Originally Posted by
Lost in Saigon
As we all know now, if the AOA fails, it can cause MCAS to trim nose down when it should not. This was a surprise to the Lion Air Pilots but after that accident Boeing sent a Bulletin to all operators explaining the system and how to deal with it.
Ethiopian Airlines got this bulletin but for some unknown reason the crew of ET302 were not able to deal with the problem.
Boeing has since changed MCAS to use info from both AOA and limited how much nose down trim can be applied. This should make it safer even if the pilots mishandle a failure or emergency.
Wow, somebody tell the authorities, Boeing already fixed it! No need for any tests, get that thing back in the air LostinSaigon apparently knows all is fine. I'll file this with all the people asking why they didn't just 'cut the trim switches' until it turned out they did cut the trim switches.
The key words in your post were 'for some unknown reason'. I expect the authorities will want to actually find out what that was before letting the plane fly again. Because they did follow the checklist, and there are points in the FDR which may suggest there is a further problem somewhere in the computers; I believe Boeing has stated they have identified an additional undisclosed problem.