Term
| How many fuel tanks are there and what are the capacities? |
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Definition
7 tanks
Center tank: 52,200 kgs each
2 and 3 mains: 38,100 kgs each
1 and 4 mains: 13,300 kgs each
2 and 3 reserves: 4,000 kgs each
Total: 163,000 kgs |
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Term
| What is the source of fuel for the APU? |
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Definition
Aft main pumps in main tanks 2 & 3
DC pump in main tank 2
Main pump 3 aft operates to prevent tank to tank transfer and provides fuel if main pump 2 aft fails |
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Term
| Fuel tank temperature is measured in which tank? |
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Definition
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Term
| When does the fuel temperature display on primary EICAS display in amber? |
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Definition
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Term
| What commands fuel valves to open or close and fuel pumps to turn on and off according to fuel management logic? |
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Definition
| Fuel system management logic cards (FSMCs) |
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Term
| How many Fuel Management System Cards are there? |
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Definition
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Term
| Which fuel pumps are system logic pumps, in other words, commanded to turn on and off by system logic during normal operations? |
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Definition
Override/jettison pumps 2 & 3
They are in inhibited from operating when pressure is detected from both CWT override/jettison pumps |
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Term
| On the crossfeed valve switches, what is the difference between the bar lights in 2&3 and 1&4? |
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Definition
2&3: crossfeed valve open when commanded by system logic
1&4: crossfeed valve is open |
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Term
| Which crossfeed valves are affected by flap extension on the ground? |
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Definition
2 & 3
Closed when flaps extend to the takeoff position |
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Term
| When do the FSMCs open the reserve transfer valves? |
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Definition
When main tank 2 or 3 fuel quantity decreases to ~18,200 kgs
Fuel transfers from reserve tanks 2 & 3 to the related main tank |
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Term
| Under what conditions will fuel transfer from main tanks 1 & 4 to their adjacent tanks 2 & 3? |
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Definition
Automatically during fuel jettison, when either main tank 2 or 3 fuel quantity decreases to ~9,000 kgs
Manually via the Fuel Xfer Main 1 & 4 switch |
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Term
| A single main tank fuel pump can provide sufficient fuel to how many engines? |
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Definition
One engine at takeoff thrust
Two engines at cruise thrust |
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Term
| A single main tank 2 or 3 override/jettison pump can provide sufficient fuel to how many engines? |
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Definition
| Two engines at takeoff and cruise conditions |
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Term
| Explain the fuel system with 7700 kgs or more in the center tank from blockout until flaps are retracted after takeoff |
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Definition
Blockout: CWT pumps on, 2 & 3 ovrd/jet pumps armed
(CWT feeds all engines)
Flaps to takeoff: 2 & 3 x-feed valves close
(CWT feeds 1 & 4, 2 & 3 main pumps feed resp. engines)
Flaps to 5: 2 & 3 x-feed valves open
(CWT feeds all engines) |
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Term
| Explain the fuel system with 7700 kgs or less in the center tank from blockout until flaps are retracted after takeoff |
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Definition
Blockout: CWT pumps off, 2 & 3 ovrd/jet pumps on
(2 & 3 ovrd/jet pumps feed resp. sides)
Flaps to takeoff: 2 & 3 x-feed valves close
(2 & 3 ovrd/jet pumps feed 1 & 4, main pumps feed resp. engines)
Flaps to 5: 2 & 3 x-feed valves open
(2 & 3 ovrd/jet pumps feed resp. sides) |
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Term
| At what fuel quantity does FUEL TANK/ENG usually begin? |
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Definition
53,152 kg total
When Mains 2 & 3 burn down to equal Mains 1 & 4
1 & 4 have not used fuel, so they will still be at 13,288 kg |
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Term
| How is Center Wing Tank fuel scavenged? |
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Definition
4 jet pumps, two pumping into each main tank 2 & 3
Begins when main tank 2 or 3 fuel quantity decreases to ~27,200 kgs |
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Term
| When are there CWT low EICAS messages? |
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Definition
7700 kg before start
3200 kg in climb
1300 kg in cruise |
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Term
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Definition
CTR tank is low (~2300 kg) and high fuel flow (6800 k/hr)
Pumps cannot override outboard main pumps
Mains 1 & 4 will supply fuel to engines (~900 kg each) |
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Term
| When is an engine on suction feed, and how would you correct a suction feed situation? |
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Definition
Main tank fuel pressure is low
Open the appropriate fuel crossfeed valve from a main tank with operating fuel pumps |
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Term
| What are the fuel imbalance differences that would generate an EICAS advisory message? |
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Definition
1360 between tanks 1 & 4
2720 between tanks 2 & 3
2720 between inboard and outboard tanks after FUEL TANK/ENG |
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Term
| When correcting a fuel imbalance condition, when would you expect the associated EICAS advisory IMBAL message to no longer display? |
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Definition
| When the difference is less than 450 kgs |
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Term
| How would you correct a fuel imbalance between tanks 1 & 4? |
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Definition
Open crossfeed valves 1 & 4
Close crossfeed valves 2 & 3
Turn off ovrd/jet pumps in 2 & 3 |
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Term
| How would you correct a fuel imbalance between tanks 2 & 3? |
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Definition
| Turn off fuel pumps in low tank |
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Term
| How would you correct a longitudinal fuel imbalance? |
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Definition
Open all crossfeed valves
Turn off fuel pumps in low tanks |
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Term
| Describe the Fuel Jettison switch A and B positions |
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Definition
Arms the jettison selector
Displays preselected fuel to remain on EICAS |
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Term
| What occurs when you push either fuel jettison nozzle valve to ON during the QRH fuel jettison procedure? |
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Definition
It activates all override/jettison pumps in the tanks containing fuel (pump switches must be on)
The related jettison nozzle valve also opens |
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Term
| Describe how the fuel quantity indication changes upon termination of fuel jettison |
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Definition
| The fuel to remain quantity indication changes from magenta to white and flashes for 5 seconds |
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Term
| What is the minimum amount of fuel that can be remaining after fuel jettison? |
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Definition
12,800 kg
3200 kg remaining in each main tank due to standpipes |
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Term
| When would the Fuel Transfer 1 & 4 switch be used? |
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Definition
| During fuel jettison if the valves fail to open or if both main pumps in 1 or 4 are inop |
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