TM 55-1520-210-23-3TECHNICAL MANUAL AVIATION UNIT AND INTERMEDIATE MAINTENANCE INSTRUCTIONS ARMY MODEL UH-1H/V/EH-1H/X This manual supersedes TM 55-1520-210-23-3, 20 February 1979, including all changes. HEADQUARTERS, DEPARTMENT OF THE ARMY 30 SEPTEMBER 1987 .......................................................................................................................................7 V Oil System ............................................ 4-41 VII Power Controls...................................... 4-1 II Cooling System .........................S......................................................................................................................................................................................................................................................... II Skids/Struts .................................................................................................................................... 4-13 II Air Induction System ............................................... Overhaul and Retirement Schedule .........................C...... 4-44 VI Ignition System........................................... III Floats................................................................................................ 4-61 VIII Quick Change Assembly (AVIM)...................... 4-86 CHAPTER 2 Section Change 8 i .............................army.. DISTRIBUTION STATEMENT A: Approved for public release........................TM 55-1520-210-23-3 TECHNICAL MANUAL HEADQUARTERS DEPARTMENT OF THE ARMY WASHINGTON..... If you find any mistakes or if you know of a way to improve the procedures.................................................................................................................................................................................................. 4-13 IV Exhaust System ............. Army Aviation and Troop Command........... Mail your letter............ distribution Is unlimited................. Hoisting......................................................... 30 September 1987 TM 55-1520-210-23-3 AVIATION AND INTERMEDIATE MAINTENANCE INSTRUCTIONS ARMY MODEL UH-1HNIEH-1HIX HELICOPTER REPORTING OF ERRORS You can help improve this manual............................................................................................ You may also submit your recommended changes by Email directly to <mpmtP/avma28@stlouisemh7......................... U.... Tailboom...............mil>.......................................... MO 631201798............................................................... ATTN: AMSATIMP.......................... IV Skis..... Mooring.............................. St................................................................................................ D................................................. 1-1 140 1-54 146 1-110 1-115 I II AIRFRAME Fuselage........ 4-42.................................................................................. and Sling Loading .... Louis........... please let us know............... DA Form 2028 (Recommended Changes to Publications and Blank Forms). or DA Form 20282 located in the back of this manual directly to: Commander.......................................... Handling............................. A reply will be furnished to you.......... Inspection Requirements ..................................................... 2-1 2-193 CHAPTER 3 Section ALIGHTING GEAR I Landing Gear.................................................. A reply will be furnished to you............................. 4300 Goodfellow Blvd................. Lubrication........................ Jacking................. Flight Safety Critical Aircraft Parts........................................................................................................... V Brakes ............................................................................................................................................................................................................................... TABLE OF CONTENTS Page CHAPTER 1 Section I II III IV V VI INTRODUCTION Servicing... 3-1 3-30 3-30 3-30 3-30 CHAPTER 4 Section POWER PLANT I Power Plant .................................. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 5-54. . . . . . . . . . . . Lighting Provisions . Tall Rotor Blades . . . . . . . . . intermediate Gearbox . . . . II. . . . . . . . . . . . DRIVE TRAIN SYSTEM Main Driveshaft . . . . 5-1 5-16 5-38. . . . . . . . . III. