
Ethiopian Pilots Followed Boeing’s Required Steps to Disable 737 Max System - radicaldreamer
https://www.wsj.com/articles/ethiopian-airlines-pilots-initially-followed-boeings-required-emergency-steps-to-disable-737-max-system-11554263276
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js2
Something is not adding up:

 _The pilots on Ethiopian Airlines Flight 302 initially reacted to the
emergency by shutting off power to electric motors driven by the automated
system, these people said, but then appear to have re-engaged the system to
cope with a persistent steep nose-down angle. It wasn’t immediately clear why
the pilots turned the automated system back on instead of continuing to follow
Boeing’s standard emergency checklist, but government and industry officials
said the likely reason would have been because manual controls to raise the
nose didn’t achieve the desired results.

After first cranking a manual wheel in the cockpit that controls the same
movable surfaces on the plane’s tail that MCAS had affected, the pilots turned
electric power back on, one of these people said. They began to use electric
switches to try to raise the plane’s nose, according to these people. But the
electric power also reactivated MCAS, allowing it to continue its strong
downward commands, the people said._

Did they just not crank the wheels enough? The motor operates quickly so it
would take a lot of hand cranking to return the trim to neutral. Maybe they
hadn't practiced the manual procedure before and were unaware of how many
turns were needed?

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LoSboccacc
well is there an indication on how long does it takes to come out of full trim
manually? because if it's 30 seconds of cranking the aircraft might very well
be descending too fast or too fast in general by the time control is regained.

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js2
It’s a lot of cranking to do by hand[1]. You could use the electric trim to
reset back to zero and then disable electric trim. (But, that isn’t the
procedure.)

1\. [https://youtu.be/xixM_cwSLcQ](https://youtu.be/xixM_cwSLcQ)

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cjbprime
It looks like the motor takes 30 seconds to move the jackscrew from one end to
the other. Cranking presumably takes much longer. It doesn't seem hard to
imagine the ground intervening before you finish cranking back to trimmed
level flight.

And that's assuming there's no issue with the aerodynamic load preventing the
stabilizer from being retrimmed until you unload the elevator (by pushing the
yoke forward), as is being theorized to be the case.

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themark
I am not surprised. When do we start to consider the possibility that the
software was compromised?

