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Old 26th Mar 2019, 18:30
  #2562 (permalink)  
GordonR_Cape
 
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Location: Cape Town, ZA
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FCeng84

Thanks for your multiple clarifications! I appreciate the fact that my 'dumb' questions elecit enlightening responses.

Something that still puzzles me (I refetred to previously) is the contradiction between making MCAS safe under faulty AOA scenario, and effective under actual high AOA conditions.

1. Under the faulty AOA scenario MCAS activates but is only allowed one trim down increment, after which it is inhibited, with a relatively harmless outcome.
2. Under an actual high AOA condition MCAS will activate, and start to trim nose down. If (for whatever reason) the pilot decided to trim the nose fractionally up, this would inhibit MCAS. Following the new rules MCAS is only allowed to make one nose down operation. If the pilot does nothing further for 5 seconds and the AOA remains high, does the remainder of the nose down cycle complete? Or does it remain where the pilot left it, leaving the aircraft in a degraded condition, potentially falling outside regulatory requirements?
3. If an aircraft encounters two high AOA events in sequence, is MCAS inhibited for the second event? What time interval or event, would allow MCAS to be enabled for a second valid high AOA event activation?

Does any of this make sense, or have the details been worked out, and I am creating imaginary difficulties?

Edit: gums is asking the same kind of question.

Edit: Disabling MCAS if AOA disagree would remove gums fault scenario.

Edit: I see similar questions (and answers) being covered in the Stabiliser Trim thread. Potentially the moderators could move this entire discussion, though it follows closely on from earlier posts.

Last edited by GordonR_Cape; 26th Mar 2019 at 19:48. Reason: Other thread questions.
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