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FUEL SYSTEM Fuel Cells . ROTORS Main Rotor System . . . . . . . IV. . . . . 11-1 11-1 ii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV. VIII. . . . . . . . . . . .45 5-105 5-107 5-119 5-132 5-138 CHAPTER 6. . . . Miscellaneous Instruments . . . . . . . FLIGHT CONTROLS Controls Surfaces . . . . . . . . . V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Instrument Panels . . . . . . . . . . . . . . . . . . . . . . . Oil Systems . . . . . . . . . . . . . . . . . . . . . . . . Main Rotor Blades . . . . . . . . . . . . . . . . . . . . . . . . . . Tall Rotor Driveshaft . Flight Instruments .. . . . . . . . . . . . . Tall Rotor System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INSTRUMENT SYSTEMS Instrument Maintenance . . . 7-1 7-51 CHAPTER 8. . . . . . . . . . . . . Fuel Systems . . . . . Flight Control Components . . II. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V. . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . .. Section I. . . . . . . VI. . . . . . . . . . . . . . . . . . . . .. . . . . . . . . Section I. . . . . . . . . . ELECTRICAL SYSTEMS Direct Current Power Distribution System . Ignition System . Section I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II. . . . . . . . . . HYDRAULIC AND PNEUMATIC SYSTEMS Hydraulic System . . . III. . . . Tall Rotor Hub and Controls. . . . . . . . . Main Rotor Controls . . . . . . . . . . VI. . Tall Rotor Hub and Blade Assembly . . . . . . . . . . . . Main Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Clutch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V. . . . . . . . II. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VII. . . . . . . . . . . . . . . . . . . . Navigation Instruments . . . . . . . . . . . . . . . . . . . Section I. . . . . . . . . . . . . . . III. . . . .TM 55-1520-210-23-3 TABLE OF CONTENTS (Cont) Page CHAPTER 5. . . . .2 6-138 6-147 6-167 CHAPTER 7. . . . . . . . . . . . . . . . . . . . . . . . . . IX. . . . . . . . . . . . . . . . . . . . . . 8-1 8-2 8-22 8-33 8-37 8-51 CHAPTER 9. . . . . . . . . . . . . . . 6-1 6-29 6-29 6-116. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pneumatic System (Not Applicable) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tall Rotor Gearbox . . . . . . . . . . . . . . Tracking Procedures . . . . . . . . . . . . . . . . . . . . . . . . . IV. . . . Miscellaneous Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . Il. . . . . 10-1 10-11 CHAPTER 11. . . . . . . . . . . . . . . . . . . . . . . . . . . Main Rotor Hub . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VI. . . . . . . . . . . . . Engine instruments . . . . . . . . . . . . . . . . . . . . Section I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Starting System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . II. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1 9-41 9-52 9-54 9-56 9-94 CHAPTER 10. . . . Alternating Current Power Distribution System . II. . . . . . Section I. . . . . . V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III. . . . . . . . . VII. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13-15 Winterization Equipment. . . . A-1 APPENDIX MAINTENANCE ALLOCATION CHART APPENDIX B Section I II III Three Levels of Maintenance Concept. . . . . . 12-5 Rear View Mirror . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-10 . . . . . . . . . . .13-1 Air Cooling System . .. 13-18 CHAPTER 14 Section I II Personnel Rescue Hoist. .. . . . . . . . . .E-3 Intermediate Storage . . . D-1 APPENDIX E Section I II III IV STORAGE OF AIRCRAFT APPENDIX WIRING DIAGRAMS. . . . . . . . . . . . . .E-2 Short Term Storage. . . . . . . . . . . . . . . . 17-1 A REFERENCE. . . . . . . . . . . . . . . . . . . . . . . . . .B-76 APPENDIX C AIRCRAFT INVENTORY MASTER GUIDE . . . . . . . . . . . . .B-1 Maintenance Allocation Chart . . . . . . . . . . . . . . . . . . . . . . . . .14-1 Cargo Suspension Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-76 CHAPTER AUXILLIARY POWER PLANTS 15 HOIST AND WINCHES (Not Applicable) . . . E-1 Flyable Storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . 