TM  1-1520-240-10 2-15-2            2-15-6.  Single-Point Pressure Refueling. The pressure refueling control panel and nozzle recep- tacle are on the right side of the helicopter above the forward landing gear (fig. 2-4-6). The landing gear ac- cess  cover  must  be  opened  to  expose  the  panel  and receptacle. A nozzle grounding adapter is located on the structure adjacent to the receptacle. a. Be sure the helicopter is at least 50 feet from any hangar or structure. b. Be sure the refueling unit is at least 10 feet from the helicopter. c. Electrically  ground  the  helicopter  and refueling unit as follows: (1) Connect one end of ground cable to the aft landing gear eyebolt or to the jack on the right side of the fuselage at sta 115. Connect the other end to a grounding rod or ramp ground point. Be sure the cable has no bro- ken strands and the clips are securely attached to the cable and ground points. (2) Be sure the fueling unit is grounded to the same ground point as the helicopter. d. At the cockpit overhead Fuel CONTR panel, set REFUEL STA switch to ON. CAUTION Be  sure  the  fueling  station  fuel  quantity indicator is operating before pressure fue- ling. If the indicator is not operating, the fuel  shutoff  valves  cannot  be  checked properly and fuel cell overpressurization may result. e. Open the right forward landing gear access panel and perform the following check: (1) Set the PWR switch to ON. Check that both REFUEL  VALVE  POSN  lights  momentarily  illuminate, then extinguish. If either light illuminates and does not extinguish, the associated refueling valve has failed and fuel will not flow into that aft auxiliary tank. If the fuel in this tank is required to complete the mission, notify mainte- nance. (2) If required, set the LIGHT switch to ON. (3) Set the FUEL QUANTITY selector switch to TOTAL. (4) Set the ALL TEST switch to PRI OFF. (5) Connect the grounding wire to the ground- ing  receptacle  and  connect  the  fueling  nozzle  to  the adapter. CAUTION If  either  the  primary  or  secondary  float switch for any tank is inoperative, do not pressure refuel that tank unless the fuel cap  is  removed  to  prevent  possible  fuel cell over-pressurization. If both switches are inoperative, do not pressure refuel the helicopter.    In    addition,    if    both    float switches  are  inoperative  for  either  main tank, the system must be repaired before flight to prevent fuel cell over-pressure. (6) Open the flow control valve on the nozzle. Check  that  fuel  flow  stops  within  4  seconds.  A  small amount  of  fuel  will  continue  to  flow  through  the  open secondary ports. (7) Set  the  ALL  TEST  switch  to  SEC  OFF. Check  that  fuel  flow  stops  within  4  seconds.  A  small amount  of  fuel  will  continue  to  flow  through  the  open primary ports. f. If  all  tanks  are  to  be  filled,  set  the  ALL  TEST switch  to  FLOW.  All  tanks  will  now  fill  independently. Rotate the FUEL QUANTITY selector switch, checking each tank for proper fill and quantity. Shutoff valves in each tank will close and stop fuel flow as each tank fills. g. When refueling is completer, close the flow con- trol valve. h. If tanks are to be partially or selectively filled, be sure to perform steps e. (6) and e. (7), then proceed as follows: (1) Set the six FUEL CELL SHUT OFF VALVE TEST switches to PRI OFF. (2) Set the ALL TEST switch to FLOW. (3) Rotate    the    FUEL    QUANTITY    selector switch to the tank to be filled. The indicator pointer will indicate tank fuel quantity. (4) Set   the   FUEL   CELL   SHUTOFF   VALVE TEST switch of the tank to be filled to FLOW. (5) Open the flow control valve. (6) When the desired fuel level is reached, set the FUEL CELL SHUTOFF VALVE TEST switch to PRI OFF. (7) Repeat steps (3), (4), AND (6) on each tank until the desired amount of fuel is in each tank. (8) Close the flow control valve and disconnect the nozzle and ground cable. i. Set the PWR switch to OFF. Check that the RE- FUEL VALVE POSN lights momentarily illuminate, then extinguish.  If  either  light  does  not  illuminate  on,  then extinguish, the fuel in that aft auxiliary tank is unusable. Notify maintenance. j. Close the landing gear access door.