TM 1-1510-223-10
2-36
1.
Standby Pump Switch (#1 Engine)
5.
Standby Pump Switch (#2 Engine)
2.
Fuel Quantity Indicator (#1 Engine)
6.
Auxiliary Transfer Override Switch
3.
Fuel Quantity Main/Auxiliary Gaging
System Selector Switch
7.
(#2 Engine)
Crossfeed Switch
4.
Fuel Quantity Indicator (#2 Engine)
8.
Auxiliary Transfer Override Switch
(#1 Engine)
Figure 2-18. Fuel Management Panel
primary high-pressure pump for engine starting and all
normal operations. Either the engine-driven boost pump
or electric standby pump is capable of supplying suffi-
cient pressure to the engine-driven primary high-pres-
sure pump and thus maintaining normal engine
operation.
b. Standby Fuel Pumps. A submerged, electrically-
operated standby fuel pump, located within each nacelle
tank, serves as a backup unit for the engine-driven boost
pump. The standby pumps are switched off during nor-
mal system operations. A standby fuel pump will be oper-
ated during crossfeed operation to pump fuel from one
nacelle tank to the opposite engine. The correct pump is
automatically selected when the CROSSFEED switch is
activated. Each standby fuel pump has an inertia switch
included in the power supply circuit. When subjected to
a 5 to 6 g shock loading, as in a crash situation, the inertia
switch will remove electrical power from the standby fuel
pumps. The standby fuel pumps are protected by two
10-ampere circuit breakers placarded STANDBY PUMP
#1 or #2, located on the overhead circuit breaker panel
(fig. 2-7), and four 5-ampere circuit breakers (two each
in parallel) on the hot battery bus.
c. Fuel Transfer Pumps. The auxiliary tank fuel
transfer system automatically transfers the fuel from the
auxiliary tank to the nacelle tank without pilot action.
Motive flow to a jet pump mounted in the auxiliary tank
sump is obtained from the engine fuel plumbing system
downstream from the engine driven boost pump and
routed through the transfer control motive flow valve.
The motive flow valve is energized to the open position
by the control system to transfer auxiliary fuel to the na-
celle tank to be consumed by the engine during the initial
portion of the flight. When an engine is started, pressure
at the engine driven boost pump closes a pressure
switch, which after a 30 to 50 second time delay to avoid
depletion of fuel pressure during starting, energizes the
motive flow valve. When auxiliary fuel is depleted, a low
level float switch de-energizes the motive flow valve after
a 30 to 60 second time delay. This time delay function
prevents cycling of the motive flow valve due to sloshing
fuel. If the motive flow valve or the associated control cir-
cuitry fails, the loss of motive flow pressure when there
is still fuel remaining in the auxiliary fuel tank, is sensed
by a pressure switch which illuminates a caution annun-
ciator placarded #1 NO FUEL XFR or #2 NO FUEL XFR.
During engine start, the pilot should note that the NO
FUEL XFR annunciator extinguishes 30 to 50 seconds
after engine start. The NO FUEL XFR annunciator will
not illuminate if auxiliary tanks are empty. A manual
override is incorporated as a backup for the automatic
transfer system. This is initiated by placing the AUX
XFER switch, located in the fuel management panel to
the OVRD position. This will energize the pedal, forward