12-1 Windshield Wiper System. . . . . . . . . . . . . . . . . .F-1 INDEX F General Information . . . . . .15-1 CHAPTER 16 MISSION EQUIPMENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12-20 ENVIRONMENTAL CONTROL SYSTEM CHAPTER 13 Section I II III Heating System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-1 CHAPTER 17 EMERGENCY EQUIPMENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Index 1 iii/(iv blank) . . . . . . . . . . . . . . . . . . . . . . . . . . . .TM 55-1520-210-23-3 TABLE OF CONTENTS (Cont) CHAPTER 12 Section I II III UTILITY SYSTEMS Fire Detector System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . C-1 APPENDIX D ILLUSTRATED FIELD MANUFACTURE ITEMS LIST . . . . . . . . . . B-6 Tools and Test Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. intermediate. and minor repair/replacement to the flight control. Perform operational and continuity checks and make minor repairs to the electrical system. service and make operational. group. or alignment. power train and fuel systems. daily. functional adjustments. Replace worn or damaged modules/components which do not require complex adjustments or system alignment and which can be removed/installed with available skills. capacity and pressure checks to hydraulic systems. tools and equipment. Identify the cause of equipment/system malfunctions using applicable technical manual troubleshooting instructions. AVIM which corresponds to an F Code in the RPSTL. The maintenance to be performed below depot and in the field as described as follows: (1) Aviation Unit Maintenance (AVUM) activities will be staffed and equipped to perform high frequency “On-Aircraft” maintenance tasks required to retain or return aircraft to a serviceable condition.TM 55-1520-210-23-3 APPENDIX B MAINTENANCE ALLOCATION CHART SECTION I. Perform maintenance inspections and servicing to include preflight. built-in-test equipment (BITE). The maintenance capability of the AVUM will be governed by the Maintenance Allocation Chart (MAC) and limited by the amount and complexity of ground support equipment (GSE). The manufacture of air frame parts will be limited to those items which can be fabricated with tools and equipment found in current air mobile tool and shop sets. Aviation Intermediate Maintenance (AVIM) and Depot Maintenance are depicted on the MAC as: AVUM which corresponds to the O Code in the RPSTL. Inspect. Perform servicing. These maintenance levels. Accomplish air frame repair which does not require extensive disassembly. MAINTENANCE CHART. battalion headquarters and detachment size units B-1 . This Maintenance Allocation Chart (MAC) assigns maintenance functions in accordance with the Three Levels of Maintenance concept for army aircraft. Evacuate unserviceable modules/components and end items beyond the repair capability of AVUM to the supporting AVIM. DEPOT which corresponds to a D Code in the RPSTL b. and number of spaces and critical skills available. facilities required. installed aircraft instruments. The range and quantity of authorized spare modules/components will be consistent with the mobility requirements dictated by the air mobility concept. THREE LEVELS OF MAINTENANCE CONCEPT INTRODUCTION B-1. the requirement to conserve personnel and equipment resources and air mobility requirements. jigging. (Assignments of maintenance tasks to divisional company size aviation units will consider the overall maintenance capability of the division. or easy to use/interpret diagnostic/fault isolation devices (TMDE).) (a) Company Size Aviation Units: Perform those tasks which consist primarily of preventive maintenance and maintenance repair and replacement functions associated with sustaining a high level of aircraft operational readiness. (b) Less than Company Size Aviation Units: Aviation elements organic to brigade. ALLOCATION a. propulsion. Aviation Unit Maintenance (AVUM). periodic and special inspections as authorized by the MAC or higher headquarters. In cases of operational necessity. Maintains authorized operational readiness float aircraft. adjusts. d. calibrates. responsive “One Stop” maintenance support. b. stop drilling. Authorized maintenance includes replacement and repair of modules/components and end items which can be accomplished efficiently with available skills. Higher maintenance levels will perform the maintenance functions of lower maintenance levels when required or directed by the appropriate commander. AVIM units will have the capability to determine the serviceability of specified modules/components removed prior to the expiration of the Time Between Overhaul (TBO) or finite life. Maintenance tasks performed by these units will be those which can be accomplished by the aircraft crew chief or assigned aircraft repairman and will normally be limited to preventive maintenance. Performs all maintenance functions authorized to be