Fuel

Question 1

There are two pumps in the Center Tank - one on each side.

These pumps are called Override AC pumps because when operating, they override the pressure of the left and right tank pumps.

Answer 1

There are two pumps in the Center Tank - one on each side.

These pumps are called Override AC pumps because when operating, they override the pressure of the left and right tank pumps.

Question 2

The left and right fuel manifolds are normally isolated by two Fuel Crossfeed Valves.
The AC pumps in the left and right tanks feed the respective manifold.
There is one Override AC pump on each side of the Center tank that feeds each manifold.

Answer 2

The left and right fuel manifolds are normally isolated by two Fuel Crossfeed Valves.
The AC pumps in the left and right tanks feed the respective manifold.
There is one Override AC pump on each side of the Center tank that feeds each manifold.

Question 3

Normally, the APU receives fuel from the left tank, but it can receive fuel from the Center tank or even from the right tank if one or both Fuel Crossfeed valves are open.

Answer 3

Normally, the APU receives fuel from the left tank, but it can receive fuel from the Center tank or even from the right tank if one or both Fuel Crossfeed valves are open.

Question 4

Normally, the APU receives fuel from the left tank, but it can receive fuel from the Center tank or even from the right tank if one or both Fuel Crossfeed valves are open.

Answer 4

Normally, the APU receives fuel from the left tank, but it can receive fuel from the Center tank or even from the right tank if one or both Fuel Crossfeed valves are open.

Question 5

An additional fuel pump, (a DC pump) automatically provides left tank fuel to the APU during APU start when no AC power is available.
It can also provide an emerg

Answer 5

An additional fuel pump, (a DC pump) automatically provides left tank fuel to the APU during APU start when no AC power is available.
It can also provide an emerg

Question 6

The Fuel Control panel allows control of the AC boost pumps and the fuel crossfeed valves.
Just above this area are the controls for Fuel jettison.

Answer 6

The Fuel Control panel allows control of the AC boost pumps and the fuel crossfeed valves.
Just above this area are the controls for Fuel jettison.

Question 7

There are two AC boost pumps in each tank.
The Center tank boost pumps are considered “override” pumps.
These pumps have a higher output pressure to ensure the center tank fuel is consumed first.

Answer 7

There are two AC boost pumps in each tank.
The Center tank boost pumps are considered “override” pumps.
These pumps have a higher output pressure to ensure the center tank fuel is consumed first.

Question 8

If no fuel boost pumps are operating, the engines can suction feed from their respective wing tanks, however suction feed may not provide adequate fuel flow at higher altitudes.
Specific information on suction feed is in your Flight Manual.

Answer 8

If no fuel boost pumps are operating, the engines can suction feed from their respective wing tanks, however suction feed may not provide adequate fuel flow at higher altitudes.
Specific information on suction feed is in your Flight Manual.

Question 9

The aircraft is equipped with a fuel jettison system that can jettison fuel from ALL tanks when selected by the pilot.
An automatic shutoff maintains a minimum level of fuel in the main tanks after jettison operations.

Answer 9

The aircraft is equipped with a fuel jettison system that can jettison fuel from ALL tanks when selected by the pilot.
An automatic shutoff maintains a minimum level of fuel in the main tanks after jettison operations.

Question 10

Each fuel tank is equipped with water detectors, density detectors, and quantity detectors.

Answer 10

Each fuel tank is equipped with water detectors, density detectors, and quantity detectors.

Question 11

The left and right tanks are each equipped with a dry dock.
This area holds no fuel and is designed to reduce the chance of fuel tank damage in event of an uncontained engine failure.

Answer 11

The left and right tanks are each equipped with a dry dock.
This area holds no fuel and is designed to reduce the chance of fuel tank damage in event of an uncontained engine failure.

Question 12

The left and right tanks are each equipped with a surge tank.
The surge tanks allow for expansion of fuel from any tank.
Fuel that moves into a surge tank will eventually find its way back into the respective wing tank when the wing tank fuel level is reduced.

Answer 12

The left and right tanks are each equipped with a surge tank.
The surge tanks allow for expansion of fuel from any tank.
Fuel that moves into a surge tank will eventually find its way back into the respective wing tank when the wing tank fuel level is reduced.

Question 13

Surge tanks also provide a method of venting the tanks to the atmosphere.
This is especially important to maintain tank integrity during descent when the outside air tends to be more dense than the air in the tanks.

