On Friday, November 2, 2018 at 12:04:25 PM UTC-4, trader_4 wrote:
So now the United Airlines pilots union is disagreeing with American
and Southwest. The latter too issued statements that said that pilots
being trained on the new 737 Max should have been informed of the new
stall avoidance system, what it does, how it operates. The United union
says we don't want to know how it works:
"Insler said many systems on an airplane work in the background without the
pilot’s knowledge. He compared it to watching television: ?
?I don’t need to know how it works.”
Quite amazing. What was added to these new planes is a "feature" where
the computers monitor the angle of attack for an impending stall and if
detected, it uses the trim to force the nose down. It will continually
nose it down, unless the pilots press and hold the trim in the opposite
direction. If they release it, the system resumes nose diving the plane.
To disable it requires open breakers on the electric trim system.
The training for the new planes for pilots already qualified on the older
737s is 3 hours of training, followed by a one hour flight. American,
Southwest and certainly Lion Air are saying that Boeing should have made
this significant change a part of that training. United? We don't care.
Nice, real nice.
It looks like the likely scenario for the deadly crash was the plane was
having problems with the air speed and angle of attack sensors, or the
computer that monitors those had a problem, or something was wrong in the
connections, because one AOA sensor caused the plane to think it was stalli
so it did the trim to force the nose down. Apparently in the confusion,
the pilots could not figure out what was happening and apply the correct
recovery procedure. MAybe if they had been trained and knew about the
different way these planes behave, they would have. I still haven't seen
anyone say whether absent getting the trim corrected the two pilots would
have been able to pull back with enough force on the controls to overcome
the wrong trim. You'd think with it nose diving for the sea, they would
be pulling with all their might.