Fuel System Flashcards
What is the total fuel capacity in kilos?
163,042 kg
What are the fuel capacities of the tanks?
Reserves 1&4: 8,036 kg
Main Tanks 1&4: 26,576 kg
Main Tanks 2&3: 76,263 kg
Centre Tank: 52,167 kg
If fuel is needed in the centre tank, what is the minimum qty it must contain prior to engine start?
1800 kg
In flight, fuel tank temps must be maintained at least how many degrees above the fuel freezing point?
3 degrees Celsius
What is the minimum fuel temp for Jet-A and Jet-B?
Jet-A: -37C
Jet-B: -47C
Where is the fuel temperature measured?
Number 1 main tank
What Xfeed valves automatically close for takeoff?
2 & 3 when flaps are extended to the takeoff position
If number 1 FWD and AFT main fuel tank pumps are INOP, how could I get that fuel to the engines under boost pump pressure?
the QRH procedure will have you use the main tank 1&4 transfer valve
Can you reset a fuel pump CB?
no
How much fuel is jettisoned per hour?
about 2000 kg
How many kilos of fuel can each of the main 2/3 ranks hold?
38,100
Which holds more fuel, CENTER, or tanks 2/3 or 1/4?
CENTER2/31/4
How many kilos of fuel can tanks 1/4 each hold?
13,300kgs
How much do reserve tanks 2/3 hold each?
4000kgs
What color are the override pumps until system logic activated them?
Cyan (blue)
If all tanks are full which tanks pumps activate to feed the engines first?
CENTER
Before takeoff when takeoff flaps are selected, how does the fuel system configuration change?
The cross feed 2/3 close causing main tank 2/3 pumps to feed their respective engines, meanwhile the CENTER tank pumps still provide fuel to engines 1&4
After takeoff with flaps up how does the fuel system config change?
The 2/3 cross feed valves open allowing the CENTER pumps to now feed all engines
> FUEL LOW CTR L>FUEL LOW CTR R
In Cruise: Fuel in CENTER tank is less than 1,300 kgs with pump switches onIn Climb: CENTER quant is 3200kgs with pump switches onBefore start: CENTER quantity is <7700kgs and switches on.
When system logic senses low pressure from the CENTER wing tank pumps or they are turned off, what does the system automatically do?
Turns on the 2/3 override/JETT pumps
How does the remaining fuel get used from the CENTER tank when the pumps are off or low press?
Scavenge pumps transfer it to main tanks 2/3
FUEL DISAGREE
Totalizer quantity and FMC calculated fuel disagree.Objective: decide if a fuel leak is suspected. Select the most accurate fuel value if a leak is not suspected
FUEL IMBAL 1-4
Imbalance of 1360kgs between tanks 1-4Objective: decide if a fuel leak is suspected. To balance fuel if a leak is NOT suspected.
FUEL IMBAL 2-3
Fuel imbalance of 2720kgs between main tanks 2/3Objective: decide if a fuel leak is suspected. To balance fuel if a fuel leak NOT suspected.
FUEL IMBALANCE
After the FUEL TANK/ENG message shows there is a longitudinal fuel imbalance of 2,720 kgs between the inboard and outboard main tanks.Objective: decide if fuel leak suspected. To balance fuel if a fuel leak is not suspected.
> FUEL JETT A, B
A fuel jettison system has failed
FUEL JETT SYS
Total fuel qty is
FUEL JETTISON
Fuel jettison is needed!
When either main tank 2/3 reaches 18100, what does system logic do?
Transfers reserve fuel to the tanks 2/3
FUEL LEAK ENGINE
An in-flight engine fuel leak is suspected.Objective: verify there is an ENGINE fuel leak. Identify the leaking engine and shut it down.
> FUEL OVD CTR L, R
The CENTER wing tank pump switch is off and one of these occurs:On the ground: CENTER tank >7700kgsIn Cruise: >1800 kgs
FUEL OVRD 2,3 AFT, FWD
Pump pressure is low
FUEL PRESS CTR L, R
FUEL LOW CTR L, R Message is shown for 60 secOrPump pressure low
FUEL PRESS ENG 1,2,3,4
Engine on suction feed Objective: open the cross feed valves to ensure fuel flow. To reconfigure if both pumps are failed in tank 1 or 4.
FUEL PUMP 1,4 AFT, FWDPRESS
Pump pressure is low
FUEL PUMP 2,3 AFT, FWDPRESS
Pump pressure is low
FUEL QTY LOW
Qty is <900 kgs in one or more main tanks.Objective: decide if a fuelLeak is suspected. Ensure that all fuel is available for use if a fuel leak is not suspected
FUEL RES XFR 2,3
Reserve transfer valve NIPS
> FUEL TANK/ENG
One of these occurs with the cross feed valve 1 or 4 open:Main tank 2 is <=equal to tank 1Main tank 3 is <= to tank 4This indicates it is time to go direct tank to engine feed.Basically it’s telling you to stop feeding off the inboards only with the overrides and let each engine take its own feed to keep even balance across the wing.Turno off 2/3 override pumps then close XFEED valves 1/4Keep this config til landing
FUEL TEMP LOW
Fuel temp near min
How much fuel can you jettison from the center tank and main tanks?
All the CENTER and up to the standpipes in the mains
FURL TEMP SYS
Fuel temp indication has failed
FUEL XFEED 1,4
Fuel XFEED valve NIPS
Must you close the fuel jettison nozzles after the jettison is complete?
Yes and turn the system offThe system can be confirmed to be deactivated when the jettison synoptic disappears
FUEL XFEED 2,3
Fuel XFEED valve NIPS
> XFEED CONFIG
Fuel cross feed valve Not in CORRECT position
> FUEL XFER 1+4
FUEL XFER MAIN 1&4 Switch is on and one of these occurs:Airplane on the groundInflight: the inboard main tank quantities are more than the outboard main tank quantities
> JETT NOZ ON
Both jettison nozzle valves are open
> JETT NOZ ON L, R
A JETT NOZ Valve is open
> JETT NOZZLE L, RVALVE
Fuel JETT nozzle valve NIPS
> SCAV PUMP ON
On the ground the CENTER wing tank scavenge pump operates
