Fuel at Low Fuel Warning point
Don't get confused, the report states an approximate fuel at Bothwell, not the point at which the Low Fuel Warnings activated. As we know, the Low Fuel Warnings are set to operate between 26-34kgs in supply tank 1 and 22 - 30 in supply tank 2.
Therefore the Low Fuel Warnings were activated at somewhere between 48 - 64 Kgs, in the supply tanks.
Assuming the GNWEM/GXMII fuel sensor fault (which I am certain of in this case and in this case there is no FUEL caution and the supply tanks are indicated as always full at 90 kgs) and knowing 76 kgs was in left trapped in the main tank, basic maths shows that at the time of activation of the Low Fuel Warnings, there was a difference between gauge readings (falsely presented due to fault) of between 76 + 90 = 166 and 76 + 64 =140 (smallest error) or 76 + 48 = 124 (biggest error).
Therefore at the time of the pilot dismissing the Low Fuel Warnings as being contrary to his fuel displays, he could have had a difference of just 166 - 140 = 26 Kgs or 7:41 minutes of flying time (smallest error case) or 166 - 124 = 42 kgs or 12:25 (largest error). I put it to you that at the point of getting the low fuel warnings, the fuel error may have easily been part of the process of dismissing the Low Fuel Warnings as spurious, if they had suffered the GNWEM/GXMII fault.
I've said this before, but thought I would show the maths this time and its certainly not a difference of 44 minutes as per a previous post!
As time goes by, the error in the faulty displayed fuel and what you actually have increases. Having dismissed the warnings as spurious, there isn't long left to monitor that fuel, and actually realise that the main tank indication is remaining the same at 76kgs. There may have been quick glances at the fuel to check it whilst tasking, at a quick glance displays will be coloured blue, showing that there is some fuel in them. Meanwhile, unseen to you, the fuel is actually emptying from your supply tanks which feeds the engines.
I said before, that errors were made, but I now know this fuel sensor fault (GXMII) had occurred before so its disgraceful that we as an aviation community had not placed it firmly in the memory banks of everyone.
If we think for a second that this fault didn't happen in GSPAO, then this pilot, ignored Fuel Caution, ignored his displays showing his supply tanks were emptying, ignored Fuel Warnings, his crew also ignored all these warnings too, then we might as well say that he didn't bother to control NR too??? In this case I would have no lessons to learn, that would be a purposefully caused accident like the German Wings airliner.
It is extremely important that we learn the correct lessons, yes the pilot made some errors, but the crew was not helped by the whole aviation community.
As reassurance now, things are being looked at and I'm sure they will be redesigned, checklists have been altered, Instruction Notices (INs) issued. If we have anything, and I mean anything wrong, the most minor snag, they are grounded instantly until Airworthiness authorities release them to fly again. Safety systems in the newly formed NPAS are brilliant with open, free reporting. Operator/Manufacturer links are so important to prevent these things happening again.