTION SEAT CARTRIDGESAND CARTRIDGE-ACTUATEDDEVICES (CAD)

The types of explosive devices incorporatedin egress systems are varied. The AME workingwith these devices must know how they function,their characteristics, how to identify them, theirservice-life limitations, and all safety precautions.

The AME who understands the importance ofall these factors and who correctly uses themaintenance manuals is better equipped tosupervise and train others. The following manualsare required for the AME to meet the aboverequirements:

1. Description, Preparation for use, andHandling Instructions, Aircrew EscapePropulsion System (AEPS) Devices, NAVAIR11-85-1

2. General Use Cartridges and CartridgeActuated Devices for Aircraft and AssociatedEquipment (CADS), NAVAIR 11-100-1.1,NAVAIR 11-100-1.2, NAVAIR 11-100-1.3

3. Specific aircraft MIMs4. OP 4, Ammunition Afloat5. OP 5, Ammunition and Explosives Ashore

Service Life

The service life of a CAD is the specific periodof time that it is allowed to be used. These periodsof time are affected by various environmentalconditions, which have resulted in the assignmentof time limits or overage requirements. Theselimits are shelf life and installed life.

The establishment of service-life limits is basedupon design verification tests, qualification tests,and surveillance evaluations. The establishedlimits are approved by the Naval Air SystemsCommand. Therefore, the establishment ofservice-life time limits is not arbitrary and mustbe adhered to as specified.

Before deployment to areas that do not permitready supply and servicing of cartridges orcartridge-actuated devices, an inspection must bemade of all CAD service-life expiration dates. If,during this inspection, it is determined that a CADwill become overage during the period of thedeployment, the CAD must be replaced prior tothe deployment. Before installation of any CAD,the service life expiration date of the unit mustbe checked to ensure that the unit is not overageand will not become overage prior to the nextperiodic maintenance cycle of the aircraft.

During standard depot-level maintenance(SDLM), the expiration dates of all installedCADs must be checked. Those CADs assigned toorganizational level for maintenance and haveexpiration dates prior to the next scheduledinspection after the aircraft is returned to itscustodian must be replaced. CADs assigned todepot level for maintenance that have expirationdates falling prior to the next scheduled SDLMshould also be replaced. The exception is systemsreplaced exclusively through the use of a fieldmodification team. Adherence to these procedureswill prevent loss of aircraft mission capability dueto CAD service-life expiration.

Expiration Dates

To determine service-life expiration dates,both the shelf life and installed life must becomputed. First, compute the shelf life of theCAD by using its lot number to determine themonth and year of manufacture. Refer to table1-1 to ensure correct interpretation of the lotnumber since there are currently two methodsused to derive lot numbers. Obtain the establishedshelf life (number of months and years) for theindividual CAD from the NAVAIR 11-100-1series manual. Add this figure (shelf life) to the

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Table 1-1.-Derivation of Lot Number

month and year of manufacture determined from (date) will be the installed-life expiration date forthe CAD lot number. The resulting sum (date) isthe shelf-life expiration date of the CAD inquestion.

Example:

Lot number/date of manufacture 0579+ Shelf-life in years + 6

Shelf-life expiration date 0585

Next, determine the installed-life expirationdate of the CAD by referring to the NAVAIR11-100-1 series manual. Obtain the installed-lifefigure (number of months or years), and add thatfigure to the date (month) the CADs hermeticallysealed container was opened. The resulting sum

the CAD in question.

Example:

Date opened 0879+ Installed life in months + 42

Installed-life expiration date 0283

Then, compare the two dates derived (shelf-life and installed-life). Whichever date occurs firstis the CAD service-life expiration date.

Example:

Shelf-lifeInstalled-lifeService-life expiration date

058502830283

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Since only the month and year are used incomputing service-life dates, the date thehermetically sealed container is opened and theexpiration date must be computed to the last dayof the month involved. If the date the sealedcontainer was opened is not available, theinstalled-life must be computed from the date ofmanufacture as determined from the lot number.

Marking Expiration Dates

Before installing a CAD in an aircraft system,both CAD service-life expiration dates (shelf-lifeand installed-life) should be computed. The timelimit that is exceeded first will be the service-lifeexpiration date of the CAD. The service-lifeexpiration date must be entered in the aircraftlogbook.

Use permanent ink for marking CADs withcontainer opened dates and service-life expirationdates. Do not scribe, scratch, or eletroetch thesedates, as damage will occur to the CAD’scorrosion resistance surface. The marking pen,NSN 7520-00-043-3408, is available from GSAsupply, and is recommended for this purpose.

When you install a CAD in an aircraft system,a log entry must be made on OPNAV Form4790/26A, as directed by OPNAVINST 4790.2(series). When a CAD’s hermetically sealedcontainer is opened, the container opened dateand the service-life expiration date (month andyear) must be marked with indelible ink on thecontainer and on each CAD in the container.

Service-Life Extension

Contingency service-life extensions for theCADs listed in the NAVAIR 11-100-1 (series), notto exceed 30 days, may be granted by thecommanding officer or his authorized repre-sentative. The extensions may be applied to aspecific CAD on a one-time only basis whenreplacements are not available and failure toextend the service-life would disrupt flightoperations. The contingency authority is grantedon the condition that Naval Ordnance Station,Indian Head, Maryland; NAVAIRSYSCOM,Washington, D.C.; and SPCC, Mechanicsburg,Pennsylvania, be immediately notified by messageor speed letter when such authority is exercised.

When the situation warrants, an additionalservice-life extension beyond the 30-daycontingency extension may be requested bymessage from NAVORDSTA. All extensionsbeyond 30 days must be approved by the

NAVORDSTA or NAVAIRSYSCOM. All ap-proved additional service-life extensions will betransmitted by message to the activity making therequest. When a service-life extension is granted,an entry must be made in the aircraft logbook.When an aircraft is transferred with a service-lifeextension in effect, the gaining activity must benotified, and no new contingency service-lifeextensions may be granted by the commandingofficer of the gaining activity.

Service-life Change

The permanent service life of a CAD maybechanged only by a rapid action change (RAC),interim rapid action change (IRAC), or formalchange to NAVAIR 11-100-1 (series) as directedby COMNAVAIRSYSCOM, Washington, D.C.If the change affects those items installed in anaircraft, the change will be recorded in theaircraft’s logbook. A line will be drawn throughthe service-life expiration date shown and the newcomputed expiration date entered, citing theauthority for the change; for example, messagenumber, rapid action change number, or changenumber. Each new expiration date will supersedethe previous date. The latest expiration dateentered in the aircraft logbook will always be thefinal date the CAD may remain installed in theaircraft.

When a contingency service-life extension hasbeen authorized for a specific CAD, the newcomputed service-life expiration date (month andyear) will be added to the original aircraft logbookentry for that CAD. When an additional service-life extension has been granted for a specificCAD, the new service-life expiration date (monthand year) will be added to the original aircraftlogbook entry.

CAD Maintenance Policy

CAD maintenance policy prohibits unauthor-ized maintenance or adjustments to a CAD at anyof the three levels of maintenance: organizational,intermediate, or depot. Authorized maintenanceactions are limited to removal, inspection, andreplacement, unless specifically detailed in theaircraft MIM or by a technical directive.

CADs and items of equipment in ejectionsystems are for one-time use only. They are neverto be refurbished or used again after firing. Thisis equally true of functional equipment, rigid lines,plumbing lines, and hoses. Ejection seats andescape system components that have been used

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in an ejection or fired, regardless of apparentcondition, are prohibited from reuse, and mustbe disposed of as directed by OPNAVINST4790.2 (series), OPNAVINST 3750.6 (series), andthe applicable CAD and rocket manual.

Because of the extreme stress and strain to theejection seats and escape system componentsduring ejection, they cannot be reused. This stresscould reduce the structural or mechanical re-liability of these items. In the case of aninadvertent firing of a cartridge or CAD, allcontaminated ballistic lines and devices must bereplaced because of the corrosive nature of theexplosive.

The service-life of wire-braid, Teflon® -linedhoses installed in ballistic applications is the sameas that of the aircraft in which it is installed, unlessit is used. A hose is considered to be used if thedevice to which it is attached is fired, eitherintentionally or accidentally. If this occurs, thehose and related fittings must be replaced. Beforeyou install a hose or fitting (line, elbow, T, etc.)make sure that it is not contaminated with hy-draulic fluid, oil, or a similar type of contaminant.All hoses in the escape system must be inspectedfor accidental damage at every phased inspection,upon seat removal, after removal of any part ofthe escape system, and for disconnection of anyhose.

When CADs are not installed in an aircraft,the inlet and outlet ports must be sealed withprotective closures to prevent the entrance ofmoisture and foreign matter. For shippingpurposes, the safety pins and protective closuresprovided with the replacement CAD must bereturned with the replaced CAD to ensure it is ina safe condition during handling and storage.During ejection system maintenance actions, alldisconnected CADs and associated ballistic linesmust be protected with flexible plastic plugs thatconform to MIL-C-5501/10A and flexible plasticcaps that conform to MIL-C-5501/11. NAV-AIR 11-100-1.1 provides information relating tothese caps and plugs,

Cartridges are carefully designed andmanufactured, but their performance in cartridge-actuated devices is dependable only when theyhave been properly handled and installed. Caremust be observed to maintain the devices inperfect condition.

Since individual cartridges cannot be tested,the responsibility for proper functioning is in thehands of the supervisor and the personnel whomaintain them. The quality and reliability of anejection system are largely dependent on the

supervisors and the mechanics who maintain thesystems.

Supervisors take note. Nothing is foolproofbecause fools are so ingenious. Personal safetyfor those who work around ejection seats cannotbe guaranteed. A high level of safety can beachieved if personnel have the proper attitude,understanding, training, and most importantlyadequate supervision. Unless proper maintenanceprocedures are followed exactly, even the mostroutine ejection seat maintenance tasks can growdrastically out of proportion and bring about anaccident or injury. Education of the workersinvolved is the best assurance for personnel safety.The workers should be made aware of potentialhazards and the proper means of protectingthemselves. Workers should be assigned tasksaccording to their capabilities.

Reporting

All malfunctions, discrepancies, and accidentsinvolving CADs must be reported by message tothe Naval Ordnance Station, Indian Head,Maryland, in accordance with OPNAVINST4790.2 (series). If the suspected defect is with theCAD, the message must be addressed toNAVORDSTA for action. If the report describesan inadvertent actuation of an aircraft systemresulting in the CAD functioning normally, theaction copy of the report must be submitted tothe cognizant field activity (CFA) for the aircraftwith an information copy to NAVORDSTA,Indian Head, Maryland. Accidents and incidentsinvolving CADs may require reporting inaccordance with OPNAVINST 3750.6 in additionto the OPNAVINST 4790.2 (series). Submissionof the reports required by the maintenanceinstruction does not satisfy the requirements ofthe safety instruction. If dual reporting isrequired, you should ensure the reports areadequately cross-referenced to satisfy therequirements of all commands involved.

All CADs suspected of being discrepant,malfunctioning, or involved in an accident orincident must be clearly identified and turned into the station or ship’s ordnance or weaponsdepartment. These CADs must be marked “holdfor 30 days for engineering investigation (EI)pending disposition instructions.” The reportshould contain the turn-in document number, andit should identify the activity holding the material.If CFA response is requested, NAVORDSTA willrespond with complete disposition and shippinginstructions.

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INSTALLED EXPLOSIVE SAFETYDEVICES (OPNAV 4790/26A)

This form (fig. 1-1) is used in the logbook andthe Aeronautical Equipment Service Record(AESR). This section of the logbook/AESRcontains a record of all explosive safety devices(for example, initiators and canopy releases)installed in the aircraft/major assemblies.Explosive devices installed in major assemblies/equipment (for example, ejection seats and in-flight refueling stores) must be recorded in theInstalled Explosive Safety Devices page of theappropriate AESR. Explosive devices installed inpersonnel parachutes are recorded on theParachute Configuration Inspection and HistoryRecord, and when installed in other safety andsurvival equipment, on the History Card -Aviation Crew System. All other explosive safetydevices must be recorded on the InstalledExplosive Safety Devices Form of the log-book/AESR. This form is not required when therecording of escape system explosive componentsin F-14A aircraft is done in accordance withNAVAIR 11-100-1.1 (NOTAL).

Certain equipment is transferred from oneaircraft to another during SDLM and replacedduring periods of scheduled maintenance. Thisemphasizes the need to carefully and periodicallycheck this record regarding the status of theexplosive devices currently installed in theaircraft/equipment. This record is maintained ina current status by all activities having custodyof performing rework on the aircraft/equipmentin which explosive safety devices are installed.

Documentation requirements is a must. Asingle line entry is required for each installedexplosive safety device. All data columns must becomplete.

The following information explains what toreport in each block.

Block 1—Aircraft Equipment/Model No.Enter the aircraft or equipment T/M/S.

Block 2—BUNO/Serial No. Enter the aircraftBUNO or equipment serial number.

Block 3—DODIC. Enter the Department ofDefense Identification Code (DODIC) or the

Figure 1-1.-Installed Explosive Safety Devices (OPNAV 4790/26A) (Logbook) (AESR).

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Navy Ammunition Logistic Code listed in theNavy Ammunition Stock Microfiche, TWO10-AA-ORD-010/NA 11-1-116A (NOTAL). DODICsare also specified in the four technical manualsmentioned in the details for block 11.

Block 4—Nomenclature or Type of Device.Enter the name/type device.

Block 5—Lot No. Enter the lot number of thedevice.

Block 6—Serial No. Enter the serial numberof the device. For devices not serialized, enter

Block 7—Purpose or Location. Enter thepurpose or the location of the device.

Block 8—Installing Activity/Date. Enter theshort title of the activity and the month and yearthat the device was installed; for example,VA34/JUL90.

Block 9—Container Open Date. Enter themonth and year the container was opened; forexample, JUL 90. When the container open dateis not required for AEPS devices, “NA” will beentered.

Block 10—Date of Manufacture. Enter thedate, month, and year of manufacture; forexample, JUL 90. For CADS enter manufacturedate, and for AEPS enter propellant manufacturedate.

Block 11—Expiration Date. Enter thecomputed month and year; for example, JUL 90.Installed service-life expiration dates for explosivedevices are computed from the date ofmanufacture, the date the hermetically sealedcontainer is opened, and the date the device isinstalled. The method used in computing theexpiration date of explosive devices and thenumber of months/years a specific device mayremain in service is contained in NA 11-85-1-1.2(NOTAL), NA 11-100-1.1(NOTAL), NA11-100-1.2(NOTAL), and NA 11-100-1.3(NOTAL).When installed explosive safety devices haveextensions granted, the expiration date will be

updated by drawing a line through the oldexpiration date and placing the new expirationdate above it. The authority granting theextension, for example, message originator anddate time group (DTG or IRAC number andmanual), will be logged in the Remarks Column(block 12).

Block 12—Remarks. Make applicableremarks. This block is limited in size; use theMiscellaneous/History page if additional space isrequired.

Block 13—Removal Date. Enter the monthand year the device was removed; for example,JUL 90.

POLICY FOR SAFETY PROGRAM

Learning Objective: Recognize theimportance of training personnel to fullycomply with safety precautions anddirectives.

While no attempt has been made in thistraining manual to cover all the areas of safetyresponsibility pertaining to the AME rating,enough has been presented to stress to the AME1and AMEC the importance of safety. SeniorAMEs must continually strive to improve thesafety program.

The AME must interpret and apply safetydirectives and precautions established by theDepartment of the Navy, type commander, localcommand, and the precautions required for eachjob. Safety directives and precautions must befollowed to the letter. This will save lives, preventinjuries, and prevent damage to equipment.Should an occasion arise in which doubt existsabout the application of a particular directive orprecaution, the measure to be taken is that whichwill achieve maximum safety. A shipboardoperation requires more attention to safety thana shore-based operation. Although, in mostinstances, the hazards and the precautions arethe same whether the work is done afloat orashore.

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“NA.”

CHAPTER 2

ELECTRICALLY OPERATED CANOPY SYSTEM

Chapter Objective: Upon completion of this chapter, you will have a workingknowledge of the electrically operated canopy system and its components toinclude normal and emergency operation procedures.

As you know, the canopy system provides anaccess for the aviator to enter and exit the cockpit.It also provides protection from the elements. Wewill use the F/A-18C canopy system to discuss atypical electrically operated canopy system (fig.2-1).

CANOPY SYSTEM

Learning Objective: Recognize the com-ponents of the canopy system.

Under normal conditions, the canopy iselectrically operated and controlled by either theinternal canopy control switch in the cockpit orthe external canopy control switch, as shown infigures 2-2 and 2-3. A manual backup controlmode operates the canopy when utility batterypower is low, internal or external electrical poweris not available, or the actuation control systemhas failed. The emergency canopy jettison systemjettisons the canopy during emergencies andejection.

SYSTEM COMPONENTS

You need to be familiar with the systemcomponents to enhance your understanding of thesystem’s operation. Therefore, the followingmajor components are described.

Canopy

The formed-stretched acrylic canopy ismounted in a metal frame. A canopy unlatch

thruster and two rocket motors and relatedballistic components are mounted on the canopyfor emergency jettison. An index pin, a controlcam, and three latches are mounted on each sideof the canopy frame.

Canopy Pressure Seal

An inflatable canopy pressure seal is locatedaround the canopy arch, along the side frames,and across the canopy deck. When the seal isinflated by the air-conditioning system, thecanopy is sealed to the fuselage and windshieldarch, allowing the cockpit to be pressurized.A noninflatable weather seal is located parallelto and outboard of the pressure seal. Whenthe pressure seal is deflated, the weatherseal prevents entry of water into the cock-pit.

Canopy Actuator

The canopy actuator is located behind theaircraft ejection seat on the canopy deck andfunctions to open and close the canopy. Athermal protection device is provided in theactuator that will automatically interrupt powerto the actuator when an overheat conditionexists. It will automatically reset within 60seconds after removal of the overheat con-dition.

The mechanical components of the canopyactuation system consist of the canopy actuatorand the canopy actuation connecting link, which

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Figure 2-1.—Electrically operated canopy.

2-2

Figure 2-2.-External canopy control switch.

Figure 2-3.-Internal canopy control switch.

is attached to the canopy unlatch thruster,as shown in figures 2-4 and 2-5.

Canopy Actuator Manual Drive Unit

The canopy actuator manual drive unit islocated in the cockpit under the left canopy

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sill. It is used to manually raise and lower thecanopy.

The internal manual canopy opening handleis located on the canopy actuator manual driveunit. The handle is used to operate the drive unitfrom inside the cockpit. The opening handle shaftassembly is located between the canopy actuatormanual drive unit and the canopy actuator. The

Figure 24.-Canopy actuator.

shaft assembly provides a mechanical link betweenthe drive unit and the canopy actuator. (See fig.2-6.)

The canopy external manual drive receptacleis mounted flush with the fuselage skin below theleft canopy sill. The drive receptacle is used tooperate the drive unit from outside the cockpitwith the aid of a 3/8-inch drive tool. (See fig. 2-7.)

Canopy Control Switches

Two canopy control switches are provided fornormal electrical operation of the canopy. Theexternal canopy control switch is located insidethe external electrical power receptacle door. (Seefig. 2-2.) The internal canopy control switch islocated in the cockpit under the right canopy sill.(See fig. 2-1.)

Canopy Contractors

The two contractors for canopy up and downare located on the forward bulkhead of the upperequipment bay. The down contactor suppliespower to the close winding of the canopy actuator.The canopy up contactor supplies power to theopen winding of the canopy actuator. (See fig.2-4.)

Canopy Locked Switch

The canopy locked switch is located in theupper equipment bay under the canopy actuator.(See fig. 2-4.) When the switch plunger isdepressed by the actuator arm, an electrical signal

2-4

Figure 2-5.-Canopy unlatch thruster.

Figure 2-6.-Canopy actuator manual drive unit and handle.

2-5

Figure 2-7.-Canopy external manual drive receptacle.

is supplied to extinguish the canopy warning light.The switch also interrupts power to the actuator.

Canopy Position Switch

The canopy position switch is mounted on theright canopy sill in the No. 4 canopy latch retainer.When the plunger switch is depressed by the No.4 right canopy latch, an electrical signal is suppliedto extinguish the canopy warning light. (See fig.2-8.)

MISCELLANEOUS COMPONENTS

Other systems and components that are relatedto the canopy system are the canopy electricalsystem, air-cycle air-conditioning system,maintenance status display and recording system,mission computer system, and the multipurposedisplay group.

The F/A-18 aircraft electrical system supplies28-volt dc power for canopy operation. Becausethe bus distribution system varies, depending uponthe bureau number of the aircraft, refer to themaintenance instruction manuals to determine theapplicable configuration. (See electrical systemschematic shown in figure 2-9.)

The air-cycle air-conditioning system suppliespartially cooled bleed air for the inflation of thecanopy pressure seal to maintain cabinpressurization.

The maintenance status display and recordingsystem, mission computer system, andmultipurpose display group all receive inputs fromthe canopy system. Inputs are processed andsupplied to the left digital display indicator andmaster caution light. The inputs are alsoprocessed, recorded, and displayed as main-tenance codes on the nosewheel well digital displayindicator. Canopy caution and warning indicators

Figure 2-8.-Canopy position switch and latch retainer.

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are made up of the following components: canopycaution light on the cockpit left digital displayindicator, master caution light on the left-handadvisory and threat warning indicator panel, andthe maintenance code display on the nosewheelwell digital display indicator.

NORMAL OPERATION

Learning Objective: Identify the canopynormal mode of operation to include themanual backup mode.

The canopy is operated electrically by theexternal or internal canopy control switches in thenormal control mode. The canopy can also beoperated manually in the backup manual controlmode if electrical power is not available.

NORMAL CONTROL MODE

The canopy may be operated with the externalcanopy control switch. To open the canopy, theswitch is held in the OPEN position. The canopystops automatically when the full open positionis reached. To close the canopy, the switch is heldin the CLOSE position until the canopy closes,moves full forward, and locks. The canopy stopsautomatically when the closed and locked positionis reached. Motion may be stopped at any pointduring opening or closing by releasing the switch.The switch returns to the HOLD position whenreleased.

To open the canopy internally with weight onthe wheels, the internal canopy control switch isset to OPEN and released. The switch ismagnetically held in the OPEN position until thecanopy raises to full open and stops. The switchthen returns to HOLD. Canopy motion may bestopped at any point during canopy opening bymanually setting the switch to the HOLD position,which overrides the magnetic holding coil. Theinternal canopy control switch opening circuit isequipped with a weight-off-wheels relay that de-energizes the magnetic holding coil when theaircraft is in a weight-off-wheels condition. Withthe holding coil de-energized, the switch must bemanually held to the OPEN position whenopening the canopy.

When the canopy closes, moves full forward,and locks, the No. 4 right canopy latch depressest h e c a n o p y p o s i t i o n switch plunger.Simultaneously, the canopy actuator arm rotatesovercenter and depresses the canopy locked switch

plunger. Depressing both switch plungers causesthe master caution light and the canopy displayon the left digital display indicator to extinguish,indicating the canopy is fully closed and locked.If both switches are not fully depressed or a failureoccurs in either switch, the master caution andcanopy caution indicators will remain illuminated.If both switch plungers are not depressed within15 seconds, the canopy switches disagree and themaintenance code (889) will be displayed on thenosewheel well digital display indicator.

Electrical inputs supplied to the canopyactuator are transformed into mechanical motionused to raise and lower the canopy. The actuatoris equipped with an up-travel-limit switch, whichautomatically interrupts power to the actuatorwhen the full open position is reached. With noaircraft generator power or external powerapplied, a utility battery supplies power forat least five open and close cycles of the canopy.On some F/A-18 aircraft, a logic circuit inthe battery and charger unit secures thecanopy control power when the battery voltagedrops below 19±1 volts.

Due to decreased battery capacity at lowtemperatures, canopy operation using batterypower is not recommended when ambient tem-perature is below 0°F. Under these conditions,external electrical power should be used. Whenexternal power is not available, the canopy canbe operated using the backup manual controlmode.

To further understand how the opening andclosing cycles function, refer to figure 2-9.

BACKUP MANUAL CONTROL MODE

The backup manual control mode is used toopen and close the canopy when utility batterypower is low, internal or external electrical poweris not available, or a failure has occurred in thecanopy actuation control system.

The canopy actuator manual drive unit isoperated from inside the cockpit by using theinternal manual canopy opening handle. Thehandle is removed from its stowage receptacle andclip, and then it is inserted into the crank socket.The handle is turned 70±1 turns clockwise toclose the canopy or counterclockwise to open thecanopy. The internal manual canopy openinghandle shaft assembly mechanically links the driveunit to the canopy actuator. By operating the driveunit internally or externally, mechanical motionis transferred through the shaft assembly to thecanopy actuator.

2-7

Figure 2-9.-Canopy electrical system schematic.

2-8

Figure 2-9.-Canopy electrical system schematic—Continued.

2-9

As previously stated, the canopy externalmanual drive receptacle is provided to operate thecanopy actuator manual drive unit from outsidethe cockpit. A 3/8-inch drive tool is inserted intothe drive receptacle and turned 35±1 turnscounterclockwise to open the canopy or clockwiseto close the canopy.

Manually operating the canopy overrides themechanical brake in the canopy actuator. Thebrake engages to hold the canopy at any positionwhen manual cranking is stopped. The actuatoris equipped with a mechanical torque limiter thatprevents damage to the actuator if excessivetorque is applied to the manual backup controlmode.

EMERGENCY CANOPY JETTISONSYSTEM

Learning Objective: Recognize the systemcomponents and procedures for emergencycanopy jettison.

The emergency canopy jettison systemprovides the capability to ballistically jettison thecanopy in case of an emergency. The canopy canbe jettisoned internally or externally withoutinitiating seat ejection. It can also be jettisonedby initiating ejection. This is accomplished bypulling the ejection control handle on the ejectionseat.

