Fuel Flashcards
How can the airplane be refueled?
- single point adapter
- overwing gravity refueling
What does the fuel control computer do?
- controls auto refueling
- powered crossflow
- fuel transfer
- measures fuel quantity/temperature
What provides venting of the tanks?
2 under-wing NACA vent scoops
Where are the collector tanks located?
Inside the center tank
Which is lower, wing tanks or collector tanks?
Collector tanks
How many pressure relief valves?
3 (1 under each wing, and 1 under the fuselage for the center tank)
What psi will the spring-loaded pressure relief valves actuate?
> 5 psi
How many fuel distribution systems?
2
- engine fuel feed system
- APU fuel feed system
What force operates the ejectors?
Motive flow
Are the boost pumps AC or DC?
DC
Where does the APU fuel feed system get its fuel?
From the left collector tank
Where does the fuel system computer get temperature readings from?
The right tank & just prior to entering the engines
What is the order of transfer ejectors as the fuel flows?
transfer ejectors
scavenge ejectors
main ejectors
What starts the process of motive flow?
Engine driven fuel pumps
Do the 2 boost pumps always turn on together?
Yes
What is the min fuel feed temperature?
5 C
What heats fuel before entering the engine?
Where is it located?
Fuel/oil heat exchanger.
On the engine.
What will close the Engine Fuel Shutoff Valve if pressed?
ENGINE FIRE PUSH switchlight
What will actuate the APU Fuel Shutoff Valve?
APU FIRE PUSH switchlight
PWR/FUEL switchlight
What imbalance of fuel will cause the auto xflow to activate?
> 200 lbs between tanks
When will the auto xflow stop?
When the low tank is +50 lbs of the other tank
When will the FUEL IMBALANCE caution message appear?
> 800 lbs between wing tanks
What is the max allowable fuel imbalance for takeoff?
300 lbs between wing tanks
When will the fuel system computer auto transfer fuel from the center to wing tanks?
When the wing tank reaches 94%
Where is the refuel/defuel panel located?
On the right side of the fuselage, forward of the wing root
What will show in the flight deck when the POWER switch on the refuel/defuel control panel is selected on?
AUTO XFLOW INHIB status message
Takeoff with fuel >500 lbs in the center tank not permitted unless each wing tank has >___ lbs?
4400
MLI
Magnetic Level Indicators
What provides a mechanical method of measuring fuel quantity?
How many are there?
MLI’s
5
What is the min fuel temp for TO?
What is the min fuel temp for flight?
-30 C
> -40 C
When does total fuel indication turn amber?
Center tank?
L/R tank?
800 …or <=600 lbs
Where are the engine driven fuel pumps located
N2 accessory gear box
How many motive flow ejector pumps?
8
- 2 transfer
- 4 scavenge
- 2 main
Will the APU continue to run if its pump fails?
Yes
How is the APU SOV closed if a fire is detected?
- FIRE PUSH switchlight
- Automatically on ground
- Manually airborne
How many capacitance probes?
17
- 6 in each wing tank
- 3 in center tank
- 1 in each collector tank
What do FAIL switchlights usually mean?
That the valve is not in the COMMANDED position
When is the Fuel Feed Check Valve Test done?
1st flight of day before 2nd engine start
to verify fuel system check valve operation
What is the backup for moving fuel from the wings to the collector tanks?
Gravity lines
What is the flight deck indication of a high pressure fuel pump failure?
Engine flameout
Which bus powers the refuel/defuel panel & refuel defuel SOV’s?
APU Battery Direct Bus
