SYSTEM DESCRIPTION (cont)
(e) The forward fuel cell is gravity fueled through a gravity filler port, or pressure fueled via the fuel inlet
breakaway valve. The air vent/pressure relief valve vents air pressure out of the fuel cell during pressure fueling.
The fuel quantity transmitter outputs analog data for use with fuel indicators. The pilot valve, pilot valve tube and
fuel shutoff valve provide automatic fuel shutoff when the fuel cell is full. In case of automatic fuel shutoff failure,
the air vent/pressure relief valve vents fuel out of the fuel cell. The fuel cell is pressurized from the aft fuel cell.
The fuel/defuel check valve provides a seal to maintain fuel cell pressure. Pressure forces the fuel through the
check/thermal relief valve to engine 1. The baffle allows fuel flow between the forward and aft sections of the
forward fuel cell during level or nose-up attitude. During nose-down attitude, the baffle provides an uninterrupted
fuel supply to engine 1.
(f) The fuel crossfeed warning system will indicate GREEN CROSSFEED when the crossfeed is
selected and both engine 4 way valves are in the proper crossfeed position. The fuel crossfeed warning system
will indicate YELLOW CROSSFEED when crossfeed or normal is selected and both engine 4 way valves are not
in the proper crossfeed/normal position.
(g) The fuel transfer warning system will indicate GREEN CROSSFEED when transfer is selected and
fuel is transfering. The fuel transfer warning system will indicate YELLOW CROSSFEED when transfer is
selected and fuel is not transfering.