Answer 13

Surge tanks also provide a method of venting the tanks to the atmosphere.
This is especially important to maintain tank integrity during descent when the outside air tends to be more dense than the air in the tanks.

Question 14

Each fuel tank contains two AC-powered fuel pumps.

A single pump can supply sufficient fuel to operate one engine under all conditions.

Answer 14

Each fuel tank contains two AC-powered fuel pumps.

A single pump can supply sufficient fuel to operate one engine under all conditions.

Question 15

The two center tank fuel pumps are override/jettison pumps.
These pumps have a higher output pressure than the left and right main tank fuel pumps.
The center tank pumps override the main tank pumps so that the center tank fuel is used before wing tank fuel - when all pumps are operating.

Answer 15

The two center tank fuel pumps are override/jettison pumps.
These pumps have a higher output pressure than the left and right main tank fuel pumps.
The center tank pumps override the main tank pumps so that the center tank fuel is used before wing tank fuel - when all pumps are operating.

Question 16

If a center pump has low output pressure with more than approximately 2,400 pounds (1200 KG) of fuel remaining, the fuel pump switch PRESS light illuminates and the EICAS advisory message FUEL PUMP CENTER (L or R) displays.
This alerts the crew to a pump malfunction.

Answer 16

If a center pump has low output pressure with more than approximately 2,400 pounds (1200 KG) of fuel remaining, the fuel pump switch PRESS light illuminates and the EICAS advisory message FUEL PUMP CENTER (L or R) displays.
This alerts the crew to a pump malfunction.

Question 17

If a center pump has low output pressure with less than approximately 2,400 pounds (1200 KG) of fuel remaining, the FUEL LOW CENTER EICAS advisory message displays.
This alerts the crew to a low quantity situation in the Center tank.

Answer 17

If a center pump has low output pressure with less than approximately 2,400 pounds (1200 KG) of fuel remaining, the FUEL LOW CENTER EICAS advisory message displays.
This alerts the crew to a low quantity situation in the Center tank.

Question 18

With the main tank pumps ON, a scavenge system operates automatically to transfer any remaining center tank fuel to the main tanks.
Fuel transfer begins when either main tank quantity is less than 29,000 pounds.
This feature ensures that remaining center tank fuel is moved to the main tanks for consumption.

Answer 18

With the main tank pumps ON, a scavenge system operates automatically to transfer any remaining center tank fuel to the main tanks.
Fuel transfer begins when either main tank quantity is less than 29,000 pounds.
This feature ensures that remaining center tank fuel is moved to the main tanks for consumption.

Question 19

When a main tank fuel pump switch is off, the switch ON label is not visible, the PRESS light illuminates and the EICAS advisory message FUEL PUMP (L, R, FWD, or AFT) display.

Answer 19

When a main tank fuel pump switch is off, the switch ON label is not visible, the PRESS light illuminates and the EICAS advisory message FUEL PUMP (L, R, FWD, or AFT) display.

Question 20

When a center fuel pump switch is off, the switch ON label is not visible, the PRESS light and pump pressure EICAS messages are inhibited.
The PRESS light in a center pump switch only illuminates amber if the switch is ON and the fuel pump output pressure is low.

Answer 20

When a center fuel pump switch is off, the switch ON label is not visible, the PRESS light and pump pressure EICAS messages are inhibited.
The PRESS light in a center pump switch only illuminates amber if the switch is ON and the fuel pump output pressure is low.

Question 21

Both center fuel pumps operate only when two electrical power sources are available.

Answer 21

Both center fuel pumps operate only when two electrical power sources are available.

Question 22

With only one power source available and the center fuel pump switches on, the switch PRESS light on the non-powered side is illuminated and the pump pressure EICAS message is inhibited.
On the ground only the right pump is always load shed when there is only one power source.
This is typical when the APU is powering the aircraft prior to starting the first engine.

Answer 22

With only one power source available and the center fuel pump switches on, the switch PRESS light on the non-powered side is illuminated and the pump pressure EICAS message is inhibited.
On the ground only the right pump is always load shed when there is only one power source.
This is typical when the APU is powering the aircraft prior to starting the first engine.

Question 23

The left main tank contains a DC-powered fuel pump.

It has no controls or indicators, other than the fuel synoptic display.

Answer 23

The left main tank contains a DC-powered fuel pump.

It has no controls or indicators, other than the fuel synoptic display.

Question 24

On the ground, with the APU switch ON and no AC power available, the DC pump runs automatically.

