TM 1-1520-238-10 2-86 Change 8 Section XV. SERVICING, PARKING, AND MOORING 2.54 SERVICING. This section describes servicing information and proce- dures for various systems and components. Servicing points for fuel, engine oil, main transmission oil, nose gearbox. and APU oil are illustrated in figure 2-45. Fuel, lubricants, specifications, and fuel capacities are listed in table 2-7. 2.54.1 External Hydraulic, Pressurized Air and Elec- trical Requirements. a. External Hydraulic Power Requirements. Exter- nal hydraulic power requirements are 3000 PSI at a flow rate of 6 GPM for both the Primary and Utility hydraulic systems. b. External Pressurized Air Requirements. An ex- ternal air source that provides 40 psig and 30 lb per min- ute (300cfm) air flow is required to pressurize the system for engine start. The maximum pressure from a ground source shall not exceed 50 psig. CAUTION 28 Vdc from an external power source is not required in order to apply 115/200 Vac to the helicopter. If 28 Vdc is applied from the external power source, damage to the helicopter may occur. Prior to ap- plying external electrical power, it must be confirmed that pins E and F of the ex- ternal power cable do not have 28 Vdc and that they are jumpered. Pins E and F must be jumpered in order to apply ex- ternal electrical power to the helicopter. c. External Electrical Power Requirements. Exter- nal electrical power requirements are 115/200 Vac, 400 Hz, and 45 KVA. 2.54.2 Fuel System Servicing. The helicopter has two crash-resistant self-sealing fuel cells located forward and aft of the ammunition bay in the center fuselage section. Each cell is serviced through gravity filler receptacles or pressure-filled through closed-circuit or single-point adapters (fig 2-45). Provisions are also made for as many as four external fuel tanks to be carried on the stores py- lons. Table 2-7 lists individual tank capacities. a. Fuel Types. Fuels are classified as primary, com- mercial equivalent, or emergency. Primary fuels are JP-4, JP-5, and JP-8. Commercial equivalent oils are listed in table 2-8. There are no emergency fuels authorized. b. Use of Fuels. There is no special limitation on the use of primary fuel, but limitations in table 2-8 apply when commercial fuels are used. For the purpose of re- cording, fuel mixtures shall be identified as to the major component of the mixture. c. Interchangeable Fuels. Fuels having the same NATO code number are interchangeable. Jet fuels (table 2-8) conforming to specification ASTM D-1655 may be used when MIL-T-5624 fuels are not available. This usual- ly occurs during cross-country flights where aircraft using NATO F-40 (JP-4) are refueled with NATO F-44 (JP-5) or commercial ASTM type A fuels. Whenever this occurs, the engine operating characteristics may change because of lower operating temperatures. Slower acceleration, lower engine speed, harder starting, and greater range may be experienced. The reverse is true when changing from F-44 (JP-5) fuel to F-40 (JP-4) or commercial ASTM type B fuels. d. Mixing of Fuels. When changing from one type of authorized fuel to another, (ie: JP-4 to JP-5), it is not necessary to drain the fuel system before adding new fuel. e. Gravity Refueling. For gravity refueling, open fuel vent shutoff valve, remove filler cap, pull chain (open- ing anti-syphoning device), and service cells with fuel to the required level (table 2-7). f. Closed-Circuit Pressure Refueling. Using ser- vice instructions printed on the inside panel of the refuel panel access door (fig 2-45), perform pressure refueling precheck. When closed-circuit pressure refueling do not exceed 15 psi fuel flow. Remove adapter cap, and using standard Army nozzle, service fuel cells with fuel to the re- quired level (table 2-7). Using the standard Army nozzle, fuel flow at 15 psi is 56 gallons per minute.