COMPONENTS

Before discussing the internal and externalmethods of jettisoning the canopy, a descriptionof the system’s components is needed.

External Canopy Jettison HandlesAnd Cables

The external canopy jettison handles andcables are stowed behind doors on each side ofthe aircraft near the radome. (See figs. 2-1 and2-10.) Each handle is attached to approximately8 feet of cable. The cables are routed through thegun bay and are joined to a common cable at thecockpit forward pressure bulkhead. This single,common cable runs through the bulkhead into thecockpit, where it connects to the internal canopyjettison lever linkage.

Figure 2-10.-External canopy jettison handle.

Internal Canopy Jettison Lever

The internal canopy jettison lever is locatedto the left of the main instrument panel. The leveris mounted on the canopy sill. (See fig. 2-11.) Thelever gives the pilot the capability of starting theemergency canopy jettison sequence from insidethe cockpit.

Canopy Jettison SMDC Initiator

The canopy jettison shielded mild detonatingcord (SMDC) initiator is located below the canopyjettison lever. The initiator receives inputs fromeither the internal canopy jettison lever or externalcanopy jettison handles to initiate the jettisonsequence.

One-way Transfer Valve

The one-way transfer valve is located on theballistic panel in the upper equipment bay. Thetransfer valve acts as a check valve to prevent thebackflow of SMDC detonation to the seatcomponents.

Emergency Escape Disconnect

The emergency escape disconnect is locatedunder the canopy deck. The disconnect providesa path for SMDC detonation to the canopy

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Figure 2-11.-Internal canopy jettison handle.

ballistic components and provides a disconnectpoint when the canopy is jettisoned or removedfor maintenance.

Canopy Unlatch Thruster andCartridge

The cartridge is mounted in the canopyunlatch thruster, as shown in figure 2-5. Pressurefrom the canopy jettison SMDC initiator fires thethruster mounted on the canopy deck. Whenfired, it moves the canopy aft to disengage thelatches and separate the canopy from theactuation connecting link. Thruster ballistic gasis provided to the canopy jettison rocket motorinitiators.

Canopy Jettison Rocket MotorInitiators

The rocket motor initiators are mounted onthe canopy deck aft of the thruster as shown infigure 2-5. The initiators receive ballistic gas input

from the thruster to produce SMDC detonationto fire the rocket motors.

Canopy Jettison Rocket Motor

The rocket motors are located on either sideof the canopy frame. The rocket motors are firedby the rocket motor initiators and provide thevertical thrust required to separate the canopyfrom the aircraft.

SMDC/FCDC Initiators

The SMDC and flexible confined detonatingcord (FCDC) are located between the variousballistic components. The SMDC and FCDCprovide the energy transfer stimulus used in theemergency canopy jettison system. The SMDC issealed in stainless steel tubing to protect the cordand to contain all gases produced by explosivedetonation. The FCDC is sealed in a metallicsheath, which is protected by a braid over-wrap.

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Figure 2-12.-Canopy jettison system schematic.

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PROCEDURES

The canopy can be jettisoned by internal orexternal means. The following discussionsummarizes both jettison procedures.

Internal Canopy Jettison

Internal canopy jettison is initiated by theinternal canopy jettison lever. (See fig. 2-11.) Byremoving the canopy jettison safety pin andpressing down the safety button and pulling thelever aft, the canopy jettison SMDC initiator isfired. Explosive stimulus produced by the initiatoris transferred through the SMDC to the emergencyescape disconnect. The one-way transfer valveprevents the explosive stimulus from continuingtoward the ejection seat components. Theexplosive stimulus continues through theemergency escape disconnect, via the FCDC, tothe canopy unlatch thruster cartridge, which firesthe canopy unlatch thruster. Firing the unlatchthruster pushes the canopy aft to disengage thecanopy latches and separates the thruster from theconnecting link. Ballistic gas produced by firingthe thruster is transferred to the canopy jettisonrocket motor initiators. The rocket motorinitiators convert ballistic-gas pressure to explosivestimulus, which is transferred through SMDC to

fire the canopy jettison rocket motors. The rocketmotors produce the vertical thrust required toseparate the canopy from the aircraft. (See fig.2-12.)

External Canopy Jettison

Ground emergency external canopy jettison isstarted by opening the door on either the left orright side of the aircraft and removing the canopyjettison handle from its retaining clip. The handleis attached to approximately 8 feet of cable. Whenthe cable is fully extended and pulled, the canopyjettison SMDC initiator is fired, which, in turn,initiates the emergency canopy jettison sequence.From this point on, the sequence is the same asinternal canopy jettison. The cable action merelybypasses the internal canopy jettison lever. Whenthe canopy is jettisoned, all canopy jettisonballistic devices are spent.

WARNING

Ensure that the proper canopy jettisonsafety pin is installed whenever the aircraftis not flying or during any maintenancetask performed on the aircraft.

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CHAPTER 3

UTILITY SYSTEMS

Chapter Objective: Upon completion of this chapter, you will have a workingknowledge of the operating principles and components of bleed-air utilitysystems.

The utility systems of an aircraft provide anadditional measure of flight safety, pilot comfortand convenience, and contribute to the overallmission capability of the aircraft.

BLEED-AIR UTILITY SYSTEMS

Learning Objective: Recognize theoperating principles and components forsystems within the bleed-air utility system.

Many aircraft have utility systems that rely ona bleed-air system to function. The P-3C deicingsystem and the A-6E rain removal system areexamples of such systems and are discussed in thischapter. This material will increase yourproficiency in troubleshooting and maintainingthese and similar systems.

DEICE SYSTEMS

An anti-icing system is designed to prevent icefrom forming on the aircraft. A deicing systemis designed to remove ice after it has formed. Anaircraft deice system removes ice from propellersand the leading edges of wings and stabilizers.These systems may use electrical heaters, hot air,or a combination of both to remove the iceformation. As an AME, you are primarilyconcerned with hot air as a method to remove theformation of ice on wings and stabilizers. TheP-3C wing deice system is used as an example inthis chapter to describe a hot-air system.

Description and Components

The P-3C wing deice system uses hot com-pressed bleed air from the engines. The air is

ducted from the 14th stage of each enginecompressor, as shown in figure 3-1. The bleed airis maintained at a fixed percentage of engineairflow for all altitudes and flight speeds.

The hot bleed air is directed and regulated tothe leading edge ejector manifold through shutoffvalves, modulating valves, thermostats, skintemperature sensors, and overheat warningsensors.

SHUTOFF VALVES.— The wing deicesystem contains several shutoff valves. Thefuselage bleed-air shutoff valves, installed in thecross-ship manifold on the right and left wings,isolate the wings from the fuselage duct section.In addition, they maybe used to isolate one wingduct from the other wing duct. Each valve isindividually controlled by a guarded toggle switchmounted on the bleed-air section of the ice controlprotection panel.

A bleed-air shutoff valve is also installed ineach engine nacelle. These shutoff valves arephysically identical. They are of the butterfly-type,and they are actuated by an electric motor.

An indicator, located on top of the valvehousing, shows the position of the valve—openor closed. This indicator enables you to visuallycheck the operation of the valve while it is stillinstalled in the deice system.

MODULATING VALVES.— The P-3C de-icing system has three modulating valves installedin each wing. These valves are thermostaticallycontrolled and pneumatically operated. Theymaintain the constant engine compressor bleed-air temperature required for the wing leadingedge. When deicing is not required, the valvesoperate as shutoff valves.

The modulating valves, shown in figure 3-2,have pilot solenoid valves that are electrically

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Figure 3-1

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Figure 3-2.-Anti-icing modulating valve.

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controlled by three switches on the bleed-airsection of the ice protection panel. When thesolenoid is energized, it admits filtered, regulated,bleed-air pressure to one side of a diaphragmchamber in the valve. The other side of thediaphragm chamber is spring-loaded to the closedposition. Movement of the diaphragm operatesa main line butterfly valve.

When the valve opens, hot air is admitted tothe leading edge distribution system. The hot airgoes through the modulator valve to the ejectormanifold, out the jet nozzles, and into the wingleading edge plenum area. The bleed air is thendirected across a pneumatic thermostat. Increasedtemperature across the thermostat actuates thesensor and opens a bleed passage from thediaphragm chamber. This reduces the pressure onthe diaphragm and allows a spring to close themain valve.

THERMOSTATS.— The wing leading edgepneumatic thermostat is installed adjacent to eachmodulating valve. (See fig. 3-2.) The thermostatcontrols air pressure on the modulating valvediaphragm, and thereby controls the valveopening.

The unit is composed of a probe and a valveassembly. (See fig. 3-3.) The probe is a core madeof layers of high- and low-expansion material thatis locked to a sliding piston. In addition, the pistoncontains an override spring and ball-type meteringvalve.

Airflow from the leading edge flows over thecore and causes the materials to expand or

contract. As temperature rises, the core pulls thepiston and metering ball from the seated position.This allows pressure from the modulating valvediaphragm to vent. Increasing temperature causesmore air to be bled from the diaphragm chamber.Because of spring action, the modulating valvemoves toward the closed position. This restrictsflow through the modulator valve and drops theskin temperature.

LEADING EDGE TEMPERATURE ANDOVERHEAT CIRCUIT.— To monitor theoverheat warning system, six skin temperaturesensors (one in the inboard section, one in thecenter section, and one in the outboard sectionof each wing) form a part of an amplifier circuit.When the wing leading edge skin temperature risesin excess of 230°F at any one or more sensors,the airfoil temperature control unit amplifiercompletes a caution light circuit, thus illuminatingthe leading edge caution hot light.

Also, there are three ducting overheat thermalswitches installed in each wing and three installedin the fuselage adjacent to the bleed-air duct.These switches form a part of a loop that isconnected to a signal light control assembly.When any one of the thermal leak detectorswitches closes, its respective caution lightilluminates. Also, when the test switch is placedin the TEST position, both lights illuminatethrough their respective loop circuit.

The ducting overheat switches are single-pole,single-throw, explosiveproof, thermally actuatedelectrical switches with an integral temperature

Figure 3-3.-Wing leading edge thermostat.

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sensing element. The switches sense still airtemperature. The outboard leading edge overheatwarning switches open at approximately 205°Fand close at approximately 220°F. The other wingand fuselage overheat warning switches open atapproximately 175°F and close at approximately190°F.

High temperature within the leading edge isgenerally caused by bleed-air leakage ormalfunctioning modulator valves. You can detectthe portion of the leading edge that has theovertemperature by placing the rotary selectorswitch, located on the ice control protection panel,to the different sensor positions: INBD, CTR, andOUTBD. (See fig. 3-4.) The temperature at theselected sensor is then read at the indicatoradjacent to the rotary switch. An excessivetemperature reading on the indicator denotes amalfunction within the area being tested.

Operation

Figure 3-4, the ice control protection panel,shows a basic diagram of the wing deice system.Each engine is labeled by an engine number.Directly below each engine block (in the diagram)is an OPEN light that illuminates when the bleed-air valve is open 2 degrees or more. The cross-ship manifold from the bleed-air valves goes to

each modulating valve and the fuselage shutoffvalves. The fuselage bleed-air shutoff valves arenormally in the CLOSE position during normaldeicing operation. The bleed-air pressure gaugereads cross-ship manifold pressure when one orboth switches are opened.

A ground air-conditioning switch is locateddirectly under the bleed-air manifold pressuregauge. Located above the switch is an annunciatorlight, which indicates VALVE OPEN when theground air-conditioning valve is open. Either oneor both fuselage bleed-air shutoff valves must beopen to direct air to the ground air-conditioningunit.

A leak test switch is mounted on the upperright-hand side of the panel. This switch is usedto determine if the leakage of the system isacceptable.

Three modulating valve control switches arelocated on the left side of the wing and empennageice panel. The outboard switch controls theoutboard modulating valve on the left and rightwing, the center switch controls the two centermodulating valves, and the inboard switchcontrols the two inboard modulating valves.

During normal operation of the deicingsystem, all four engine bleed-air valves are opento supply bleed air to the cross-ship manifold, andboth fuselage bleed-air shutoff valves are closed.

Figure 3-4.-Ice control protection panel.

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The modulating valves maintain a controlled flowof bleed air to the leading edge distributionsystem, and they are controlled by pneumaticthermostats. The complete system is monitoredfor hot spots by heat-sensing switches.

Before flight, the deicing manifold system maybe tested for leakage. This leak testis performedby pressurizing the system: OPEN the No. 4engine bleed-air valve; the Nos. 1, 2, and 3 enginebleed-air valves remain CLOSED, and bothfuselage shutoff valves are in the OPEN position.When the bleed-air pressure on the bleed-airmanifold reads 70 psi, the No. 4 engine bleed-airvalve is closed and the leak test switch is actuated.As the bleed-air pressure drops, the time-delayrelay will illuminate the ACCEPT light after an8-second delay if the system is tight. The light willgo out when the test switch is released.

Maintenance

The involvement of the AME2 and AMEC inthe maintenance of the deicing system normallyconsists of troubleshooting. To troubleshootintelligently, you must be familiar with the system.

In addition, you must know the function of eachcomponent in the system and have a mentalpicture of the location of each component inrelation to other components in the system. Thiscan be achieved by studying the schematicdiagrams of the system.

As an aid, the aircraft manufacturer furnishestroubleshooting charts, which give recommendedprocedures to follow during troubleshooting.Figure 3-5 shows a deicing system overheatwarning troubleshooting chart. This chart lists themost probable cause first and then branches tothe next most probable cause. By following therecommended charts and procedures, you cansave many valuable maintenance hours.

RAIN REMOVAL SYSTEM

The rain removal system shown in figure 3-6controls windshield icing and removes rain bydirecting a flow of heated air over the windshield.This heated air serves two purposes. First, the airbreaks the rain drops into small particles, whichare then blown away. Secondly, the air heats thewindshield to prevent the moisture from freezing

Figure 3-5.-Deicing troubleshooting chart.

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Figure 3-6.-Rain removal system.

on it. The A-6E rain removal system (for thoseaircraft with airframes change number 268incorporated) is discussed in the followingparagraphs.

Description and Components

The rain removal system is controlled by thewindshield switch located on the air-conditioningcontrol panel in the cockpit. (See fig. 3-7.) The

system uses hot bleed air from the 12th stagecompressor section of each engine. The nosewheelwell bleed-air shutoff valve controls the flow ofhot bleed air to the rain removal system.

Then the rain-removal, pressure-regulatorshutoff valve controls the airflow from the rain-removal system to the windshield. When this valveis open, it allows hot bleed air to flow to the rain-removal nozzle assembly. The nozzle distributesthe air through a series of diffuser outlets to forma wide stream of hot air over the windshield. Thetemperature of the air is lowered by a mixingejector at the inlet of the rain-removal nozzleassembly. The ejector uses hot bleed air as itsprimary air, and it draws secondary air from thenose radome compartment to cool the rain-removal air.

In the next several paragraphs, we will discussthe major components of the rain removal system.You should know the location and functions ofthese components to aid you in troubleshootingand maintaining the system.

NOSEWHEEL WELL BLEED-AIR SHUT-OFF VALVE.— The nosewheel well bleed-air

Figure 3-7.-Air-conditioning panel. shutoff valve is a butterfly-type that is

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electrically actuated and operated. The valve isinstalled in the hot bleed-air duct in the starboardengine compartment. The valve is controlled bythe nosewheel well bleed-air switch on the fuelmanagement panel. When the switch is set to theOFF position, the valve is closed by 115-volt acpower from the bleed-air circuit breaker. Whenthe switch is set to the AUTO position, power isrouted to the nosewheel well bleed-air relay. Whenthe windshield switch on the air-conditioningpanel is moved to the AIR position, or when leftmain landing gear weight-on-wheels switch isclosed, the relay is activated and the valve opens.If electric power is lost, the valve will remain inthe last selected position. The valve has a positionindicator that can be viewed with the starboardengine-bay door open.

RAIN-REMOVAL PRESSURE-REGULATORSHUTOFF VALVE.— The rain-removal pres-sure-regulator shutoff valve is a pneumatically

operated, solenoid-controlled, 2-inch valveinstalled in the hot bleed-air duct to the rain-removal nozzle assembly. (See fig. 3-8.) Operationof the valve is controlled by the windshield switchon the air-conditioning control panel. Placing theswitch to the AIR position energizes the solenoidof the valve. When the inlet pressure to the valveis between 15 and 50 psi, the valve is fully opened.When it is between 100 and 250 psi, the valveregulates the outlet pressure to the rain-removalnozzle at 75±3.5 psi. By placing the windshieldswitch to OFF, it de-energizes the solenoid. Thiscauses the valve to close and shuts off the flowof bleed air to the rain-removal nozzle.

In the closed position, air from the upstreamside of the valve passes through the control airpassages to chamber A and leaks past the pilotvalve stem to chamber B. With equal pressure onboth sides of the large diaphragm, the pressureon the small diaphragm and the spring force on

Figure 3-8.-Rain-removal Pressure-regulator shutoff valve.

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top of the large diaphragm combine to hold thevalve closed.

When the solenoid is energized, air suppliedto chamber B bleeds off through the solenoid andthe butterfly valve opens. As the butterfly valveopens, air pressure from the downstream side ofthe valve is applied to the bottom of the pilotregulator diaphragm. This unseats the regulatorvalve stem and permits upstream air to flow tochamber B. As the downstream pressure varies,a varying amount of air is metered by the pilotregulator valve to chamber B. The meteringpositions the diaphragm and the butterfly valveto maintain the proper downstream pressure. Ifthe downstream pressure increases to a value inexcess of the regulator setting, the pilot valveopens. When this occurs, the solenoid valve is notcapable of bleeding off the increased airflow inchamber B. Therefore, chamber B pressure in-creases, and the butterfly valve moves toward theclosed position until regulation pressure isreached.

RAIN-REMOVAL NOZZLE ASSEMBLY.—The rain-removal nozzle assembly consists of twoejectors, a plenum chamber, and 26 nozzles. Thebleed-air duct has two nozzles aligned with andlocated beneath each ejector tube. The ejectorsmix cool air from the nose radome compartmentwith the hot bleed air. The mixture is distributedby the plenum to the nozzles, which results in awide stream of air across the windshield. Theplenum chamber provides an approximately equalpressure at each nozzle. The rain-removal nozzleassembly is beneath the left windshield,

WINDSHIELD SWITCH.— The windshieldswitch is a single-pole, three-position switchmounted on the air-conditioning control panel inthe cockpit. The three positions are OFF, AIR,and WASH. This switch controls the operationof the windshield-washing shutoff valve and rain-removal pressure-regulator shutoff valve. Theswitch is spring-loaded to the OFF position. TheAIR and WASH positions are momentary con-tacts. If the switch is placed in the WASHposition, it directs streams of washing fluidagainst the base of the windshield. If it is placedto the AIR position, it directs a wide stream ofhot air across the glass.

N O S E W H E E L W E L L B L E E D - A I RSWITCH.— The nosewheel well bleed-air switchis a single-pole, two-position switch mounted onthe fuel management panel in the cockpit. The

two positions are OFF and AUTO. This switchcontrols the operation of the nosewheel well bleed-air shutoff valve. Placing the switch in the OFFposition closes the nosewheel well bleed-airshutoff valve. When the switch is set to AUTOposition, the nosewheel well bleed-air shutoffvalve will open when the rain-removal system isenergized or when the left main landing gearweight-on-wheels switch is actuated.

NOSEWHEEL WELL BLEED-AIR RE-LAY.— The nosewheel well bleed-air relay is adouble-pole, double-throw, relay mounted in aftbay relay box No. 3. Its operation is controlledby the windshield switch on the air-conditioningpanel or by the left main landing gear weight-on-wheels switch. When energized, the relay com-pletes a 115-volt ac circuit to open the nosewheelwell bleed-air shutoff valve. When de-energized,the relay completes a 115-volt ac circuit to closethe nosewheel well bleed-air shutoff valve.

LEFT MAIN LANDING GEAR WEIGHT-ON-WHEELS SWITCH.— The left main landinggear weight-on-wheels switch is a double-pole,double-throw switch mounted on the lower torquearm of the left gear shock strut. The switch isclosed when the shock strut piston is extended.When the shock strut piston is compressed, theplunger of the switch is fully extended. When theswitch plunger is extended, a 28-volt dc circuit iscompleted to energize the nosewheel well bleed-air relay.

WINDSHIELD RAIN-REMOVAL WARN-ING RELAY.— The windshield rain-removalwarning” relay is a double-pole, double-throw,sealed relay mounted in the cockpit center consolebelow the wing fold panel. Its operation iscontrolled by the windshield switch on the air-conditioning panel. When the windshield switchis in the AIR position, 28 volts of dc power isdirected from the air-conditioning circuit breakerto energize the relay and illuminate the windshieldair caution light. The relay is de-energized whenthe windshield switch is set to OFF. At this time,the windshield air caution light will go out.

WINDSHIELD AIR CAUTION LIGHT.—The windshield air caution light is located on thecaution light panel in the cockpit. It illuminatesto indicate that the windshield switch is in theAIR position. The operation of the light iscontrolled by the windshield rain-removal warningrelay.

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System Operation

The rain-removal system is activated byplacing the windshield switch in the AIR position.With the switch in the AIR position, a 28-volt dccircuit is completed from the air-conditioningcircuit breaker, through the windshield switch, tothe solenoid of the rain-removal pressure-regulator shutoff valve, to the nosewheel wellbleed-air relay, and to the windshield rain-removalwarning relay. When the nosewheel well bleed-air relay is energized, the 115-volt ac circuit fromthe bleed-air circuit breaker, through the AUTOposition of the nosewheel well bleed-air switch,is completed to the open windings of thenosewheel well bleed-air shutoff valve. With thecircuit completed, the windshield air caution lightwill illuminate. When you move the windshield

switch to the OFF position, the windshield aircaution light will go out. The nosewheel wellbleed-air shutoff valve directs the 115-volt acpower to the close windings of the motor. Theweight-on-wheels switch will energize thenosewheel well bleed-air relay.

When the rain-removal pressure-regulatorshutoff valve solenoid is energized, the valveopens and allows pressure-regulated (75±3.5 psi)hot bleed air to flow to the ejectors of the rain-removal nozzles. To lower the temperature of thehot bleed air, the ejectors draw cool air from thenose radome compartment. The cool air and hotbleed air mix in the plenum of the nozzleassembly. The air passes through the plenum to26 nozzles, which direct the hot air in a widestream across the windshield.

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CHAPTER 4

AIR-CONDITIONING SYSTEMS

AMEs

Chapter Objective: Upon completion of this chapter, you will have a workingknowledge of the operating principles and components of air-condi-tioning.

maintain the air-conditioning andpressurization systems of naval aircraft. Thesesystems provide heating and cooling of the cabinand, at altitude, the pressurization required forbreathing. As an AME, you will be assistingaircrews and troubleshooting discrepancies. Agood knowledge of the systems is necessary toperform effectively. This chapter uses the S-3environmental control system as the basis fordiscussion. To simplify matters, we havedivided the system into two subsystems: bleedair and air-conditioning.

BLEED-AIR SYSTEM

Learning Objective: Identify the operatingprinciples and components of a bleed-airsystem.

The bleed-air system is the air source for theenvironmental control system (ECS) and fordeicing functions. There are three sources of bleedair available. The primary source is the com-pressor sections of the two aircraft engines.Secondary sources are from the auxiliary powerunit (APU) and from an external air supply suchas support equipment (SE).

SYSTEM OPERATION

As previously stated, the source of air for thebleed-air system may be from the aircraft engines,the APU, or SE. Operation of the system usingeach of these sources is presented in the followingparagraphs. Frequent referral to the bleed-air

system schematic (fig. 4-1) will aid you in under-standing the material.

Engine Bleed Air

The engine bleed air is extracted from the 10th-and 14th-compression stages of each engine. Thelow-stage bleed-air check valve supplies the 10th-stage air, which is the primary source foroperation of the ECS. When 10th-stage air isinsufficient to meet ECS demands, 14th-stage airis supplied through the high-stage, bleed-airregulator valve.

One bleed-air shutoff valve is installed in eachengine pylon downstream of the 10th- and 14th-stage engine-compressor bleed ports. The bleed-air shutoff valves are controlled by switches onthe eyebrow panel in the flight station. Lights onthe instrument panel indicate the position of thebleed-air shutoff valves. The lights illuminatewhen the valves are closed regardless ofthe position of the switches. When open,the bleed-air shutoff valves allow enginecompressor bleed air to flow into the bleed-airmanifolds.

The bleed-air manifold distributes bleed airfrom both engines into the air-conditioning andpressurization systems. Two crossover ductisolation check valves prevent the possibilityof an overbleed of both engines should arupture occur in the left or right bleed-airmanifold.

The check valves, located in the left and rightmanifolds, allow bleed air to flow in one direction

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Figure 4-1.-Bleed-air system schematic.

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only. If the left or right engine bleed air is secured,or if a rupture occurs in the left or right bleed-airmanifold, the appropriate check valve closes. Thisallows the air-conditioning and pressurizationsubsystems to operate from the opposite bleed-air source. An open engine bleed-air bypass andshutoff valve allows bleed air to bypass thecheck valves and flow from the left-to-right orright-to-left manifolds. The engine bleed-airbypass and shutoff valve is open during enginestarting. It is also open when operating the deicingsystem with one engine secured.

Bleed-air pressure is sensed by the bleed-airpressure transmitter located in the bleed-air supplyduct downstream of the crossover duct isolationcheck valves. The pressure is displayed on thebleed-air pressure indicator on the environmentalpanel.

Bleed air from the left and right manifoldsflows through the crossover duct isolation checkvalves to the bleed-air flow control and shutoffvalve. The bleed-air flow control and shutoff valveis electrically controlled and pneumaticallyactuated to modulate the bleed-air flow to the air-conditioning and pressurization systems inresponse to predetermined flow schedules.

