[WalterBright]

> MCAS activation is not, and was not, a runaway stabilizer situation.

It presented as a runaway stab trim. Repeatedly coming on and driving the nose down is runaway trim. No two ways about it. And the usual, standard, runaway trim procedure would stop it.

> they had a third set of eyes that could spend time going through reams of documentation

From my reading of that incident, nothing of the sort happened. The 3rd pilot simply reached forward and flipped off the cutoff switches. The crew landed safely and went on with their day. Nobody bothered to inform the next crew flying that same airplane.

[inferiorhuman]

It presented as a runaway stab trim. Repeatedly coming on and driving the nose down is runaway trim. No two ways about it.

No, it didn't. From the latest QRH:

Condition: Uncommanded stabilizer trim movement occurs continuously.

Well that's not met as MCAS doesn't run continuously. By design it stops periodically. Put it another way. You're arguing semantics while the 737 MAX remains a smoldering pile of aluminum and hubris.

2.) Control airplane pitch attitude manually with control column and main electric trim as required.

4.) If the runaway stops after the autopilot is disengaged ....

MCAS also stops after the trim switches are hit. So, again MCAS activation is not a runaway trim condition.

From my reading of that incident, nothing of the sort happened. The 3rd pilot simply reached forward and flipped off the cutoff switches.

Reread the report. The third pilot went back into the cabin to fetch reading material.

[WalterBright]

> You're arguing semantics

Trying to argue that the trim system erratically coming on and driving the nose down is not "runaway trim" is arguing semantics. Runaway trim is when the trim is doing something dangerous without command from the pilot.

If the cockpit voice recorder reveals them discussing the definition of "runaway trim" and deciding that the instructions Boeing provided didn't apply, I'd be surprised and interested.

> MCAS also stops after the trim switches are hit.

Exactly, the trim switches override the MCAS. That's why you use the trim switches to set it back to normal, then hit the cutoff switches. That's what the Emergency Airworthiness Directive says to do.

> Reread the report.

I haven't read that anywhere. I don't know what report that is. Reference, please.

[Gibbon1]

> Exactly, the trim switches override the MCAS. That's why you use the trim switches to set it back to normal, then hit the cutoff switches.

On the 737 Max there is no way to disable the MCAS without also disabling the electric trim.

[WalterBright]

Sigh. With the electric trim enabled, the trim switches will override any MCAS commands. This is why, again:

1. trim to normal with the electric trim switches

2. cut off the stabilizer trim

Do it in that order. Doing step 2 before step 1 won't work.