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Old 26th Apr 2019, 23:44
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MurphyWasRight
 
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Originally Posted by Lost in Saigon


The “problem” was explained in the Boeing Bulletin issued back in November 2018 after the Lion Air accident.

“Uncommanded nose down stabilizer trim due to erroneous Angle of Attack during Manual flight only”

Ethiopian airliner down in Africa
It is interesting that the revised runaway trim card in the official emergency AD is significantly different from the one in above, the note about using manual electrical trim was moved to the bottom and is not directly below the 'action' items. See page 7:

http://rgl.faa.gov/Regulatory_and_Gu...2018-23-51.pdf

Would a pilot converting to MAX in November have seen the Boing bulletin or just the revised per emergency AD manual?
Are the bulletins typically discarded when an official AD is issued?

Both of them talk of 'higher control forces may be needed' they do not specifically state that the manual trim might be unusable in a significantly mistrimed state.
Would be easy to read that as referring to column forces, especially by a someone not trained in the 'unloading'/ roller coaster maneuver

Last edited by MurphyWasRight; 27th Apr 2019 at 00:07. Reason: Added Comment on forces
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