Fuel Flashcards
How many fuel tanks and approximate capacities
7 tanks - total: 163,042kg
CWT - 52,167kg
Main 1 - 13,288kg
Main 2 - 38,131.5kg
Main 3 - 38,131.5
Main 4 - 13,288
Reserve 2 (L) - 4,018
Reserve 3 (R) - 4,018
(1kg =2.205 lb)
What commands the fuel valve to open or fuel pumps to come on
Fuel system management cards
Which cross feed valves are affected by flap extension on the ground?
Cross feed 2&3 close
Which fuel pumps are system logic pumps
(Which turn on and off by system logic in normal ops)
Override/jettison controlled by switch position and system logic
Trace fuel to engines when there are 7700kg or more in CWT
- Both CWT switches on
- FSMC close x-feed 2&3 when flaps extended to T/O
- override/jettison 2&3 inhibited w/ press detect from CWT pumps
- CWT override/jettison provide fuel to engines 1&4
- main pumps 2&3 provide fuel to respective engines
Trace fuel to engines when there are less than 7700kg in CWT
- CWT Pump switches OFF
- FSMC close crossfeed valves 2&3 when flaps extended for T/O
- override/jettison pump 2 provides to engine 1
- override/jettison pump 3 provides to engine 4
- main pumps 2&3 provide fuel to their respective engines
When do FSMC’s open the reserve transfer valves
When main tank 2 or 3 quantity decreases to approximately 18,200kg
Under what conditions would fuel automatically transfer from main tanks 1 and 4 to 2 and 3
During fuel jettison
- main tank 2 and 3 decreases to 9072kg during jettison both 1 and 4 transfer valves open
Can fuel be manually transferred fr any tank to another tank
Yes
- main 1 and 4 transfer switch on overhead
- fuel can be transferred from the outboard to inboard tanks until the outboard tank quantity decreases to approximately 3,200 kg
What occurs when fuel jettison switch is selected to either a or b
Arms jettison selector
Displays preselected fuel to remain on Eicas
Fuel temp replaced with To Remain on primary Eicas
Jettison manifold symbols and jettison time displays on fuel synoptic
Describe how fuel quantity indication changes upon termination of fuel jettison
Decreases TO REMAIN quantity, the color of TO REMAIN quantity turns from magenta to white and flashes for 5 seconds. Then redisplayed as TOTAL FUEL
What happens when you push either fuel jettison nozzle valve on during the QRH fuel jettison procedure?
Activates all override/jettison pumps in tanks containing fuel (provided pump switches are on)
Opens required jettison valves
What is the source of fuel for the APU?
Main tank 2
AC power available - Main Pump 2 AFT
Main pump 3 aft also operates to prevent tank to tank fuel transfer and backup
How are fuel imbalance situations handled
By opening and closing crossfeed valves and turning on and off fuel pumps
What is the impact on the aircraft of excessive fuel imbalance
Adverse CG
Adverse Aerodynamic Drag
Adverse fuel economy
How are suction feed situations corrected
Fuel pressure can be supplied from any main tank with operating pumps to any engine by opening the appropriate fuel crossfeed valves.
Does suction feed line go through the main tank pumps
No, bypasses
A single main tank fuel pump can provide sufficient fuel to how many engines
Each pump has capacity to provide sufficient pressure to operate one engine at takeoff thrust or two engines at cruise thrust
A single main tank 2 or 3 override/jettison pump can provide sufficient fuel to how many engines
One engine at takeoff thrust or two engines at cruise thrust
Can main tank 2 or 3 jettison/override pump operate when related main tank is below 3200kg at standpipe level
No, can operate down to standpipe- not below
Fuel tank temperature is measured in which tank
Main tank 1
When does fuel temperature display on the primary Eicas in amber
Fuel is -37deg or below
How is the center wing fuel scavenged?
Four jet/scavenge pumps
Ensures all CWT is moved to 2&3
No Pilot control
Begins when 2 or 3 quantity drops to 27,200kg
Three different conditions will generate fuel imbalance message on Eicas
- FUEL IMBAL 1-4: 1360kg between 1&4 (cleared when 450kg)
- FUEL IMBAL 2-3: 2720kg between 2&3 (cleared when 450kg)
- FUEL IMBALANCE: after FUEL TANK/ENG longitudinal IMBAL of 2720kg (cleared when (450kg)
When does the fuel imbalance message mo longer display on the Eicas?
450kg
What does the crossfeed valve amber light on with bar visible indication mean for crossfeed valve switches 2&3?
Crossfeed valve not is system logic commanded position
What does the crossfeed valve amber light on with bar visible indication mean for crossfeed valve switches 1&4?
Crossfeed valve position does not agree with switch position
When are Override/jettison pumps 2&3 displayed cyan on the fuel system synoptic
When pump is armed for system logic operation
Cyan only applies to override jettison pumps
