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Old 04-11-2019, 05:30 PM   #11  
sgrd0q
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Joined APC: Jan 2006
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Quote:
Originally Posted by Adlerdriver View Post
100 lbs of pull on the control column is going to tell any competent pilot that he's going to have to trim like crazy to get it back into a normal range. He's not going to give a couple of clicks of trim, have the control forces go to 99 lbs, shrug his shoulders and give up because the problem wasn't instantly corrected. This whole "feedback loop" discussion is nonsense.
Incredibly, the Ethiopian crew did just that. I refer you to page 26 of the preliminary report. Look at the graph at time 5:43:15 - two short clicks. That is it. Then the MCAS dials in nose down trim and it is over:

https://assets.documentcloud.org/doc...X-Ethiopia.pdf

I am not going to label them as competent or incompetent - all I know is that they sure knew how to trim and did it all the time under normal circumstances. Then when the forces were too great and the feed back loop non-existent they all of a sudden could not do it.

Same report, page 11, quote:

At 05:40:27, the Captain advised the First-Officer to trim up with him.

Why on earth would you want someone to click on their thumb switches with you unless you believe the trim on your side is not working? And why does he think it is not working? Surely because the feed back loop is distorted - the correction is small, he does not feel it and he gives up. This is my interpretation, you are welcome to disagree.
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