done at AVUM. This level will perform aircraft weight and balance inspections and other special inspections which exceed AVUM capability. tests. Established the Direct Exchange (DX) program for AVUM units by repairing selected items for return to stock when such repairs cannot be accomplished at the AVUM level. Authority to requisition. Only the lowest level of maintenance authorized to perform a maintenance function is indicated. MAINTENANCE a. Provides quick response maintenance support. (2) Time required. c. module/component fault diagnosis and replacement of selected modules/components. minor adjustments. repairs. Provides B-2 collection and classification services for serviceable/unserviceable material. and aligns aircraft system modules/components. tools. f. The Maintenance Allocation chart assigns maintenance functions to the lowest level of maintenance based on past experience and the following consideration: (1) Skills available. Additional intermediate maintenance support will be provided by the supporting nondivisional AVIM unit. stock. A maintenance function assigned to a maintenance level will automatically be authorized to be performed at any higher maintenance level. at the request of the lower maintenance level. application of nonstress patches. Inspects. USE OF THE ALLOCATION CHART. Repair functions will normally be accomplished by the supporting AVIM unit. (2) Aviation Intermediate Maintenance (AVIM) provides mobile. Air frame repair and fabrication of parts will be limited to those maintenance tasks which can be performed with available tools and test equipment. troubleshoots. e. and equipment. The assignment of a maintenance function will not be construed as authority to carry the associated repair parts in stock. and technical assistance through the use of mobile maintenance contact teams. Operates a cannibalization activity in accordance with AR 750-50. or otherwise secure necessary repair parts will be as specified in the repair parts appendix. fittings and items of common hardware. Module/component disassembly and repair will support the DX program and will normally be limited to tasks requiring cleaning and the replacement of seals. diagnoses. servicing. inspections. Repair of equipment for return to user will emphasize support or operational readiness requirements. (The aircraft maintenance company within the maintenance battalion of a division will perform AVIM functions consistent with air mobility requirements and conservation of personnel and equipment resources. Unserviceable reparable modules/components and end items which are beyond the capability of AVIM to repair will be evacuated to Depot Maintenance.) B-2. be . on-the-job training. spot painting. A maintenance function that cannot be performed at the assigned level of maintenance for any reason may be evacuated to the next higher maintenance organization. maintenance functions assigned to a higher maintenance level may. including aircraft recovery and air evacuation. (Maintenance functions which are not conducive to sustaining air mobility will be assigned to depot maintenance).TM 55-1520-210-23-3 are normally small and have less than ten aircraft assigned. Normally there will be no divation from the assigned level of maintenance. (3) Tools and test equipment required and/or available. h. d. malfunction. (3) If the authorization will be granted to perform maintenance. to paint. or compressed air supplies. or failure in a part. one of which is a certified standard of known accuracy. to drain. fault. equipment. The act of emplacing. or to replenish fuel. Maintenance functions. i. The rebuild operation includes the act of returning to zero those age measurements (hoursmiles. b. Overhaul is normally the highest degree of maintenance performed by the Army. g. Test. to preserve.S.) considered in classifying Army equipments/components. The special tools. Change 4 B-3 . Army Electronics Command equipment will be performed by designated U. hydraulic fluids. k. part. g. Service. or module (component or assembly) for an unserviceable counterpart. Operations required periodically to keep an item in proper operating condition. Army Electronics Command personnel. Inspect. mechanical and/or electrical characteristics with established standards through examination. to detect and adjust any discrepancy in the accuracy of the instrument being compared. subassembly. To verify serviceability and detect incipient failure by measuring the mechanical or electrical characteristics