AIRPLANE
OPERATIONS
MANUAL
FUEL
REVISION 39
2-08-05
Page
3
Code
01
AOM-145/1114
ENGINE AND APU FUEL DISTRIBUTION AND CONTROL
There are three electric pumps for each wing tank that provides
pressurized fuel to the engines and APU. One pump is capable to
supply fuel for both engines and APU under all phases of flight, except
takeoff and go-around.
During takeoff and go-around one electric pump is required for each
engine and the APU.
Engine-driven fuel pumps will provide suction feed if the electric fuel
pumps operation is not available limited up to a ceiling altitude of
25000 ft.
NOTE: Crossfeed Selector Knob must be OFF during takeoff and go-
around.
Five knobs located in the overhead fuel panel controls the electric
pumps and crossfeed operation. Two PUMP PWR knobs
energizes/de-energizes the electric pumps and the other two PUMP
SEL knobs selects which pumps will be operating. The remaining
pumps will be on standby. If the fuel pressure drops below 6.5 psi, the
remaining pumps are automatically switched on and start cycling, until
the pilot selects one of them.
The XFEED knob controls the crossfeed operation.
Crossfeed operation should be performed in case of fuel imbalance
between tanks. The crossfeed knob acts over the crossfeed valve and
over the electric pumps. Selecting the knob to LOW1 or LOW2 will
deenergize the pump associated to the side with low level. The
crossfeed valve will open connecting the engine 1 and engine 2 fuel
feed lines. The fully-opened crossfeed valve position is indicated on
the EICAS by an advisory message. In case of valve failure, the
EICAS displays a caution message.
NOTE: Crossfeed operation does not allow fuel transfer between
tanks.
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