Two alternate air supply sources, APU air andground start air, connect to the left and rightbleed-air manifold. The APU air duct suppliesbleed air through two check valves to the leftmanifold. The ground start duct supplies high-pressure air through a check valve to the rightmanifold. These alternate air supply sourcesare used primarily for starting engines andfor ground operation of the air-conditioningsystem.

APU Bleed Air

Bleed air flows from the APU compressorthrough two one-way check valves in the APUduct to the left one-way check valve in the cross-breed manifold. Bleed air is also supplied to thebleed-air shutoff valve, the left side of the enginebleed-air bypass and shutoff valve, empennagedeice valve, the left wing deice valve, and the ramair anti-icing valve. With the bleed-air switch inthe ON position, the left bleed-air shutoff valveis opened. In the open position, bleed air issupplied to the left engine starter control valve.

To provide bleed air to the right side of the cross-breed manifold, the engine bleed-air bypass andshutoff valve is opened to allow bleed air to theright bleed-air shutoff valve and to the right wingdeice valve. With the bleed-air engine No. 2 switchset to ON, the right bleed-air shutoff valve isopened. In the open position, bleed air is suppliedto the right engine starter-control valve.

SE Ground Start Air

When support equipment is the source of air,the ground air start hose is connected to theground start connection nipple located in the rightwheel well. External high-pressure air flowsthrough the engine starting duct check valve intothe right cross-bleed manifold. Normal flow isthrough the right one-way check valve in the cross-breed manifold to the bleed-air flow control andshutoff valve. High-pressure air is available to theright bleed-air shutoff valve and the right wingdeice valve. Opening the right bleed-air shutoffvalve provides air to the right engine starter-control valve.

To provide SE air to the left cross-bleedmanifold, the engine bleed-air bypass and shutoffvalve is opened. When the valve is open, air flowsaround the cross-bleed check valves to the leftbleed-air shutoff valve, the left wing deice valve,the ram air anti-icing valve, and the empennagedeicing valve. To provide air to the left enginestarter-control valve, open the left bleed-airshutoff valve.

SYSTEM COMPONENTS

Now that you are familiar with the operationof the system as a whole, let’s look at itscomponents and their operation. Knowledge ofthe individual components makes troubleshootingeasier and faster. To aid you in locating parts ofthe components, numbers within parenthesis ( )are included that correlate to the numbers on theillustrations.

High-stage Bleed-Air RegulatorValve

The high-stage, bleed-air regulator valve is anormally closed, differential-pressure regulator.

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(See figure 4-2.) Air from the inlet (13) passesthrough the filter (14), and then through thereverse-flow check valve (15). The air then entersthe reference regulator (16), where it is pressureregulated (as a function of altitude) by anevacuated bellows (1). The air is then passedthrough a control orifice (6), a shuttle valve (8),and to the actuator section (10) of the high-stage,bleed-air regulator valve to open the butterfly (12).The pressure of the air entering the regulatorsensing line (11) with the spring pressure of theactuator section of the valve modulates the valve

toward the closed position, as regulated bypressure from the shuttle valve. As aircraftaltitude increases, the evacuated bellows expandand cause the reference regulator to close. Theambient vent (5) decreases the pressure to the openside of the actuator section, and thereby allowsthe spring to close the actuator section. This actionalso closes the butterfly.

When the cross-bleed start solenoid (3)is energized, the reference regulator largerdiaphragm (2) is vented to ambient (4). Springpressure on the reference regulator larger

Figure 4-2.-High stage, bleed-air regulator valve schematic.

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diaphragm causes the reference regulator toopen. This results in pressure being passedthrough the control orifice, which is regulated bythe cross-bleed start relief regulator (7). Thepressure commands the actuator section toopen with a corresponding opening of thebutterfly.

During deicing operations, control pressurefrom the temperature control regulator valve isapplied to the temperature control connection (9).This changes the shuttle valve position to allowthe temperature control regulator valve pressure

to open the actuator section and the butterfly.During deicing operations, pressure from thetemperature control regulator valve overrides allother inputs to the shuttle valve.

Bleed-Air Shutoff Valve

The bleed-air shutoff valve is a normallyclosed, pneumatically operated, electricallycontrolled shutoff valve with provisions forautomatic closure in the event of overtemperature,overpressure, or loss of electrical power (fig. 4-3.)

Figure 4-3.-Bleed-air shutoff valve schematic.

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Inlet air pressure flows through the filters. tothe shuttle valve (14), which selects the higher airpressure on each side of the butterfly (15) androutes the selected pressure to the solenoid (2) andchamber B (8). With the solenoid de-energized (asshown in figure 4-3), the opening side of theactuator (4), or chamber A (6), is vented (5) toambient pressure through the solenoid. The re-sulting pressure differential between chambers Aand B produces a force to keep the butterflyclosed. A butterfly position indicator switch (3)controls a light (1) that indicates the butterfly isin a closed position. With the solenoid energized(opposite to the position shown in figure 4-3), airpressure is ported to chamber A, which opens thebutterfly and keeps it open.

In the event of an overpressure that causes theinlet pressure downstream (16) of the butterfly toattain the preset value of the pressure switch (7),the switch actuates and de-energizes the solenoidelectrical circuit to close the valve. When the inletpressure returns to the switch reset value, theelectrical circuit closes to re-establish solenoidcontrol.

In the event of an overtemperature that causesthe inlet temperature to attain the preset value ofthe temperature switch (9), the switch de-energizesthe solenoid and closes the valve. When thetemperature returns to the switch reset value, thesolenoid re-establishes control.

Check Valves

Five check valves are used in the bleed-airsystem: two in the cross-bleed duct, two in theauxiliary power unit (APU) bleed-air duct, andone in the ground starting duct. These are 3-inchdiameter, insert-type, spring-loaded closed split-flapper valves, which are designed to be insertedinto, and contained by, the aircraft duct.

Low-Stage Bleed-Air Check Valve

The low-stage bleed-air check valve is installedin the engine pylon bleed-air duct on the right sideof the engine. The low-stage bleed-air check valveallows bleed air from the 10th-stage enginecompressor to enter the bleed-air subsystem toprotect the engine when high-stage bleed air isscheduled.

The low-stage bleed-air check valve consistsof a main housing and two semicircular flappershinged on a post positioned radially through thecenter of the housing. The low-stage bleed-aircheck valve permits flow in the direction indicatedby the arrow, and restricts flow in the oppositedirection. The flappers are spring-loaded in theclosed position.

Engine Bleed-Air Bypass andShutoff Valve

The engine bleed-air bypass and shutoff valve,located in the cross-bleed manifold, is normallyclosed. It is open for engine starting and duringsingle-engine, wing-deicing operations. (See figure4-4.) When the solenoid (1) is energized, theshuttle valve (7) senses the higher pressure air fromthe right and left pressure inlets (3 and 5) anddirects it through the solenoid to chamber A (6)to open the butterfly (4). When the solenoid isde-energized, air bypasses the solenoid andenters chamber B (2) to assist the spring inclosing the engine bleed-air bypass and shutoffvalve.

Bleed-Air Flow Control andShutoff Valve

The bleed-air flow control and shutoff valveis a normally closed valve with two flow schedules:fixed and inlet pressure regulated. (See figure 4-5.)The valve is electropneumatically controlled andpneumatically actuated.

The venturi inlet (17) and throat pressure (18)are routed to the delta-P servo diaphragm (22).As the inlet pressure to the bleed-air flow controland shutoff valve is increased, regulated pressurerouted to the actuator diaphragm (13) causes thebutterfly (15) to open. When the resultant venturidelta-P reaches the predetermined value, as set bythe calibration spring (12), the delta-P servodiaphragm moves. This causes the flexure beam(11) to lift off the servo valve and seat (20). Thisdecreases pressure downstream of the controlorifice (3), which closes the butterfly to a positionthat maintains the desired venturi delta-P. Thisdelta-P corresponds to the desired high-flowsetting when solenoid A (26) is de-energized.

When solenoid A is energized, regulatedpressure acting on the high-flow low-flow resetdiaphragm (7) moves the reset lever to the low-flow stop (10) and reduces the calibration springload on the delta-P servo diaphragm. This causesthe delta-P servo diaphragm to regulate theairflow at low condition. Solenoid A is operatedelectrically by an altitude switch (25). As theventuri inlet pressure increases, the inlet pressurecompensating piston (5) moves against the resetlever (9) and modulates the air flow to a low value.The inlet pressure compensating spring preloadand rate are selected to provide a prescribedschedule. When solenoid B (27) is energized,actuator pressure is vented to ambient, and thebutterfly valve closes.

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Figure 4-4.-Engine bleed-air bypass and shutoff valve.

4-7

Figure 4-5

4-8

Bleed-Air Transmitter

The pressure transmitter senses the bleed-air pres-sure in the duct upstream from the bleed-air flowcontrol and shutoff valve. The pressure transmittertransmits the pressure indication to the bleed-airpressure indicator on the environmental panel.

AIR-CONDITIONING SYSTEM

Learning Objective: Identify the operatingprinciples and components of an air-conditioning system.

The air-conditioning system consists of twosubsystems: refrigeration and cabin temperaturecontrol. These subsystems and their componentsare discussed in the following paragraphs.

REFRIGERATION SUBSYSTEM

The refrigeration subsystem, shown in figure4-6, consists of two physically separated packages:refrigeration and cabin air/water separator. Therefrigeration subsystem operates on bleed air,which is temperature and pressure regulated.Passage through the ram air-cooled heatexchanger reduces the bleed-air temperature to

Figure 4-6.-Refrigeration subsystem schematic.

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within a few degrees of ambient air temperature.Further temperature reduction results fromexpansion at the turbine. Condensation isremoved in the water separator.

System Operation

Regulated hot bleed air from the bleed-airsupply subsystem enters the refrigeration unit heatexchanger, where it is cooled to within a fewdegrees of ram-air temperature. The cooled high-pressure bleed air enters a radial flow turbine,where it expands to approximately cabin pressure.The power output of the expansion turbine drivesan axial-flow cooling air fan. A substantialtemperature drop occurs in the expansion of high-pressure air to cabin pressure (165 psi bleed-airto 15 psi cabin air), which results in airtemperatures well below ram-air temperature.

Depending upon the cool air temperature anddew point, a portion of the water vapor in the aircondences as small droplets. A water separatoris installed downstream from the turbine dischargeto remove between 50 and 70 percent of themoisture in the cooled air. If the turbine dischargeair is also below 32°F, the water vapor condensesas ice crystals. Potential icing and blockage areeliminated by the nonice and low-limit controlvalve, the ice screen, and the mixing muff. Thenonice and low-limit control valve senses anypressure drop through the ice screen. If iceaccumulates, the nonice and low-limit controlvalve admits turbine bypass air into the mixingmuff to increase air temperature above icingconditions.

Ram cooling air for the heat exchanger flowsthrough the heat exchanger core. The turbineshaft drives the fan, which pulls the ram airthrough the heat exchanger and discharges itoverboard through the heat exchanger exhaustduct.

Components

There are nine basic components in therefrigeration subsystem. Each of thesecomponents is discussed in the followingparagraphs. The relationship of the items is shownin figure 4-6.

TURBINE AND FAN ASSEMBLY.— Theturbine and fan assembly (fig. 4-7), which ismounted in the heat exchanger upper plenum (7),is a removable component of the refrigerationpackage. High-pressure, partially cooled bleed air

drives the turbine, which is mechanically coupledto an axial flow fan. The fan is used to impel ramair through the heat exchanger and an overboardexhaust duct. Pressure reduction and final heatloss occur as a result of energy loss and expan-sion of bleed air as it passes through theturbine.

Wool wicks, with one end submerged in MIL-L-23699 oil, transmit lubricant to the bear-ings supporting the common shaft of the turbineand fan assembly. A sight gauge on theturbine housing is used to check the oillevel.

Two overtemperature indicators are installedon the turbine. Each sensor probe head holdsdown a spring-loaded pop-up stem with an eutec-tic solder alloy. If the air in the passage reachesthe melting point for the solder alloy, the indicatorhead pops up and stays exposed to alertmaintenance personnel that the cooling turbinehas been exposed to an excessive temperature leveland needs to be replaced. The probe in the turbineinlet is set to trip at 217°±10°F, and the probein the fan inlet will trip at 450°±10°F.Obstructions or collapse of the ram air inletduct is the most likely cause of actuating thisindicator.

HEAT EXCHANGER CORE, UPPER ANDLOWER PLENUMS.— The heat exchanger lowerplenum (2) contains the ducting for the ram airinlet and outlet. Cooling ram air (4) flows intothe lower plenum and through the heat exchangercore (3) and out through the overboard exhaustduct (6) to the upper plenum, or to the ram airaugmentation subsystem (5).

The heat exchanger upper plenum, which sup-ports the turbine and fan assembly (1), is mountedon the opposite side of the heater core. Ram airdrawn through the heater core for cooling pur-poses is diverted to the heat exchanger exhaustduct through the heat exchanger upper plenum.The heat exchanger core is the air-to-air heatsink, and it uses ram air to cool the bleed-airsupply.

NONICING AND LOW-LIMIT CONTROLMODULATING VALVE.— The nonice and low-limit control valve maintains conditioned airflowthrough the water separator by adding bleed airat the mixing muff to prevent water separator

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Figure 4-7.-Refrigeration package and water separator.

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icing. (See figure 4-8.) Ice forming on the wirescreen at the water separator discharge duct isdetected by two pneumatic pickups located justbefore and after the water separator. Thesepickups sense a differential pressure across thewater separator. If differential pressure is sensedacross the water separator, the nonice and low-limit control valve will remain open until thetemperature of the inlet air to the water separatoris high enough to melt collected ice. When the iceis melted, the pressure differential returns tonormal. In addition, the refrigeration pack low-limit control electrically signals the nonice andlow-limit control valve when separator outflowdrops to 0°F.

REFRIGERATION PACK LOW-LIMITCONTROL.— The refrigeration pack low-limitcontrol (fig. 4-6) is located in the ECScompartment. It is mounted downstream from thewater separator in a 6-inch duct of cooleddischarged bleed air.

The refrigeration pack low-limit control uses28-volt dc power to energize its circuitry. Athermistor senses duct air temperature andcompares it with an internally generated reference.The difference is amplified to modulate a torquemotor in the nonice and low-limit control valve.(See figure 4-8.) The torque valve controls theregulated air supply (3) with a flapper valve (1),which controls the diaphragm pressure in abutterfly actuating linkage (12). The nonice andlow-limit control valve can be returned to thedifferential pressure control mode by opening thecabin temperature high-limit thermostat (4). Thiscauses the upper chamber (6) of the switcher valve(7) to be vented (17) and returned to its primaryposition. A check valve (5) is provided to preventextraneous signals from affecting the nonice andlow-limit control valve.

REFRIGERATION UNIT CHECK VALVE.—The refrigeration unit check valve (fig. 4-7, detailA) is an insert-type check valve with a split flapperspring-loaded in the closed position. The valve,which is installed in the refrigeration unit toprevent hot bleed air from entering directly intothe turbine, is located in a tee arrangement in thesystem just downstream of an orifice.

Icing of the water separator will occur onlyat low altitudes where mass airflow and tempera-ture are relatively high. Only a small amount ofhigh-temperature air is required through theorifice to melt such a deposit. However, at highaltitude where the mass flow and bleed-air

temperatures are low, the refrigeration pack low-limit control operates to open the nonice and low-limit control valve. When the nonice and low-limitcontrol valve is open, high differential pressureacross the bleed-air orifice permits the refrigera-tion unit check valve to open. This allowsintermediate-temperature air to bypass theturbine, and thereby maintain water separatortemperature above 0°F. (See figure 4-6.)

CABIN AIR/WATER SEPARATOR, CO-ALESCER CONE, AND COALESCER BAG.—The water separator is a welded cylindricalaluminum container installed downstream fromthe turbine and fan assembly. Its purpose is toremove a portion of the moisture condensedduring the air-expansion process within theexpansion turbine. (See figure 4-6.) The waterseparator container holds a coalescer bag, whichcollects the finely dispersed fog-like moisturedischarged from the turbine. The wet air flowsthrough the coalescer cone and through louveredswirl vanes to cause the heavier water particles tobe deposited by centrifugal force against the outersurface of the collector section. Accumulatedwater is drained through the sump in the bottomof the collector section. The partially dried airthen leaves the water separator by way of the airoutlet duct. The coalescer bag may be removedfor cleaning through an access cover secured witha quick-disconnect band coupling to the waterseparator shell.

WATER SEPARATOR ICE SCREEN.— Anice screen is located in the discharge end of thewater separator to collect ice when moisturizedairflow temperature is below the dew pointtemperature, or below 32°F. The condensed icecrystals gathered across the ice screen cause apressure differential, which is sensed by the noniceand low-limit control valve. The nonice and low-limit control valve then increases the warm airsupply through the mixing muff, the coalescerbag, and to the ice screen to melt collectedice.

WATER SEPARATOR BYPASS VALVE.—The bypass valve is a spring-loaded valve mountedin the water separator container. A failure of thenonice and low-limit control valve could cause iceparticles to build up in the water separatorcoalescer bag. This ice would block the cabin airsystem. To ensure that air is supplied to the cabin,the water separator bypass valve allows turbineair to bypass the coalescer bag.

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Figure 4-8.-Nonicing and low-limit control modulating valve schematic.

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CABIN TEMPERATURE CONTROLSUBSYSTEM

A cabin air temperature control sensor islocated mid cabin adjacent to the TACCO coolingair inlet. Its purpose is to ensure adequate airflowover the sensor, which measures cabin tempera-ture and sends a signal, along with a signal fromthe cabin air temperature selector, to the cabinair temperature control. The cabin air temperaturecontrol then directs the cabin temperature controlmodulating valve to maintain a selected tempera-ture in the cabin. During normal cruise, cabin airtemperature is controlled by mixing water separa-tor cold air with hot bleed air. The control alsoacts as an anticipator to stabilize response fromthe supply duct sensor to the cabin temperaturedemand.

System Operation

The cabin temperature control subsystemcools the bleed-air supply by air-cycle refrigerationand ram air mixing to provide a cabin temperaturewithin the range of 60° to 80°F during steady andmild transient conditions. The cabin temperatureis maintained within ±3°F of the selected valueand a temperature differential of 10°F betweenthe floor level and the head level. Humiditycontrol ranges from a relative humidity of 5 to70 percent. The cabin exhaust air, after passingthrough the internal avionics and the sonobuoyand weapons bays, is exhausted overboard.

Cabin air temperature is monitored by a sensormounted on the aisle next to the cooling air inletat the TACCO side console. The sensor measuresthe flight station air temperature and generatesa signal that is transmitted to the cabin airtemperature control. Additionally, a signal fromthe temperature select switch is sent to the control.The cabin air temperature control senses the inletduct temperature and compares the signals tomodulate the cabin temperature control valve.Based on this comparison, it allows the properamount of hot bleed air to enter the mixing muffat the conditioned air outlet. The cabin airtemperature control acts as an anticipator tostabilize the response of the supply duct airtemperature to cabin temperature demands. Italso minimizes cabin air supply duct temperaturechanges because of bleed- or ram-air temperaturechange. (See figure 4-9.)

In the manual mode, the automatic controlsare overridden to provide manual control of thecabin temperature control valve. Since the cabin

air temperature control is bypassed, the160°±5°F limit on the cabin air temperaturecontrol is raised to 185°±15°F, as sensed by thecabin air high-temperature limit thermostat. If thepilot has selected the temperature select switchposition for which this 185°±15°F is exceeded,the cabin temperature control subsystem will cycleopen and closed until manual control isrepositioned or conditions change to reducemaximum supply temperature.

The augmented air system provides ram air,as required, to supplement the conditioned bleedair and to provide auxiliary ventilation. This ramair is drawn from the ram-air scoop located in thebase of the vertical stabilizer. The ram air isinjected into the cabin air distribution ductingdownstream from the mixing muff at the junctionbetween the water separator discharge air and thecabin temperature control valve.

During unpressurized flight up to 3,500 feet(+1000 or –500 feet) with a ram air temperaturebetween 20°±6°F and 72°±6°F, ram airsupplements the conditioned bleed-air flow to thecabin. When operating in the automatic mode,the ram-air shutoff valve controls the duct-to-cabin pressure differential to 7.5 ± 2 inches ofwater to prevent flooding the cabin with ram airwhen the aircraft is flying at high speeds.

The ram-air shutoff valve is also used toprovide auxiliary ventilation by securing therefrigeration package and relying on the pilot-operated auxiliary vent switch to adjust theram-air shutoff valve. (See figure 4-10.) With theair-conditioning switch set to OFF, setting theauxiliary vent switch to ON closes the cabinrecirculating air temperature control valve andopens the cabin pressure regulator valve. If thesetting of the ram-air shutoff valve is such thatram pressure fails to satisfy cabin exhaust fanrequirements, the negative pressure relief valveopens. This draws additional ambient air from theenvironmental control system compartment tocompensate for any airflow deficiencies.

In the event of an automatic shutdown of theair-conditioning or pressurization system duringsingle-engine waveoff, the cabin air supplytemperature may change because the ram-airshutoff valve opens. Operation is restored bysetting the air-conditioning switch toOFF/RESET and then back to ON, or by settingthe auxiliary vent switch to modulate the ramairflow.

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Figure 4-9.-Environmental control system operation during pressurized flight.

4-15

Figure 4-10.-ECS operation in aux vent mode.

System Components

Seven components are used to control cabintemperature. These components are discussed inthe following paragraphs.

CABIN TEMPERATURE CONTROL MODU-LATING VALVE.— The cabin temperaturecontrol modulating valve has a visual positionindicator and is spring-loaded to the closedposition. It is located between the hot bleed-airduct going to the refrigeration unit and the cooledair duct coming from the refrigeration unit. Thecabin air temperature control provides electricalpower to a torque motor in the valve, whichconverts electrical signals into pneumatic

signals that modulate the butterfly to a specificopening.

CABIN AIR TEMPERATURE CONTROL.–The cabin air temperature control, which islocated in the cabin inlet duct, senses ducttemperature with two thermistors and a controlcircuit for signal comparison. The cabin airtemperature control output signal is in proportionto the sensed temperature differential between theinlet duct temperature and an input from the cabinair temperature sensor. The output of the cabinair temperature control, which goes through thecabin air temperature selector, provides acontrolling signal for the cabin temperaturecontrol valve.

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CABIN AIR HIGH-TEMPERATURE LIMITTHERMOSTAT.— The cabin air high-tempera-ture limit thermostat is a pneumatic control valvethat actuates as a function of cabin inlet airtemperature sensed at the cabin air inlet duct. Thethermostat’s internal valve opens between 182°and 200°F and dumps regulated air pressure fromthe cabin temperature control valve and the noniceand low-limit control valve. This induces bothvalves to close.

The thermostat uses a temperature-sensingliquid contained in a sealed-wall probe. Vaporforms above the liquid, varies in pressure withsurrounding temperature, and actuates a discspring that dumps the air pressure supply.

CABIN AIR TEMPERATURE CONTROLSENSOR.— The cabin air temperature sensor,located mid cabin, consists of two thermistorprobes in parallel that have a nominal 4,000-ohmresistance at 77°F. The sensor, which operatesover a temperature range of 55° to 85°F, isconnected to the cabin air temperature control,and it is designed to control cabin temperatureto within ±3°F of the selected temperature.

RAM-AIR SHUTOFF VALVE.— The ram-air shutoff valve (fig. 4-11) consists of a butterflyvalve (9) and linkage. It is opened by a spring andclosed by an air-pressure actuated diaphragm (11).The diaphragm is activated by a regulated air

Figure 4-11.-Ram-air shutoff valve schematic.

4-17

supply that is controlled by a fluidic controlsystem or a torque motor and flapper (5),depending upon whether the solenoid is energizedor de-energized.

During the ram-air augmentation mode (auto-matic mode), the ram-air shutoff valve regulatesdownstream pressure to a fixed differential of7.5 ± 2 inches of water above cabin pressure. Theautomatic mode is selected by energizing thesolenoid. This allows the fluidic control toestablish the differential across the valve actuatoras determined by valve downstream pressure (6)and cabin pressure (1).

During manual operation (override mode), theauxiliary vent switch on the environmental panelis used to place the ram-air shutoff valve in anyposition from fully closed to fully open by varyingelectrical power to the valve torque motor. In theoverride mode, selected by de-energizing thesolenoid, power is applied to the torque motorto close the pneumatic supply pressure nozzle andto open the vent nozzle, thereby lessening the ram-air shutoff valve actuator closing pressure. Thispermits the actuator spring to move the butterflytoward an open position.

RAM-AIR HIGH-AND LOW-TEMPERA-TURE LIMIT SWITCH.— The ram-air high- andlow-temperature limit switch senses air tem-perature at the ram-air inlet duct. There are twocircuits in the ram-air high- and low-temperaturelimit switch that are normally closed. One circuitopens with decreasing ram-air temperature, andthe other opens with increasing ram-air tempera-ture. The ram-air high- and low-temperature limitswitch circuitry is interconnected with the bleed-air flow control valve, the ram-air shutoff valve,and the auxiliary vent switch. The ram-air high-and low-temperature limit switch operationcontrols the ram-air shutoff valve position whenthe ram-air shutoff valve is operating in theautomatic mode.

GROUND AIR SUPPLY CHECK VALVEAND GROUND COOLING AIR CONNEC-TOR.— Support equipment provides low-pressureconditioned air when it is attached to the groundcooling air connector. The connector is locatedon the right side of the aircraft in the right wheelwell at fuselage station (FS) 465. It is accessiblethrough a hinged door on the underside of thesonobuoy deck. The connector consists of asilicone-impregnated nylon hose and a clampsupporting the air check valve.

The ground air check valve is a 4-inchdiameter, split-flapper valve spring-loaded to theclosed position. Ground cooling air opens thecheck valve and closes the ram and recirculatedair check valves. The ground source low-pressureair bypasses the refrigeration unit and enters thecabin area because the air-conditioning system isnot used when low-pressure ground air isconnected. Therefore, the bleed-air flow controlvalve will be closed.