of an item and comparing those characteristics with prescribed standards. To adjust specified variable elements of an item to bring about optimum or desired performance. B-3. within prescribed limits. The higher level of maintenance has the authority to determine: (1) If the lower level is capable of performing the work. or module (component or assembly) in a manner to allow the proper functioning of an equipment or system. or system. Install. This transfer of a maintenance function to a lower maintenance level does not relieve the higher maintenance level of the responsibility of the function. or by setting the operating characteristics to specified parameters. Adjust. j. or fixing into position an item. To determine the serviceability of an item by comparing its physical. etc. (2) If the lower level will require assistance or technical supervision and on-site inspection. DEFINITIONS. subassembly. To maintain. Repair.TM 55-1520-210-23-3 specifically authorized by the maintenance officer of the level of maintenance to which the function is assigned. Replace.e. module (component or assembly). end item. h. Align. Maintenance functions will be limited to and defined as follows: a.e. The application of maintenance services or other maintenance action to restore serviceability to an item by correcting specific damage. e. to clean (decontaminate). DMWR) in appropriate technical publications. Rebuild. Rebuild is the highest degree of materiel maintenance applied to Army equipment. seating. Overhaul does not normally return an item to like new condition. lubricants. To determine and cause corrections to be made or to be adjusted on instruments or test measuring and diagnostic equipments used in precision measurement. Organizational through depot maintenance of the U. c. Changes to the Maintenance Allocation Chart will be based on continuing evaluation and analysis by responsible technical personnel and on reports received from field activities. Overhaul. by bringing into proper or exact position. Consists of comparisons of two instruments. That maintenance effort (service/action) necessary to restore an item to a completely serviceable/operational condition as prescribed by maintenance standards (i.S. Consists of those services/actions necessary for the restoration of unserviceable equipment to a like new condition in accordance with original manufacturing standards. f. Calibrate. required by the lower level of maintenance to perform this function will be furnished by the maintenance level to which the function is assigned. etc. i. The act of substituting a serviceable like type part. and refueling systems. mounts (engine and transmission). motors. navigation instruments. mooring. clutches. sending units. preservation requirements. force gradients. engine instruments. miscellaneous instruments (i. pulleys. Fuselage. and mechanical mechanisms. handling. 11 Flight Controls System Control sticks. oil systems. as systems. blades. actuators. hangers. skids. swashplates. hub moment springs. armor. hubs. spot painting. carburetors. and freewheeling units. Change 1 Electrical Systems regulators. 03 Drive Train Systems 10 Fuel Systems Tanks. cylinders. filters. clocks). and subassembly painting requirements. hoisting. cooling Removal. generators. 07 08 Alighting Gear 09 B-4 Propellers/Rotors Systems Propellors. filters. complete painting. servos. filters/particle separators. STANDARD GROUPS. rotors (main and tail). gearboxes. modules. ignition systems. Landing gear. Power Plant Installation installation. systems. for more detailed functions. and tiedowns. jacking. control surfaces. floats. cleaning. dampeners. 02 Airframe Transmissions. subsystems. 04 Hydraulic and Pneumatic Systems Pumps. figure 2. batteries. skis. pumps.TM 55-1520-210-23-3 B-4. air induction. empennage. auxiliary fuel systems. oil tanks. bellcranks. panels. decks. retirement requirements. pedals. e. starters and accumulators. components. applicable. reservoirs.. and trim actuators (mechanical). pylons. rotor brakes. and avionics provisions. lighting. valves. push-pull rods. seats. stabilizer bars. components. or specific parts noted. and flow meters. ramps. oil systems. groupings as individual chapters with sections in each chapter relative to the individual complete The standard groupings shown below are used. wings. torque tubes. and Quick Change Assemblies (QCA). and support assemblies. harnesses. . inverters. power control. quadrants. exhaust. bearings. wheel brakes. caution and warning lights. governors. valves. pumps (engine driven). throughout this MAC Maintenance assemblies. starters. cells. fuel controls. towing. inspection lubrication requirements. and overhaul requirements. Motors. shafting. cables.) 