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.