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Give me whoever you consider the best two pilots on earth and I promise you they'll have a collective minute of suboptimal decision making at some point, especi
by chmod775 4y ago
Give me whoever you consider the best two pilots on earth and I promise you they'll have a collective minute of suboptimal decision making at some point, especially when confronted with an extremely sudden stressful situation. Humans don't work the way you're implying they do.
However we design systems and procedures such that suboptimal usually doesn't mean fatal, and in those specific instances where it would, we train humans so they perform adequately.
If humans were so great, we wouldn't need a lot of the technology in modern aircraft. It's mostly there because humans suck. Taking work away from the meatbags, putting in safeguards, and designing with the human element in mind, produces more desirable outcomes.
And it's not like this crew had the wrong ideas. They attempted all the right things, but execution was lacking and sadly the situation had no room for error:
1. Did use cut out, but left it on normal for a few crucial seconds without any manual input, allowing the computer to mess everything up again.
2. Did try to fix trim before cut out, but only got it halfway there to the point where they could at least achieve level flight and a slight climb. Tried to trim the rest of the way manually, but that didn't work.
> There's enough time to respond.
Disregarding that the situation could have been avoided, the second time this crew didn't have time to react anymore. It took only 3.5s from the automatic nose down engaging to descending at -5,000 ft/min, pitching -8° down and quickly increasing to -40°, despite the pilots pulling on their sticks full force. They had maybe a second or two to nip it in the bud, then had twenty seconds left to somehow arrest the rapid descent of an aircraft that is trimmed precisely the wrong way with the horizon in a place you don't ever want to see it in a commercial airliner. I don't think it was physically possible?
It's not hard imagining situations where an aircraft doing something like that within 3.5s out of nowhere would be disastrous. There certainly wouldn't be time to respond. This crew was warned by earlier misbehavior, so the situation was theoretically avoidable, but there was little room for error and so we should be glad for all the times something didn't happen.
> All three crews correctly restored normal trim immediately.
Are you counting this crew? I don't think they had normal trim at any point once the incident started. They were trying to get there.
- WalterBright 4y agoYes, people make mistakes. And we should design systems to be tolerant of those mistakes. With airplanes, we try to think through all the emergencies first, figure out how to fix them at leisure, then write it down in the form of a checklist or an Emergency Airworthiness Directive. We expect pilots to pay attention to those things. They make mistakes, sure, but they are still responsible for those mistakes. The EA pilots did not follow the procedure laid out as "how to not die like the Lion Air pilots". Seems to me that should be worth reading, understanding, and remembered. Especially as there was nothing complicated about it - trim to normal, turn it off. Wouldn't you prefer to fly with pilots who did? I do.