Answer 24

On the ground, with the APU switch ON and no AC power available, the DC pump runs automatically.

Question 25

On the ground, with the APU switch ON and no AC power available, the DC pump runs automatically.

Answer 25

On the ground, with the APU switch ON and no AC power available, the DC pump runs automatically.

Question 26

In flight, the DC fuel pump operates automatically for quick left engine relight with the loss of both engines and all AC power.

Answer 26

In flight, the DC fuel pump operates automatically for quick left engine relight with the loss of both engines and all AC power.

Question 27

When main tank fuel pump pressure is low, each engine can draw fuel from its corresponding main tank through a suction feed line that bypasses the pumps.

Answer 27

When main tank fuel pump pressure is low, each engine can draw fuel from its corresponding main tank through a suction feed line that bypasses the pumps.

Question 28

As the aircraft climbs, dissolved air (released from the fuel in the tank due to the reduction in air pressure), may collect in the suction fuel line and restrict fuel flow.
At high altitude, thrust deterioration or engine flameout may occur as a result of the fuel flow reduction.
The dissolved air in the fuel tank will eventually deplete after reaching cruise altitude.

Answer 28

As the aircraft climbs, dissolved air (released from the fuel in the tank due to the reduction in air pressure), may collect in the suction fuel line and restrict fuel flow.
At high altitude, thrust deterioration or engine flameout may occur as a result of the fuel flow reduction.
The dissolved air in the fuel tank will eventually deplete after reaching cruise altitude.

Question 29

The depletion time is dependent upon aircraft altitude, fuel temperature, and type of fuel.
Once the dissolved air is depleted, the engine should effectively operate on suction feed.

Answer 29

The depletion time is dependent upon aircraft altitude, fuel temperature, and type of fuel.
Once the dissolved air is depleted, the engine should effectively operate on suction feed.

Question 30

The fuel manifolds are arranged so that any fuel tank pump can supply either engine.
The crossfeed valves are closed during normal operations.
The closed crossfeed valves isolate the left and right systems.

Answer 30

The fuel manifolds are arranged so that any fuel tank pump can supply either engine.
The crossfeed valves are closed during normal operations.
The closed crossfeed valves isolate the left and right systems.

Question 31

The fuel manifolds are arranged so that any fuel tank pump can supply either engine.
The crossfeed valves are closed during normal operations.
The closed crossfeed valves isolate the left and right systems.

Answer 31

The fuel manifolds are arranged so that any fuel tank pump can supply either engine.
The crossfeed valves are closed during normal operations.
The closed crossfeed valves isolate the left and right systems.

Question 32

Either crossfeed valve can be opened to feed an engine from the opposite fuel tank.
Fuel pressure can be provided from a main tank with operating fuel pumps to both engines by opening the fuel crossfeed valve(s).
Continued crossfeed use will result in a progressive fuel imbalance.

Answer 32

Either crossfeed valve can be opened to feed an engine from the opposite fuel tank.
Fuel pressure can be provided from a main tank with operating fuel pumps to both engines by opening the fuel crossfeed valve(s).
Continued crossfeed use will result in a progressive fuel imbalance.

Question 33

The Crossfeed VALVE lights illuminate if the associated crossfeed valve is not in the commanded position.
If the valve position does not agree with the switch position, the CROSSFEED switch VALVE light illuminates and the EICAS advisory message FUEL CROSSFEED FWD or AFT displays.

Answer 33

The Crossfeed VALVE lights illuminate if the associated crossfeed valve is not in the commanded position.
If the valve position does not agree with the switch position, the CROSSFEED switch VALVE light illuminates and the EICAS advisory message FUEL CROSSFEED FWD or AFT displays.

Question 34

The fuel jettison system allows jettison from ALL fuel tanks in flight.
The jettison nozzles cannot open on the ground, regardless of switch positions.

Answer 34

The fuel jettison system allows jettison from ALL fuel tanks in flight.
The jettison nozzles cannot open on the ground, regardless of switch positions.

Question 35

Additional jettison pumps in the main tanks and the override/jettison pumps in the center tank can pump fuel overboard through the jettison nozzle valves.

Answer 35

Additional jettison pumps in the main tanks and the override/jettison pumps in the center tank can pump fuel overboard through the jettison nozzle valves.

Question 36

Fuel jettison is initiated by pushing the FUEL JETTISON ARM switch to select ARMED.
Main tank jettison begins when the fuel jettison nozzle switches are pushed ON:
- The jettison nozzle valves open
- The center tank jettison isolation valves open, and
- The main tank jettison pumps operate.

