1—2
Page 4
when the pump may be switched OFF. Each pump has a telltale gland
drain which protrudes through the pumps blister on the underside of the
main plane. The telltale drain is connected to the space between the
two gland seals separating the electric pump from the fuel impeller.
10. A three-position switch (marked TEST ON-OFF-PUMP ON) on the
Flight Engineer’s fuel panel, controls each pump. A red hinged cover
guards the No. 3 tank switches. The switches are selected up for TEST,
central for OFF and down for ON. Power for each booster pump is supplied
through an associated circuit breaker on the main electrical panel when
the switch is selected ON. The TEST position is used with a collocated
ammeter, to check the pumps current consumption of a nominal 4 to 7
amps. No. 3 tanks current consumption is normally greater than No. 2
tank which is greater than No. 1.
CAUTION:
Due to the age of the switches, it is imperative that when
switching the pumps OFF that a positive check of the central OFF position
is made to avoid the pump inadvertently being left running.
Note:
All pumps take their electrical TEST supply through the circuit
breaker that supplies the port No. 3 tank.
11. A manual priming pump is at the forward end of each wheel bay. Its
fuel feed is taken from a fuel line collocated with the pulsometer pump in
each No. 1 tank. Downstream of the priming pump are two stopcocks,
one for each engine on that wing. The system is used prior to engine
start to feed fuel directly into the induction system providing a rich mixture
for starting.
Fuel Supply
12. The No. 3 tanks booster pumps only supply fuel to its adjacent No.
2 tank.
13. No. 1 and 2 tanks are connected downstream of their booster pump
to their associated tank cock. The tank cocks are behind the leading
edge of the wing inboard of the inner engines. Chains and cables operate
the two tank cocks from tank cock wheels on the Flight Engineer’s fuel
panel, which are labelled PORT TANKS and STBD TANKS. Each wheel
has three positions: OFF, INNER ON and OUTER ON. The function of
each position is:
UNCONTROLLED DOCUMENT - NOT FOR USE IN FLIGHT OR TO BE PRINTED
UNCONTROLLED DOCUMENT - NOT FOR USE IN FLIGHT OR TO BE PRINTED