This Topic is relevant to the whole fleet

FROM THE FWD APU PUMP

The forward APU pump supplies fuel to the APU from the engine 1 collector in the left inner tank via the APU ISOL valve when :

	On ground (except during trim tank refueling) or,
	In flight below FL 255, or,
	In flight above FL 255 when trim tank is empty.

The AFT APU pump is not running.

FROM THE AFT APU PUMP

During trim tank refueling or aft transfer the trim pipe supplies fuel to the APU.

In flight above FL 255 as long as the trim tank is not empty, or during a forward transfer the trim tank supplies fuel to the APU.

In these cases, the AFT APU pump is running, the forward APU pump is not running and the APU isolation valve is closed.

FOR INFO