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Old 4th Apr 2019, 10:19
  #3062 (permalink)  
gmx
 
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Originally Posted by quentinc
Agreed.. I think the FAA's AD acknowledges the challenge that pilot's might face. At the bottom of (h) it reads:
"Initially, higher control forces may be needed to overcome any stabilizer nose down trim already applied. Electric stabilizer trim can be used to neutralize control column pitch forces before moving the STAB TRIM CUTOUT switches to CUTOUT. Manual stabilizer trim can be used before and after the STAB TRIM CUTOUT switches are moved to CUTOUT."

The pilots runaway stabilizer checklist.... is clear... operate the CUTOUT. It doesn't say... try and trim first. For me the AD has never been clear. Are the pilots supposed to follow their trained checklists... and the very same AD, a few paragraphs above, that simply says operate the CUTOUT... Or are they required to make the judgment that they'll never have the strength to turn the trim manually, so they need to rely on the failing electrical trim first.... and then CUTOUT?
It's a reasonable point. However, after the LionAir investigation, everyone knew the electric trim could be used to neutralize MCAS, even if temporarily (as the accident crew had done 20-odd times on the disaster flight). Having MCAS run the trim to its maximum nose down position, and being fully aware of the LionAir situation, wouldn't it make sense to re-trim the aircraft to neutral attitude *before* hitting the cutout switches? Having said that, the pilots have clearly encountered a terrifying circumstance. The only thing you might hope is that after the LionAir incident they were better equipped to deal with it than what seems to have been the case.
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