[DanielBMarkham]

So this was just a Darwinian exercise, where the plane kept malfunctioning until it found a crew that responded incorrectly?

I hear you about runaway trim, but it seems that you are quite focused on the blades of grass and not looking so much at the lawn.

Nobody has given me an adequate answer to one simple question: what is the indicator the industry will use to determine when it has made the cockpits so complex that the complexity itself becomes a danger? Because we can play this game for a few decades more: manufacturers mod-up old planes with new software, extra training is added to the pilot's schedules, there are crashes where commenters in good faith can say "but that's an obvious part of any pilot's training". Repeat and rinse -- with the proviso that with each round the overall complexity continues to increase.

Technology developers, more than anyone else, are quite cognizant of the fact that we can create technology we ourselves cannot understand. Perhaps the aviation industry and the associated regulators somehow missed this?

[WalterBright]

I view it a bit like an engine failure. Jets have twin engines so they can keep flying if one quits. Pilots are trained to deal with an engine out. It doesn't particularly matter why the engine quit, just that the pilots know how to fly on one engine.

The pilots are supposed to know how to deal with runaway stab trim. It doesn't matter why it was running away, just that the pilots know how to deal with it. Whether it was MCAS or the autopilot or a short circuit, does not matter.

After it is safely back on the ground, then the specific cause of the failure can be ascertained and corrected.

[DanielBMarkham]

With respect, I believe you are viewing this in far too simplistic a manner.

Let's take engine failure. When you're training twins, you're going to get one of the engines pulled on you quite a bit -- usually when you least expect it. That's because a lot of people died educating the industry to how important it is to be able to handle engine failure in all flight modes: takeoff, climb-out, cruise-climb, and so on. That reaction sequence has to be drilled into pilots to such a degree that there's no thinking involved.

But runaway trim? Seriously? Sure, you'll get the training, but in all modes of flight? Drilled into you until you can handle it in your sleep? No way. That's preposterous. We _thought_ we knew that those kinds of problems don't happen at weird times to cause people to die. So if you're flying along in cruise and you've got a runaway trim, somebody does a mental lookup -- which might take 3 or 4 seconds -- locates the breaker, then throws it. We do this other type of training a lot too, but there are tons of subsystems on your average commercial airliner. We don't train for that the way we train for engine failure. We've got huge reams of checklists in commercial cockpits dedicated to this kind of slower problem-solving.

So yes, in both cases a person could argue that training was either not given or not implemented by the crew. But that ignore the realistic limitations of trying to train crews on modern equipment. You simply can't do some kind of weird cross-tab grid where everything is trained everywhere and to the same degree. At some point the human factor has to come into play. People aren't robots. It looks like these accidents happened on takeoff/climb-out, one of the most busy and complex things a crew can do (not near the complexity of hand-flying the various instrument approaches, of course).

You gotta ask yourself: if I'm watching my turbine numbers, my airspeed, looking for traffic, the copilot's talking to the pax, and so forth? Would I catch a runaway trim right away? More to the point, if I missed it, would the ensuing chaos, _in some cases_ prevent me from being able to cognitively switch back to diagnostic mode? After all, we teach pilot when all else fails, fly the plane first. Add to that systems like MCAS that might exist in the software that the pilots are unaware of?

If these accidents turn out to be MCAS/runaway trim related, I would be interested in learning about the crew environment when it happened, specifically other issues taxing the pilots and whether or not the flight director was engaged.

So yes, sure. You can train your way out of this. At some point, however, you have to ask if the cost we're paying in lives is worth the lessons we're learning which all seem to boil down to "people are cognitively limited in many ways"

[WalterBright]

It's a good point, but the prominent placement of those cutoff switches, and the criticality of runaway stab trim, suggests it should be solidly there in training.

I'm sure the training issue will be prominent in the NTSB report.

Note that stall recovery is heavily trained, but airliners still crash because the pilot reflexively commands nose up in a stall instead of nose down. And the MCAS system is there to nose it down in a stall.