AF447 Thread No. 3

[bearfoil]

Lonewolf50

Yes, I get. In Unreliable a/s, the a/c is in Alternate Law, out of autopilot and autothrottle. So some (ill-defined?) combination of Manual and residual control is necessary. To maintain cruise, (that's the idea?), until A/S is recaptured and auto pilot can be reselected, the idea is Pitch and Power. At the beginning of the thread, my assumption is, well, Pitch and Power, then. Some combination of NU and %N1, yes? Table, PNF, memory, Bob's yer oncle?

I may have missed a key piece of info in the plethora of posting around maintaining aero flight. I may need to re-assess; Did our boys have access to means of pulling the fat back from the fire, and screwed the Poodle?

Within the realm of cruise in a commercial airliner, and a knife fight with duelling Vipers or Phantoms, AoA? Am I wrong in taking for granted that in Commercial flight at the "edge", Pitch and N1 are insufficient to keep the flight safe?

If Pitch and Power are the fallback, de jure, someone needs to teach the Airbus pilot to fly AoA? Okay, Fine?

bear

t54

"From 2 h 10 min 05 , the autopilot then auto-thrust disengaged and the PF said "I have the controls". The airplane began to roll to the right and the PF made a left nose-up input. The stall warning sounded twice in a row."

This is reliant on the undivulged time line, for BEA state only "From....."
Anyways, after the 2:10:05 id. "Twice in a row" means to me, two short alarms, and my guess is that these were related to AoA rate transients, not a Stall per se. "chirp, chirp." In any case, the Stall warning happened at the same time (between a/p drop, and PF's left,NU input). This is in legal jargon, exculpatory.

"...and because of this the PF followed standard (low altitude) stall procedure, setting power to full and raising the nose somewhat?"

Not "raising the nose" in recovery from approach to Stall, but "Maintaining Altitude", two very different things. Since the Nose was dropping at handover, PF's flying was by the book, no matter the Training Syllabus.

Airbus instituted its "MODIFICATION OF STALL RECOVERY" AFTER 447 went in.

LW

"Put another way, if your aircraft stalls at 6, or 8, or 10 or 12 units/degrees AoA, and you are at 30, you are well behind the aircraft. A design assumption seems to be "if you get this far into stall, the computer may be a problem contributing to the situation, get it out of there so you can get this bird out of a stall!" "

So some means of "get" and control movement needs some tweaking, eh?

I may be letting some AB philosophy in, finally. "That does not absolve the airframe builder of responsibility here. Selling someone some hardware and not training it exhaustively is a chasm of Arrogance."

This will no doubt be at least one of Plaintiff's claims (theories).