Fuel Flashcards
What are the different compartments of each main fuel tank and the different pumps?
Main - storage tank with 3 motive flow scavenge pumps that keep collector full
Collector - keeps the main ejector and AC/DC fuel pumps submerged that feeds the engine
Surge - during uncoordinated maneuvers and high bank this tank is a spill over for the main that uses gravity
How many total pumps on each wing?
5 pumps on the left wing and 6 pumps on the right wing
Where can we see fuel temperature?
Only in the left tank on the Fuel synoptic page
Where in the fuel system are the ACFPs
Left and right wings’s collector tanks
What is the purpose of the ACFPs?
The AC fuel pumps serve as a backup to the main ejector pumps in case of engine failure. They will automatically run as long as AC power is established.
When will ACFP 1 turn on in AUTO?
Engine 1 is starting
Xfeed selected to LOW2
Left Main Ejector Pump fails
Not powered during an electrical emergency
When will ACFP 2 turn on in AUTO?
Engine 2 is starting
Xfeed selected to LOW 1
APU start without engine running
Right Main ejector pump fails
RAT powers this fuel pump
What does XFEED do?
There is no direct transfer of fuel from tank to tank. The Xfeed valve permits fuel supply to both engines from one tank. The amount of fuel supplied to the low level side is higher than the actual burn causing an indirect transfer to balance the tanks. AC pump feeds the other side’s EDP.
Where is the DC pump located?
Right wing collector tank and supplies fuel only from the right side
What purpose does the DCFP serve?
When AC power or the AC fuel pump is not available it provides:
• pressurized fuel for normal APU operation and;
• engine start
DCFP in AUTO?
Commands the pump on when engine 2 is running or APU is started AND AC Fuel Pump 2 is not available.
Where are the main ejector pumps?
In the collector tanks
What purpose do the main ejector pumps serve?
It is the primary pump used to transport fuel from the collector tank to the engine.
It has no moving parts. It relies on motive flow from the engine driven fuel pump (EDP).
How can the aircraft be refueled? What about 20,935lbs?
Pressure refueling: on the right under wing side. EICAS message will display. HOT BATT BUS 2 powers this panel
Overwing gravity refueling: on both sides. Can look out PAX window to check the caps In order to get to 20,935lbs it needs to be gravity fed
Can the plane be refueled while engines are running? What about with no engines running?
If engines are running then only crew may be onboard.
If no engines are running then refueling can happen while PAXs are boarding as long as crew maintains communication with the refuelers