ENVIRONMENTAL CONTROL PANEL

The environmental control panel (fig. 4-12) islocated on the center console and is used by theflight crew to control temperature, pressurization,and anti-icing functions. The discussion of thispanel is limited to the ram-air valve positionselector, air-conditioning switch, and the cabinair temperature selector.

Ram-Air Valve Position Selector

When the ram-air valve position selector(AUX VENT switch) is placed in the OFFposition, the automatic mode is established byway of the fluidic control system. Clockwiserotation towards the ON position overrides logiccontrols of the air-conditioning system. Controlof the ram-air shutoff valve is determined by the

Figure 4-12.-Environmental control panel.

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magnitude of the current, which is proportionalto the setting of the auxiliary vent switch.

Air-Conditioning Switch

The air-conditioning switch (AIR CONDswitch) is used to activate the air-conditioningsystem. When air conditioning is automaticallyshutdown and the ram-air shutoff valve has fullyopened, the air-conditioning switch must be set

to OFF/RESET, and then back to ON to restorenormal operation.

Cabin Air Temperature Selector

The cabin air temperature selector (TEMSELECT switch) has a manual and an automaticmode of operation. The temperature select switchoperates manually in the same manner as the auxi-liary vent switch. In the automatic mode, cabintemperature is selectable from 60° to 80°F.

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CHAPTER 5

NAVY AIRCREW COMMON EJECTIONSEAT (NACES)

Chapter Objective: Upon completion of this chapter, you will have a workingknowledge of the Navy Aircrew Common Ejection Seat (NACES), includingfunctional description, physical description, component identification, andmaintenance concepts.

The incorporation of the Navy Aircrew Com-mon Ejection Seat (NACES) in Navy aircraft re-presents a significant improvement in ejection-seatdesign that takes advantage of the latest escapesystem technology. The NACES system gives theaircrew improved chances for escape in all ejectionsituations, reduced potential for injury, extendedpreventive maintenance intervals, and a significantreduction in life-cycle costs. This Martin-Bakerejection seat will be fitted to the new GrummanF-14D Tomcat, the McDonnel Douglas/BritishAerospace T-45A Goshawk two-seat trainer, andthe McDonnel Douglas F/A-18C and D aircraft.

The purpose of the common ejection seat isto ease the logistics and maintenance problems onthe Navy’s inventory of aircraft. The new seat willincrease the standardization and reliability ofaircraft emergency escape and aircrew and groundcrew training. The electronically controlledNACES represents the state-of-the-art in escapesystem technology, and it has been selected as thefuture standard of the U.S. Navy. The NACESseries was engineered from the outset for futuregrowth potential. The ejection seat is designed forsimple reprogramming or modification to ensurethat it maintains current technology.

As a senior AME, you already have the prere-quisite knowledge and experience to understandejection seat theory. New ideas have beenincorporated into the NACES. Now all that isrequired is your willingness to learn these newideas so that NACES characteristics become asfamiliar as previous Martin-Baker ejection seats.

SYSTEM DESCRIPTION ANDCOMPONENTS

Learning Objective: Recognize the func-tional and physical description of the NA-CES and the components within the system.

The NACES system uses a flexibleconfiguration to meet the exact requirements ofthe crew station designer. Although this is acommon ejection seat, the designator number forthe seat versus aircraft types are different, asshown below.

SEAT TYPE AIRCRAFT-LOCATION

1. SJU-17(V)1/A F/A-18C, F/A-18D, rear cockpit

2. SJU-17(V)2/A F/A-18D, front cockpit

3. SJU-17(V)3/A F-14D, rear cockpit

4. SJU-17(V)4/A F-14D, front cockpit

5. SJU-17(V)5/A T-45, rear cockpit

6. SJU-17(V)6/A T-45, front cockpit

Although the physical description may differbetween the seats used in the F-14D as comparedto the F/A-18 and T-45 (fig. 5-1), the functionsof all the seats are the same. In this chapter wewill use the F/A-18 ejection seat to discuss systemdescription, operation, function, and componentidentification.

FUNCTIONAL DESCRIPTION

WARNING

The emergency escape system incorporatesseveral explosive cartridges and rocketscontaining propellant charges. Inadvertentfiring of any of these may result in seriousor fatal injury to personnel on, or in thevicinity of, the aircraft.

5-1

Figure 5-1.-Forward ejection seat; (A) right-hand view, (B) left-hand view.

Ejection control handle safety pins andsafe/armed handles are provided to renderthe ejection seats safe when the aircraft isparked between flights and at all othertimes on the ground. The ejection controlhandle safety pins are removed by theaircrew before flight and installed by theplane captain after flight. Movement of thesafe/armed handle is the responsibility ofthe aircrew.

Before entering the cockpit, personnelshould ensure that the correct safetyprecautions have been applied.

The F/A-18 aircraft is equipped with a typeSJU-17(V)1/A ejection seat. The F/A-18D

aircraft is equipped with a type SJU-17(V)2/A anda type SJU-17(V)1 /A ejection seat installed in theforward and aft cockpits, respectively. The seatsare interconnected by a command sequencingsystem. The two types of seat are essentially thesame, but with differences to suit the two cockpitinstallations. For convenience, the description thatfollows applies equally to both ejection seats,except where noted. Where reference is made tothe aft seat configuration on the F/A-18D, thedescription applies equally to the single seat(F/A-18C) installation.

All NACES seats incorporate fully automaticelectronic sequencing and are cartridge operatedand rocket assisted. Safe escape is provided formost combinations of aircraft altitude, speed,attitude, and flight path within the envelope of

5-2

Figure 5-1.-Forward ejection seat; (A) right-hand view, (B) left-hand view—Continued.

zero speed, zero altitude in a substantially levelattitude to a maximum speed of 600 knotsestimated air speed (KEAS) between zero altitudeand 50,000 feet.

Ejection is initiated by pulling a seat firinghandle situated on the front of the seat bucketbetween the occupant’s thighs. The parachutecontainer is fitted with canopy breakers to enablethe seat to eject through the canopy should thejettison system fail. After ejection, droguedeployment, man/seat separation, and parachutedeployment are automatically controlled by anonboard multimode electronic sequencer. Abarostatic harness release unit caters for partialor total failure of the electronic sequencer, andan emergency restraint release (manual override)

system provides a further backup infailure of the barostatic release.

the event of

The seat is ejected by action of the gas pressuredeveloped within a telescopic catapult when thecartridges are ignited. An underseat rocket motorsituated under the seat bucket is fired as thecatapult reaches the end of its stroke, and sustainsthe thrust of the catapult to carry the seat to aheight sufficient to enable the parachute to deployeven though ejection is initiated at zero speed, zeroaltitude in a substantially level attitude. The seatis stabilized and the forward speed retarded bya drogue and bridle system, followed by automaticdeployment of the personnel parachute andseparation of the occupant from the seat. Timingof all events after rocket motor initiation is

5-3

controlled by the electronic sequencer, which usesaltitude and airspeed information to select thecorrect mode of operation.

PHYSICAL DESCRIPTION

Each ejection seat, as installed in the aircraft,consists of five main assemblies. Each assemblyis briefly described in the following paragraphs:(See figure 5-2.)

1. The catapult assembly is the means bywhich the ejection seat is secured to the aircraftstructure during normal flight, and provides theinitial force necessary to eject the seat from theaircraft during emergency conditions. The catapultassembly includes the barrel, ballistic latches, thepiston, and the catapult manifold valve.

2. The main beams assembly includes thetop and bottom crossbeams, top latch assembly,shoulder harness control handle, parachutedeployment rocket motor, electronic sequencer,

barostatic release unit, drogue deploymentcatapult, two multipurpose initiators, time-delaymechanism, two pitot assemblies, two ballisticmanifolds, and two thermal batteries.

3. The seat bucket assembly includes theunderseat rocket motor, lateral thrust motor,ejection control handle, safe/armed handle, legrestraint snubbers, emergency restraint releasehandle, shoulder harness control lever, seat heightactuator switch, pin puller, and lower harnessrelease mechanism.

4. The parachute assembly includes theparachute container and parachute canopy anddrogue.

5. The seat survival kit assembly includes thelid assembly, emergency oxygen system, radiolocator beacon, and rucksack assembly.

Catapult Assembly

The catapult assembly (figs. 5-3 and 5-4)secures the ejection seat to the aircraft structure

Figure 5-2.-Forward ejection seat main assemblies.

5-4

Figure 5-3.-Catapult assembly, forward seat.

5-5

Figure 5-4.-Ejection gun initiator (JAU-56/A) and catapultmanifold valve.

and provides the initial power for the ejection ofthe seat. The catapult consists of an outer barreland an inner telescopic piston. The barrel isattached to the aircraft structure, and the pistonand barrel are engaged at the top end by the toplatch plunger installed in the main beamsassembly.

The catapult assembly is operated by explosivecharges. Assembly operation is discussed later inthis chapter.

BARREL.— The barrel is a built-up structureconsisting of a light alloy tube to which arepermanently attached top and bottom end fittings.A housing situated towards the bottom endcontains the secondary cartridge. Five bracketssupport two guide rails bolted on the outboardsides of the tube. The bottom end fittingincorporates the lower mounting bracket forattaching the catapult to the aircraft and studs forattachment of the ballistic latches.

The upper mounting consists of a bracketclamped on the barrel towards the upper end. Itincorporates an interference shoulder on one side

to ensure location of the catapult in the correctcockpit (fig. 5-5). An interference arm mountedon one of the guide rail brackets ensures that thecorrect main beams assembly is installed. Acrossbeam secured to the barrel provides ananchorage point for the RH ballistic manifoldquick-disconnect lanyard. The top end fitting ofthe barrel has a square aperture, the barrel latch,through which the plunger of the top latchmechanism fitted on the seat main beam protrudeswhen the seat is installed on the catapult. A guidebushing, fitted in the internal diameter of the topend fitting, is secured by three dowel screws; atthe end of the catapult stroke, the dowel screwsare sheared by the head of the piston striking theguide bushing. The piston then separates from thebarrel, and the guide bushing remains on thepiston (fig. 5-3).

BALLISTIC LATCHES.— Two ballisticlatches are attached to the bottom end fitting bystuds and nuts. Each latch comprises a body,which is internally drilled to form a cylinder andcontains a spring-loaded piston. When operatedduring the ejection sequence, gas pressure fromwithin the catapult acts on the latch pistons,

Figure 5-5.-Interference devices, forward and aft seats.

5-6

overcoming the springs and retaining the multi-purpose initiator lanyard spigots (fig. 5-3).

PISTON.— The piston consists of a light alloytube, attached to the lower end of which is anecked end fitted with piston rings to provide agas seal between the piston and the barrel. At theupper end of the piston is a breech, into whichthe cartridge-activated initiator is inserted. Thebreech has a groove machined around its outerdiameter, into which the plunger of the top latchmechanism on the seat main beams engages whenthe seat is installed on the catapult. A V-groovein the top of the breech engages a dowel on theseat top crossbeam when the seat is installed inthe aircraft (fig. 5-3).

CATAPULT MANIFOLD VALVE.— Thecatapult manifold valve provides an interfacebetween the ejection seat and the catapult. Thecatapult manifold valve is mounted on the top ofthe catapult. The valve is locked onto thecartridge-activated initiator by a spring-loadedplunger and a retaining pin. The valve containstwo inlet ports that connect the hoses from thetime delays.

Main Beams Assembly

The main beams assembly is manufacturedalmost entirely from light alloy and comprises twoparallel main beams bridged by top and bottomcrossbeams. Bolted to the inside face of each mainbeam are three slippers, which engage in the guiderails on the catapult. Two-seat bucket runnerguides are attached to the front face of each mainbeam and accommodate the top and bottom seatbucket slippers. The slippers provide smoothmovement of the seat bucket and incorporatethreaded studs for attachment of the seat bucketto the main beams. Friction pads are incorporatedin the studs to damp out lateral movement of theseat bucket. Drogue bridle retaining channels aresecured to the rear of both main beams. Locatingpins for the parachute container hooked bracketsare bolted to the upper outside face of each mainbeam. Interference blocks on the right-hand (RH)beam (forward seat) or left-hand (LH) beam (aftseat) correspond with interference devices on thecatapult and the seat bucket to ensure that onlythe correct assemblies are installed in forward andaft cockpits.

TOP CROSSBEAM.— The top crossbeamaccepts and locates the top of the catapult, and

takes the full thrust of the catapult duringejection. Incorporated into the crossbeam is theupper drogue bridle release unit. A dowel in thetop crossbeam locates in one of the catapultbreech V-grooves when the seat is installed in theaircraft.

BOTTOM CROSSBEAM.— The bottomcrossbeam retains and separates the main beamsat the bottom end. Incorporated into thecrossbeam is a gas passage that forms part of thedrogue bridle release system.

TOP LATCH ASSEMBLY.— The seatstructure is secured to the catapult by the top latchassembly (fig. 5-6) fitted to the LH main beam.The assembly consists of a housing that containsa spring-loaded latch plunger, one end of whichis shaped to engage the catapult piston. Theplunger may be withdrawn by using the top latchwithdrawal tool (handwheel). Passing through thecenter of the latch plunger is a spring-loadedindicator plunger. When the ejection seat is fitted

Figure 5-6.-Operation of top latch assembly.

5-7

Figure 5-7.-Shoulder harness control system.

5-8

to the catapult and the handwheel removed, thelatch plunger passes through the top crossbeamand engages with the barrel latch. The shaped endof the plunger protrudes still further to engagethe groove of the catapult piston.

SHOULDER HARNESS CONTROL HAN-DLE.— The shoulder harness control handle (fig.5-7) is located on the left side of the seat bucket.The handle is connected to the inertia reel. In theaft position, the reel is allowed to rotate freely.When the forward position is selected, straps willratchet in, allowing no forward movement.

SHOULDER HARNESS REEL.— Theshoulder harness reel (fig. 5-8, view A) is fittedhorizontally across the front faces of the mainbeams and serves as a center crossbeam for themain beams assembly, as well as a means ofsecuring the upper harness. It ensures that theoccupant will be brought to, and locked in, thecorrect posture for ejection. For normal flightoperations, the shoulder harness is free to extendand retract as the occupant moves in the ejectionseat. The shoulder harness control lever on theLH side of the seat bucket can be moved to theforward (locked) position, which will permit the

Figure 5-8.-View A, shoulder harness reel; view B, shoulder harness reel, sectioned view.

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harness straps to retract but prevent them fromextending. When in the normal unlocked state,automatic locks protect the occupant against rapidforward movement under high g-loading.

PARACHUTE DEPLOYMENT ROCKETMOTOR MK 122 MOD 0.— The parachutedeployment rocket motor (PDRM) (fig. 5-9) ismounted on the LH main beam of the seat. Wheninitiated by the sequencer, restraint release unit,or manual override (MOR) system, the PDRMextracts the personnel parachute from its stowageby means of a withdrawal line attached to thedeployment sleeve.

The PDRM is a sealed unit. It consists of acylindrical body that contains a gas-operatedsecondary cartridge in a breech at the lower endand a rocket with an integral gas-operated ignitercartridge in a barrel at the upper end. In a parallelconnected chamber is an electrically initiatedprimary cartridge. A gas inlet is connected by agas pipe to the harness release system.

Figure 5-9.-Parachute deployment rocket motor (Mk 122Mod 0).

Fitted around the rocket is a sliding stirrup,which is connected to the parachute withdrawalline and is free to slide down the rocket as it leavesthe barrel.

ELECTRONIC SEQUENCER.— The NACESsequencer assembly (fig. 5-10) is composed of thesequencer, connectors to the interface with pitotstatic and dynamic pressure sources, and cableloom sleeving. It is mounted across the main beamassembly, below the parachute assembly. Uponactivation, the sequencer determines the ejectionmode and controls the functions of the droguerelease, parachute deployment, and seat/manseparation.

BAROSTATIC RELEASE UNIT (BRU).—The barostatic release unit (fig. 5-11) provides ahousing for the cartridge that provides the gasflow to initiate harness release and parachuterocket deployment. The cartridge is activatedeither electrically by the sequencer or by the right-hand start switch (via the delay mechanism). Thecartridge incorporates an aneroid capsule toprevent mechanical initiation above a presetaltitude. The cartridge may also be initiated byoperation of the MOR handle after ejection.

Figure 5-10.-Electronic sequencer.

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Figure 5-11.-Barostatic release unit.

Barostat Assembly.— The barostat consists operating. As altitude decreases, the capsuleof an aneroid capsule in a housing that is screwed peg retracts and allows the mechanism tointo the release unit in a position that allows function.a peg attached to the capsule to engage a starwheel in the delay mechanism. At altitudes in Impulse Cartridge. — The impulse cartridgeexcess of the barostat rating, the peg engages the (CCU-102/A) provides the gas necessary for thestar wheel and prevents the delay mechanism from functions of the restraint release assembly.

5-11

DROGUE DEPLOYMENT CATAPULT.—The drogue deployment catapult (fig. 5-12) ismounted outboard of the RH main beam of theejection seat. Its function is to deploy thestabilization drogue and bridle assembly rapidlywithout becoming entangled with the seat. Thefiring of the drogue deployment catapult iscontrolled by the electronic sequencer to ensurethat the seat has cleared the aircraft before thedrogue is deployed. The drogue deploymentcatapult consists of a cylindrical body containingan electrically operated impulse cartridge(CCU-101/A), a two-piece telescopic pistonassembly, and an enlarged upper end, into whichis fitted a drogue and canister assembly.

The drogue and canister assembly contains a1.45mm (57-inch) diameter ribbon drogue,pressure packed into a 210mm (8.25-inch) longlight alloy cylinder, closed at the upper end. Thecanister assembly is closed by an end cap attached

to the drogue strap. At the lower end of the endcap, a link assembly is attached by the same boltthat secures the drogue strap. When installed onthe ejection seat, the link assembly attaches to thedrogue bridle, and the canister assembly isretained in the body by a threaded locking ring.At the upper end of the catapult body is riveteda threaded ring on to which the locking ring isscrewed when installing the drogue canister.

MULTIPURPOSE INITIATORS.— Twomultipurpose initiators (IMP) (fig. 5-13) areattached to the lower outer faces of the seat’s mainbeams. During the ejection sequence, the IMPssupply gas pressure to operate the barostaticrelease unit delay mechanism, the underseat rocketmotor, the pitot deployment mechanisms, and theinternally mounted start switch assemblies.

Each IMP comprises a body, machined anddrilled to accept a start switch, a static lanyard

Figure 5-12.-Drogue deployment catapult.

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Figure 5-13.-Multipurpose initiator, left-hand.

assembly, a spring-loaded firing pin, and animpulse cartridge. A gas passage through the unitbody connects the cartridge breech to the lowerend of the start switch plunger. Incorporated intothe unit body, but mechanically separate, is alower drogue bridle release unit.

The static lanyard assembly comprises alanyard, precoiled into a cylindrical container andwith special fittings swaged on to each end. Theupper end fitting incorporates a wedge-shapeddisconnect device, which engages with the lowerend (similarly wedge-shaped) of a spring-loadedfiring pin positioned below the cartridge. Thelower end fitting protrudes through the lower endof the body and is retained by a shear pin. Whenthe seat is installed on a catapult, the protrudinglower end fitting locates in one of the catapult-mounted ballistic latches.

The start switch assembly is installed verticallyand comprises a series of metal sleeves and

insulated sections to form an electrical switchassembly. An internal plunger is partially sleevedwith insulating material, has a short gold-platedsection, and incorporates a piston head at its lowerend. Movement of the plunger before operationis prevented by a shear pin. Two start switchassemblies are incorporated into the multipurposeinitiators. During ejection, the start switchessupply a start signal to the sequencer at the correcttime in the sequence.

The impulse cartridge is percussion operatedby the firing pin and is screwed into a breech atthe upper end of the body. A gas gallery machinedin the upper part of the cartridge ensures evendistribution of gas pressure when the cartridgefires.

TIME-DELAY MECHANISM.— The time-delay mechanism consists of a spring-loaded rackassembly in mesh with a gear train controlled by

5-13

Figure 5-14.-Pitot assembly, right-hand.

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an escapement. The gear train consists of aprimary spur and pinion, a secondary spur andpinion, an idler wheel, an escapement wheel andan escapement rocker.

The rack assembly consists of a rack endscrewed into a slotted end. The two componentsare secured together with a locking screw. Theupper end of the rack end is shaped to form afiring pin.

To retain the rack in the cocked position, oneface of a pawl in the bottom housing engages inthe slotted end of the rack assembly. Another faceof the pawl engages in a groove in a gas-operated

Figure 5-15.-Pitot assembly, operation.

piston installed in a housing attached to the lowerpart of the unit body. The piston is retained inposition by a frangible disc.

PITOT ASSEMBLIES— Two pitot assemblies(figs. 5-14 and 5-15) incorporating deployablepitot heads are mounted on the main beamsbehind the parachute container. Removablecovers are provided to prevent entry of foreignbodies,

The pitot heads are maintained in the stowedposition by locking mechanisms that are releasedduring seat ejection, as the seat separates fromthe catapult, by gas pressure from themultipurpose initiator cartridges. When deployed,the pitot head assemblies supply dynamic pressureinputs to the electronic sequencer. Static (base)pressure is supplied to the sequencer from thevoids within the LH and RH main beams.

Each pitot assembly comprises a body, drilledand plugged to form a series of gas passages, andtwo cylinders containing upper and lower pistons.A deployable pitot arm incorporating a pitot headis attached to the aft face of a bracket, formingpart of the body. Attached to the forward faceof the bracket is a pitot connector that isconnected to the pitot head. A spring-loadedlocking plunger, which locates in one of two holesin the body, is installed inside the lower end ofthe pitot arm. The locking plunger locks the pitotarm in the stowed or deployed positions. Aseparate passage in the body, incorporatingconnectors at each end and a filter, forms partof the static pressure supply system for thesequencer.

BALLISTIC MANIFOLDS.— There are twoballistic manifold assemblies-right-hand and left-hand.

Manifold Assembly Right-Hand.— The right-hand (RH) assembly is a gas distribution centerthat is connected to the seat bucket trombonetubes and incorporates the upper harness releasepiston, the ejection gas line quick disconnect, anda housing for the bridle release cartridge. Theassembly also provides a mounting for a delaycartridge. The drogue bridle release impulsecartridge is installed in a threaded housingon the upper face. The upper harness releasepiston protrudes from the manifold upper face.

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The lower face of the RH ballistic manifold(fig. 5-16) has four connectors. Two of theseconnectors accommodate the RH seat initiationtrombone tube (outboard) and the harness locksto release the trombone tube (inboard). Theconnections are secured by a key-operated, quick-release pin that passes through a hole in themanifold and cutouts in the trombone tubes. Theother two connectors accommodate the gas pipefrom the barostatic release unit and the gas pipeto the lower drogue bridle release mechanisms.

Manifold Assembly Left-Hand.— The left-hand (LH) assembly is a gas distribution centerthat is connected to the seat bucket trombonetubes and houses a seat rocket initiation systemcheck valve. The assembly also provides amounting for a delay cartridge.

The upper face of the LH ballistic manifold(fig. 5-17) has three socket connectors, to whichare connected a flexible hose to the LH pitotdeployment mechanism, a rigid pipe from the

RH multipurpose initiator, and a delay initia-tor.

The lower face of the LH ballistic manifoldhas three socket connectors. Two of theseconnectors accommodate the LH seat initiationtrombone tube (outboard) and the underseatrocket motor trombone tube (inboard). The otherconnector accommodates a gas pipe to the thermalbatteries. A bracket on the front face of themanifold accommodates the shoulder harnesscontrol mechanism torque shaft. A connection onthe aft face accepts a gas pipe from the LHmultipurpose initiator.

THERMAL BATTERIES.— Two thermalbatteries (fig. 5-18) supplying power for sequenceroperation are mounted together in a manifold onthe LH main beam.

Seat Bucket Assembly

The seat bucket assembly (fig. 5-19) fits ontothe lower portion of the main beams and

Figure 5-16.-Right-hand ballistic manifold.

5-16

Figure 5-18.-Thermal battery assembly.

Figure 5-19.-Seat buckets to main beams.

5-17

Figure 5-17.-Left-hand ballistic manifold,(F/A-18D).

mechanisms and provides a mounting for thesurvival kit assembly, rocket motor, and backpadassembly. The seat bucket assembly is configuredfor a particular seat by adding application-peculiar components, such as a seat heightactuator. The bucket is secured by four nuts tostuds incorporated into sliding runners on theseat’s main beams. Interference devices on the rearof the seat bucket and on the main beamsassembly ensure that only the correct seat bucketis installed in forward and aft cockpits.

The back of the seat bucket contains a rigid,molded pad that forms the back rest. It iscontoured so that when the seat occupant isautomatically pulled back by the shoulder harnessreel when ejection is initiated, he/she assumes thecorrect posture. A cushion attached to thebackrest provides additional comfort for the seatoccupant.

Contained within the lower rear corners of theseat bucket are the lower harness locks and releasemechanism. These are connected by a cross shaftand connecting links to the leg restraint line lockslocated in the side plates. The same connectinglinks connect the negative-g strap lock that issituated in the floor of the seat bucket to the rearof the seat firing handle. Half way up the innerface of the seat bucket sides are sticker clips. Thepin puller is mounted at the rear of the seat bucketon the lower right-hand side (fig. 5-2).

UNDERSEAT ROCKET MOTOR.— Theunderseat rocket motor (fig. 5-20) is a sealed unitand consists of a manifold (machined, drilled, andthreaded to accept ten propellant tubes), a lateralthrust motor tube, a cartridge tube, and fourefflux nozzles. The propellant tubes are

Figure 5-21.-Operating controls.

Figure 5-20.-Underseat rocket motor Mk 123 Mod 0 (forward seat).

