Fuel Flashcards
Fuel temp indicator gets temp from?
Left main tank.
DC fuel pump?
Located in left main wing, used to supply fuel to APU before AC power is established.
LOW FUEL message?
Fuel in either Left or Right main tank drops below 2200lbs. The FUEL CONFIG light illuminates & a LOW FUEL caution message is displayed on EICAS.
When are centre tanks inhibited?
Below 50% N2 RPM
L or R FUEL SYS PRESS EICAS message?
Displays when all fuel pumps have low output pressure or all fuel pumps on one side have low output pressure and the cross feed switches are off.
Is there a fuel scavenge system?
Yes it operates automatically when main tanks are approx half empty. It transfers any remaining centre tank fuel to main tanks.
CTR L FUEL PUMP or CTR R FUEL PUMP on EICAS?
Several seconds after the message shows, power is automatically removed from the pump.
When are the L or R FUEL SYS PRESS lights inhibited?
With the cross feed valve open.
FUEL CONFIG light comes on when?
Fuel quantity in left and right main tanks differs by more then 2000lbs (+/-500lbs) OR the centre tank pumps are off with more then 1200lbs in the centre tank. ALSO Config light, LOW FUEL caution message and beeper sounds when fuel quantity is less then 2200lbs in either main tank.
What fuel pumps operate the APU
DC pump automatically on ground with no AC power. Forward left AC pump after AC power applied.
How many fuel pumps are fitted per tank and what is there power source?
Each tank contains 2 AC driven fuel pumps. Left main tank also has a DC driven fuel pump for APU feed.
Is engine operation still possible without the fuel pumps turned on?
Yes. When main tank fuel press is low, each engine can draw fuel through its corresponding tank through a suction feed line that bypasses the pumps. However at high altitude thrust erosion or engine flame out may occur as a result of fuel flow reduction.
What is the purpose of the Nitrogen Generation System?
Converts bleed air to nitrogen enriched air at all phases of flight. Nitrogen enriched air is then delivered to the centre tank to reduce flammability in the tank.
