Originally Posted by
patplan
How did the crew of ET302 know there had been an "Angle of Attack Disagreement"? Was it being displayed on their PFD's?? Did you even read the previous thousand or so postings before you posted yours? I'm curious.
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.