This is very important, as it shows the ratio of pilots aware of the mitigation is low, and/or the stress of fighting with the the computer makes you forget you training amendments
Edited to add it’s a training amendment
Edited to add it’s a training amendment
What people (including pilots) do under stress is resort to simple actions drilled in by training. That's why emergency procedure training is a major part of pilot training curriculum.
What goes away first under stress is capability for complex reasoning, which is what one would need to figure out what the heck is going on and take appropriate action. In this case an a/c doing uncommanded dive can be a result of three things: elevator controls malfuncion (unlikely in modern jets, the mechanisms for transmitting control forces from the yoke to the elevator are multiply redundant and well-understood to be critical), structural breakdown (empennage falling off would do that), or run-away elevator or stabilizer trim.
In most a/c the runaway trim can be only caused by malfunctioning auto-pilot (that's why APs have multiple redundant ways to disable them), so the pilots faced this situation react by trying to disable AP in all available ways and then immediately jumping to conclusion that there's something catastrophically wrong with elevator system or even airframe integrity. The thought that there could be yet another system which can do major trim adjustment doesn't even enter their consciousness.
Training (and/or being in a position where there's no immediate stress of wrangling misbehaving a/c) would help to get to the correct solution (disabling trim motor by pulling the circuit breaker).
That said, flying an a/c seriously out of trim is hard, and can cause an accident on its own (the fine pitch control is gone, and you can even be so far out of trim that you cannot do landing flare no matter how hard you pull up, which in heavy jets would result in structural breakdown when the plane slams into runway).
You could almost certainly disable just about anything by pulling the appropriate circuit breaker. You don't want to do that because the plane may be left in a state where you can't control it manually and you only have a few thousand feet of altitude to recover.
There are, in fact, two switches to turn off the electronic control of the horizontal stabilizer. The previous Lion Air crew used them after the pilot riding in the jumpseat went back and grabbed his copy of what I'd assume was the flight manual and had an ah-hah moment[1]. The flight 610 crew were pouring over something (quick reference handbook?) but didn't express any awareness of the stabilizer being trimmed[2].
Depending on how bad things got there are a few problems with this. First, electrically moving the stabilizer is much faster than moving it manually. MCAS can operate at two speeds, IIRC both are slower than the speed dictated by the buttons on the yoke (plus the buttons on the yoke will pause MCAS). But even MCAS will move the stabilizer much faster than a pilot could by cranking the manual wheels. I believe that moving the stabilizer from one extreme at the fastest speed to the other takes about a minute. You can find videos of the stabilizer mechanism on a 777 on youtube, it's just not something that's designed to move quickly.
The next problem is that if the stabilizer is pitched down sufficiently (perhaps by MCAS), your first instinct may be to pull back on the yoke (to move the elevator) to regain pitch. Well, once you've done that the aerodynamic forces may be such that you can't move the stabilizer into a nose up position until you let go of the yoke and let the plane pitch down further (Boeing references needing to unload the stabilizer in some documents). That's something you've gotta have cat-like reflexes for when you're already flying so low.
The really sad part is that the pilots could have disabled MCAS and retained electric control over the stabilizer by extending the flaps. But how are the pilots going to know this when Boeing refused to document anything?
0: http://avherald.com/h?article=419f2f9e
1: https://www.grid.id/read/04966850/deretan-kejanggalan-yang-d...
2: https://www.straitstimes.com/asia/se-asia/cockpit-voice-reco...
I can't help thinking things would be safer and the Ethiopian crash may not have happened if they just published all the info rather leaving this kind of thing to anonymous leaks to the press.
Remember, a few fatal crashes are worth it as long as it means higher corporate profits.
A single data point is still a data point.
That doesn't tell us that it's reasonable to expect pilots in command under stress to always figure it out. And they have to figure it out 100% of the time to avoid statistically unacceptable crashes. So I don't agree that pilot training is an acceptable answer given what we know so far.
The pilots were stressed in part because they didn't know -- they had plenty of time to recognize the issue and take action had they known, but they didn't, so no amount of time would have helped them. We don't know if one more thing to know about would too much, but I rather doubt that.