Fuel Tanks

Fuel is stored in the wings and the trimmable horizontal stabiliser. The wings have inner and outer tanks. In addition there is a centre tank in the centre fuselage, and optionally 1 or 2 ACT [Additional Centre Tank] s. The FCMS [Fuel Control and Monitoring System] controls the fuel system.

Each engine is fed by 1 main fuel pump, and there is 1 crossfeed valve for each engine.

Fuel feed

Fuel is always fed to the engines from inner tanks.

Fuel pumps

There are 2 pumps per engine: 1 main and 1 standby (which automatically operates if the main fails). Each pair is isolated in a collector box in the inner tank.

In an electrical emergency, only main pump 1 remains powered. If it fails or is off, STBY pump 4 replaces it automatically. After land recovery, fuel feed is by gravity only.

Fuel transfer

Tanks are emptied as follows.

Fuel is transferred from centre tank to inner tanks via 2 transfer pumps.
Inner tanks are emptied.
Fuel from trim tank is transferred to inner tanks.
Fuel from outer tanks is transferred to inner tanks by gravity.

Centre Tank → Inner Tanks

Inner tanks cycle between full - 2,000 kg and full.

Quantity

	Outer Tank	Inner Tank	Centre Tank	Trim Tank	Total	ACT [Additional Centre Tank] (optional)
litres	3,650 × 2	42,775 × 2	42,420	6,230	141,500	7,200
kg (SG 0.785)	2,865 × 2	33,578 × 2	33,300	4,890	111,078	5,652