12 - Fuel Flashcards
The fuel flow displayed on the Fuel Synoptic is generated by ______
It __does/does not__ display actual fuel flow
valve positions and pump status
does not
(therefore the display may not represent actual system operation)
During jettison operation, where is fuel to remain indicated?
Magenta - indicates _____
White - indicates _____
replaces fuel temperature, (below Total Fuel), on Primary EICAS
fuel to remain at completion of jettison
jettison has completed (flashes for five seconds)
Fuel temperature is measured in ______ and displays on primary EICAS
Temperature normally displays in __color__
It displays in __color__ when the fuel temperature is ____
main tank 1
white
amber
at or below -37°C
Standpipe level approximately ____ in each tank
3,200 kgs
Each main tank contains ___ AC-powered fuel pumps
A single pump supplies sufficient fuel to operate one engine at _____ or two engines at _____
two
takeoff thrust
cruise thrust
Main tanks 2 and 3 each contain ___ AC-powered override/jettison pumps.
A single override/jettison pump supplies sufficient fuel to operate ____ engine(s) during ____
two
takeoff
cruise
The ___ center wing tank (CWT) fuel pumps are also override/jettison pumps
Together, the CWT pumps ____ 2 and 3 override/jettison pumps and _____ the main pumps so CWT fuel is used before wing tank fuel
two
inhibit
override
(one CWT pump alone does not inhibit 2 and 3 override/jettison pumps or override the outboard
main pumps)
CWT fuel is scavenged by an electric pump activated by system logic. The scavenged fuel is pumped into _____
main tank 2
When does CWT scavenge pump activate?
when a CWT override/jettison pump has low output pressure OR,
main tank 2 or 3 fuel quantity decreases to
approximately 18,200 kgs
When main tank fuel pump pressure is low, engines can _____
At high altitude, thrust deterioration or engine flameout may occur as a result of _____
suction feed through a suction feed line that bypasses the pumps
dissolved air released from the fuel in the tank due to the decrease in air pressure
(The dissolved air will eventually deplete after reaching cruise altitude. The engine may be capable of suction feed operation at cruise power)
Fuel Tank Capacities
Center - 2 and 3 Main - 1 and 4 Main - Reserves - Total -
- 2 C
- 3 2/3
- 6 1/4
- 0 R
- 0 total
Each reserve tank contains ___ transfer valves
Fuel ______ transfers to the inboard main tanks when main tank 2 or 3 fuel quantity decreases to approximately ____ kgs
two
gravity
18.2
Main tank 1 and 4 each contain ___ transfer valve(s)
During fuel jettison, fuel ______ transfers from the outboard main tanks to the inboard main tanks when either main tank 2 or 3 fuel quantity decreases to ______ kgs
one
gravity
9.1 kgs
APU fuel is normally supplied from ______
When AC power is available, fuel is supplied by __(pump)__
If AC power is not available _______ supplies fuel to the APU
main tank 2
main pump 2 aft
dedicated DC pump in main tank 2
What commands fuel valves open or closed and fuel pumps on or off according to fuel management logic?
Fuel system management cards (FSMCs)
With _____ or more fuel in the CWT, both CWT pump switches should be ON
The FSMCs activate override/jettison pumps 2 and 3 when low pressure is detected from either CWT override/jettison pump. The electrical CWT scavenge pump is automatically activated to pump into ____ . The pump is deactivated after _____
7,700 kgs
main tank 2
120 minutes, or no pressure, whichever occurs first
Override/jettison pumps 2 and 3 are inhibited from operating when pressure is detected from ______
both CWT override/jettison pumps
The FSMCs close crossfeed valves 2 and 3 when _____ on the ground
With 7,700 kgs or more CWT fuel: ____ pumps provide fuel to engines 1 and 4, and ____ pumps provide fuel to their related engine
flaps extend to takeoff position
CWT override/jettison
main tank 2 and 3
The FSMCs close crossfeed valves 2 and 3 when _____
With less than 7,700 kgs of fuel in the CWT:
_____ pumps provide fuel to engine 1
_____ pumps provide fuel to engine 4
_____ pumps provide fuel to their related engine
flaps extend to takeoff position on the ground
override/jettison 2
override/jettison 3
main tank 2 and 3
The FSMCs open crossfeed valves 2 and 3 when _____
CWT pump switches ON ____ pumps provide fuel to all engines
CWT pump switches OFF ____ pumps provide fuel to engines 1 and 2 and ____ pumps provide fuel to engines 3 and 4
flaps are out of takeoff setting (10/20)
CWT override/jettison
override/jettison 2
override/jettison 3
With no fuel in center wing tank, (and not tank to engine), the FSMCs activate _____
The FSMCs close crossfeed valves 2 and 3 when ____
____ pumps provide fuel to engine 1
____ pumps provide fuel to engine 4
____ pumps provide fuel to their related engine
override/jettison pumps 2 and 3
flaps extend to takeoff position on the ground
override/jettison 2
override/jettison 3
main 2 and 3
The fuel jettison system allows jettison from which tanks?
When _____ the _____ indication on EICAS is
replaced with the fuel to remain quantity indication.
The jettison manifold and _____ display on the fuel synoptic.
all
jettison control system A or B is selected
fuel temperature
jettison time
Pushing _____ switch ON activates all override/jettison pumps in tanks containing fuel (pump switches must be ON) and opens the
required jettison valves
The jettison time is initially estimated using preprogrammed rates. The system begins updating
the estimate based on actual fuel quantity rate of change ___ after jettison begins
either fuel jettison nozzle valve
90 seconds
______ controls fuel balancing between main tanks 2 and 3 as fuel is jettisoned
If fuel balancing is necessary _____
until the tanks are balanced
jettison control system
override/jettison pumps in the low tank deactivate
Jettison terminates when _____
The fuel to remain quantity indication changes color from ____ to ____ and flashes for ___ seconds
The ____ deactivates all override/jettison pumps
The related FUEL OVRD pump EICAS
messages display until ____
total fuel quantity decreases to fuel to remain
magenta / white / 5
jettison control system
jettison selector is OFF
FUEL IMBAL 1-4 :
FUEL IMBAL 2-3 :
FUEL IMBALANCE :
1,360 kgs
2,720 kgs
2,720 kgs
FUEL QTY LOW: Caution Beeper ____ kgs or less in one or more main tanks
900
FUEL TEMP LOW Advisory: fuel temperature ____ or less
-37°C
What three things happen when jettison control system A or B is selected?
jettison discharge nozzles armed
fuel to remain replaces fuel temperature (below fuel quantity on upper EICAS)
jettison manifold and jettison time are displayed on the fuel synoptic
What two things happen when the fuel jettison nozzle valve is pushed on?
jettison valve opens
all override/jettison pumps activate in tanks with fuel, (if pump switches are on)
