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32 Cards in this Set

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  • Back
describe operation of scavenge pump
When center pump switches are placed to OFF, allows main pump 1 to operate a jet scavenge pump for 20 minutes to get left over fuel that is below the level of the main center pumps
Where is fuel heated, and when
Fuel/oil heat exchanger, just prior to mec. Continuously
What is the problem with suction feed in a climb?
Air pressure in tank decreases, allowing air in fuel to dissolve. This air might accumulate in the suction line and restrict fuel flow. Should deplete over time at altitude. Stay below 30,000.
Do you need to manually test the fuel quantity indicators?
No they are automatically self tested at power up.
Where is temperature measured?
Main tank 1.
crossfeed valve powered by?
Battery bus
Fuel shutoff valves powered by?
Hot battery bus
What tank does APU suction feed from?
Main tank 1
Where does APU get fuel from?
Left side of fuel manifold
Why is all center tank fuel used prior to the fuel in the main tanks (when all six pumps are operating)?
Center tank check valves open at a lower differential pressure than check valves from the main tanks.
How are the fuel manifolds linked?
Battery operated crossfeed valve, allows either engine to be supplied fuel from any of the 3 tanks.
What powers the fuel shutoff valves?
Hot Battery Bus. Actuated by fire handle or start lever.
Does the center tank fill with gravity feed?
No, have to transfer fuel to center tank if need be.
Where are the left and right center tank fuel pumps?
Tanks 1 and 2 respectively.
Will the engine operate if the low section of the engine driven fuel pump fails? High pressure section?
It will not flameout, but it cannot be started without the low stage. Will flame out w/o high pressure section.
If both center tank pumps fail, can you use this fuel?
What allows suction feed from the main fuel tanks? What else does this enable?
Bypass valve in each main fuel tank. Can also use these bypass valves for suction defueling.
Which of the 6 aircraft fuel pumps is strongest/weakest?
All are same power.
What sources of electrical power must be available for pressure fueling?
-GPU plugged in and operating, (ext. AC bus powered)
-APU operating and powering busses
-Battery with BAT ON and STANDBY POWER to BAT.
What is the concern about doing standby power test during fueling?
Interruption of power to the fuel quantity indicators can cause fueling valves to close. So wait until fueling finished to do test.
What are the respective differences between the left and right center fuel pump positions?
Left is in rear third of main tank 1. Right is in middle section of main tank 2.
What is the concern below 2000 lbs in the center tank?
At high pitch attitudes, right center fuel pump may become uncovered, causing right center tank fuel pump LOW PRESSURE to come on.
WHat powers the 3 separate fuel quantity indicators?
AC standby bus
Should you test the fuel quantity indicators?
No, test is a maintenance function. It performs a self test on power up.
Where is the temperature sensor?
Main tank 1
What does the fuel vent system do?
Equalizes pressure in the fuel tanks and provides ram air pressure. Vents into a surge tank outboard then thru a opening in the wing tip. Fuel in surge tanks returns to main tanks.
What must you do if you see indication of a fuel vent system pressure relief valve actuation?
Notify maintenance.
What is a FUEL quantity soft error?
Fuel weight value is valid (w/in 3%) and usable. Analog arc is operative. ERR is displayed. Proceed.
What is a FUEL quantity hard error?
zero replaces fuel weight value. ERR displays, but no analog arc. Use of test switch reveals error code of 1 to 10 for use by maintenance.
FWD AFT CTR fuel pump power sources?
-Onside Main Gen Bus
-Onside Transfer Bus
-Offside Main Gen Bus
What do the FILTER BYPASS lights indicate?
Impending or actual bypass of fuel filter due to contamination.
What do the outside FUEL Quantity indicators do?
Repeaters of cockpit fuel quantity indicators.