Originally Posted by
safetypee
Vessbot, how do you recognise the need to disconnect ?
Are you able to describe the process which you use, which will always apply in every situation.
Yes. You compare what you would like the airplane to be doing with what it is actually doing, and if those 2 things mismatch (and especially if you feel behind in any way in recognition, or proposed solution), you disconnect. (The old cutesy chestnut,
"What's it doing now?")
An exception would be if the result is a common sequence of events in type, that you recognize immediately as well as the automation solution, (you never felt mentally behind) then it's OK to just do the automations solution. (
"It's doing that thing again"). Such as in the R&N thread about the 777 stall warning out of JFK, people are talking about a common speed loss due to too-early altitude capture, and a double-push of the altitude button to deal with that)
If you're not sure which one you're in, you're in the first one.
If this starts with understanding the situation, then how do you understand.
To you it might be obvious, to others no so depending on the situation, experience, training - even of this can be trained at all.
How can we be sure that the situation as we understand it is correct, and even if correct that we will choose an appropriate course of action; errors in understanding or errors in acting (not acting).
This doesn't sound to me like a question about comparison of the understanding in your mind vs. the understanding in the airplane's computers, but just a question about the understanding in your mind. How do you understand? You take all your mental habits and abilities you've built up since flight lesson 1, and bring them to bear on all of the information you're receiving about the current situation. Could that be faulty? Yes. Could the airplane have a more accurate SA than the pilot, therefore the automation should be trusted? Yes, and there have been accidents due to that, like the Sukhoi business jet on a sales flight with a customer and a test pilot or something like that, where everything was functioning correctly and they got a GPWS but they blew it off and CFIT'ed.
We spend a lifetime/career assembling all of our experiences into the ability to build accurate SA and judgement... from mentors, hangar stories, accident reports, ground school, books by old sages, official manuals, etc. And hopefully become better at it than this crew. But at the end of the day in the cockpit, we're still the final arbiter of which SA picture is the most accurate, and must act on that; there's no logical way around that. If the computer has a better picture than you, then you still must decide that, and by virtue of that, that has become your own picture as well, to replace your previous one . There's no second version of you, outside of the situation, that judges which picture is better, and decides which one to pick. No, it's only the first you (until they make automation that can override you. So far it can make strong suggestions, but it doesn't override you.)
Evaluating that you're too confused for now, and making the willful choice to trust the automation for the time being, may also be valid, but in the end it's still an example of the same thing. Once you've made that evaluation then you, as the final arbiter, are making the choice (good or bad, result not known yet) which way to go.
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I haven't had time to look at the links, but hopefully I will tomorrow.