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manufactured from seamless steel. The tubescontain solid propellant drilled lengthwise throughthe center and having three equally spaced ribsto provide rapid and even burning. A cross-shapegrid is positioned between the propellant and themanifold to ensure that the gas generated can passunrestricted to the manifold. The cartridge tubeis internally threaded to accept a gas-operatedigniter cartridge incorporating twin firing pins andtwin primers. A lateral thrust motor with anintegral cartridge is screwed into the manifold atthe LH end (forward seat) or RH end (aft seat).The efflux nozzles are fitted under the manifoldand are sealed at the inner end by flanged blow-out discs, which cause a pressure build-up toensure rapid and even burning of the propellantand an even thrust from the motor. Threadedholes in the manifold end plugs and a steadybracket clamped to the lateral thrust motor areused to secure the motor under the seat bucket,The threaded holes in the manifold end plugs varyin size between forward and aft seats to ensurelocation in the correct cockpit.

LATERAL THRUST MOTOR.— The lateralthrust motor (fig. 5-20) forms an integral part ofthe main rocket motor, being screwed into themanifold. An igniter cartridge is initiated by gaspressure from the rocket motor propellant andignites the propellant in the lateral thrust motorto permit a divergent trajectory to the ejectedseat.

EJECTION CONTROL HANDLE.— Theejection control handle (figs. 5-21 and 5-22) islocated on the front of the seat bucket. It is theonly means by which ejection can be initiated. Thehandle is molded in the shape of a loop, and isconnected to the sears of the ejection seatinitiators. The seat initiators have two rigid linesthat connect to the trombone fittings. An upwardpull of the loop removes both sears from the dualinitiators to initiate ejection. Either initiator canfire the seat. After ejection the handle remainsattached to the seat. The ejection control handleis safetied by using the ejection seat safe/armhandle and safety pin.

Figure 5-22.-Ejection control handle.

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Figure 5-23.-Locations of safety devices.

5-20

SAFE/ARMED HANDLE.— The SAFE/ARMED handle (figs. 5-21 and 5-23) is located onthe RH side of the seat bucket immediatelyforward of the emergency restraint release handle.Contained within the handle is a catch that locksthe handle in either the ARMED or SAFEposition. The handle is connected to a linkage thatterminates in a safety plunger, which passesthrough the link of the ejection control handlewhen the handle is in the SAFE position andprevents operation of the ejection controlhandle. When in the ARMED position, the visibleportion of the handle is colored yellow andblack stripes and engraved ARMED; when inthe safe position, the visible portion is coloredwhite and engraved SAFE. An electrical visual

SAFE/ARMED indicator is incorporated inthe cockpit central warning panel, and is operatedby a microswitch actuated by the safety plunger.

LEG RESTRAINT SNUBBERS.— Two legrestraint line snubbers (fig. 5-24), each with a legrestraint line, are attached to the front face of theseat bucket. Release of the leg restraint linesnubbers to adjust the leg lines is effected bypulling inboard on the fabric loops attached tothe release plungers on the inboard side of eachsnubber. The leg restraint lines taper plugs aresecured in locks positioned on the seat bucket sideplates.

EMERGENCY RESTRAINT RELEASEHANDLE.— The emergency restraint release

Figure 5-24.-Leg restraint system.

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handle (figs. 5-21, 5-25, and 5-26) is connected the thumb button allows the handle to be rotatedby two link assemblies to the lower harness lock rearward. Operation of the handle when the seatrelease mechanism and to a firing mechanism is installed in the aircraft is restricted by the pinhoused in the rear lower RH side of the seat puller, and releases only the lower torso restraintbucket. The handle is locked in the down position and leg restraint lines to permit emergency groundby a catch operated by a thumb button situated egress. On ejection, the pin puller is automaticallyat the forward end of the handle; depression of disengaged from the handle operating link.

Figure 5-25.-Emergency restraint release system.

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Operation of the emergency restraint releasehandle simultaneously operates the SAFE/ARMED handle to the SAFE position. In theevent of automatic sequence failure, operation ofthe emergency restraint release handle subsequentto ejection will fire a cartridge to operate the upperand lower harness locks and the parachutedeployment rocket motor.

SHOULDER HARNESS CONTROL LEVER.–The shoulder harness control lever (fig. 5-21) isattached to the LH side of the seat bucket andis connected to the shoulder harness reel. Whenthe lever is in the forward position, the shoulderharness reel is locked, preventing all forwardmovement of the seat occupant. When moved tothe rear position, the seat occupant is free to moveforward and backward. Should the seat occupantmove forward rapidly, however, the shoulderharness reel will lock and remain locked until theload on the webbing straps is eased.

SEAT HEIGHT ACTUATOR SWITCH.—The seat height actuator switch (fig. 5-21) is

situated immediately forward of the shoulderharness control lever. Forward movement ofthe switch toggle lowers the seat bucket, andrearward movement raises the seat bucket. Whenreleased, the toggle assumes the center OFFposition.

PIN PULLER.— The pin puller (figs. 5-25 and5-26) is installed on the aft right side of the seatbucket. Full aft rotation of the manual overridehandle is prevented by the pin puller. A pinextended from the pin puller engages a slot in themanual override linkage. During the ejectionsequence, gas pressure from the right-hand seatinitiator cartridge retracts the pin.

LOWER HARNESS RELEASE MECHA-NISM.— The lower harness release mechanism(fig. 5-26) includes the two lower harness locks,the two leg restraint line locks, the negative-g straplock, the emergency restraint release pistonhousing, and associated connecting levers andlinkages.

Figure 5-26.-Lower harness release mechanism.

5-23

Parachute Assembly

The parachute assembly (fig. 5-27) comprisesa 6.2m (20-foot) GQ type 2000 personnel para-chute packed, together with a ribbon drogue, intoa rigid container and connected to the parachuterisers. The parachute risers incorporate seawateractivated release switches (SEAWARS) forattachment to the upper torso harness. Theseswitches will automatically release the occupantfrom his/her parachute following descent intoseawater. The parachute assembly is attached tothe upper forward face of the ejection seat mainbeams. Some seats may contain the GQ-5000type parachute, depending on date of manu-facture.

PARACHUTE CONTAINER.— The para-chute container is of light alloy construction, with

canopy breakers fitted to each upper outboardside. The breakers on the forward seat are longerthan those on the aft seat. Two hooked bracketson the lower rear face of the container locate overpins on the main beams. Brackets, integral withthe rear of the canopy breakers, are bolted tobrackets on the main beams. A shaped headpadis attached to the front face of the container toprovide head location during ejection. A hook andpile fastener is fitted to the front face of theheadpad to locate the parachute risers. Thecontainer is closed by a rigid top cover, with asingle lug on the RH side and two lugs on the LHside. The LH lugs deform during parachuteextraction, releasing the cover to permit rapidparachute deployment. A fairing on the LHrear corner of the cover protects the para-chute withdrawal line where it leaves thecontainer.

Figure 5-27.-Parachute assembly, forward seat.

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PARACHUTE CANOPY AND DROGUE.—The parachute canopy incorporates a crownbridle, at the apex of which is attached, via a shortstrap, a 1.5m (60-inch) ribbon drogue. Theparachute canopy and drogue are packed,drogue first, into a deployment bag, the closedend of which is attached via a withdrawal lineto the stirrup on the parachute deployment rocket.

Seat Survival Kit Assembly

The survival kit assembly (fig. 5-28) fits intothe seat bucket and comprises a contoured rigidplatform (lid assembly), to which are attached anemergency oxygen system and a fabric survivalpackage. A cushion on top of the platform pro-vides a firm and comfortable seat for the occupant.

The lid assembly is a rigid platform thatincorporates the emergency oxygen system and lapbelts. The lid assembly also provides stowage forthe radio beacon and mountings for the rucksackassembly. The lid assembly is retained in positionin the seat bucket by brackets at the front and lugssecured in the lower harness locks at the rear,Attached to the lugs are two adjustable lap beltswith integral quick-release fittings.

EMERGENCY OXYGEN SYSTEM.— Anemergency oxygen cylinder, a pressure reducer,and associated hardware are mounted on theunderside of the lid assembly. A green manual-operating handle is mounted on the LH side ofthe assembly, and a cylinder contents gauge is onthe inside face of the left-hand thigh support. The

Figure 5-28.-Seat survival kit assembly; (A) top view; (B) bottom view.

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emergency oxygen system is automaticallyactivated during ejection by a lanyard connectedto the cockpit floor. An oxygen/communicationshose is connected to unions on the LH rear topof the lid assembly, and provides connectionsbetween the seat occupant and the aircraft andsurvival kit systems.

RADIO LOCATOR BEACON.— A URT-33A radio locator beacon is located in a cutoutin the left thigh support. The beacon is actuatedduring ejection by a lanyard connected to acommon anchorage point with the emergencyoxygen lanyard.

RUCKSACK ASSEMBLY.— The rucksackassembly is attached to the underside of the lidassembly by five fabric straps and a double coneand pin release system. The rucksack contains alife raft and the survival aids. Yellow manualdeployment handles mounted on the kit enablethe occupant to deploy the rucksack and contentsonto a lowering line after seat/man separation.The LRU-23/P life raft inflates automatically onrucksack assembly deployment.

COMPONENT OPERATION

The operation of each component andsubsystem is discussed in the followingparagraphs. The operation of the system as awhole is discussed later in the chapter.

Catapult Assembly

Explosive charges are contained in an ejectiongun initiator, JAU-56/A (figs. 5-3 and 5-4), anda secondary cartridge. Gas pressure from the seatfiring system or the aircraft command sequencingsystem operates twin firing pins in the ejection guninitiator to fire the explosive charge.

Gas enters the manifold valve through one orboth of the inlet ports, depresses the check valves,and passes down through the vertical bore intothe initiator. Gas pressure acts upon the twinfiring pins in the initiator, shearing the shear pinsand forcing the firing pins down to strike thepercussion caps and ignite the explosive filling.The gas pressure generated within the catapult—

1. Passes to the ballistic latches to operate thepistons, which retain the multipurpose initiatorstatic lanyards.

2. Propels the catapult piston upwards.The initial movement of the piston forces the

spring-loaded top latch plunger out of the breechgroove back into the barrel latch (fig. 5-4). Thepiston continues to rise, thrusting against the topcrossbeam of the seat, the upward movementcausing the shaped end of the top latch plungerto ride out of, and disengage from, the barrellatch. Further upward movement of the pistonuncovers the secondary cartridge, which is firedby the pressure and heat of the initiator gas. Afterapproximately 38 inches (965mm) of travel, thepiston head strikes the guide bushing and shearsthe three dowel screws. After a further 4 inches(101mm) of travel, the piston separates from thebarrel and moves away with the ejected seat.

Main Beams Assembly

The main beams assembly supports the majorcomponents of the ejection seat. The operationof the components supported by the main beamsassembly is discussed in the following paragraphs.

SHOULDER HARNESS CONTROL SYS-TEM.— When the ejection control handle ispulled, gas from the RH seat initiation system ispiped into the breech to operate the cartridge. Thegas also passes to the operating piston in thegovernor housing, forcing it upwards to operatethe trip lever and bring the locking pawl intocontact with the ratchet wheel.

The gas from the impulse cartridge in thebreech impinges on the end of the piston forcingit along the cylinder. Horizontal movement of thepiston is transmitted via the threaded drive screwto rotate the splined shaft, spool assemblies, andratchet wheel, which winds in the webbing strapsto pull back and restrain the occupant’s shoulders.The engaged locking pawl locks the spools in therestrained position.

Withdrawal of the webbing straps at excessivespeed causes the two governor pawls to rotateoutwards under centrifugal force and engage theteeth on the housing, preventing rotation of thesplined shaft and spool assemblies and furtherwithdrawal of the straps. This system prevents theoccupant from being thrown forward on crashlanding or sudden deceleration if the shoulderharness control lever is in the disengaged position.Easing of tension on the webbing straps allowsthe pawl springs to reassert themselves anddisengage the pawls from the teeth, permitting freewithdrawal of the straps again.

PARACHUTE DEPLOYMENT ROCKETMOTOR.— Upon seat ejection, gas pressure from

5-26

the primary and secondary cartridges passes to therocket igniter cartridge to fire the rocket, shearingthe flange of the rocket igniter cartridge. As therocket moves upward, the stirrup slides down therocket and aligns itself directly below the thrustaxis line to extract and deploy the personnelparachute.

In the event of sequencer failure, gas enteringthe unit through the gas inlet ports from theharness release unit cartridge or the emergencyrestraint release cartridge will initiate thesecondary cartridge to face fire the primary.

ELECTRONIC SEQUENCER.— When theejection seat is fired, two onboard thermalbatteries are immediately energized, supplyingusable electrical power to the sequencer after just100 milliseconds, with the seat having travelledabout 5 inches up the ejection catapult. Thesequencer’s microprocessors then run through aninitialization routine, and by 120 milliseconds thesequencer is ready and waiting to perform.

As the seat rises from the cockpit, two steelcables (approximately 42 inches) are pulled fromthe multipurpose initiators, actuating twopyrotechnic cartridges. The gas generated by thesetwo cartridges is piped around the seat to performthe following functions:

Initiate the underseat rocket motor.

Deploy the pitot tubes from the sides ofthe seat headbox.

Close two electrical switches (sequencer“start” switches).

The sequencer responds to the closure of eitherstart switch by changing to the “ejection” mode.The switch starts an electronic clock, and all sub-sequent events are timed from this point. In theabsence of a start switch signal, the sequencer willsimply continue in the “wait” mode. This modeis a safety feature designed to ensure that thedrogue and parachute can only be deployed afterthe seat has physically separated from the aircraft.

The ignition of the underseat rocket motor istimed to occur just as the seat separates from theejection catapult, at about 200 milliseconds, soas to maintain a uniform vertical accelerationprofile on the seat and occupant. The motor hasa burn time of 250 milliseconds. Once thesequencer is switched into the “ejection” mode,its first action is to electrically fire the droguedeployment canister, which occurs precisely 40

milliseconds after start switch (approximately 220milliseconds from seat initiation), while the seatrocket motor is burning. This happens regardlessof the speed and altitude conditions.

The sequencer then enters its most crucialperiod, when it will sense the seat’s airspeed andaltitude and choose the appropriate timings froma set of five available sequences. This is doneduring a 60 millisecond “environmental sensingtime window” that starts just after the droguecanister is fired, and is completed before thedrogue is fully deployed and pulling on the backof the seat. The sequencer measures the speed andaltitude from the information it receives fromthree types of sensor: pitot pressure, basepressure, and accelerometer.

Several samples of each parameter aretaken during the environmental window. Theseare used to determine the ejection conditions.The sequencer then selects the appropriatetimings for the remaining events, knownas “mode selection,” and completes the se-quence accordingly.

Overview of Sequencer Electronics andHardware.— The electronic sequencer and itsthermal batteries are packaged in two separateunits. The sequencer and associated electronicsare contained in a cast aluminum enclosure, whichis mounted between the main seat beams directlybeneath the parachute container headbox. A totalof nine shielded cables attached to the housingtransmit electrical signals to and from thesequencer. The input and output actions are asfollows :

Input—

. thermal battery power supply lines (2)

. start switch circuits (2)

output—

drogue deployment canister squib-firecircuit

drogue bridle release squib-fire circuit

parachute extractor squib-fire circuit

seat harness release squib-fire circuit

seat harness release (backup) squib-firecircuit

The sequencer also has air pressure couplingsto connect it to the two pitot pressure tubes onthe headbox and the two base pressure sensingpoints inside the main seat beams. A functional

5-27

block diagram of the electronic circuitry is given provide the optimum seat performance under allin fig. 5-29. ejection conditions, both in terms of maximizing

the survivable escape envelope and minimizing theModes of Operation.— The operational risk of occupant injury. Figure 5-30 shows the five

envelope of the NACES is divided into five zones, zones on the speed versus altitude chart, andeach of which is associated with a particular table 5-1 gives the corresponding squib-firetiming sequence, known as modes. These timings timings.

Figure 5-29.-NACES functional block diagram.

Figure 5-30.-Ejection modes.

5-28

Table 5-1.-Squib-Fire Event Times

SQUIB-FIRE EVENT TIMESIN MODES 1 to 5

Altitude (ft) 0—8K 8K—18K 18K+

KEAS 0—350 350—500 500—600 ALL ALLMODE 1 2 3 4 5

1

2

3

4

5

6

7

8

Gas pressure from seat initiator cartridges,delay cartridge or command sequencingsystem initiates catapult and thermal batteries

Start switches close after 39 inches of seattravel

Sequencer supplies dual pulse to fire droguedeployment catapult

Sequencer supplies dual pulse to fire droguebridle release cartridge and release droguebridle

Sequencer supplies dual pulse to fire parachutedeployment rocket

Sequencer supplies dual pulse to fire droguebridle release cartridge and release droguebridle

Sequencer supplies dual pulse to fire barostaticrelease unit cartridge and release harness locks

Sequencer supplies dual pulse to fire barostaticrelease unit cartridge (backup)

0.00 0.00 0.00 0.00 0.00

0.18 0.18 0.18 0.18 0.18

0.22 0.22 0.22 0.22 0.22

Environmental sensingtime window 0.245 — 0.305 seconds

0.32 — — — 4.80 +t(See Note 3)

0.45 1.10 1,30 2.90 4.87 +t

— 1.25 1.45 3.05 —

0.65 1.30 1.50 3.10 5.07 +t

0.66 1.31 1.51 3.11 5.08 +t

All times are references to ejection seat initiation. The start switches operated approximately 0.18 secondsafter initiation. N. B: This is a nominal time. The actual time will vary between 0.13 and 0.19 seconds.

In Mode 5 operation, altitude sensing is to recommence at 4.80 seconds, continuing until fall-through-condition (below 18,000 ft) is detected.

t = time interval between 4.80 seconds and fall-through-condition.

Mode 1 is designed for low-speed/low-altitude deploying drogue and bridle assembly movesejection conditions. The aim is to deploy the main rapidly clear of the seat in readiness for theparachute as soon as practicable after the seat has immediate main parachute deployment.separated from the aircraft. A drogue decelera- Modes 2, 3, and 4 cater for high-speedtion phase is not required so the bridle releases ejections at low and medium altitudes. Theseare operated very quickly, thus ensuring that the ejection conditions require a delay before the

5-29

parachute is deployed, to allow the velocity of theseat to reduce. The stabilizer drogue providesmaximum deceleration while maintaining the seatin the optimum attitude for the occupant. Thesequence timings of modes 2, 3, and 4progressively extend the drogue phase withincreasing speed and altitude so as to ensure thatthe parachute extractor is fired only when the seatvelocity has reduced to a suitable level. The droguebridle is jettisoned shortly after the parachutestarts to deploy, both to avoid an entanglementand to allow the seat to fall clear of the occupant.

Mode 5 is the high-altitude ejection sequence,in which deployment of the main parachute isdelayed until the drogue-stabilized seat fallsthrough the 18,000-feet altitude boundary. Thisallows the occupant to be brought down to a saferatmospheric condition in the shortest possibletime. Once the parachute deployment sequenceis initiated, the seat performs in an identicalmanner to that of modes 2, 3, and 4.

BAROSTATIC RELEASE UNIT (BRU).—When the RH multipurpose initiator cartridgefires during ejection, gas pressure from thecartridge enters the piston housing and moves thepiston upwards, rupturing the frangible disc andallowing the pawl to pivot clear of the rackassembly slotted end. When the altitude is suchthat the barostat is not restraining the mechanism,the rack assembly will rise under the action of itsspring, the rate of ascent being governed by thedelay mechanism. After the delay has elapsed, therack disengages from the gear train and the firingpin rises rapidly to strike the cartridge. If thecartridge has not previously been fired electricallyby the sequencer, the gas produced by the car-tridge passes out of the BRU to operate the upper-and lower-harness locks and the secondarycartridge in the parachute deployment rocketmotor.

DROGUE DEPLOYMENT CATAPULT.—During ejection, the drogue deployment catapultfires and ejects the drogue and canister. As thedrogue deploys, the bridle breaks out of thefrangible container and detaches from thechannels on the main beams. The drogue stabilizesand decelerates the seat. In the high-altitudemode, the seat descends rapidly on the drogue toa predetermined altitude. The drogue bridlereleases then operate, the personnel parachutedeploys, and the occupant separates from the seat.In all other modes, the upper and lower droguebridle releases operate after a short predetermined

delay, as the personnel parachute deploys andseat/man separation occurs.

The impulse cartridge is fired by an electricalsignal from the sequencer. Gas from the cartridgepropels the telescopic piston upwards, shearingthe end cap rivets. Continued movement of thepiston thrusts the canister upwards, shearing therivets in the threaded ring and propelling thecanister and drogue assembly away from the seat.The bridle is pulled from its frangible containerand out of the channels on the seat’s main beams.As the bridle reaches full extension, inertia causesthe canister to fly clear, and the drogue isextracted and deployed to stabilize and deceleratethe seat.

MULTIPURPOSE INITIATOR.— Whenejection is initiated, the catapult ballistic latchesoperate to retain both multipurpose initiatorlanyard spigots. As the seat moves up the guiderails, the static lanyard spigots break the shearpins and the lanyards pay out from the housings.When the lanyards become taut, the upper fittingswithdraw the firing pins against spring pressureuntil the wedge-shaped disconnect devicesseparate. The firing pins move rapidly upwardunder spring pressure to fire the cartridges. Thegas generated passes to the underside of the pistonheads on the start switch plungers. The plungersmove up, shearing the shear pins, until the gold-plated portions of the plungers complete anelectrical connection in the switch assemblies.Sequencer timing then commences.

Gas from the cartridges also passes out of theunits to the barostatic release unit (RH side only),the pitot deployment mechanisms, and theunderseat rocket motor.

PITOT ASSEMBLY.— When the pitotassembly is installed on the seat beam, the inboardstatic pressure connector connects to a void in theseat beam. The sequencer is installed on theforward face of both pitot assemblies andconnects to the dynamic and forward staticpressure connectors.

On ejection, gas pressure from the impulsecartridges in the multipurpose initiators enters thebody and operates the lower piston. Movementof the lower piston pushes the pitot arm lockingplunger out of engagement with the hole in thebody, and at the same time, opens a gas passageto the upper piston. The upper piston movesoutward to move the pitot arm to the deployedposition. The pitot arm locking plunger engageswith the second hole in the body and locks thepitot arm in the deployed position.

5-30

Figure 5-31.-Seat initiator.

RH AND LH BALLISTIC MANIFOLDS.—Pulling the ejection control handle withdraws thehandle from its housing and both sears from theseat initiator firing mechanisms to fire bothimpulse cartridges (fig. 5-31).

Gas pressure from the RH initiator cartridgewithdraws the pin puller, freeing the emergencyharness restraint release linkage (figs. 5-32 and5-33). RH gas pressure also passes to the following:

1. The shoulder harness reel to initiate harnessretraction.

2. The thermal batteries.3. The 0.75-second (forward seat) delay

cartridge-actuated initiator mounted on the LHballistic manifold.

4. The 0.30-second (aft seat) delay cartridge-actuated initiator mounted on the RH ballisticmanifold.

Figure 5-32.-Forward ejection seat gas flow diagram.

5-31

Figure 5-33.-Aft ejection seat gas flow diagram.

Gas pressure from the LH impulse cartridgepasses to the following:

1. The thermal batteries.2. The 0.75-second (forward seat) or 0.30-

second (aft seat) delay cartridge-actuated initiatormounted on the LH ballistic manifold, whichpasses gas to the LH inlet of the catapult manifoldvalve to initiate the catapult.

THERMAL BATTERIES.— To providesystem redundancy, each battery is initiatedindependently by a manifold-mounted, gas-operated firing mechanism. Both firingmechanisms are initiated by gas pressure from theseat initiator cartridges.

Seat Bucket Assembly

The ejection seat is fitted with a seat bucketassembly. The operation of the components

supported by the seat bucket assembly is discussedin the following paragraphs.

UNDERSEAT ROCKET MOTOR/LAT-ERAL THRUST MOTOR.— The underseatrocket motor Mk 123 Mod 0 (forward seat) or Mk124 Mod 0 (aft seat) is secured under the seatbucket, and is ignited as the catapult nears theend of its stroke. The thrust is approximately4,800 pounds for 0.25 second, and sustains thethrust of the catapult to carry the seat to a heightsufficient for a safe ejection. The thrust alsoprovides the zero-zero capabilities that ensure asafe ejection.

EJECTION SEAT SAFE/ARM HANDLE.—To prevent inadvertent seat ejection, an ejectionseat safe/arm handle is installed. To safety theseat, you must rotate the handle up and forward.

5-32

To arm the seat, you rotate the handle down andaft. When in the ARMED position, the portionof the handle that is visible to the pilot is coloredyellow and black, with the word ARMEDshowing. In the SAFE position, the visible portionof the handle is colored white, with the wordSAFE showing. By placing the handle to theSAFE position, it causes a pin to be inserted intothe ejection firing mechanism. This preventswithdrawal of the sears from the dual-seatinitiators.

LEG RESTRAINT SNUBBERS.— As the seattravels up the guide rails during ejection, the legrestraint lines, which are fixed to a floor bracket,are drawn through the snubbers. Inertia draws thelegs against the front of the seat bucket, and thelegs are retained in this position by the leg restraintlines. When the lines become taut and a pre-determined load is attained, the special break ringsfail and release the lines, leaving only a short looseend protruding from the snubbers. The leg linesare restrained by the snubbers, and the legssecured until the taper plugs are released fromtheir locks when harness release occurs.

EMERGENCY RESTRAINT RELEASEHANDLE.— Rotation of the emergency restraintrelease handle to permit emergency ground egresswill rotate the cross shaft of the lower harnessrelease mechanism to release the lower harnesslocks, leg restraint line locks, and negative-g straplock. Full rotation of the handle to withdraw thesear of the firing unit is prevented by the pin pullerengaging the rear end of the slot in the emergencyrestraint release operating link.

