The low fuel action is to land within 10 minutes.
At that stage the low fuel warnings would have both be on at about 22:09 hrs, with the fuel readings being 20/76/17. (36 kgs) This is the time at which they were about to commence a job, they then did another, followed by the start of the trip back to base.
Why would they do all this while being presented with;
LOW FUEL 1...................LOW FUEL 2
PRIME PUMP...................PRIME PUMP
......................FUEL
..................F PUMP AFT
..................F PUMP FWD
......20
…….........76
…….........17
(Possibly not the prime pumps but maybe)
Interesting to note that on three occasions when the low fuel one warnings were acknowledged, the caption also cleared.
After the normal start-up sequence warnings had cleared, the next recorded snapshot showed that a low fuel 1 warning (caption and audio) was triggered, relating to the level of fuel in the supply tank cell supplying the left engine.
The audio attention-getter was acknowledged and then the caption cleared. The low fuel 1 warning was triggered again, the audio attention-getter was acknowledged once more and the warning then cleared for the second time.
The next warning was low fuel 2, relating to the level of fuel in the supply tank cell supplying the right engine. The audio attention-getter was acknowledged and the caption on the WU remained for the rest of the flight.
This was followed by another sequence of a low fuel 1 warning, the audio attention-getter being acknowledged and the caption clearing. A further, final onset of this warning was followed by the audio attention-getter being acknowledged and the warning caption remaining for the rest of the flight.
But everything was working and indicating ok .... wasn't it !
page 95.
No significant pre-impact technical defect was identified in any part of the aircraft or its systems.