bear, you take us back to trying to unravel
What nose attitude did the flying crew see?
What nose attitude did the captain see when he re-entered the cockpit?
The primary flying instrument to reference when you are flying in instrument conditions is the attitude indicator.
There were three possible displays for the captian to view.
There is no reported evidence of failed attitude indication.
We do not see BEA report something amiss with attitude indications from the voice info released.
Considerable attention is given to attitude information from the FDR in their description of what happened, just as THS position is given considerable attention.
IF nose down input induced stall warning (the second series) due to an alpha function reawakening (and alpha/airspeed restoration, system confidence, etc) it seems odd to me for a crew to interpret that the alpha driving that warning is a high speed buffet sort of warning. From what I glean in various downloaded pdfs on A330 systems, high speed buffet, or approach to it, doesn't evoke a stall warning alert. If you get too close to VMO, or try to get past it, the system tries to correct you. It doesn't want to get beaten up by high speed buffet any more than the pilots do. (Or so the programming can be characterized).
Does that initial pitch have an innocuous origin?
"The AP will disengage if the high-speed protection is active."
Some have asked if the AP initial disengage led pilots to believe that they were in HS protection ... which if AS wasn't reliable, they'd have no way to cross check.
It seems to be the consensus that Alt 1 Law was in operation, and HS prot looks to be available in Alt 1, but not Alt 2. If the capability degraded to Alt 2, robot isn't making inputs for HS protection.
(From Flgt Trn Manual ... alt 2 ... in the case of failure of 3 ADRs, no high speed protection. )
You can expect up to a 1.75 g input (nose up) from the robot if HS protection is called for. After many posts, and four different threads, and going over this again and again, nobody has solid evidence that this feature is where nose up came from. The Abnormal Law possiblity remains open, but the reported evidence of a nose up command from SS keeps cropping up.
Even with ND inputs followed by a stall warning, there remains the matter of attitude flying.
If your nose is up and your are falling, aren't you usually
either
stalled,
in a deliberate powered descent (no applicable here, their mission was "maintain altitude and course" at this point in the flight)
or
undepowered for your desired flight profile?
The power levers were last reduced to ~55%, so the third consideration must be rejected ... which takes you back to nose high and falling, you are stalling.
What did they see on their attitude display?
Last edited by Lonewolf_50; 8th Jul 2011 at 18:43.