Fuel Flashcards
Which tanks are primary tanks for fueling for a flight?
Main tanks
How many fuel pumps are in each wing?
Left Wing= 2 AC powered fuel boost pumps
Right Wing= 2 AC powered fuel boost pumps and 1 DC start pump
What do the check valves that are associated with each AC pump do?
- One prevents reverse flow if pump is inoperative
- One allows fuel to bypass the pump so the engine will suction feed from the tank
What will happen with both AC pumps failed?
The engine will suction feed from the main tank
What is the DC Start Pump used for? How is it powered?
APU or engine starting when AC power is not available
Powered by the DC Transfer Bus
When will the “FUEL LEVEL LOW” annunciator illuminate?
At approx 2,500 lbs in either main tank
How are the fuel boost pumps powered?
One is powered by the Left AC Bus, the other is powered by the Right AC Bus
Except the AFT Right pump is powered by the Ground Service Bus
When do the Aux pumps transfer to the center tank?
When the Aux pump switches are in AUTO and the center tank quantity drops to approx 13,000 lbs.
How do you correct a fuel imbalance between the main tanks?
-Open crossfeed valve
-Turn off boost pumps for tank with the lower
quantity
This allows the tank with the higher quantity to feed both engines and reduce its fuel level
What will the indication be with a fuel probe fault?
All 9’s on the associated fuel tank gauge
What will the indication be with a fuel quantity processor fault?
The associated quantity gauge will go blank
What pressure do the fuel boost pumps supply?
15 psi
2 pumps rigged in line with each other in Center tank create 30 psi. However a Poppet Valve restricts pressure slightly by -1.5 psi. The 28.5 psi remaining is enough to allow the Center tank to be used before main tanks. Be cautious of Center tank pump failure which would result in 13.5 psi, not enough to over power main tank pumps. H
When is Fuel Heat used?
- When fuel temp is 0* or less, after start/before takeoff
- When fuel temp is 0* or less, cycled on before final approach
- Inflight if FUEL FILTER PRESS annunciator illuminates
What tank does the APU normally feed out of? Can it feed out of any other tanks?
Normally out of the right main tank
Can also feed out of the left main tank via the crossfeed or the center tank
What are all of the tanks and their quantities?
Main Tanks= 9,100 lbs each Center Tank= 20,600 lbs Aux Tanks (if installed)= 3,800 lbs each
When must the Aux Trans pumps be OFF?
Taxi, Takeoff, and Landing
How is the fuel quantity indicating system powered?
AC electrical system
How many dripless sticks are installed?
9
4 (x2) under each main tank
1 under the center tank
How is Defueling accomplished?
- Open the defueling valve
- Turn on fuel pumps in tank with excessive fuel
How is ground transfer of fuel accomplished?
- Open the defueling valve
- Turn on fuel pumps in tank with excessive fuel
- Open fill valves for the destination tank
What powers the Refuel/Defuel panel?
Controls and Valves:
Normal= DC Transfer Bus
No Power= Batter Direct Bus (cold airplane)
Digital Displays:
Normal Power= Right AC Bus
No Power= Emergency Inverter (direct line from inverter to panel)
Will the EDP suction feed through the crossfeed?
No
What does moving the Fuel lever to ON do?
- Turns on fuel to engine
- Arms ignition (sparks as long as ignition switch is on)
What will you see when pressing the TEST knob on the fuel quantity indicator?
Main tanks= 3000 each Center tank= 3000 Aux tanks (if installed)= 3000 each
Min fuel for dispatch?
4,000 lbs each main tank
Min fuel for Go Around?
500 each main tank
Max fuel imbalance between main tanks?
1,500 lbs
Max fuel imbalance between aux tanks?
400 lbs
