Systems - Fuel Flashcards
When the fuel jettison switch is armed, what is displayed on the EICAS?
Fuel to remain at max landing weight
If you wish to dump below max landing weight, what must you do?
Manually select the fuel quantity
What is the minimum fuel to remain you can dump to?
Roughly 11,500 lbs in each main tank
How much flying time does this equate to?
About 2 hours
Why do we have 2 cross feed valves?
Redundancy
During preflight with all fuel boost pumps off you notice the left forward boost pump pressure light extinguished.
Why?
APU is using the FWD left main AC pump
Is there any other fuel pump available to the APU?
Dedicated DC pump in the left main tank
With full tanks what is the sequence of fuel usage?
Center burn off first, then the mains
How does the fuel scavenge system work?
After center tank fuel pumps are deenergized scavenge pumps transfer fuel into the main tanks
Where can you find jettison time displayed?
- EICAS (replacing fuel temperature)
- FUEL synoptic page
Is there a way to tell if the fuel is approaching the fuel freeze point?
Fuel temp turns amber
When would an expanded fuel quantity display appear on the EICAS?
During and imbalance condition or during crossfeed
What are fuel imbalance indications?
- EICAS MSG
- expanded display
- amber pointer to the lowest tank
How is a “wrong way” fuel cross feed indicated?
Pointer flashes
Is it possible to dump fuel on the ground?
Yes it is
How is the fuel heated?
Prior to entering the engine it passes through an air/oil cooler then an oil/fuel heat exchanger
At what imbalance amount does the expanded fuel display appear?
When does it go away?
- When main tank fuel differs by more than a 1000 lbs
- Pointer flashes and disappears after the fuel is within 200lbs
Where can the actual fuel temperature and minimum fuel temperature be found?
FUEL synoptic
With center fuel pumps on, why is center tank fuel used before fuel from the main wing tanks?
Higher output fuel pumps
When main tank fuel pressure is low, how does the engine receive fuel?
Suction
What fuel condition generates an FMC message INSUFFICIENT FUEL?
Fuel at destination is below programmed fuel in performance