SHOULDER HARNESS CONTROL LEVER.–The shoulder harness control lever, mounted onthe left side of the seat bucket, is connected tothe inertia reel, and provides manual control forthe shoulder straps. In the forward position, theshoulder straps will be locked, and in the aftposition, the shoulder straps will be unlocked sothe occupant will be free to turn and move about.

SEAT HEIGHT ACTUATOR SWITCH.—The seat height actuator switch controls electricalpower to raise and lower the seat bucket to suitthe needs of the occupant.

PIN PULLER.— During ejection, gas fromthe RH seat initiator cartridge enters the pin pullerplunger housing and lifts the plunger out ofengagement with the groove in the piston.

Movement of the plunger allows gas to enter thecylinder and withdraw the piston out ofengagement with the slot in the emergencyrestraint release operating link, the piston beingheld in the operated position by residual gaspressure. The operating link is then disengagedfrom the lower harness release cross shaft by theaction of a spring-loaded plunger in the operatinglink guide bracket mounted on the seat bucketside.

LOWER HARNESS RELEASE MECHA-NISM.— When the sequencer fires the barostaticrelease unit cartridge, the piston in the RH ballisticmanifold acts on the harness reel cross-shaft lever.It rotates the cross shaft to withdraw the plungersin the upper harness locks and release the shoulderharness reel straps. At the same time, gas passesvia the RH ballistic manifold down the RHtrombone tube assembly, entering the emergencyrestraint release piston housing and face-firing thecartridge. The combined gas pressure from thetwo cartridges operates the emergency restraintrelease piston, operating the linkages to releasethe lower harness locks, the leg restraint line locks,and the negative-g strap lock.

Parachute Canopy and Drogue

During the ejection sequence, the parachutedeployment rocket motor fires, extends thewithdrawal line, and withdraws the parachute inits bag. The parachute canopy emerges from thebag, periphery first, followed progressively by theremainder of the canopy and the drogue. Theextractor rocket and bag clear the area. Thedrogue and crown bridle impart a force on thecanopy, proportional to airspeed, to inhibit fullcanopy inflation until g-forces are reduced.

Rotation of the emergency restraint releasehandle to permit emergency ground egress willrotate the cross shaft of the lower harness releasemechanism to release the lower harness locks, legrestraint line locks, and negative-g strap lock. Fullrotation of the handle to withdraw the sear of thefiring unit is prevented by the pin puller engagingthe rear end of the slot in the emergency restraintrelease operating link.

During ejection, gas from the RH seat initiatorimpulse cartridge enters the pin puller plungerhousing and lifts the plunger out of engagementwith the groove in the piston. Movement of theplunger allows gas to enter the cylinder andwithdraw the piston out of engagement with theslot in the emergency restraint release operating

5-33

link, the piston being held in the operated positionby residual gas pressure. The operating link is thendisengaged from the lower harness release crossshaft by the action of a spring-loaded plunger inthe operating link guide bracket mounted on theseat bucket side.

Seat Survival Kit

The seat survival kit (SKU-7/A) operatesautomatically upon seat ejection. Kit componentsare maintained by the PR rating. The SKU-7/Acontains new equipment. Specific information onthe new items was not available at the time ofdevelopment of this manual.

EJECTION SEQUENCE

When the ejection control handle is pulled (fig.5-34), the sears are withdrawn from the seatinitiator firing mechanisms and the two impulsecartridges are fired.

Gas from the RH cartridge is piped as follows:

1. To the pin puller, which withdraws a pistonfrom engagement in the lower operating link ofthe emergency restraint release mechanism.

2. To the inboard connector of the commandsequencing quick-disconnect on the RH ballistic

Figure 5-34.-Ejection seat gas flow (block diagram).

5-34

manifold to operate the command sequencing andcanopy jettison systems.

3. To the 0.30-second delay cartridge-actuatedinitiator (aft seat only) on the RH ballisticmanifold. Gas from the initiator passes to the RHinlet of the catapult manifold valve to initiate thecatapult.

4. To the breech of the shoulder harness reel,where it fires the impulse cartridge to pull the seatoccupant into the correct position for ejection.

5. To the thermal batteries.6. Via a check valve to the 0.75-second delay

cartridge-actuated initiator on the LH ballisticmanifold. Gas from the initiator passes to the LHinlet of the catapult manifold valve to initiate thecatapult.

7. If the seat (F/A-18D only) is commandejected (i.e., the ejection control handle on theother seat has been pulled), gas from thecommand sequencing system enters the RH seatinitiating system through the inboard connectorof the command sequencing quick-disconnect onthe RH ballistic manifold, and operates asdescribed in 1 through 6 above. On the forwardseat only, gas pressure also enters the outboardconnector of the command sequencing quick-disconnect and is passed to the catapult manifoldvalve to initiate the catapult. This gas pressure isalso piped, via a check valve, to the shoulderharness reel and thermal batteries.

Gas from the LH cartridge is piped as follows:

1. To the thermal batteries.2. To the 0.75-second delay, cartridge-

actuated initiator on the LH ballistic manifold.Gas from the initiator passes to the LH inlet ofthe catapult manifold valve to initiate the catapult.

Gas from the delay initiator is piped to theejection gun initiator via the manifold valve. Gaspressure developed by the initiator passes downthe catapult to operate the ballistic latches,retaining the IMP lanyard end fittings. As thepressure increases within the catapult, the catapultpiston rises, releases the top latch, and begins tomove the seat upwards. Further movement of thepiston uncovers the catapult secondary impulsecartridge, which is fired by the heat and pressureof the ejection gun initiator gas. Staggered firingof the catapult cartridges provides a relatively evenincrease in gas pressure during catapult stroke toeliminate excessive g-forces during ejection.

As the seat goes up the guide rails:

1. The IMP lanyards begin to withdraw.

2. Personal services between seat and aircraftare disconnected.

3. The emergency oxygen supply is initiated.4. The URT-33A beacon is activated.5. The leg restraint lines are drawn through

the snubbers and restrain the occupants legs tothe front of the seat bucket. When the leg restraintlines become taut, the special break ringincorporated in each leg line fails, and the linesare freed from the aircraft. Forward movementof the legs is prevented by the lines beingrestrained by the snubbers.

Near the end of the catapult stroke, the IMPlanyards become taut and operate the firingmechanisms. Gas pressure from the IMP cartridgepasses:

1. To the start switch plungers. Closure of thestart switches commences sequencer timing.

2. To the barostatic release unit release piston(from the RH IMP only).

3. To the pitot mechanisms to deploy the pitotheads.

4. Via the LH ballistic manifold andtrombone tube to the underseat rocket motor. Therocket motor ignites, sustaining the thrust of thecatapult to carry the seat clear of the aircraft.

SEQUENCER MODES

Electronic sequencer timing (table 5-2)commences when the start switches close. Modeselection is dependent on altitude and airspeedparameters. (See figure 5-35.)

All modes. The start switches close afterapproximately 39 inches of seat travel and, after0.04 second, the drogue deploys onto the bridleto stabilize and decelerate the seat.

Mode 1, low speed - low altitude. The droguebridle is released, the parachute deploymentrocket motor fires to deploy the personnelparachute, and the harness release system operatesto free the occupant from the seat. The occupantis momentarily held in the seat bucket by thesticker straps.

Modes 2, 3, and 4, medium and high speeds- low altitude and all speeds - medium altitude.The parachute deployment rocket motor fires todeploy the parachute, the drogue bridle isreleased, and the harness release system operatesto free the occupant from the seat. The occupantis momentarily held in the seat bucket by thesticker straps.

5-35

Table 5-2.-Sequencer Timings

Altitude (ft) 0 – 8 K 8K—18K 18K+

KEAS 0—350 350—500 500-600 ALL ALLMODE 1 2 3 4 5

1

2

3

4

5

6

7

8

Gas pressure from seat initiator cartridges,delay cartridge or command sequencingsystem initiates catapult and thermal batteries

Start switches close after 39 inches of seattravel

Sequencer supplies dual pulse to fire droguedeployment catapult

Sequencer supplies dual pulse to fire droguebridle release cartridge and release droguebridle

Sequencer supplies dual pulse to fire parachutedeployment rocket

Sequencer supplies dual pulse to fire droguebridle release cartridge and release droguebridle

Sequencer supplies dual pulse to fire barostaticrelease unit cartridge and release harness locks

Sequencer supplies dual pulse to fire barostaticrelease unit cartridge backup)

0.00

0.18

0.22

0.32

0.45

—

0.65

0.66

0.00

0.18

0.22

—

1.10

1.25

1.30

1.31

0.00

0.18

0.22

—

1.30

1.45

1.50

1.51

0.00

0.18

0.22

—

2.90

3.05

3.10

3.11

0.00

0.18

0.22

4.80 +t(See Note 3)

4.87 +t

5.07 +t

5.08 +t

NOTES TO TABLE 5-2

1. All times are referenced to seat catapult initiation. To obtain times referenced to sequencer startswitches, subtract 0.18 sec.

2. Mode selection environmental sensing takes place between 0.245 sec and 0.305 sec (8 microprocessorcycles).

3. In Mode 5 operation, altitude sensing recommences at 4.80 see, continuing until the seat falls to18000 ft. ´t´ = time interval between 4.80 sec and falling to 18000 ft.

4. Mode decision parameter values are stored in the on-board NOVRAM.

5-36

Figure 5-35

5-37

Mode 5, all speeds - high altitude. Thedrogue bridle remains connected until the seat hasdescended to 18,000 feet. This arrangementprevents prolonged exposure to low temperatureand thin air and enables the occupant to ride downin the seat, controlled by the drogue and suppliedwith emergency oxygen, to a more tolerablealtitude. The seat attitude will be horizontal withthe occupant facing down. When the seat hasdescended to 18,000 feet, the drogue bridle isreleased, the parachute deployment rocket motorfires to deploy the personnel parachute, and theharness release system operates to free theoccupant from the seat. The occupant is momen-tarily held in the seat bucket by the sticker clips.

All modes. The personnel parachute, whendeveloped, lifts the occupant and survival kit fromthe seat, pulling the sticker lugs from their clips.This arrangement ensures that there is nopossibility of collision between seat and occupantafter separation.

ORGANIZATIONAL-LEVELMAINTENANCE

Learning Objective: Identify the organiza-tional-level maintenance philosophy forthe NACES system.

The primary task of maintenance techniciansis to keep the systems they are responsible for inan operational condition. To achieve this goal,the technician must be proficient in themaintenance, removal, installation, testing, andadjustment of system components. All of thismust be performed in accordance with applicabletechnical publications. Most importantly, all thesefunctions must be done “safely.”

Ejection seats and associated components arecarefully designated, manufactured, and tested toensure dependable operation. This equipment

must function properly the first time. Malfunctionor failure to operate usually results in severe injuryor death to crew members. You must always usethe utmost care in maintaining escape systemequipment. Strict compliance with themaintenance procedures presented in the MIMsand the maintenance requirement cards (MRCs)are mandatory and cannot be overemphasized.

NOTE: The information presented in thischapter must NOT be used in place ofinformation provided in the MIMs.

With the increasing use of diverse and exotic(composite) materials in the manufacture ofaircraft components, it is imperative that theproper methods and materials be used to preventand/or correct corrosion. NAVAIR 13-1-36,Organizational Maintenance with Illustrated PartsBreakdown Manual, has been developed toprovide specific instructions and repair actions forNACES seat components. It is an in-shop manualwritten to provide the most complete andtechnically correct information available to themaintenance technician in one publication.Remember, these manuals are your primarysource of maintenance information.

SUMMARY

The Martin-Baker Navy Aircrew CommonEjection Seat (NACES) represents the very latestin escape system technology. It has been designedto provide maximum personnel survivability, ahigh level of escape comfort, total reliability, andease of maintainability. For the first time in thisfield, the power of the microchip has beenharnessed to give the seat the unique ability torespond to the variable demands of an ejectionsituation in a manner far more flexible than waspossible with earlier mechanically controlled seats.

5-38

APPENDIX I

GLOSSARY

ABO—Aviators breathing oxygen.

ACM—Air-cycle machine.

ACS—Air-conditioning system.

ADC—Air data computer.

AFC—Airframes change.

AIMD—Aircraft intermediate maintenancedepartment.

ALLOY—A metal that is a mixture of two ormore metals.

AMBIENT—Surrounding; adjacent to; nextto. For example, ambient conditions are physicalconditions of the immediate area such as ambienttemperature, ambient humidity, ambient pressure,etc.

AN—Air Force—Navy (standard or specifica-tion).

ANOXIA—A complete lack of oxygen in theblood stream.

APU—Auxiliary power unit.

BIT—Built-in tester.

BLEED AIR—Hot, high-pressure air, takenfrom the compressor section of a jet engine.

BRU—Barastatic release unit.

CAD—Cartridge and cartridge-actuateddevices.

CAUTION—An operating procedure,practice, etc., that if not strictly observedcould result in damage to or destruction ofequipment.

CCU—Component control unit.

CDI—Collateral duty inspector.

CELSIUS—A temperature scale using 0 as thefreezing point of water and 100 as the boilingpoint. The scale has 100 equal divisions betweenthe 0 and 100 with each division designated adegree. A reading is usually written in anabbreviated form; for example, 75°C. This scalewas formerly known as the centigrade scale, butit was renamed in recognition of Anders Celsius,the Swedish astronomer who devised the scale.

CF3Br—The chemical symbol for trifluoro-bromomethane.

CNO—Chief of Naval Operations.

CONTAMINANT—An impurity such asharmful foreign matter in a fluid.

DODIC—Department of Defence Informa-tion Code.

DTG—Date-time group.

ECS—Environmental control systems.

EI—Engineering investigation.

FCDC—Flexible confined detonating cord.

FLSC—Flexible linear shaped charge.

GPM—gallons per minute.

Hg—Mercury.

IMA—Intermediate maintenance activity.

IMP—Initiator multi-purpose.

IPB—Illustrated parts breakdown.

AI-1

JULIAN DATE—The year and numerical dayof the year identified by four numeric characters.The first character indicates the year, and theremaining three characters specify the day of theyear. For example, 3030 indicates the 30th dayof 1983.

KINKED—A twist or curl, as in cable, wire,or tubing, caused by its doubling or bending uponitself.

LOX—Liquid oxygen.

LRU—Leg restraint unit.

MAINTENANCE—The function of retainingmaterial in or restoring it to a serviceablecondition.

MBEU—Martin-Baker Ejection Unit (seat).

MIM—Maintenance Instruction Manual.

MRC—Maintenance Requirement Card.

MULTIMETER—An instrument used formeasuring resistance, voltage, or amperage.

NACES—Naval aircrew escape system.

NADEP—Naval Aviation Depot.

NATOPS—Naval Air Training and OperatingProcedures Standardization.

NAVAIRSYSCOM—NAVAIR; NA (NavalAir Systems Command).

NFO—Naval flight officer.

NOMENCLATURE—A system of names;systematic naming.

NOTE—An operating procedure, condition,etc., which, because of its importance, is essentialto highlight.

NSN—National stock number.

OPNAV—Office of the Chief of NavalOperations.

OXIDATION—That process by which oxygenunites with some other substance, causing rust orcorrosion.

PHYSIOLOGICAL—Of or pertaining to thebody.

PRESSURE—The amount of force distri-buted over each unit of area. Pressure is expressedin pounds per square inch (psi) . -

PSI—Pounds per square inch.

PSIA—Pounds per square inch absolute.

PSIG—Pounds per square inch gauge.

PSYCHOLOGICAL—Pertaining to, or de-rived from the mind or emotions.

RAC—Rapid action change.

SAFETY WIRE/LOCKWIRE—A wire setinto a component to lock movable parts into asafe, secure position.

SDLM—Standard depot-level maintenance.

SE—Support equipment. All the equipmenton the ground needed to support aircraft in a stateof readiness for flight. Formerly ground supportequipment (GSE).

SERVICING—The filling of an aircraft withconsumables such as fuel, oil, and compressedgases to predetermined levels, pressure, quantities,or weights.

SJU—Seat jettison unit.

SMDC—Shielded mild detonating cord.

SOLVENT—A liquid that dissolves othersubstances.

SPCC—Ships Parts Control Center.

TENSION—A force or pressure exerting apull or resistance.

TM—Type maintenance.

T/M/S—Type/model/series.

TORQUE—A turning or twisting force.

TOXIC—Harmful, destructive, deadly; poi-sonous.

AI-2

VOLATILE LIQUIDS—Liquids that are could result in personal injury or loss orreadily vaporizable at relatively low temperatures. life.Explosive liquids.

WORK—The transference of energy from oneWARNING—An operating procedure, body or system to another. That which is

practice, etc., that if not followed correctly accomplished by a force acting through a distance.

AI-3

APPENDIX II

REFERENCES

CHAPTER 1

Aviators Breathing Oxygen Surveillance Program and Field Guide,AG-332AO-GYD-000, Naval Air Systems Command, Washington, D.C.,October 1985.

General Use Cartridges and Cartridge-Actuated Devices (CADS) for Aircraftand Associated Equipment, NAVAIR 11-100-1.1, Naval Air SystemsCommand, Washington, D.C., September 1984.

Cartridges and Cartridge-Actuated Devices (CADS) for Unique AircraftSystems, NAVAIR 11-100-1.2, Naval Air Systems Command, Washington,D.C., September 1984.

Naval Aviation Maintenance Program (NAMP), OPNAVINST 4790.2 (series),Vol II, Office of the Chief of Naval Operations, Washington, D.C.,January 1989.

NAVOSH Programs Manual for Forces Afloat, OPNAVINST 5100.19B,Department of the Navy, Office of the Chief of Naval Operations,Washington, D.C., April 1989.

NAVAIROSH Requirements for the Shore Establishment, N A V A I RA1-NASOH-SAF-0001P-5100.1, Naval Air Systems Command,Washington, D.C., February 1986.

CHAPTER 2

F/A-18 Seat, Canopy, Survival Equipment, and Boarding Ladder,A1-F18AC-120-100, Naval Air Systems Command, Washington, D.C.,August 1988.

F/A-18 Seat, Canopy, Survival Equipment, and Boarding Ladder,A1-F18AC-120-300, Naval Air Systems Command, Washington, D.C.,August 1988.

General Use Cartridges and Cartridge-Actuated Devices for Aircraft andAssociated Equipment, NAVAIR 11-100-1.1, Chapter 1, Naval Air SystemsCommand, Washington, D.C., September 1984.

Principles of Operation Environmental Control System, A1-F18AA-410-100,Work Packages 008 00,012 00, and 013 00, Naval Air Systems Command,Washington, D.C., March 1980.

AII-1

CHAPTER 3

P-3 Utility Systems, NAVAIR 01-75PAA-2-2.4, Naval Air Systems Command,Washington, D.C., January 1988.

A-6 Environmental Control Systems, NAVAIR 01-85ADF-2-2.5.1, Naval AirSystems Command, Washington, D.C., August 1988.

Escape and Survival Systems, NAVAIR 01-85ADF-2-2.4, Naval Air SystemsCommand, Washington, D.C., May 1987.

Utility, Environmental and Personnel Survival Equipment, NAVAIR01-85WBA-2-2.4, Section II, Naval Air Systems Command, Washington,D.C., April 1981.

CHAPTER 4

Navy Electricity and Electronics Training Series, NAVEDTRA 172-03-00-85,Module 3, Chapter 1, Naval Education and Training Program DevelopmentCenter, Pensacola, Fla., 1985. (The Naval Education and Training ProgramDevelopment Center became the Naval Education and Training ProgramManagement Support Activity on 1 Sep 1986.)

Principles of Operation Environmental Control System, N A V A I R01-S3AAA-2-2.7, Naval Air Systems Command, Washington, D.C.,September 1985.

Principles of Operation Propulsion System, NAVAIR 01-S3AAA-2-2.6, WorkPackage 00408, Naval Air Systems Command, Washington, D.C., April1980.

Principles of Operation Airframe Group Systems, NAVAIR 01-S3AAA-2-2.2,Work Packages 00307, 00308, 00309, and 013 13, Naval Air SystemsCommand, Washington, D.C., July 1977.

S-3 Testing and Troubleshooting Environmental Control System, NAVAIR01-S3AAA-2-3.7, Naval Air Systems Command, Washington, D.C.,September 1985.

CHAPTER 5

Organization Maintenance With IPB Aircraft Ejection Seat SJU-17(V)1/Aand SJU-17(V)2/A, F/A-18C and F/A-18D Aircraft, NAVAIR 13-1-29,Preliminary Technical Manual, Naval Air Systems Command, Washington,D.C., April 1990.

NATOPS Flight Manual F/A-18C and F/A-18D Aircraft Ejection Seats,Al-F18AE-NFM-000, Preliminary Technical Manual, Martin-BakerAircraft Company, Oxford, England, January 1990.

Description and Principles of Operation, Navy Aircrew Common EjectionSeats (NACES) SJU-17(V)1/A and SJU-17(V)2/A, F/A-18C and F/A-18DAircraft, A1-F18AE-120-100, Preliminary Technical Manual, Martin-BakerAircraft Company, Oxford, England, January 1990.

Turnaround Check List, F/A-18C and F/A-18D Aircraft, A1-F18AE-MRC-100, Preliminary Technical Manual, Martin-Baker AircraftCompany, Oxford, England, January 1990.

AII-2

INDEX

A

Air-conditioning systems, 4-1 to 4-19air-conditioning systems, 4-9 to 4-19

cabin temperature control subsystem,4-14 to 4-18

system components, 4-16 to 4-18system operation, 4-14 to 4-16

environmental control panel, 4-18 to4-19

air-conditioning switch, 4-19cabin air temperature selector,

4-19ram-air valve position selector,

4-18 to 4-19refrigeration subsystem, 4-9 to

4-13components, 4-10 to 4-14system operation, 4-10

bleed-air system, 4-1 to 4-9system components, 4-3 to 4-9

bleed-air flow control andshutoff valve, 4-6 to 4-9

bleed-air shutoff valve, 4-5 to4-6

bleed-air transmitter, 4-9check valves, 4-6engine bleed-air bypass and

shutoff valve, 4-6high-stage bleed-air regulator

valve, 4-3 to 4-5low-stage bleed-air check valve,

4-6system operation, 4-1 to 4-3

APU bleed air, 4-3engine bleed air, 4-1 to 4-3SE ground start air, 4-3

B

Bleed-air system, 4-1 to 4-9Bleed-air utility systems, 3-1 to 3-10

C

Cabin temperature control subsystem, 4-14 to4-18

Canopy system, electrically operated, 2-1 to2-13

D

Deice systems 3-1 to 3-6

E

Ejection seat cartridges and cartridge-actuateddevices (CAD), 1-8 to 1-11

Ejection seat check-outs, 1-7 to 1-8Electrically operated canopy system, 2-1 to

2-13canopy system, 2-1 to 2-7

miscellaneous components, 2-6 to 2-7system components, 2-1 to 2-6

canopy, 2-1canopycanopy

unit,canopycanopycanopy

2-6canopycanopy

actuator, 2-1 to 2-3actuator manual drive2-3 to 2-4contractors, 2-4control switches, 2-4locked switch, 2-4 to

position switch, 2-6pressure seal, 2-1

emergency canopy jettison system, 2-10 to2-13

components, 2-10 to 2-12canopy jettison rocket motor,

2-11canopy jettison rocket motor

initiators, 2-11canopy jettison SMDC initiator,

2-10canopy unlatch thruster and

cartridge, 2-11

INDEX-1

Electrically operated canopy system—Con-tinued

emergency canopy jettison system—Con-tinued

components—Continuedemergency escape disconnect

2-10 to 2-11external canopy jettison handles

and cables, 2-10internal canopy jettison lever,

2-10one-way transfer valve, 2-10SMDC/FCDC initiators, 2-11 to

2-12procedures, 2-13

external canopy jettison, 2-13internal canopy jettison, 2-13

normal operation, 2-7 to 2-10backup manual control mode, 2-7 to

2-10normal control mode, 2-7

Environmental control panel 4-18 to 4-19Explosive safety devices (OPNAV 4790/26A),

installed, 1-12 to 1-13

G

Gaseous oxygen, 1-5 to 1-6Glossary, AI-1 to AI-3

H

High-pressure air, 1-6 to 1-7

L

Liquid oxygen, 1-4 to 1-5

M

Management safety and supervision, 1-1 to1-13

policy for safety program, 1-13safety 1-1 to 1-4

enforcement, 1-3environmental conditions, 1-2equipment, 1-2 to 1-3organization and administration of

a safety program, 1-2

Management safety and supervision—Con-tinued

safety—Continuedplanning for advanced base or

foward area operations, 1-3 to 1-4safety education, 1-3safety inspections, 1-3tools, 1-2work areas, 1-2

safety precautions for ejection seats andexplosive devices, 1-7 to 1-13

ejection seat cartridges and cartridge-actuated devices (CAD), 1-8 to

1-11CAD maintenance policy, 1-10

to 1-11expiration date, 1-8 to 1-10marking expiration dates, 1-10reporting, 1-11service life, 1-8service-life change, 1-10service-life extension, 1-10

ejection seat check-outs, 1-7 to 1-8installed explosive safety devices

(OPNAV 4790/26A), 1-12 to 1-13safety precautions for hazardous sub-

stances, 1-4 to 1-7gaseous oxygen, 1-5 to 1-6

gaseous oxygen servicing trailer,1-6

quality control requirements ofgaseous oxygen, 1-6

high-pressure air, 1-6 to 1-7liquid oxygen, 1-4 to 1-5

description and properties ofliquid oxygen, 1-4 to 1-5

LOX contamination, 1-5personnel, 1-5physical properties of liquid

oxygen, 1-5

N

Navy Aircrew Common Ejection Seat(NACES), 5-1 to 5-38

organizational-level maintenance, 5-38system description and components, 5-1

to 5-38component operation, 5-26 to 5-34

catapult assembly, 5-26main beams assembly, 5-26 to

5-32parachute canopy and drogue,

5-33 to 5-34

INDEX-2

Navy Aircrew Common Ejection Seat(NACES)—Continued

system description and components—Continued

component operation—Continuedseat bucket assembly, 5-32 to

5-33seat survival kit, 5-34

ejection sequence, 5-34 to 5-35functional description, 5-1 to 5-4physical decryption, 5-4 to 5-26

catapult assembly, 5-4 to 5-7main beams assembly, 5-7 to

5-16parachute assembly, 5-24 to 5-25seat bucket assembly, 5-16 to

5-23seat survival kit assembly, 5-25

to 5-26sequencer mode, 5-35 to 5-38

summary, 5-38

R

Rain removal system, 3-6 to 3-10References, AII-1 to AII-2

Refrigeration subsystem, 4-9 to 4-13

S

Safety precautions for ejection seats andexplosive devices, 1-7 to 1-13

SMDC/FCDC initiators, 2-11 to 2-12

U

Utility systems, 3-1 to 3-10bleed-air utility systems, 3-1 to 3-10

deice systems, 3-1 to 3-6description and components, 3-1

to 3-5maintenance, 3-6operation, 3-5 to 3-6

rain removal system, 3-6 to 3-10description and components, 3-7

to 3-9system operation, 3-10

INDEX-3

Assignment Questions

Information: The text pages that you are to study areprovided at the beginning of the assignment questions.

