WHY is a philosophical question, and requires patience, and an open mind.
Now, HOW. There is a reason these two words exist, and I suggest that for purposes of understanding, HOW is the one that should drive.
Per mm43's post, I see the possibility for the PF to be "tagging along" to an incremental climb of his own command. It implies a misunderstanding of how his a/c works, imo, but does that matter to HOW? His roll inputs are thought to be a possible PIO. At his first pull up, BEA said the a/c did not immediately respond. If true, that is important, because if the climb was the result solely of PF's command, how like a PIO is it? If the a/c was bobbing on the ascent, each loss of trajectory ND wants a correction NU.
Can a climb be the result of a PIO? Of course. Without VS reads, he may think the a/c is losing the altitude it had acquired, needing incrementally more NU to maintain "Level". If his screen was not dependable, and he was unaware, why should he hand the a/c off?
Tangentially answering Glueball, yes, this a/c can climb without autopilot 3000 feet without manual input. And it has, it's in the record, here.
"You don't start moving the controls until you have a good idea what the problem is...." per DOZY.
If you mean PF first inputs were a blunder, you are dead wrong. The a/p quit, two seconds later he announced "I have controls". That means that any handling to follow will be done by the pilot. At some point in time, that is just the way it is, and it gets done. The record shows that he made inputs clearly demonstrating he wanted to correct a flight path that had deviated from S/L IN HIS OPINION. So stop trying to insinuate one's own alternate into the facts. That has been criticised, validly, as compromising a later Pitch and Power solution to maintaining control.
As stated previously, An autopilot will disconnect for reasons other than Unreliable airspeeds. This thread quickly glossed over that the pilot may have been maneuvering with the assumption of loss of a/p to turbulence induced inability to keep up.
It would be interesting to read how the 330 annunciates specific failures to its pilot, to establish that he KNEW disconnect was UAS, and maneuvered quickly in spite of that. Because in the record, the UAS loss of speeds/ALTERNATE LAW, is announced by the PNF, eleven seconds later.
Too fine a point? How so? This is the absolute beginning of the disastrous man/machine interface that brought her down. IMHO.
MASTER CAUTION. CAVALRY CHARGE. PITCH DARK. TURBULENCE. DUFF SPEEDS. HARPY F/O (imo). (DOES he have a screen?)
OK, heroes, what do YOU do?
Dozy: "After autopilot disconnect" re: the pilot commanding THS NU.
Who wants autotrim in ALTERNATE LAW 2? Raise your hand.
Last edited by Lyman; 20th Oct 2011 at 16:51.