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Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

bbc.co.uk

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Re: Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

#5
post #4

If this was indeed MCAS, it is my understanding they 'could have' stopped this by turning off power to the electronic stabilizer trim.

Per the friendly article, "Pilots "repeatedly" followed procedures recommended by Boeing before the crash, according to the first official report into the disaster."

Re: Ethiopian Airlines Boeing 737 pilots 'could not stop nosedive'

#7
Will be interesting to see the details when the report is actually public. It does sound like the scenario that Mentourpilot explored in the simulator is close to what happened, namely:

Bad AoA probe causes MCAS to trim down, and also to indicate IAS disagree. Pilots increase throttle as per non-normal checklist to reduce the risk of stalling due to unreliable airspeed. Pilots disable electric stabilizer trim, as per Boeing's advice, without trimming back to neutral trim. Plane is now low, accelerating, and trimmed nose down. Pilots likely started to trim up with the manual trim wheels, but that's very slow, and gets harder as airspeed increases. And you don't want to reduce power, because that will cause a pitch-down, and you're close to the ground. At this point you've run out of options that are recommended by Boeing. The only remaining option is to re-enable electric stabilizer trim, and use that to trim nose-up.

Now, from what I understand, appying nose-up electric trim should override MCAS, and so this course of action should be possible. However, at this point, you're basically a test pilot - this is not on any of Boeing's checklists or training. Why didn't it work? We'll have to wait for the full report for that I think.

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