A S S I G N M E N T 1

Textbook Assignment: “Management Safety and Supervision,” chapter 1, pages 1-1 through1-13.

1-1. What manual contains Navy enlistedmanpower and personnelclassifications and occupationalstandards?

1. NAVPERS 180862. NAVPERS 18084-13. NAVPERS l80684. NAVPERS 18068-1

1-2. Because of the inherent dangersassociated with duties, senior AMEpersonnel should be concerned withwhich of the following safetyfactors?

1. Personnel safety2. Equipment safety3. Both l and 2 above4. Shop/flight line safety

1-3. The absence of which of the followingfactors accounts for most accidentswith and around safety and survivalequipment?

leadership

1-4. Who has the basic responsibility topromote and adhere to safety rulesand regulations?

1-5. It is only necessary to providesafeguards, safety will take care ofitself.

1. True2. False

1-6. What does the term safety mean asdiscussed in this course?

1. Freedom from injury2. Freedom from danger3. Providing protection4. Freedom from risk

1-7. What is the objective of the workenvironment?

1. To operate with maximumefficiency and safety

2. To operate with minimumefficiency and waste

3. To operate freely frominterruption and difficulty

4. To eliminate hazards and providesafeguards

1-8. Which of the following is anobjective of supervision?

1. To operate with minimumefficiency and waste

2. To operate free frominterruption and difficulty

3. To operate with maximumefficiency and safety

4. Each of the above

1. Supervision and leadership only2. Education and training only3. Supervision and training only4. Training, supervision, and

1. The safety petty officer2. The individual3. The work center supervisor4. The commanding officer

1

1-9. To establish a good safety recordrequires a good safety program.

1. True2. False

1-10. Ninety-eight percent of all accidentscan be prevented. The remaining 2percent are caused by what factor?

1. Faulty equipment2. Poor supervision3. Natural elements4. Lack of communication

1-11. How is enforcement defined as itapplies to safety?

1. Reprimanding violators2. Monitoring a continuous safety

program3. Formulating rules and regulations

and a safety policy

1-12. Supervisors must enforce safety ruleswithout fear or favor.

1. True2. False

1-13. When determining the requirements forforward or advance base operations,you must consider what factors?

1. Safety, mission, and environmentonly

2. Operating factors and facilitiesonly

3. Safety and mission only4. Safety, mission, environment,

operating factors, and facilities

1-14. According to its primary function, afunctional component is formed fromwhat total number of major groups?

1-15. Which of the following items is oneof 300 standardized Navy units usedto build and operate advanced bases?

1. Expenditure2. Functional3. Planning4. Logistic

1-16. What is the major group designationfor aviation?

1. H2. I3. J4. K

1-17. What factors are included on thelist of requirements for theperformance of a specific task at anadvance base?

1. A combination ofequipment only

2. A combination ofpersonnel only

3. A combination ofmaterial, and/or

4. A combination of

material and

equipment and

equipment,personnelequipment,

1-18.

supplies, and repair parts

Other necessary repair parts,supplies, and equipment may bedetermined from the outfitting listfor what activity or action?

1. The type aircraft and mission tobe supported

2. The mission and weapon system tobe supported

3. The type aircraft and weaponsystem to be supported

4. All of the above

1. 102. 113. 124. 13

2

1-19. What section of the Advanced Base andInitial Outfitting List providescomplete information and datarequirements?

1. Abridged and supply2. Index3. Outfitting and support4. Abridged and detailed outfitting

for functional components

1-20. What instruction is used to implementthe NAVOSH program ashore?

1. OPNAVINST 4790.2E, Vol. IV2. OPNAVINST 5100.19B, Vol. I3. OPNAVINST 5100.19B, Vol. II4. OPNAVINST 5100,23B, Vol. III

1-21. An AME must deal with what threemajor hazardous substances?

1. CADs, LOX, rocket motors2. CADs, nitrogen, hot bleed air3. High-pressure air, CADs, LOX4. High-pressure air, LOX, gaseous

oxygen

1-22. What are the two states of aviatorsbreathing oxygen?

1. Type I Liquid, Type II Gaseous2. Type I Gaseous, Type II Gaseous3. Type I Liquid, Type II Liquid4. Type I Gaseous, Type II Liquid

1-23. What publication should be used tofollow established safety proceduresfor

1.2.3.4.

the handling of LOX?

NAVAIR 06-03-501NAVAIR 06-30-501NAVAIR 06-03-509NAVAIR 06-30-509

1-24. At atmospheric pressure, oxygenexists as a solid at whattemperature below its melting point?

1. -297°F2. -297°C3. -361°C4. -361°F

1-25. Which of the following typedesignators is classed as liquidoxygen?

1. I2. II3. III4. IV

1-26. What is the critical temperature ofgaseous oxygen?

1. -119°C2. -l83°c3. -297°C4. -281°C

1-27. Gaseous oxygen will turn into aliquid at atmospheric pressure byraising the temperature above-297°F.

1. True2. False

1-28. What is the critical pressurerequired to liquify oxygen?

1. 736 psia2. 736 psig3. 736.5 psia4. 736.3 psig

3

1-29. Gaseous oxygen will condense to aliquid under which, if any, of thefollowing conditions?

1. Temperatures above it’s criticaltemperature

2. Atmospheric pressure3. Pressure above it’s critical

pressure4. None of the above

1-30. What are the physical characteristicsof gaseous oxygen?

1. Odorless, tasteless, colorless2. Pale blue fluid that flows like

water3. 1.5 times heavier than air4. None of the above

1-31. How much heavier is 1 gallon ofliquid oxygen than 1 gallon of water?

1. 1.10 lb2. 1.12 lb3. 1.13 lb4. 1.14 lb

1-32. What is the total weight of 1 gallonof liquid oxygen?

1. 9.159 lb2. 9.519 lb3. 9.5 lb4. 9.1 lb

1-33. What are the two most importantfactors a supervisor looks for in anindividual before assigning him/herduties and responsibilities ofhandling LOX?

1. An understanding of safety andLOX cart operation

2. A current LOX license andknowledge of LOX cart operation

3. Consciousness, safety, and firstaid ability

4. An understanding of safety and ahistory of reliable performance

1-34. How often should an aircraft LOXconverter system be sampled andtested?

2. Every 30 days3. AS soon as possible after a

report of in-flight odors byaircrew personnel

4. When the AME suspects the systemdoesn’t smell right

1-35. What contaminants must be preventedfrom entering a LOX system duringthe handling and transfer process?

1. Water2. FOD3. Oil4. Atmospheric gases

1-36. Reports concerning LOX contaminationwill be submitted in accordance withwhat OPNAVINST?

1. 3750.62. 4790.23. 5100.194. 8023.1

1-37. Under which of the followingconditions must a LOX converter oroxygen system be purged?

1. If the system is left open tothe atmosphere

2. Whenever contamination issuspected

3. When empty4. All of the above

1-38. An aircraft oxygen system or LOXconverter must be purged inaccordance with what publications?

1. OPNNAVINST 4790.2 and the MIMs2. OPNAVINST 3750.6 and the MIMs3. NAVAIR 01-LOX-6.4 and the MIMs4. NAVAIR 01-13-1-6.4 and/or the

MIMs

4

1. Every 210 days

1-39. What type of test is used forstation monitoring of aviatorsgaseous breathing oxygen?

1. Liquid sample2. Cryogenic3. MICRO contamination4. Sniff-odor

1-40. The on-station procurement ofaviators gaseous breathing oxygenmust meet the requirements of whatpublication?

1. OPNAVINST 4790.22. OPNAVINST 5100.193. NAVAIR 13-1-6.44. MIL-0-27210

1-41. What publication will be used in theperformance of sample testing ofgaseous oxygen?

1. MIL-0-272102. A6-332AO-QYD-0003. NAVAIR 13-1-6.44. NAVAIR 06-30-501

1-42. Cylinders used for aviators gaseousbreathing oxygen that are found withopen valves and/or a positiveinternal pressure of less than 25psig should be tagged with whatinformation?

1. Empty2. Needs filling3. Dry before filling4. Needs purging

1-43. Which of the following is a methodfor providing high-pressurecompressed air?

1-44. A malfunctioning pressure regulatorshould be disconnected from the lineby what method?

1. Removing the line2. Removing the regulator3. Closing the associated shut-off

valve4. Closing the associated bottle by

turning the bottle valve

1-45. Under which, if any, of thefollowing circumstances, may anunmarked or unidentified cartridgebe installed in an ejection seat?

1. When directed by the commandingofficer

2. When directed by the maintenanceofficer

3. Only in emergency situations4. None of the above

1-46. When must newly assigned personnelreceive an ejection seat check-out?

1. Within 60 days of reporting2. Within 90 days of reporting3. Within 180 days of reporting4. Prior to performing any

maintenance tasks

1-47. Each AME must receive a seat check-out a minimum of how often?

1. Once per assignment2. Once every 6 months3. Once every 9 months4. Once a year

1. Portable cylinder2. Pump station air compressor3. Cascade-type cylinder4. Each of the above

5

1-48. What information must be listed on anindividual’s records for havingreceived a seat check-out?

1. Date due, date given, signatureof individual

2. Date due, date given, signatureof supervisor

3. Date due, date given, signatureof AME supervisor

4. Date due, date qiven, signatureof AME giving check-out

A. Description, Preparationfor Use, and HandlingInstructions, AircrewEscape PropulsionSystem (AEPS) Devices

B. General Use Cartridgesand Cartridge ActuatedDevices for Aircraftand AssociatedEquipment

C. Ammunition Afloat

D. Ammunition andExplosives Ashore

Figure 1. --Ordnance Publications

IN ANSWERING QUESTIONS 1-49 THROUQH 1-52,SELECT THE PUBLICATION TITLE FROM FIGURE 1THAT RELATES TO THE PUBLICATION NUMBER USEDAS THE QUESTION. USE EACH TITLE ONLY ONCE.

1-49. NAVAIR 11-85-1.

1. A2. B3. C4. D

1-50. OP 4.

1. A2. B3. C4. D

1-51. OP 5.

1. A2. B3. C4. D

1-52. NAVAIR 11-100-1.

1. A2. B3. C4. D

1-53. The specific period of time that aCAD is allowed to be used is knownas its

1. shelf life2. service life3. installed life4. removed life

1-54. What date must be checked prior toinstalling a CAD into any system?

1. Open2. Expiration3. Installed4. Manufacture

1-55. To determine the service-lifeexpiration date of a CAD, whatdate(s) must be computed?

1. Aircraft life2. Shelf life3. Installed life4. Both 2 and 3 above

6

1-56. If the date of manufacture of a CAD 1-61.is 0981 and the shelf life is 6years, what is the shelf-lifeexpiration date?

1. 09852. 09863. 09874. 0988

1-62.1-57. To which of the following manuals

should you refer to determine theinstalled-life expiration date of aCAD?

1. NAVAIR 11-100-12. NAVAIR 11-85-13. OP 44. OP 5 1-63.

1-58. To determine the installed-lifeexpiration date, the installed-lifedate is added to the date what actionwas performed on the container?

1. Opened2. Received from supply3. Received from the manufacturer 1-64.4. Sealed by the manufacturer

1-59. If the installed life is 66 months,what is the installed-life expirationdate of a CAD whose container wasopened during 1183?

1. 05882. 06883. 0589 1-65.4. 0689

1-60. A hermetically sealed container wasopened on 15 March. Which of thefollowing dates is used to computethe expiration date?

1. 1 January2. 1 March3. 15 March4. 31 March

Which of the following is anapproved method for markingexpiration dates on CADs?

1. Paint2. Scribe3. Permanent ink4. Electroetch

Which of the following dates must bemarked on a CAD that is beinginstalled in an aircraft?

1. Installed2. Shelf-life3. Container opened4. Installed-life

A logbook entry for a CAD must bemade when which of the followingevents occurs?

1. Actuation2. Replacement3. Reinstallation4. Refurbishment

A contingency service-life extensionfor a CAD granted by the commandingofficer may not exceed what maximumnumber of days?

1. 152. 303. 454. 60

For an additional service-lifeextension beyond the contingencyextension, a message reply will bereceived from which of the followingactivities?

1. NAVORDSTA2. NAVAIRLANT3. NAVAIRSYSCOM4. NAVORDSYSCOM

7

1-66. A change to NAVAIR 11-100-1 may 1-70.change the permanent service life ofCADs. Which of the following methodsis used to change NAVAIR 11-100-1?

1. Rapid action change2. Interim rapid action change3. Formal change4. Each of the above

1-67. What associated attachment 1-71.determines the service life of wire-braid, Teflon®-lined hoses?

1. The initiator to which it isattached

2. The aircraft in which it isinstalled

3. The CAD to which it leads4. The rocket motor to which it 1 -72.

leads

1-68. When should the hoses in an escapesystem be inspected?

1. At every phased inspection2. Upon removal of the seat3. After the hoses are disconnected4. All of the above

1-69. For safety reasons, which of thefollowing devices will be installedin CADs when they are removed fromthe aircraft?

What OPNAVINST provides theguidelines for reporting ordnancemalfunctions, discrepancies, andaccidents?

1. 8023.32. 5100.193. 4790.24. 3750.6

What OPNAV form is used in theaircraft logbook/AESR for recordingall explosive safety devices?

1. 4790/21A2. 4790/25A3. 4790/26A4. 4790/26B

The best assurance of personnelsafety lies in the safety educationof the people themselves.

1. True2. False

1. Caps2. Plugs3. Safety pins4. All of the above

8

A S S I G N M E N T 2

Textbook assiqnment 1: “Electrically Operated Canopy System,” chapter 2, pages 2-1 through2-13.

2-1. What function does the canopy serveon the F/A-l8C?

1. Protection from the elements2. Entry and exit for the cockpit3. Both 1 and 2 above4. A means for total visibility

2-2. The F/A-l8C canopy is normallyoperated in which of the followingmodes?

1. Pneumatic2. Hydraulic3. Electrical4. Manual

2-3. Under normal conditions, the canopyis controlled by which of thefollowing devices?

1. Internal canopy control switch2. External canopy control switch3. Both 1 and 2 above4. Manual canopy control handle

2-4. When the canopy actuation controlsystem has failed, what method willbe used to open and Close the canopy?

1. Manual back-up mode2. External electrical power3. Internal electrical power4. Utility battery power

2-5. Which of the following components ismounted on the canopy?

1. Canopy unlatch thruster2. Canopy contactor3. Canopy actuator4. Canopy actuation link

2-6. The canopy actuator, used to openand close the canopy, is protectedby a thermal device that senses anoverheat condition.

1. True2. False

2-7. What total number of manual methodsare available to open and close thecanopy?

1. One2. Two3. Three4. Four

2-8. What total number of canopy controlswitches are provided for normalelectrical operation of the canopy?

1. One2. Two3. Three4. Four

9

2-9. What canopy contactor supplies powerto the close windings of the canopyactuator motor?

1. Up2. Down3. Open4. Close

2-10. In what canopy latch retainer is thecanopy position switch mounted?

1. Number 12. Number 23. Number 34. Number 4

2-11. What switch(es) must be depressed toextinguish the master caution light?

1. Canopy position switch2. Canopy locked switch3. Both 1 and 2 above4. Canopy caution switch

2-12. How much power does the F/A-18aircraft electrical system supply forcanopy operation?

1. 24 volts ac2. 24 volts dc3. 28 volts dc4. 28 volts ac

2-13. The air-cycle air-conditioning systemsupplies cold air for the inflationof the canopy pressure seal.

1. True2. False

2-14. Both canopy switch plungers must bedepressed within what maximum numberof seconds?

2-15. If you use the internal manualcanopy handle, what maximum numberof turns may be required to closethe canopy?

1. 70±12. 75±13. 80±14. 85±1

2-16. What component transfers themechanical motion of the manualdrive unit to the canopy actuator?

1. Handle assembly2. Actuator arm3. Shaft assembly4. Torque limiter

2-17. What maximum number of turns may berequired to externally operate thecanopy actuator manual drive unit?

1. 5±12. l5±13. 25±14. 35±1

2-18. What component prevents damage tothe actuator if excessive force isapplied in the manual back-upcontrol mode?

1. Handle assembly2. Actuator arm3. Shaft assembly4. Torque limiter

2-19. Which of the following handles willcause the canopy to be jettisoned?

1. Internal jettison2. External jettison3. Ejection control4. Each of the above

1. 52. 103. 154. 20

10

2-20. What device(s) prevents the backflowof an SMDC detonation from reachingthe seat components?

1. Emergency escape disconnect2. One-way transfer valve3. SMDC initiator4. Both 2 and 3 above

2-21. What component provides the ballisticgas that fires the canopy jettisonrocket motor?

1. Canopy jettison SMDC initiator2. Emergency escape disconnect3. Canopy unlatch thruster4. Canopy jettison FCDC initiator

2-22. What component provides the verticalthrust needed to separate the canopyfrom the aircraft?

1. Canopy actuator2. Rocket motor3. Unlatch thruster4. SMDC initiator

2-23. Which of the following devices isused to protect SMDCs?

1. Metallic sheath2. Braid overwrap3. Stainless steel tubing4. Aluminum tubing

2-24. What is the approximate length of theexternal jettison initiator cable?

1. 6 feet2. 8 feet3. 10 feet4. 12 feet

2-25. What device prevents the internaljettison handle from being squeezedand pulled?

2-26. The rocket motor initiators convertballistic-gas pressure to whatforce?

1. Explosive canopy thrust2. Explosive stimulus3. Explosive energy4. Mechanical energy

2-27. What total number of SMDC initiatorsare in the F-18C canopy jettisonsystem?

1. One2. Two3. Three4. Four

2-28. How many methods are available tojettison the canopy on the F-18Caircraft?

1. One2. Two3. Three4. Four

2-29. On the F-18 aircraft, how much timemust elapse+before the thermalprotection device will reset aftersensing an overheat condition?

1. 15 seconds2. 39 seconds3. 60 seconds4. 90 seconds

1. Shear pin2. Safety pin3. Shear wire

11

IN ANSWERING QUESTIONS 2-30 THROUGH 2-35,REFER TO THE CANOPY JETTISON SYSTEMSCHEMATIC AT FIG. 2-12 IN THE TEXT. SELECTFROM COLUMN B THE CORRECT MEANING OF THESYMBOLS IN COLUMN A.

COLUMN A

2-30. a

1. 52. 63. 74. Both 6 and 7

2-31. ------

1. 52. 23. 34. 4

2-32.

1. 12. 23. 34. 4

2-33. @

1. 72. 63. 54. 4

2-34.

1. 12. 23. 34. 4

COLUMN B

1. Shieldedmilddetonatingcord

2. Flexibleconfineddetonatingcord

3. Ballisticgas

4. Structuralpivotpoint

5. Mechanicallinkage

6. Ejectionseat

7. Emergencyescapesequencingsystem

IN ANSWERING QUESTION 2-35, REFER TO THECANOPY JETTISON SYSTEM SCHEMATIC AT FIG. 2-12 IN THE TEXT. SELECT FROM COLUMN B THECORRECT MEANING OF THE SYMBOL IN COLUMN A.

COLUMN A COLUMN B

2-35. 1. Shieldedmild

1. 2 detonating2. 3 cord3. 54. 4 2. Flexible

confineddetonatingcord

3. Ballisticgas

4. Structuralpivotpoint

5. Mechanicallinkage

6. Ejectionseat

7. Emergencyescapesequencingsystem

2-36. What component(s) act(s) as a solidlink during normal canopy operation?

1. Canopy actuation connecting link2. Canopy actuator3. Both 1 and 2 above4. Canopy unlatch thruster

12

2-37.

2-38.

What maintenance code is displayed onthe nosewheel well DDI in the eventthe canopy switches disagree?

1. 8882. 8893. 8904. 898

The electrical inputs supplied to thecanopy actuator are transformed intowhat type energy?1. Electrical2. Direct power source3. Mechanical motion4. Logic circuit power

IN ANSWERING QUESTIONS 2-39 THROUGH 2-42,REFER TO FIGURE 2-9 IN THE TEXT.

2-39. The canopy system will be removedfrom the battery circuit when batteryvoltage drops below

1. 19 Vac2. 19±1 Vac3. 19 Vdc4. 19±1 Vdc

2-40. When is the left main landing gearWOW relay #2 energized?

1. With weight on wheels2. With external power applied3. With weight off wheels4. With battery power applied

2-41. From what circuit breaker/relaydoes the canopy control receivepower?

1. 62. 23. 84. 4

panelits

2-42. What component houses the thermalprotection device?

1. Canopy control switch2. Canopy actuator3. #3 relay panel4. #8 relay panel

IN ANSWERING QUESTIONS 2-43 THROUGH 2-49,REFER TO FIGURE 2A, BELOW, AND FIGURE 2-9IN THE TEXT. MATCH THE COMPONENT NAME INTHE QUESTION WITH THE ALPHABETIC INDICATORIN FIGURE 2A.

Figure 2A.--Canopy Actuator

2-43. Canopy up limit switch--up contact.

1. B2. C3. D4. E

2-44. Canopy actuator electrical ground.

1. A2. C3. E4. G

13

2-45. Canopy actuator field windings--open.

1. A2. B3. C4. F

2-46. Canopy actuator brake winding.

1. D2. C3. B4. A

2-47. Canopy actuator thermal protectiondevice.

1. D2. E3. F4. G

2-48. Canopy up-travel-limit switch--not upcontact.

1. B2. C3. D4. E

2-49. Canopy actuator field windings--close.

1. A2. B3. C4. G

2-50. How many systems and components arerelated to the electrical canopysystem?

1. Seven2. Nine3. Three4. Four

2-51. Unlike the external canopy controlswitch, the internal canopy controlswitch has only two positions, openand close.

1. True2. False

IN ANSWERING QUESTION 2-52, REFER TO FIGURE12-9 IN THE TEXT.

2-52. Which of the following switchesis/are a double pole double throwswitch(es)?

1. Canopy position switch2. Internal canopy control switch3. External canopy control switch4. Both 2 and 3 above

2-53. Explosive stimulus produced by theinitiator is transferred through theSMDC to what component?

1. Canopy unlatch thruster2. Emergency escape disconnect3. Flexible confined detonating

cord4. Rocket motors

2-54. What component prevents explosivestimulus from continuing toward theejection seat components duringinternal canopy jettison?

1. FCDC2. Canopy unlatch thruster3. Emergency escape disconnect4. One way transfer valve

2-55. What action does each rocket motorproduce to separate the canopy fromthe aircraft?

1. Thrust aft and up2. Sufficient burn time3. Vertical thrust4. Horizontal thrust

14

2-56. During canopy jettison, the thrusterunlocks internally and forces thecanopy aft to disengage the canopylatches.

1. True2. False

IN ANSWERING QUESTIONS 2-57 THROUGH 2-60,REFER TO FIGURE 2-9 IN THE TEXT. IDENTIFYTHE TYPE SWITCHES USED IN THE ELECTRICALCANOPY SYSTEM.

2-57. Canopy locked switch.

1. Single pole double throwmomentary contacts

2. Single pole double throw3. Double pole double throw

momentary contacts4. Double pole double throw

2-58. External canopy control switch.

1. Double pole double throw2. Single pole three position3. Double pole double throw

momentary on4. Single pole double throw three

position

2-59. Canopy up contactor.

1. Single contact2. Momentary on3. Double contact4. None of the above

2-60. Holding coil.

1. Single pole double throw normalor momentary contacts

2. Single pole double throw3. Single pole single throw4. Single pole single throw normal

or momentary contacts on

15

A S S I G N M E N T 3

Textbook Assignment: “Utility Systems,” chapter 3, page 3-1 through 3-10 and “Air-Conditioning Systems,” chapter 4, pages 4-1 through4-19.

3-l.

3-2.

3-3.

3-4.

Which of the following systems isused to prevent ice from forming onan aircraft?

1. Anti-ice2. Deice3. Rain-removal4. Defrost

The P-3 aircraft uses what source ofheat for its deicing system?

1. Electrical energy2. Bleed air3. Hydraulic pumps4. Solar energy

What total number of bleed-airshutoff valves are on the P-3aircraft?

1. Five2. Six3. Three4. Four

By what method are the deicing systemmodulating valves controlled?

1. Pneumatic2. Hydraulic3. Electric4. Thermostatic

3-5 . What component causes the modulatingvalve to close when the pressure isreduced on the modulating valvediaphragm?

1. Spring2. Solenoid3. Sensor4. Spoon

3-6. Which of the following conditionswill cause high temperature withinthe leading edge of the wing?

