Fuel Flashcards
The expanded fuel quantity display (left main, center and right main) appears
for any of the following conditions.
One or both crossfeed valves open
One or more fuel tank qty indications inop
Fuel in Center(qty is amber)
FUEL QTY LOW
FUEL IMBALANCE
On the ground & one or more engines off
AIMS BP-16 or later software: FUEL FLOW ENG L/R
The temperature is normally displayed in white.
It is displayed in amber when
the fuel temperature is
at or below the minimum defined temperature.
During jettison, the TO REMAIN quantity replaces the EICAS display
fuel temperature indication.
Each fuel tank has 2
AC-powered pumps.
There is one DC-motor-driven pump located in the left main tank, which
supplies the APU when
AC power is not available.
Center tank fuel pumps are called override / jettison pumps.
They operate at a higher output pressure than main tank pumps,
to ensure center tank fuel is
used before wing tank fuel.
For main tank pumps, any one pump can supply adequate fuel to operate
one engine under all thrust conditions.
The fuel jettison system allows jettison from
all fuel tanks during an in-flight emergency.
Fuel is jettisoned through jettison nozzle valves inboard
of each aileron.
Jettison pumps in the main tanks and override / jettison pumps in the center tank
pump fuel
overboard through the jettison nozzle valves.
For the normal pre-flight configuration of the fuel panel, all pump switches
should be
OFF.
With center tank pump switches “OFF” the pressure lights are inhibited.
With AC power established and the APU running the left forward pump
operates regardless of switch position.
Prior to engine start all main tank pumps must be
selected ON.
With fuel in the center tank, and any MAIN tank fuel pump selected ON,
EICAS
FUEL IN CENTER displays.
Additionally EICAS fuel quantity indications are expanded on the ground and
one or both engines are off.
On the ground, both center fuel pumps operate only when two electrical sources
are available.
With only one power source available and the center pump switches ON,
the right center pump is
load shed.
The right PRESS light illuminates
but the pump pressure EICAS message is
inhibited.
As the center tank fuel pumps operate at a higher pressure than the main tank
pumps, notice that APU fuel is being supplied by
the left center tank fuel pump whenever it is running.
A fuel imbalance pointer is displayed on the expanded fuel quantity display next
to the low tank quantity for the following imbalance conditions.
A solid white pointer is displayed if:
A solid amber fuel imbalance pointer replaces the white pointer if the “FUEL IMBALANCE” message is displayed.
main tank fuel differs more than 1,000 lb, main tank fuel differs more than
200 lb and a crossfeed valve is open.
the “FUEL IMBALANCE” message is displayed.
The pointer will flash if fuel balancing is going in the wrong direction.
When fuel is back in balance within 200 lb between the main tanks,
the EICAS message “FUEL IMBALANCE” disappears and
the “FUEL BALANCED” replaces “FUEL QTY” on the expanded fuel quantity
display and flashes for 5 sec.
If a center pump has low output pressure with less than approximately
2,400 lb of fuel remaining, the FUEL LOW CENTER EICAS advisory message
displays with the PRESS light.
Then turn OFF the center pump switches.
Scavenge pumps operate automatically to transfer any residual
center tank fuel to the main tanks.
Fuel scavenging begins when either main tank quantity is less than
29,000 lb.
When the desired FUEL TO REMAIN value is reached,
the selector is released and it returns to the center position.
The selector knob must be left in the out position. If it is pushed in the TO REMAIN fuel reverts to Maximum Landing Weight fuel.
the TO REMAIN fuel reverts to Maximum Landing Weight fuel.
Note that center tank fuel will not jettison with
center tank pumps OFF.
When the airplane is heavy and loaded near the forward CG,
fuel is jettisoned
from
the center tank first to keep CG within limits.
Main tank jettison pump operation is
delayed and jettison time is automatically adjusted.
When the fuel to remain target is reached,
jettisoning terminates.
The TO REMAIN value on EICAS flashes to alert the crew. Note: at least 11,500 lb of fuel will remain in each main tank after jettison is complete.
flashes to alert the crew.
Note: at least 11,500 lb of fuel
will remain in each main tank after jettison is complete.
After automatic jettison termination, the nozzle valves must be———
the FUEL TO REMAIN selector ———-,
as it was used to manually set fuel to remain,
and finally, the ARM switch is———–
manually closed,
pushed in
turned OFF.
If the valve position does not agree with the switch position,
the CROSSFEED switch VALVE light
illuminates
and the EICAS advisory message
FUEL CROSSFEED FWD or AFT displays.
