AF447 Thread No. 3

[bearfoil]

@Graybeard

"Does anybody understand the rationale for two sets of control laws between Normal and Direct? It seems to make systems management take precedence over aviating."

GB

That basic question lit the original thread on fire for pages, and from the git go.

Firstly, I believe there are three control domains twixt N and D, if one counts Abnormal (ironic?). Just as Piloting is changing its format to reliance on automation, what gets left behind is what has become most important, Know the Airplane.

There is no challenge to the gestating supremacy of Auto Flight in allowing, (Training) airmen and women to know the personality of their a/c backwards and forwards. What is the insult to parochial aero programming inherent in aviating skills? Such Hubris. "It did exactly what it was supposed to".

I beg to differ, for if any of the doubts expressed here are proven, what remains is "I'll do this, and if it 'doesn't work', it's on you". Always the defensive, and dismissive attitude. Arrogance has always been deadly in aviation.

The lack of a fossil AH on the panel was a shorter discussion, as many were astonished to find that so 'common' an occurrence as 'Unreliable Airspeed' could (did) leave both pilots without attitude, or 'assiette' data, (display).

@gbnf

"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."

The Plane rolling right meant that a/p had been trimming out a chronic and trending condition, both Right wing heavy, and NOSE HEAVY. The THS was at 3 degrees when a/p dropped, what was the nature of the dropping Nose? Was it dropping continually, and continued to drop after a/p drop? Yes, because the THS was running behind its trim command from FMC, by definition. Nose and right wing dropping, a condition identified by both the a/p and the handed-to PF. This is suggestive not of Turbulence, but controls damage, weight issues (cg), Fuel scatter, etc. or ICE. Even an inop or over limited Rudder. Perhaps?