Fuel System Flashcards
it is normal to not display any fuel in the lines when the N1 is below 60% TF
T
how many fuel tanks are incorporated into the wing?
3
what are the tanks?
collector tanks
surge tank
vent tank
What is the purpose of the collector tank?
it’s located inboard and is designed to collect fuel in order to keep the fuel tanks submerged. this will keep a constant flow of fuel to the engines
what is the purpose of a surge tank?
designed to hold the fuel that may have entered in to the vent system during uncoordinated manuever.
How does the vent system work in the aircraft?
fuel vent lines that run to the surge tanks keep the differential pressure within structural limits . it also prevents fuel spillage during maneuvering.
What prevents fuel tank overpressure?
high capacity pressure relief valve
where does the water collect in each tank?
2 gravity water drain valves.
How does the ejector pump operate and where is it located?
ejector pumps are on each wing and are the primary pumps for fuel supply. they have no moving parts and operate by a venturi motive flow. No electrical power is needed to operate it.
How many AC pumps are available and what is the purpose?
1 in each tank. they provide fuel flow for engine start, cross engine fuel for crossfeed operations, and APU fuel when engine isn’t running and are there in case the main ejector pump fails.
which BUS system is the right and left AC pumps hook up to?
left: AC BUS 1
right: AC essential BUS
how many scavenger pumps, location and purpose.
3 each tank in the collector tank, ensuring normal fuel flow.
How many DC fuel pumps? Purpose and location.
1, right tank. provides pressure for normal APU operation and engine start when AC pumps not available. can be used on ground or flight.
Setting LOW 1 switch does what?
opens the crossfeed valve
turns on AC pump 2
transfers fuel from tank 2 to 1 at a higher rate than the fuel burn
How many pounds of fuel will the FUEL IMBALANCE EICAS caution light comes on?
800ibs
