TM  1-1520-240-10 2-15-14            WARNING The  manually  operated  fuel/defuel  valve must be placed in the closed position fol- lowing pressure refueling. Failure to do so could permit significant fuel leakage in the event of a crash and the vent self-sealing breakaway valve fails to actuate. j. Manual FUEL/VENT VALVE at each tank assem- bly — CLOSED. k. Single-Point Pressure Refueling Hose Assembly- Unisex valve at the ERFS II tank — CLOSE. l. Fuel hose from refueling source — Disconnect from aircraft single-point pressure refueling connection. m.    Electrical ground — Disconnect electrical ground from refueling source to the aircraft. 2-15-11.  Gravity Refueling. a. Electrical  ground  —  Connect  electrical  ground from refueling source to aircraft. b. Grounding Cable on each ERFS II tank — Check connection security. c. Filler cap — Remove. d. Service tank. CAUTION The  operator  must  exercise  caution  to avoid ERFS II tank overflow during gravity refueling. there is no automatic fuel flow shutoff. e. FUEL QUANTITY switch — Set to 1, 2, 3, TOTAL to confirm tanks and system contain desired fuel quanti- ties. (Will indicate only when aircraft power is applied). f. Filler Cap — Replace. g. Electrical ground — Disconnect electrical ground from refueling source to aircraft. 2-15-12.  Fuel Transfer. Fuel transfer from the ERFS II tanks to the helicopter’s main tanks is accomplished through the use of dual cen- trifugal pumps in each ERFS II tank. During fuel transfer, the  manually  operated  fuel/defuel  valve  on  each  tank must be closed to prevent fuel circulation inside the tank. With the fuel/defuel valve closed, fuel is pumped into the fuel manifold at a rate of approximately 20 gpm. Fuel is delivered by the fuel manifold to the helicoter main fuel tanks through the aircraft fuel system quick disconnect fittings in the left and right side cargo compartment at STA 380. During transfer, the roll-over vent valve in each ERFS  II  tank  allows  venting  and  equalization  of  tank pressure above 5 psi from thermal expansion, contrac- tion, and barometric pressure changes in the bladders. The high level fuel shutoff valves in the tanks prevent overfilling. The high level fuel shutoff valves in the tanks prevent overfilling. The metallic float and ball in the roll- over vent valve prevents fuel from escaping should the tank become inverted in a roll-over and prevents slosh from uncoordinated flight from leaking to the overboard vent lines. To transfer fuel from the FARE system, fuel is pumped from the ERFS II tanks by the FARE pump. The manually operated fuel/defuel valve must be in the open position for the FARE transfer. 2-15-13.  Engine Oil System. The engine oil tank and oil quantity indicator are an inte- gral part of the engine (fig. 2-15-2). Service either engine oil system as follows: a. If the engine has not been operated in the preceding 24 hours and the oil level is low, run it and then recheck the oil level. Otherwise an inaccurate oil level may be indicated. b. Check oil level by looking through the grilled opening on the left side of the engine cowling at the 9 o’clock posi- tion. c. If the indicator shows less than full, open the oil filler access panel on the forward top side of the engine cover. d. Refer to DA Form 2408-13-1 and table 2-15-1 for the type of oil to use. Under normal conditions, engines shall be serviced with one type of oil only. If one type of oil is in an engine and that oil is not available, the other type may be used in an emergency. e. Remove the filler cap. Fill the tank with oil until the indicator shows full. Do not overfill tank. f. Install the filler cap. Close both access panels. 2-15-14.  APU Oil System. Service the APU as follows: CAUTION Do not use the APU drip pan as a hand- hold. Damage to equipment will result. a. Remove the filler cap from the left side of the APU (fig. 2-15-2). CAUTION Do  not  overfill.  Damage  to  the  APU  can result from overfilling. b. Add oil to the APU oil tank until the level reaches the FULL mark on the sight gage. Under normal conditions, the APU shall be serviced with one type of oil only. If one type of oil is in an APU and that oil is not available, the other type may be used in an emergency. c. Reinstall and check security of the filler cap.