Originally Posted by JD-EE
Lone, I noticed this, "Alt 2 latched does not mean "flight control locked and no longer able to be moved"" before I noticed it was to bear and ignored the message. I have an idle question that does not bear on this crash.
I saw what you did there.
Why might Alt 2 latch in and not be able to be escaped back to normal once the aircraft is flying normally again? Permanently latching out the aircraft safety systems for half of a long (10 hours?) flight seems counter productive.
I think Dozy had a better answer than I do,
at post 564.
According to the documents I've got, inhibition of A/P is not necessarily the case as a result of Alternate Law latching, in fact the only control law where the manuals specifically state A/P is unavailable is Direct. However, the A/P disconnect in this case was due to ADR disagree. If I recall correctly, it was possible in some cases to re-engage A/P once stability was restored, but according to the Flight article below, EASA are mandating a change to inhibit A/P for as long as ADR disagree is active. They don't say if this behaviour should be latched.
A330/340 change to inhibit autopilot if airspeed unreliable
It's curious in a way, because it appears the AF447 crew did not try to re-engage A/P, but maybe as part of the simulator testing they've discovered anomalous behaviour if you try.
Ian: post #565. Well said.
Old Cathrusian, good points in response.
Comment: You addressed scan breakdown, Ian addressed "data channels" in the human brain. These are both matters of interest in the human engineering side of this equation.
Likewise, Old Carthusian, the following:
The maxim that all pilots should follow - know your machine and these guys didn't. This is not the responsibility of the machine. It is the responsibility of the pilots and the airline.
The balance between self initiated systems knowledge growth, and training in its application to the mission seems to be a sticking point.
Dozy:
Did you get this impression from reviewing the traces?
Of course if neither of them had had manual handling training, that question could be academic, but I'm struck by the difference in handling approach by the two F/Os. The PNF appears to be doing as one would expect, gingerly handling the controls until the aircraft starts pointing the way he wants it to go, whereas the PF seems to be handling them with a frankly astonishing coarseness from the outset.