TM  1-1520-240-10            2-15-13 2-15-7.  Gravity    Refueling.  Perform     the    following steps: a. Be sure the helicopter is at least 50 feet from any hangar or structure. b. Be sure the fueling vehicle is at least 10 feet from the helicopter. c. Electrically ground the helicopter as follows: (1) Connect  one  end  of  an  approved  ground cable to the aft landing gear eyebolt or to one of the jacks on the side of the fuselage. Grounding jacks are located at sta. 115 on the RH side and sta. 530 on the LH side in the fuselage skin. Connect the other end to a grounding rod or ramp ground point. Make sure the cable has no broken strands and the clip are securely attached to the cable and ground points. (2) Make sure the fueling unit is grounded to the same ground rod or ground point as the helicopter. (3) Before  opening  the  filler  cap,  ground  the nozzle to the ground jack directly above the fuel tank filler. d. When the fuel is at the desired level, remove the nozzle. Secure the filler cap. Then, disconnect the nozzle ground wire. e. Remove the ground connection. If the helicopter is  to  remain  parked,  do  not  disconnect  the  helicopter ground. 2-15-8.  ERFS Refueling and Fuel Transfer. ERFS Refueling and Fuel transfer will be in accordance with existing Air Worthiness Release (AWR). 2-15-9.  ERFS II Refueling. Refueling the ERFS II tanks is performed by either single point pressure refueling or gravity refueling. WARNING The  manually  operated  fuel/defuel  vent valve on each tank must be placed in the closed position following pressure refue- ling. Failure to do so could permit signifi- cant fuel leakage in the event of a crash and the vent self–sealing breakaway valve fails to actuate. CAUTION If  the  fuel/vent  valve  is  not  opened,  the tank cannot be pressure refueled. a. Single  Point  Pressure  Refueling.  The  ERFS  II tanks are single point pressure refuled from a connection at the motorized gate valve. The motorized gate valve must be open to pressure refuel and is controlled by the refuel  valve  switch  on  the  ERFS  II  fuel  control  panel located on the forward most ERFS II tank installed. The fuel transfer hose is connected to the forward intercon- necting  ERFS  II  fuel  manifold.  Fuel  from  the  transfer hose  passes  through  the  breakaway  valve  and  the manual fuel/defuel valve to the lower fuel/shutoff valve in the tank bottom. CAUTION The  operator  must  exercise  caution  to avoid ERFS II tank overflow during gravity refueling. There is no automatic fuel flow shutoff. b. Gravity Refueling. If pressure refueling of ERFS II tanks is not performed or prevented, each tank can also be gravity filled through the gravity filler opening on the top of each tank. To gravity fill, the crashworthy filler cap is removed and external fuel source nozzle is inserted and the tank is filled. Low pressure flow rates must be maintained as venting or vapors bypass the filler opening and the fuel/defuel vent valve is closed during this opera- tion. Because fuel is not entering the tank through the fuel/defuel line, the high level shutoff valve has no effect stopping the fuel flow into the tank. 2-15-10.  Single Point Pressure Refueling. a. Electrical  ground  —  Connect  electrical  ground from refueling aircraft. Check that the ground wire from each  ERFS  II  tank  is  connected  to  an  aircraft  ground receptacle. b. Fuel hose from refueling source — Connect to aircraft single-point pressure refueling connection. c. Single-Point Pressure Refueling Hose Assembly - Unisex valve at the ERFS II tank — OPEN. d. Manual FUEL/DEFUEL VALVE at each tank as- sembly — OPEN. e. REFUEL  STA  switch  located  on  the  overhead FUEL CONTR Panel — ON. f. REFUEL VALVE switch on the ERFS II Fuel Con- trol Panel OPEN. IN TRANSIT light will briefly illuminate g. Refuel the ERFS II tanks. Fuel flow will automati- cally stop when tanks are full. h. FUEL QUANTITY switch — Set to 1, 2, 3, and TOTAL to confirm tanks and system contain desired fuel quantities. i. REFUEL VALVE switch. — CLOSE. IN TRANSIT light will briefly illuminate.