Originally Posted by
wheelsright
"One last time" the FDR trace does not track thumb switch trim inputs. Therefore, it cannot be said with certainty what the pilots were doing. The assumption is that Boeing advice is correct but it is not absolutely certain. Unless you can authoritatively show that MCAS has no authority during thumb switch input in all circumstances then you are speculating.
Ok I will bite:
Unless you can authoritatively show the FDR trace does not track thumb switch trim inputs a reasonable interpretation of the traces is that it does. I have not seen anything that shows otherwise.
As to whether the switches tracked the pilots thumb and or intentions is possibly an open question, especially the blips at the end.
Don't know about "all circumstances" but the trace at 05:40:27 shows the manual trim stopping MCAS before the full 9 or seconds it would have run.
The schematic that was posted also shows manual electric trim overriding automatic,the 'trim motor' is shown as a block so can't 'prove' this.
In any case not clear where this is going, in ET case MCAS is clearly disabled by pilot trim (for 5 seconds) and cutout, had they succeeded with manual trim we would not be having this discussion.
No need for elaborate undisclosed actions, the stated behavior explains what is seen.
Occam's razor might be constructively considered here.