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0 pointstwtw7y ago0 comments

For reference, here is the runaway stabilizer memory item (the "checklist") for 737:

1. Control column ............................. Hold firmly

2. Autopilot (if engaged) ..................... Disengage

3. IF the runaway stops:

------------------------ [done]

4. IF the runaway continues:

STAB TRIM CUTOUT switches (both) ...... CUTOUT

IF the runaway continues:

Stabilizer trim wheel ............ Grasp and hold

EDIT:

It's #4 that's of interest here. People saying that the interface changed are saying that it's fine if pilots stop after #1, even when dealing with runaway stabilizer for 12 minutes.

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4 comments · 2 top-level

Someone12347y ago· 2 in thread

Accurate but irrelevant. This assumes the pilots knew they were dealing with a runaway stabilizer, and considering M.C.A.S. wasn't behaving similar to their previous training/experience/simulations with Runaway Stabilizers, it isn't clear they'd know they should follow this checklist. Now had they been actually trained on M.C.A.S. inc. faults, they may have known to do exactly this and we wouldn't even be discussing it.

This has been discussed in great detail on other flight forums.

twtwOP7y ago

It's not really possible to not know that you are dealing with a runaway stabilizer. MCAS (and every other automatic system to adjust trim) causes large physical wheels at the side of the pilot's knee to spin.

sokoloff7y ago

And these large wheels have small bell/clackers on them so you get a distinctly audible signal in addition to the large black wheels with white stripes on them.

1 more reply

rocqua7y ago

As I read the article, it seemed like before, step 1 would suffice before. If this is not the case with MCAS, it could at the very least throw the pilot's diagnostics. "Is it runaway stabilizers? Well, no response from holding the control column firmly so I guess not. Lets check other things".

Sure, the correct response is to follow the checklist, but should we really rely on pilots always knowing the correct response? Especially when that goes against their previous experience? Not that I am defending these pilots not knowing the checklists, instead I am arguing we should take into account learning from experience rather than theory.

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