Originally Posted by
Arydberg
I have a question, Apparently the AoA sensor is switched from right to left and left to right on successive flights of the Max 8. But in the case of the Lion crash the aircraft experienced problems with the working AoA on the preceding flight and after landing this AoA was replaced. But on the next flight i would expect the opposite AoA to be used. Thus it appears two AoA sensors were malfunctioning. This seems deeper than simply a single AoA. What am i missing.
This was discussed previously. Apparently turning off power to the aircraft always resets MCAS to the captain's side AOA. The next flight carried out would then alternate the AOA side as you describe. Obviously during maintenance to replace the AOA sensor the technicians would have to turn off the power. This reset the AOA to the captain's side again.
BTW, since there was no way to change which AOA sensor used by MCAS while in flight (unlike the twin autopilots), there was zero use of redundancy (and only a minuscule escape route). IMO the twists and turns in this story are deeply bizarre (and sometimes lost in the multiple posts on this thread).