1. Solar radiation2. Bleed-air leakage3. Malfunctioning modulating valve4. Both 2 and 3 above

3-7. The fusalage bleed-air shutoffvalves are normally open duringdeicing operations.

1. True2. False

3-8. To perform a deicing leak test, themanifold pressure must reach whatminimum psi reading?

1. 402. 553. 704. 85

16

3-9. What should be the maximum number ofseconds required for the accept lightto Illuminate during a leak test?

1. 82. 123. 154. 20

3-10. The P-3C wing deice system usesbleed-air from what stage(s) of theengine compressor?

1. 12th2. 13th3. 14th4. Both 2 and 3 above

3-11. Where is the wing leading edgepneumatic thermostat located?

1. Wing leading edge tips2. Adjacent to each modulating valve3. Adjacent to shut-off valve4. Wing leading edge ducting

3-12. What component allows pressure fromthe modulating valve diaphragm tovent?

1. Leading edge temperature andoverheat circuit

2. Overheat thermal switch3. Fuselage bleed-air shutoff valve4. Wing leading edge thermostat

3-13. At what temperature will the leadingedge caution hot light illuminate?

1. 210°F2. 220°F3. 230°F4. 240°F

3-14. The ducting overheat switches areexplosiveproof, thermally actuatedelectrical switches with an integraltemperature sensing element.

3-15. At what temperature will theoutboard leading edge overheatwarning switch open?

1. 205°F2. 210°F3. 215°F4. 220°F

3-16. Where is the rotary selector switchlocated?

1. Bleed-air coated panel2. Leading edge caution panel3. Ice control panel box4. Ice control protection panel

3-17. What total number of duct overheatthermal switches are installed inthe P-3C aircraft?

1. Three2. Six3. Nine4. Twelve

3-18. What will cause the OPEN light onthe ice control protection panel toilluminate?

1. Failure of system components2. When the air-conditioning valve

is open3. When the bleed-air valve opens

more than 2 degrees4. When the modulating valve opens

more than 2 degrees

3-19. Either one or both fuselage bleed-air shutoff valves must be open todirect air to the wing anti-icingducting?

1. True2. False

1. True2. False

17

3-20. How many modulating valve controlswitches are located on the left sideof the wing and empennage ice panel?

1. One2. Two3. Three4. Four

3-21. What switch(s) on the wing andempennage ice panel controls theoutboard modulating valve on the leftand right wings?

1. Inboard2. Outboard3. Center4. Both 1 and 2 above

3-22. What switches will open when anoverheat is sensed at 175°F andcloses at 190°F?

1. Leading edge overheat warningswitches

2. Wing overheat warning switchesonly

3. Fuselage overheat warningswitches only

4. Wing and fuselage overheatwarning switches

3-23. During normal operation of the de-icing system, two of the four enginebleed-air valves are open to supplybleed-air to the cross-ship manifold?

1. True2. False

3-24. When should the deicing manifoldsystem be tested for leakage?

1. Before each flight2. Before each engine turn3. During each flight4. Both two and three above

3-25.

3-26.

3-27.

3-28.

3-29.

3-30.

The involvement of the AME 1 andAMEC in the maintenance of thedeicing system normally consists ofsupervision only.

1. True2. False

The A-6 rain-removal system usesbleed-air from what stage of theengine compressor?

1. 12th2. 13th3. 14th4. 15th

Upon loss of electrical power, thenosewheel well bleed-air shutoffvalve will be in what position?

1. Open2. Closed3. In the last selected position4. In the manual position

What type of power is used tooperate the rain-removal pressure-regulator shutoff valve?

1. Hydraulic2. Pneumatic3. Electric4. Manual

What shutoff valve controls theairflow from the rain-removal systemto the windshield?

1. Nosewheel well bleed air2. Rain-removal pressure regulator3. Main-engine bleed air4. Cabin bleed air

What total number of nozzles are onthe A-6 windshield?

1. 222. 243. 264. 28

18

3-31. What rain-removal system componentmixes cool air with hot bleed air?

1. Ejector2. Plenum3. Nozzle4. Coupler

3-32. In what two positions may thenosewheel well bleed-air switch beplaced?

1. ON and OFF2. AUTO and ON3. AUTO and OFF4. MANUAL and OFF

3-33. When the windshield switch is placedin the AIR position, through whatcircuit breaker does the dc voltageflow?

1. Anti-ice2. Air conditioning3. Rain-removal4. Windshield air

3-34. The windshield air caution lightilluminates to indicate that thewindshield switch is in whatposition?

1. ON2. OFF3. AUTO4.AIR

3-35. Where is the nosewheel well bleed-air relay mounted for the rain-removal system?

1. Air-conditioning panel2. Aft bay relay box no. 33. Left main landing gear4. Cockpit center console

3-36. The windshield rain-removal warningrelay is a single throw, double polesealed relay?

1. True2. False

3-37. What are the three positions of thewindshield switch?

1. ON, OFF, AUTO2. AUTO, MANUAL, OFF3. AIR, WASH, AUTO4. WASH, AIR, OFF

3-38. Where is the rain-removal nozzleassembly located?

1. Beneath the pilot’s windshield2. Beneath the b/n’s windshield3. Both 1 and 2 above4. Inside and under the radome next

to the windshield

3-39. What switch controls the rain-removal pressure-regulator shutoffvalve?

1. Windshield wash2. Rain removal3. Windshield4. Air conditioning

3-40. The rain-removal system removes rainby directing a flow of heated airacross the windscreen. What is thefunction of this heated air?

1. It blows the water away2. It drys the windscreen, keeps it

dry3. It breaks the raindrops into

small particles4. It evaporates the raindrops

3-41. The left main landing gear weight-on-wheels switch controls thenosewheel and bleed-air relay?

1. True2. False

19

3-42. Under what condition(s) is the leftmain landing gear weight-on-wheelsswitch in the closed position?

1. When the strut is compressed2. When the strut is extended3. Neither of the above

3-43. What stage of the compressor is theprimary source of bleed air foroperation of the ECS?

1. 1Oth2. 12th3. 14th4. 16th

3-44. Which of the following methods isused to (a) control and (b) actuatethe bleed-air flow control andshutoff valve?

1. (a) Electric (b) pneumatic2. (a) Electric (b) electric3. (a) Pneumatic (b) electric4. (a) Pneumatic (b) pneumatic

3-45. What air supply source(s) could beused for engine starting and groundoperation of the air-conditioningsystem?

1. Ram air2. Ground start air3. APU air4. Both 2 and 3 above

3-46. Which of the following conditionswill cause the bleed-air shutoffvalve to close?

1. Overtemperature2. Overpressure3. Loss of electrical power4. All of the above

3-47. Whenwithmustboth

operating the deicing systemone engine secured, what valvebe open to allow bleed air tosides of the aircraft?

1. Bleed-air shutoff2. Bleed-air flow control and

shutoff3. Engine bleed-air bypass and

shutoff4. Crossover duct isolation check

3-48. What valve will open because of asensed pressure drop through the icescreen?

1. Bleed-air shutoff2. Bleed-air flow control and

shutoff3. Engine bleed-air bypass and

shutoff4. Nonice and low-limit control

3-49. What do the lights for the bleed-airshutoff valves indicate?

1. Switch position2. Valve position3. Both 1 and 2 above4. High temperature

3-50. In the event of a rupture in theleft or right manifold, what valvewill prevent overbleeding of theengines?

1. Bleed-air shutoff2. 10th-stage check3. High-stage check4. Crossover duct isolation check

3-51. What is the total number of basiccomponents in the refrigerationsubsystem?

1. 72. 83. 94. 10

2 0

3-52. What component, if any, is used tocheck the oil level in the coolingturbine?

1. Dip stick2. Pressure gauge3. Siqht gauge4. None

3-53. Which of the following conditionswill cause the temperature indicatorprobe in the fan inlet to trip?

1. Obstruction of the ram-air inletduct

2. Collapse of the ram-air inletduct

3. Temperature above 440°F4. All of the above

3-54. What component allows air to passthrough the water separator if icehas accumulated in the coalescer bag?

1. Water separator ice screen2. Coalescer cone3. Swirl vanes4. Water separate bypass valve

3-54. What name is given to the air used tocool the sonobuoy and weapons bays?

1. Refrigerated2. Partially cooled3. Cabin exhaust4. Ram

3-56. What component prevents ram air fromflooding the cabin when the aircraftis flying at high speeds?

1. Outflow valve2. Cabin pressure regulator3. Cabin air temperature control4. Ram-air shutoff valve

3-57.

3-58.

3-59.

3-60.

When the air-conditioning switch isOFF, the AUX vent switch is ON, andthe ram-air pressure does not meetcabin exhaust fan requirements, whatvalve will open?

1. Ram-air shutoff2. Water separator bypass3. Cabin outflow4. Negative pressure relief

The torque motor in the cabintemperature control modulating valveconverts electrical signals to whattype signals?

1. Pneumatic2. Mechanical3. Magnetic4. Hydraulic

What component provides thecontrolling signal for the cabintemperature control valve?

1. Cabin air thermistors2. Cabin air sensor3. Cabin air temperature control4. Cabin air high-temperature

thermostat

The opening of the cabin air high-temperature limit thermostatinternal valve causes what valve(s)to close?

1. Cabin temperature control valve2. Nonice and low-limit control

valve3. Both 1 and 2 above4. Bleed-air flow control and

shutoff valve

21

3-61. The cabin temperature control sensoris designed to control the cabintemperature within what number ofdegrees of the selected temperature?

1. ±32. ±73. ±104. ±ll

3-62. In the ram-air augmentation mode, theram-air shutoff valve regulatesdownstream pressure to what fixeddifferential above cabin pressure?

1. 7.5±22. 5.5±13. 3.0±.54. 4.0±l

3-63. During manual operation, what switchis used to position the ram-airshutoff valve?

1. Cabin pressurization2. Air-conditioning3. Auxiliary vent4. Temperature select

3-64. When the air conditioning auto-matically shuts down and the ram-airshutoff valve is fully open, whataction, if any, must be taken torestore normal operation?

1. 70°F to 90°F2. 60°F to 80°F3. 65°F to 85°F4. 75°F to 95°F1. Secure the AUX VENT switch

2. Turn the air-conditioning switchto OFF and then to ON

3. Turn the air-conditioning switchto OFF, then to RESET, and thento ON

4. None

3-65. What valve is controlled by the auxvent switch?

3-66. What is the function of theenvironmental control panel?

1. To control temperature2. To control pressurization3. To control anti-icing function4. All the above

3-67. The ground-aircheck valve is asplit-flapper valve which is spring-loaded to the open position untilengine start-up.

1. True2. False

3-68. What component(s) interconnect withthe ram-air high and low-temperaturelimit switch circuitry?

1. Auxiliary vent switch2. Bleed-air flow control valve and

ram-air shutoff switch3. Both 1 and 2 above4. Aux bent valve and aux vent

switch

3-69. With the cabin air temperatureselector in the automatic modewithin what temperature range canthe cabin temperature be selected?

3-70. What is the temperature limit on thecabin temperature control valvewhile in the automatic mode?

1. 160°±5°F2. 160°±15°F3. 185°±5°F4. 185°±15°F

1. Cabin temperature modulatingvalve

2. Ram-air valve3. Aux-vent valve4. Cabin-outflow valve

22

3-71. Icing of the water separator willonly occur at low altitudes wheremass airflow and temperature arerelatively high.

1. True2. False

1. 0°F2. 15°F

3-72. What component in the refrigerationpack low-limit control senses ductair temperature and compares it withan internally generated reference?

1. Pneumatic pickups2. Inlet air sensor3. Thermistor4. Temperature limit thermostat

3-73. What are the two physically separatedpackages of the refrigerationsubsystem?

1. Refrigeration and airconditioning

2. Heating and air conditioning3. Refrigeration and cabin air/water

separator4. Air conditioning and

pressurization

3-74. Water vapor condenses as icecrystals when the turbine dischargeair drops below what maximumtemperature

3. 32°F4. 40°F

3-75. In the bleed-air system, whatcomponent senses the bleed-airpressure in the duct upstream fromthe bleed-air flow control andshutoff valve?

1. Overtemperature pressure sensor2. Temperature control orifice3. Temperature sensor4. Pressure transmitter

23

A S S I G N M E N T 4

Textbook Assignment: “Navy Aircrew Common Ejection Seat (NACES),” chapter 5, pages 5-1through 5-38.

4-1. What configuration is used in theNACES system to meet the exactrequirements of the crew stationdesigner?

1. Reversible2. Flexible3. Standard4. State-of-the-art

4-2. What does the acronym NACES mean?

1. Navy Aircraft Ejection Seat2. Navy Aircrew Common Ejection Seat3. Naval Aircrew Escape System4. Naval Automatic Control Escape

System

4-3. What type ejection seat is used inthe F/A-18C aircraft?

1. SJU-17(V) 1/A2. SJU-17(V) 2/A3. SJU-17(V) 3/A4. SJU-17(V) 4/A

4-4. The NACES may be used in either theF/A-18C/D, F-14A or A-6E aircraft?

1. True2. False

4-5. Who is responsible for removing andinstalling the ejection controlhandle safety pin prior to and afterflight?

1. Plane captain only2. Aircrew only3. Plane captain prior to and

aircrew after4. Aircrew prior to and plane

captain after

4-6. The SJU-17(V)1/A ejection seatprovides escape capabilities withinwhich of the following parameters?

1. All altitudes and airspeeds2. A maximum of 600 knots speed and

50,000 feet altitude3. Zero altitude and zero airspeed4. Both 2 and 3 above

4-7. What is the primary purpose of thebarostatic release unit?

1. To act as a backup in the eventof electronic sequencer failure

2. To release the occupant from theseat

3. To release the personalparachute at a determinedaltitude

4. To provide automatic operationof the emergency restraintrelease

24

4-8. After seat ejection, the seat is

4-9.

4-10.

4-11.

4-12.

stabilized and the forward speed isretarded by what component(s)?

1. Personal parachute2. Drogue parachute3. Bridle system4. Both 2 and 3 above

What component automatically controlsdrogue deployment, seat/man separa-tion, and parachute deployment afterejection?

1. Barostatic release unit2. Time release mechanism3. Drogue/bridle release system4. Multimode electronic sequencer

The NACES consists of what totalnumber of main assemblies?

1. Six2. Five3. Three4. Four

What is the primary purpose of thecatapult assembly?

1. To jettison the seat from theaircraft

2. To provide initial power for seatejection

3. To secure the seat to theaircraft structure

4. Both 2 and 3 above

The seat bucket assembly consists ofthe underseat rocket motor, lateralthrust motor, leg restraint snubbers,two pitot assemblies, shoulderharness control lever, and pinpuller.

1. True2. False

4-13. When the ejection seat is installedin the aircraft, what componentlocks it to the catapult?

1. Upper right main beam2. Upper left main beam3. Top latch plunger4. Barostatic release unit

4-14. What barrels make up the catapultejection gun?

1. Inner, outer only2. Inner, intermediate only3. Intermediate, outer only4. Inner, intermediate, outer

4-15. What crossbeam takes the full thrustof the catapult during ejection?

1. Top crossbeam2. Center crossbeam3. Bottom crossbeam

4-16. What services do the seat bucketslippers provide?

1. Attachment points for theseatbucket to the mainbeam

2. Damping out lateral movement3. Smooth movement of the seat

bucket

4-17. What total number of slippers areattached to the guide rails of themainbeam assembly?

1. Five2. Six3. Three4. Four

4-18. What handle is located on the leftside of the seat bucket?

1. Safe/arm control2. Seat height adjustment3. Shoulder harness control4. Manual override

25

4-19. What component on the NACES protects the occupant in the event of rapid forward deceleration?

1 . Static lanyard 2 . Spring loaded withdrawal plunger 3 9 Shoulder harness reel 4 a Shoulder harness strap quadrant

4-20. Which of the following is a charac- teristic of the PRDM?

1 . Has a cylindrical body 2 8 Has a gas operated secondary

cartridge 3 . Is a sealed unit 4 . Each of the above

4-21. The PRDM primary cartridge is fired by what means?

1 . Mechanically 2 . Ballistically 3 . Electrically 4 * Gas

4-22. The PRDM can be initiated by which of the following means?

1 . Electronic sequencer 2 . Manual override system 3 0 Restraint release unit 4 I Each of the above

4-23. The parachute withdrawal line is attached to the PDRM by what means?

1 . By scissor mechanism 2 * By a bolt and lock nut 3 . By a sliding stirrup 4 . By a spring-loaded quick release

pin

4-24. The electronic sequencer is mounted on the NACES at what point?

1 * Across the mainbeam assembly behind the seat bucket

2 . Across the mainbeam assembly above the main parachute

3 8 Across the mainbeam assembly below the main parachute

4 . Across the mainbeam assembly’s lower aft end

4-25. Upon activation, the electronic sequencer determines the mode of ejection and supplies power to the start switches?

1 . True 2 a False

4-26. Which of the following is a function of the barostatic release unit impulse cartridge?

1 6 Provides the necessary gas for the restraint release assembly

2 . Provides the necessary gas pressure to retract the capsule Peg

3 . Provides the necessary gas to prevent mechanical initiation

4-27. What component of the barostat assembly prevents the delay mechanism from operating at altitudes in excess of barostat ratings?

1 . Quick release pin 2 . Bellows device unit 3 . Peg engagement mechanism 4 . Diaphragm assembly

26

4-28. What action or component supplies thepower source to fire the droguedeployment catapult cartridge?

1. Retraction of the capsule peg2. Gas pressure from the primary

initiators3. The delay mechanism firing pin4. The electrical inputs from the

electronic sequencer

4-29. What is the primary function of thedrogue deployment catapult?

1. To stabilize the ejection seat2. To rapidly deploy the drogue and

bridle assembly3. To prevent parachute entanglement4. To ensure a rapid escape from the

ejection seat

4-30. Which of the following is a charac-teristic of the drogue deploymentcatapult assembly?

1. Contains a two-piece telescopepiston

2. Contains an enlarged upper end3. Is fitted with a drogue and

canister4. Each of the above

4-31. The drogue deployment catapult ismounted in what location on theejection seat?

1. Aft RH aide of the seat structure2. Aft LH side of the upper cross

beam3. Outboard of the LH lower cross

beam4. Outboard of the RH main beam

4-32. What size drogue chute is used in theNACES?

4-33. During the ejection sequence, whatcomponent(s) supplies the gaspressure to operate the barostaticrelease unit delay mechanism?

1. Primary initiators2. Multipurpose initiators3. Start switch assemblies4. Electronic sequencer

4-34. Which of the following componentshouses the start switches?

1. Multipurpose initiator2. Static lanyard assembly3. Electronic sequencer

4-35. During ejection, the start switchesprovides what action?

1. Battery power2. Initiation set-up3. Start signal to the electronic

sequencer4. Time-delay start time

4-36. What is the primary purpose of thepitot assemblies?

1. To supply pressure to the startswitches for ejection

2. To supply dynamic pressureinputs to the electronicsequencer

3. To supply static base pressureto the electronic sequencer

4-37. Which of the following componentsreceives gas pressure from the upperface of the RH ballistic manifold?

1. Shoulder harness reel2. Parachute deployment rocket

motor3. Upper drogue bridle release4. Each of the above

1. 1.45 mm2. 2.10 mm3. 2.50 mm4. 8.25 mm

27

4-38. What total number of ballisticmanifolds is/are installed on theNACES seat?

1. One2. Two3. Three4. Four

4-39. What item or action secures the pitotarms in the stowed or deployedpositions?

1. Release piston2. Locking plunger3. Quick release pin4. Static gas pressure

4-40. What total number of connectorsis/are present on the upper face ofthe LH ballistic manifold?

1. One2. Two3. Three4. Four

4-41. What is the primary purpose of thethermal batteries?

1. To supply power for seat opera-tion

2. To supply backup power forsequencer operation

3. To supply initial power forsequencer operation

4. To supply initial power for theseawars

4-42. Thermal batteries are mounted in eachof the main beam assemblies?

1. True2. False

4-43. What total number of propellanttubes make up the underseat rocketmotor?

1. Ten2. Thirteen3. Fifteen4. Seventeen

4-44. What is the purpose of the lateralthrust motor?

1. Serves the same purpose as theunderseat rocket motor

2. To provide additional boost tounderseat rocket motor

3. Permits a divergent trajectoryto the ejected seat

4-45. When the safe/arm handle is in thesafe position, the pilot sees thehandle as what color(s)?

1. Yellow2. Black and yellow3. White4. Red

4-46. What total number of connectors areon the lower face of the RH ballis-tic manifold assembly?

1. Five2. Two3. Three4. Four

4-47. Forward movement of the legrestraints is prevented by whatcomponent?

1. Seat bucket snubbers2. Leg restraint locks3. Leg restraint snubbers4. Leg restraint control lever

28

4-48. What component restricts the opera-tion of the manual override handlewhen the seat is installed in theaircraft?

1. Safety pin2. Thumb button3. Pin puller4. Safe/arm handle

4-49. Operation of the manual overridehandle simultaneously operates thesafe/armed handle to the safeposition?

1. True2. False

4-50. During ejection, what component(s)provides the gas pressure to operatethe pin puller?

1. The right hand seat initiatoronly

2. The left hand seat initiator only3. Both 1 and 2 above

4-51. Which of the following component(s)are part of the lower harness releasemechanism?

1. Leg restraint line locks2. Negative-g strap locks3. Lower harness locks4. Each of the above

4-52. The parachute container houses whichof the following parachute?

1. Controller drogue2. Main drogue3. Personnel and ribbon drogue

4-53. In the NACES, what type drogue isattached to the parachute crownbridle apex?

1. 1.5m main2. 1.5m personnel3. 1.5m ribbon4. 1.5m controller

4-54. What force actuates the firing pinin the catapult firing mechanism?

1. Ballistic gas2. Mechanical3. Electrical inputs

4-55. What maximum number of inches oftravel is required before the pistonhead shears the three dowel screwsin the guide bushing?

1. 382. 423. 604. 72

4-56. During ejection sequence, gaspressure from what cartridge is usedto operate the shoulder harnessrelease cartridge?

1. Multipurpose initiator2. Shoulder harness impulse

cartridge3. Left hand seat initiator4. Right hand seat initiator

4-57. Which of the following forces causesthe secondary cartridge to face firethe parachute deployment rocketmotor in the event of sequencerfailure?

1. Ballistic gas from the harnessrelease unit cartridge

2. Ballistic gas from the emergencyrestraint release cartridge

3. Both 1 and 2 above4. Ballistic gas from the multi-

purpose initiator cartridge

4-58. After ejection has been initiated,what source supplies the electronicsequencer with electrical power?

1. A single on-board thermalbattery

2. Two on-board thermal batteries3. Internal aircraft power4. Start switches

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4-59. What source activates the multipur-pose initiators upon ejection?

1. Ballistic gas pressure fromprimary initiators

2. Ballistic gas pressure fromthermal batteries

3. Two pyrotechnic cartridges, after42 inches of travel

4. Electronic sequencer, 120milliseconds after activation

4-60. In the absence of a start switchsignal, the electronic sequencertakes what action?

1. It continues in the “wait” mode2. It activates automatically after

approximately 200 milliseconds3. It initiates the underseat rocket

motor4. It activates the start switch

4-61. What is the total burn time of theunderseat rocket motor?

1. 200 milliseconds2. 220 milliseconds3. 250 milliseconds4. 2 seconds

4-62. Which of the following is/are thecritical actions for an electronicsequencer?

1. Sensing the seats altitude andairspeed

2. Choosing the appropriate timingsfrom a set of available sequences

3. Both 1 and 2 above4. Providing initial start-up from

the thermal batteries

4-63. Speed and altitude are measured fromthe sequencer by what three types ofsensors?

1. Pitot pressure, altitude,airspeed

2. Pitot pressure, altitude, basepressure,

3. Pitot pressure, base pressure,accelerometer

4. Altitude, airspeed, attitude

4-64. What total number of shielded cablesare used to transmit electricalsignals to and from the electronicsequencer?

1. Six2. Seven3. Eight4. Nine

4-65. What is the total number of opera-tional ejection modes of the NACES?

1. Five2. Seven3. Three4. Nine

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IN COMPLETING ITEMS 4-66 THROUGH 4-70,SELECT FROM COLUMN B THE AIRSPEED ANDALTITUDE INFORMATION THAT APPLIES TO THEMODE OF OPERATION IN COLUMN A. ITEMS INCOLUMN B MAY BE USED MORE THAN ONCE.

A. Modes B. Airspeeds/Altitudes

4-66. Mode 1 1. Airspeed above 500knots and altitude

4-67. Mode 2 below 8,000 feet

4-68. Mode 3 2. Altitude above18,000 feet

4-69. Mode 43. Altitude between

4-70. Mode 5 8,000 and 18,000feet

4. Airspeed below 350knots and altitudebelow 8,000 feet

4-71. During the ejection sequence, thePDRM fires and withdraws the para-chute in its bag.

1. True2. False

U. S. GOVERNMENT PRINTING OFFICE: 1993–5 3 3-1 3 1 / 0 0 0 2 331

4-72. During ejection and shortly afterthe parachute starts to deploy, whatparachute part is jettisoned toavoid entanglement and allow a cleanseat/man separation?

1. Parachute extractor2. Drogue bridle3. Drogue chute4. Stabilizer chute

4-73. What seat survival kit is used withthe NACES?

1. SKU-7/A2. SKU-8/A3. RSSK-74. RSSK-8

4-74. At what time during ejection willelectronic sequencer timing begin?

1. When the ejection control handleis pulled

2. After approximately five inchesof seat upward travel

3. Immediately after seat ejection4. When the start switches close

4-75. What NAVAIR manual should be used toorder repairable/nonrepairable partsfor the NACES?

1. A1-F18AE-442. 01-F18AE-4-13. 01-13-1-364. 13-1-36