Extinguished – related engine or spar fuel shutoff valve is open.
Illuminated (blue) –
bright – related engine or spar fuel shutoff valve is in transit, or valve position and engine start lever or engine fire switch disagree.
dim – related engine or spar fuel shutoff valve is closed
Which tank contains the temperature sensor?
Indicates fuel temperature in No. 1 tank
Crossfeed VALVE OPEN Light
Extinguished – crossfeed valve is closed.
Illuminated (blue) –
bright – crossfeed valve is in transit, or valve position and CROSSFEED selector disagree.
dim – crossfeed valve is open
FILTER BYPASS Lights
Extinguished – fuel filter operating normally.
Illuminated (amber) – impending fuel filter bypass due to a contaminated filter.
Center Tank FUEL PUMP LOW PRESSURE Lights
Illuminated (amber) – fuel pump output pressure is low and FUEL PUMP switch is ON
Extinguished – fuel pump output pressure is normal, or FUEL PUMP switch is OFF
Main Tank FUEL PUMP LOW PRESSURE Lights
Illuminated (amber) – fuel pump output pressure is low, or FUEL PUMP switch is OFF.
Extinguished – fuel pump output pressure is normal.
When does #1 assert?
Fuel LOW Alert
Displayed (amber) – fuel quantity less than 2000 lbs in related main tank display remains until fuel tank quantity is increased to 2500 lbs
When does #2 assert?
Fuel Configuration (CONFIG) Alert
Displayed (amber) –
- either engine running
- center fuel tank quantity greater than 1600 lbs; and
- both center fuel tank pump switches positioned OFF
Display remains until –
-both engines not running
-center fuel tank quantity less than 800 lbs
-one center fuel tank pump switch ON
When does #3 assert?
Fuel Imbalance (IMBAL) Alert
Displayed (amber) –
- main tanks differ by more than 1000 lbs
- displayed below main tank with lower fuel quantity
- displayed when airplane is on the ground or in the air
- inhibited by fuel LOW indication when both indications exist
- displayed until imbalance is reduced to 200 lbs
What does #1 do?
PUSH - tests displays for auxiliary fuel quantity, ALERT Messages and MAINT Messages.
What does #2 do?
Illuminated (amber) - ALERT message being displayed.
- with ALERT message present and light illuminated; clears message and extinguishes ALERT light
- if more than one message is active, repeated depressions cycle display through all existing ALERT messages.
- following display of last active ALERT message, display is blanked and ALERT light is extinguished.
What does #3 do?
Maintenance (MAINT) Switch
Illuminated (amber) -
- on the ground - MAINT message active
- in flight - MAINT message being displayed.
Note: MAINT messages will not display in flight without operator action.Pushing the MAINT switch in flight with active MAINT messages causes the MAINT light to illuminate and message to display. Engaging the auxiliary fuel Maintenance Switch in flight is prohibited.
What do #1 and #2 do?
FWD AUXILIARY FUEL TRANSFER Valve
Switches (A and B)
OFF - closes forward auxiliary fuel transfer valves.
AUTO - arms forward auxiliary fuel transfer valves to begin fuel transfer.
AFT AUXILIARY FUEL TRANSFER Valve Switches (A and B)
OFF - closes aft auxiliary fuel transfer valves.
AUTO - arms aft auxiliary fuel transfer valve to begin fuel transfer.
What does #1 do?
AUXILIARY FUEL BLEED AIR Switches (FWD and AFT)
OFF - closes auxiliary fuel bleed air valve.
Note: When GRD TRANSFER switch is ON, auxiliary fuel bleed air valves are automatically armed, enabling bleed air to pressurize auxiliary fuel tanks for fuel transfer while airplane is on the ground.
OVRD- allows bleed air valve to operate if A or B auxiliary fuel transfer valve is open and auxiliary fuel tank pressure is less than 4.5 psi.
What does #2 do?
AUXILIARY FUEL Ground (GRD) TRANSFER Switch
OFF (Guarded Position) - prevents fuel transfer from auxiliary tanks while airplane is on the ground.
ON - disables air/ground logic and arms auxiliary fuel bleed air valves, allowing bleed air to pressurize auxiliary fuel tanks for fuel transfer while airplane is on the ground.
Which one of these valves is controlled by the start lever?
Which one of these valves is controlled by the engine fire switch?
Which of these valves is controlled by the EEC?
What is the maximum fuel temperature?
What is the minimum fuel temperature?
-43C or 3C above the fuel freezing point, whichever is warmer
How does the fuel crossfeed? Tank to tank, or tank to engine?
Tank to engine
How many valves are controlled with the crossfeed switch?
What electrical power source powers the crossfeed valve?
When are the center tank FUEL LOW PRESS lights armed?
Always, regardless of switch position
If only one center tank FUEL LOW PRESS is on, will the Master Caution illuminate?
Yes, it only takes one
With one center tank pump OFF, will illumination of the opposite FUEL LOW PRESS light illuminate the Master Caution light?
What is the electrical power source for the center tank fuel pumps?
What is the electrical power source for the main tank fuel pumps?
What indication would you get with the illumination of just one LOW PRESS light in the center tank?
Master Caution and FUEL annunciator on the recall panel
What indication would you get with the illumination of both lights in the same tank?
Master Caution and FUEL annunciator lights
How many fuel sticks are in each main tank?
How many fuel sticks are in the center tank?
Which pumps produce a higher output pressure?
Which tanks can fuel be suction fed from?
Mains only, not center because mains have a bypass valve and center does not
What does the scavenge jet pump do?
Transfers center pump fuel to main tank #1 when main tank #1 is approximately half full
Which tank can supply the APU?
Any tank with the appropriate pump on and crossfeed open (if required)
Which tank can the APU suction feed from?
Main tank #1
What is the total capacity of the fuel system?
What is the capacity of each of the main tanks?
What is the capacity of the center tank?
When do the AUX fuel pumps begin to transfer, and to where?
No sooner than 10 minutes after takeoff with the center tank fuel quantity less than 27,000 lbs. Transfers to the center tank.
What is the capacity of the AUX tanks?
When does residual center tank fuel begin to transfer after the center tank pumps are turned off? Where does it transfer to and how?
With the main tank fuel pump No. 1 FWD Switch ON, the center tank fuel scavenge jet pump operates automatically to transfer any remaining center tank fuel to main tank No. 1. Fuel transfer begins when main tank No. 1 quantity is about one-half. Once the fuel scavenge process begins, it continues for the remainder of the flight.
What is the power source for the Spar Valve?
DC power from the hot battery bus
If AC power is lost in flight, which fuel tanks will contain trapped fuel that cannot be suction fed from the engines?
Center and Aux
For ground operation, center tank fuel pump switches must not be positioned ON unless the center tank fuel quantity exceeds ___, except when defueling or transferring fuel.
Random fuel imbalance must not exceed ___ for taxi, takeoff, flight or landing.
True or False. The Aux tanks may contain fuel if the center or main tanks are not full.
False. The center and main fuel tanks must be scheduled to be full if the auxiliary fuel system is to be loaded or contains fuel.
During normal operation, how and where is AUX fuel transferred?
During normal operation, fuel is transferred from the auxiliary fuel tanks into the center fuel tank. This transfer is accomplished using pressurized air from the cabin. If the cabin pressure is not adequate for fuel transfer, bleed air can be selected for fuel transfer.
Check the cross feed valve during the _____ on an EROPS leg.