Airbus A340 - Fuel system
Electrical power requirements for refueling are:
Fuel is simultaneously jettisoned only from the trim and the center tanks.
Fuel is simultaneously jettisoned from the trim, inner and the center tanks.
Refueling can be accomplished:
Inner Tank Pumps - During normal operation, all main pumps run. If a main pump fails, or is switched off, then the standby pump of that inner tank runs. With the crossfeed valves open, one pump is capable of supplying all four engines in cruise.
The wings have inner and outer tanks. Each inner tank contains two collector cells that:
Refueling Control Panel - The HI LVL light comes on blue, when:
When a tank fuel temperature is displayed amber:
The normal fuel JETTISON is stopped when:
Automatic refueling ensures that:
After refueling to maximum tank capacity, fuel can expand by:
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The Airbus A340 fuel system:
Once refueling is finished, the END light flashes first and then stays on.
Once refueling is finished, the END light stays on.
In normal operation, engines are always fed from:
The fuel system is controlled by:
With tanks nearly empty, time for refueling all the tanks of the aircraft is approximately:
Maintenance panel - The END light flashes when:
In normal operation, the automatic control of CG is ended:
FUEL FEED WITH ALL ENGINES FLAME OUT (ELEC EMER CONFIG) - When the speed goes below _____ kt, or when LAND RECOVERY is selected ON, all MAIN and STBY pumps are lost.
In case of Fuel Center Pumps fault:
The fuel level sensing data is independent of the fuel quantity indication, therefore even in the case of fuel system erroneous computation, the fuel level warnings are still valid.
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Magnetic level indicators are fitted in the lower surfaces of the center and wing tanks to allow the manual measurement of each tank's fuel quantity.
There are two fuel pumps in each collector cell. They are normally selected On and:
In normal conditions, the automatic control of CG is starting:
As long as FUEL JETTISON p/b are selected ON:
The trim tank transfer system controls the aircraft's Center of Gravity (CG). The system either transfers fuel to the trim tank (aft transfer) or from the trim tank (forward transfer).
This movement of fuel changes the aircraft's CG. When the aircraft is in cruise, the system optimizes the CG position to increase fuel economy by reducing drag. Normal operation is automatic, but the crew can manually select a forward fuel transfer. The Fuel Control and Monitoring Computer (FCMC) calculates the aircraft's CG and compares it to a target value. This target depends on the aircraft's actual weight. Based on this calculation, the FCMC determines the quantity of fuel to be moved aft or forward in flight.
X-FEED valves 1 and 2 open in the event of aft transfer from the inner tanks.
X-FEED valves 2 and 3 open in the event of aft transfer from the inner tanks.