Fuel System Flashcards
What are the fuel quantities for pressure refueling?
700, 900, 900EP:
Total: 19,594 lbs
Mains: 7,492 lbs
Center: 4,610 lbs
What are the fuel quantities for gravity refueling (900 and 900EP)?
Total: 14,810 lbs
Mains: 7,405 lbs
Center: N/A
What are the fuel quantities for gravity refueling (700)?
Total: 14,580 lbs
Mains: 7,290 lbs
Center: N/A
How is the fuel moved from the main tanks to the collector tanks?
Scavenge ejectors
Gravity line used as a backup
How is the fuel moved from the center tank to the main tanks?
Transfer ejectors
How is fuel moved from the collector tanks to the engine driven high pressure fuel pump?
Main ejectors
Backed up by boost pumps
What is the function of the electric boost pumps?
To provide initial fuel for engine start and to back-up the main ejectors
What is the flight deck indication of a high pressure fuel pump failure?
Engine flameout
When will the fuel system automatically begin transferring fuel?
200 lb fuel imbalance
What is the maximum fuel imbalance?
300 lb for takeoff
800 lbs for all other phases
When are the boost pump automatically energized?
Low pressure from the main ejectors (as long as the boost pumps are armed)
Where is the high pressure fuel pump located?
N2 accessory gearbox
Where is the bulk fuel temperature taken?
Right Main Tank
What is the Minimum Bulk Fuel Temperature for take-off (Jet A)?
-30º C
What is the minimum bulk fuel temperature during flight (Jet A)?
above -40º C
How is engine fuel heated?
Fuel/oil heat exchanger
What is the minimum engine fuel temperature for takeoff?
+5º C
What is the takeoff limitation if the center tank has more than 500 lbs of fuel?
Each main tank must have at least 4400 lbs of fuel
Which Bus powers the refuel/defuel panel and refuel/defuel SOVs?
APU direct battery bus
Where is the refuel/defuel panel located?
The fuselage forward of the right wing
Where is the singe point adapter located?
Right Wing Root
How are the fuel system faults annunciated?
The switch lights on the overhead panel and on EICAS in the form of messages
What is used to provide the fuel computer with fuel quantity information?
6 fuel quantity probes with compensator units in each of the main tanks and 3 in the center
What maintains fuel symmetry between the main tanks?
Automatically or manually controlled by the XFLOW pump
How are the collector tanks kept full?
Gravity feed lines and scavenge ejectors
What is used to back up the main ejectors?
2 electric boost pumps
The electric fuel boost pumps…
1) are energized during engine start
2) can feed fuel to either engine from 1 collector tank
3) back up the main ejector pumps
From what source is APU fuel feed supplied?
From the left collector tank via APU fuel pump
Where is the bulk fuel temp taken?
Right main tank
How is pressure refueling and suction defueling accomplished and how is it controlled?
Accomplished through the single point refuel/defuel adapter. Controlled from the refuel/defuel control panel
If a fuel asymmetry condition exists between main tanks, what visual amber CAUTION message is presented on EICAS?
FUEL IMBALANCE
What fuel system information is displayed on the EICAS Primary page?
Individual tank quantities, total fuel quantity, fuel flow per engine
For automatic pressure refueling, what does the refuel/defuel control panel permit?
Preselection of the fuel quantity
Built in test feature (BITE)
Refuel/defuel SOV’s to close automatically if the maximum fuel level is reached