Answer 36

Fuel jettison is initiated by pushing the FUEL JETTISON ARM switch to select ARMED.
Main tank jettison begins when the fuel jettison nozzle switches are pushed ON:
- The jettison nozzle valves open
- The center tank jettison isolation valves open, and
- The main tank jettison pumps operate.

Question 37

The jettison system automatically sets the fuel-to-remain to the maximum landing weight (MLW) fuel quantity, and the TO REMAIN quantity replaces fuel temperature on the EICAS display.
If the TO REMAIN quantity is not as desired, pull on and rotate the FUEL TO REMAIN selector to manually decrease or increase the TO REMAIN quantity.
The FUEL TO REMAIN selector can be rotated to the slow or fast rate position.

Answer 37

The jettison system automatically sets the fuel-to-remain to the maximum landing weight (MLW) fuel quantity, and the TO REMAIN quantity replaces fuel temperature on the EICAS display.
If the TO REMAIN quantity is not as desired, pull on and rotate the FUEL TO REMAIN selector to manually decrease or increase the TO REMAIN quantity.
The FUEL TO REMAIN selector can be rotated to the slow or fast rate position.

Question 38

If the center tank override/jettison pumps are on, center tank fuel also jettisons.

Answer 38

If the center tank override/jettison pumps are on, center tank fuel also jettisons.

Question 39

In flight, jettison time is displayed in minutes on the Fuel synoptic when the jettison arm switch is positioned on while in the air.
Jettison automatically stops when the TO REMAIN quantity is reached.
The system shuts off the main tank jettison pumps and closes the center tank jettison isolation valves.

Answer 39

In flight, jettison time is displayed in minutes on the Fuel synoptic when the jettison arm switch is positioned on while in the air.
Jettison automatically stops when the TO REMAIN quantity is reached.
The system shuts off the main tank jettison pumps and closes the center tank jettison isolation valves.

Question 40

You should know that the fuel quantity indication will not be accurate immediately after fuel jettison is terminated.
A one-minute delay filter exists as part of the jettison system.
This means that fuel jettison quantity requested will only be accurate after at least a one-minute after fuel jettison is terminated.

Answer 40

You should know that the fuel quantity indication will not be accurate immediately after fuel jettison is terminated.
A one-minute delay filter exists as part of the jettison system.
This means that fuel jettison quantity requested will only be accurate after at least a one-minute after fuel jettison is terminated.

Question 41

When the airplane is heavy and loaded near the forward CG, fuel is jettisoned from the center tank first to keep CG within limits; main tank jettison pump operation is delayed.
The computed jettison time is automatically adjusted to reflect the increased jettison time.

Answer 41

When the airplane is heavy and loaded near the forward CG, fuel is jettisoned from the center tank first to keep CG within limits; main tank jettison pump operation is delayed.
The computed jettison time is automatically adjusted to reflect the increased jettison time.

Question 42

A fuel jettison nozzle VALVE light illuminates amber if the jettison nozzle valve is not in the selected position.

Answer 42

A fuel jettison nozzle VALVE light illuminates amber if the jettison nozzle valve is not in the selected position.

Question 43

The Fuel Jettison FAULT light illuminates amber if a system fault has occurred or if the Fuel jettison is inoperative.

Answer 43

The Fuel Jettison FAULT light illuminates amber if a system fault has occurred or if the Fuel jettison is inoperative.

Question 44

At least 11,500 pounds (5,200 kg) of fuel remains in each main tank after jettison is complete, but all center tank fuel may be jettisoned.
Please read the pop-up notes on available jettison rates, then, let’s answer some questions…

Answer 44

At least 11,500 pounds (5,200 kg) of fuel remains in each main tank after jettison is complete, but all center tank fuel may be jettisoned.
Please read the pop-up notes on available jettison rates, then, let’s answer some questions…

Question 45

Jettison Rates:

1) With 4 pumps operating to jettison from the center and main tanks, the Jettison rate is approximately:
- 5400 lbs/min or 2,500 kg/min

2) With 2 main tank jettison pumps operating and the center tank empty

Answer 45

Jettison Rates:

1) With 4 pumps operating to jettison from the center and main tanks, the Jettison rate is approximately:
- 5400 lbs/min or 2,500 kg/min

2) With 2 main tank jettison pumps operating and the center tank empty