Both STANDBY PUMP switches shall
be OFF during crossfeed operation.
The loss of fuel pressure due to
failure of an engine-driven boost
pump will illuminate the MASTER
glareshield, and will illuminate the
respective #1 FUEL PRESS or #2
FUEL PRESS annunciator on the
warning annunciator panel. Turning
annunciator. The MASTER WARNING
annunciators must be manually reset.
(3) Fuel transfer control switches. Two
switches on the fuel management panel (fig. 2-20),
placarded AUX XFER OVRD - AUTO, individually
control operation of the fuel transfer pumps. During
normal operation both switches are in AUTO, which
allows the system to be automatically actuated. If either
transfer system fails to operate, the fault condition is
indicated by the MASTER CAUTION annunciators on
the glareshield and a steadily illuminated amber #1 NO
FUEL XFR or #2 NO FUEL XFR annunciator on the
caution annunciator panel.
(4) Fuel crossfeed switch. The fuel
crossfeed valve is controlled by a 3-position switch
located on the fuel management panel (fig. 2-20),
placarded CROSSFEED - OFF. Under normal flight
conditions the switch is left in the OFF position. During
emergency-single engine operation, it may become
necessary to supply fuel to the operative engine from the
fuel system on the opposite side. The crossfeed system
Figure 2-23. Auxiliary Fuel Tank Fuel Gage
is placarded for fuel system selection with a simplified
diagram on the overhead fuel control panel. Place the
STANDBY PUMP switches in the off position when
CROSSFEED, is moved from the center OFF position to
the left or to the right, depending on direction of fuel flow.
This opens the crossfeed valve and energizes the
standby pump on the side from which crossfeed is
desired. During crossfeed operation with firewall fuel
valve closed, auxiliary tank fuel will not crossfeed. When
the crossfeed mode is energized, a green FUEL
CROSSFEED annunciator on the caution/advisory panel
will illuminate. Crossfeed system operation is described
in Chapter 9. The crossfeed valve is protected by a 5-
ampere circuit breaker, placarded CROSSFEED, located
on the overhead circuit breaker panel (fig. 2-9).
f. Firewall Shutoff Valves.
Do not use the fuel firewall shutoff
valve to shut down an engine, except
in an emergency. The engine-driven
essential lubrication from fuel flow.
When an engine is operating, this
pump may be severely damaged
(while cavitating) if the firewall valve
is closed before the CONDITION lever
is moved to the FUEL CUTOFF
The fuel system incorporates a fuel line shutoff
valve mounted aft of each engine firewall. The firewall
shutoff valves close when the fire extinguisher T-handles
on the instrument panel are pulled out. The firewall
shutoff valves receive electrical power from the main
buses, and also from the hot battery bus which is
connected directly to the battery. The valves are
protected by 5-ampere circuit breakers, placarded
FIREWALL VALVE #1 and #2, on the overhead circuit
breaker panel (fig. 2-9).
g. Fuel Tank Sump Drains. A sump drain
wrench is provided in the aircraft loose tools to simplify
draining a small amount of fuel from the sump drain.
(1) There are five sump drains and one filter
drain in each wing (table 2-3).
(2) An additional drain for the extended
range fuel system line extends through the bottom of the
wing center section adjacent to the fuselage. Any time