Fuel Flashcards
How is fuel transferred and delivered?
By a motive flow jet pump system and two engine drive pumps (low pressure pump and FCU high pressure pump)
What two purposes do the electric boost pumps serve?
To provide px during engine start sequence and when the normal px system fails
How is refueling accomplished?
Using over-wing filler caps
How much fuel can each wing hold?
201 US gal (761 liters)
Where are the fuel vents located?
On the lower surface of the outer fuel bay
What does the check valve on the motive flow line do?
It stops fuel flow between the left and right wing tanks
What are the three kinds of pumps in the wings and what are their purposes?
Electric boost pumps - provide pressure during engine start and when the normal pressure system fails
Transfer ejector pumps - transfer fuel from the wing tanks to the collector tanks
Delivery ejector pumps - transfer fuel to a common manifold
How is motive flow created?
By fuel under pressure from the low pressure engine driven pump returning to the wings
What does the low engine driven low pressure fuel pump relief valve do?
It maintains a fuel pump outlet pressure of 43.5 psi
When the boost pumps are set to AUTO, when will they operate and when will they shutoff?
They operate whenever the fuel system pressure drops below 2 psi and shutoff 10 seconds after reaching 3.5 psi
T/F? A boost pump is capable of supplying the engine in case the low pressure pump fails.
True
T/F? A boost pump is capable of supplying the engine in case the high pressure pump fails.
False
When fuel supply is greater than the engine demand, where does the excess fuel go?
It returns from the FCU to the vent bays
Left and right fuel quantities are monitored to detect fuel asymmetry exceeding _____% of each wing total fuel capacity (approximately _____ US gallons, _____ LCS segments)
5; 10.5; 2
Up to _____ LCD segments will be automatically handled by the fuel balance system.
6
