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Old 14th Nov 2018, 10:46
  #1169 (permalink)  
A Squared
 
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Originally Posted by silverstrata


Good point.

The trim sheet has: Indexes, MACs, and Units. The FCOM has Units. Nowhere that I can see mentions trim degrees.

If Boeing is quoting real degrees here, and not trim units, then that is a whole different ballgame. What is the conversion between degrees and units? Besides, if the aircraft was slow, nearing the stall, you would indeed need 2.5 units (or degrees?) of forward trim. The problem being that you definitely don’t want 2.5 units (degrees?) when doing 250 kt...

Silver
You're probably correct that "degrees" doesn't appear in *operational* publications, But I would speculate that you would find "degrees" in design/engineering/maintenance publications, and that's probably where the numbers in the AD come from; drawn directly from the design specs for the MCAS.

Originally Posted by silverstrata
The problem being that you definitely don’t want 2.5 units (degrees?) when doing 250 kt...


..or *another* 2.5 degrees/units 5 seconds later ...

Last edited by A Squared; 14th Nov 2018 at 11:28.
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