Originally Posted by
yoko1
I have no idea what you mean by “balance of probability.”
This is likely one source of misunderstanding here, as there are many posters here unable to fully comprehend why the grounding is ongoing or what the long delay is a result of.
In the absence of conclusive evidence that demonstrates with absolute certainty that the main electric trim system was 100% operative throughout all phases of both fatal accidents [for the record, there is none], investigators are left drawing probable conclusions based on the available evidence:
1> It is not very plausible that two separate crews comprised four trained, experienced, pilots all elected not to attempt to trim ANU (more than a sub-second blip) when presented with life-threatening ongoing opposing trim in clear conditions in sight of the ground, whilst simultaneously commanding nose up at forces likely not previously experienced.
2> The "blips" are present in the last seconds of both fatal accidents.
3> The "blips" are consistent with an initial ANU trim
command, but each has no resulting actual ANU
trim of any significance whatsoever, certainly nothing like that required to improve the situation they were presented with. See 1> above.
4> The "blips" are entirely consistent with a shorted and/or overpowered motor.
5> The "blips" look exactly as we would expect a command to an overpowered motor to record; a power spike then null.
6> The manual trim was also overpowered under the aerodynamic loads experienced at that time.
7> "Trim with me" is not the announcement one would expect to be made by a PF who's trim is functioning correctly.
8> The actions of the MS crew, including attempting to briefly trim AND in such a situation, are consistent with a crew dealing with an inoperable main electric trim
in the ANU moment.
9> Both crews were aware that an 'auto' trim was trimming against them but were ultimately
unable to prevent their aircraft from trimming them into the ground to their certain death and the demise of all onboard.
10> XAA's all around the world have grounded all aircraft of this type until further notice.
I could go on, however... given just the above, and all the other facts as known at this time, we can safely conclude that ON THE BALANCE OF PROBABILITY the main electric trim was totally inoperable in the ANU moment during the last seconds or minutes of the fatal accidents.
That conclusion inexorably leads to some uncomfortable truths, and it is understandable that many here do not wish to go there. But, just as the Soviets learnt the hard way at Chernobyl, in the end, only by shining a bright light on all of the flaws can real progress be made towards rectification.
This aircraft remains grounded worldwide until that happens, despite protestations otherwise, whether on this forum or elsewhere.