05 Instrument Systems Flight instruments. (See Power Plant Items. weight and balance requirements. struts. manuals and RPSTLs reflect these standard AIRFRAME ITEMS GROUP NUMBER DESCRIPTION GROUP NUMBER DESCRIPTION 00 Aircraft System 06 01 Aircraft General Servicing. fault isolation systems. axes. and de-ice/anti-ice systems. In addition. slings. TOOLS AND TEST EQUIPMENT/ (SECTION III). oxygen systems.pods. 15 Mission Equipment 18 Communications and Navigational Black Boxes. Hoists and Winches Installed Avionics Components Cargo/rescue hoists. B-8. stores. REMARKS (SECTION IV). windshield wiper systems. WORK TIMES. loading systems. the number to aid in identifying the tool/device. as 0. hooks. and litters. B-7. SYMBOLS. test. control mixing valves.TM 55-1520-210-23-3 GROUP NUMBER 12 DESCRIPTION Utility System. and support equipment required to do maintenance functions are listed with a reference number to permit cross-referencing to column 5 in the MAC. GROUP NUMBER DESCRIPTION 16 Fire detecting/extinguishing systems. portable fire extinguishers. Column 6 of the MAC contains alphabetic reference codes which are explained in Section IV of this appendix. air conditioners. AVIM AND DEPOT” as placed on the Maintenance Allocation Chart indicate the level of Maintenance responsible for performing the particular maintenance function based upon assigned skills. The symbol -o— identifies the level of Maintenance authorized to perform a maintenance function and indicates that work time figures are being developed and will be entered at a later date. tools and test equipment and time required to accomplish maintenance. canopies. Special tools. defrosters. and first aid kits. and ducts. and ducting. and emergency release systems.1 and also indicates the level of authorized maintenance. mirrors. B-5 . When developed. B-5. armament. photography. Spraying equipment. the maintenance category authorized to use the device is listed along with the item National Stock Number and if applicable. 17 13 14 Emergency Equipment Environmental Control Systems (ECS) Heaters. winches. The letters “AVUM. Ejection seats. B-6. jettison system. this time will appear: for example. reconnaissance. racks. Auxiliary Power Plants (APP) Fuel. exhaust. Specific notes are given to further Identify or describe the extent or limit of maintenance to be performed. and b.102 Inspect Repair 100.TM 55-1520-210-23-3 SECTION II.102 102.120.102 0105 Hoist — ● — 0106 Preservation — ● — 0107 Weight & Balance 0108 Spot Paint 0109 Complete Painting 0110 Sub-Assembly Painting Servicing 0110 0200 Airframe 100. 0100 Aircraft General 0101 Clean — ● — 0102 Moor — ● — 0103 Tow — ● — 100 0104. Jack — ● — 100. MAINTENANCE ALLOCATION CHART MAINTENANCE ALLOCATION CHART NOMENCLATURE OF END ITEMS HELICOPTER UTILITY – TACTICAL TRANSPORT UH-1H/UH-1V/EH-1H (1) GROUP (2) (3) NUMBER COMPONENT/ASSEMBLY MAINTENANCE FUNCTION (4) MAINTENANCE CATEGORY AVIM AVUM DEPOT (5) TOOLS AND EQUIPMENT (6) REMARKS NOTE The extent of maintenance to be performed by AVUM as indicated in this MAC is governed by the size of the Unit and the TOOlS authorized (Refer to paragraph B-1 b(1) a.).118 121 — ● — 100 118 100. 118 Overhaul B-6 A .102 103 117. Part Number Fabricate from: Material: 206-072-221-3 LANYARD NSN 4010-00-075-7941 D-309 .TM 55-1520-210-23-3 Figure D-278. Assembly NSN 8305-00-267-3009 Nylon Webbing Type XVIl. MIL-W-4088 . D-310 Part Number Fabricate from: Material: 205-070-772-1 STRAP.TM 55-1520-210-23-3 Figure D-279. 11.063 Inch Thick. 0.TM Figure D-280.5 Inch Wide. Part Number Fabricate from: Material: 55-1520-210-23-3 205-070-795-1 COVER NSN 9535-00-232-0378 2024 AL ALY. Federal Specification QQ-A-362 T3. 3.70 Inch Long D-311 . TM 55-1520-210-23-3 D-312 Figure D-281. . Type 2 Grade 1 D-313 . Part Number Fabricate from: Material: 205-070-882-1 STENCIL NSN 9310-00-265-6797 Stencil Board.TM 55-1520-210-23-3 Figure D-282. Federal Specification UU-S-625. 0531 Inch Wide Make From MS20257HP2-130 (Length 13. 14. Part Number Fabricate from: Material: D-314 205-072-039-1 DOOR.2 Inch Wide.187 Inch Thick. 4. Federal Specification MIL-P-5425 FINA. Assy Of NSN 9330-00-291-4800. 0.TM 55-1520-210-23-3 Figure D-283. NSN 5340-00-993-1461 Plastic sheet Acrylic Transparent.4 Inch Long Leaf. Butt Hinge A1 A AL ALY 0.0) .