Hello
RR_NDB;
Originally Posted by RR_NDB 28th Mar 2012, 00:37 Post # 1033
The context of the question, "why?" is Phase 2 (as stated in IR3) of this accident: Why the pitch-up and then the continued pitch-up post-apogee? So, yes, there are remaining many possible and important reasons in answer to the question, "Why?" in this context but there are also a number of explanations which are less probable as to why. The focus on aircraft system anomalies after entry into the full stall and descent will not answer the question regarding Phase 2. The extreme stress and confusion/cognitive dissonance indicated in Phase 3 resulting from aircraft/system behaviours that were inconsistent with the crews' view that they were still flying despite the stall warnings (crew comments in IR3 regarding "high speed") and the recurring stall warning and airspeed indications, likely contributed to the significantly-decreased chances of assessment of the problem and swiftly reducing opportunity for recovery.
Quote: At present I think it is not complicated.
Please comment.
Well, I have been commenting all along since last May up to these series of posts on why I think this is not complicated but I will try to make that uncomplicated!
First, "not complicated" doesn't mean that details of both human and aircraft behaviour are dismissed as sidebars or non-causal factors...not at all. But some theories and notions of what happened are more in accord with what we know and therefore more relevant than others which we have seen. It is not always easy to know when one is merely jamming a notion into the small box of known facts so that a theory fits a preconceived notion, or whether one is "on to something" and just needs to ask more questions.
But as more becomes known, one is able to parse such interesting activity and ideas and then tentatively set aside some notions and turn towards others which are more plausible, at least until something else comes along which hints or even proves that one might be off-base so that one can start again. It isn't a perfect way to do things but it works.
"Not complicated" here means, this is a loss-of-control accident which resulted from stalling the aircraft. Why did that happen?
That happened because the airplane was pitched up and held there until the stall. Why? This was done immediately, without announcement, standard crew coordination, (CRM) or following SOPs. Why? The PM made no interventions. Why? One simply never pitches a transport aircraft up to 10 to 15degrees at cruise altitude and holds it there because intuitively knows what will happen...a rapid loss of energy. We have to assume the PF was earnest in his response yet the response was not correct. Why?
Some details for this exact point would be the prior crew discussion regarding climbing and the FMGC MAX ALT message. That was a clear indication that the airplane was already very near its altitude limit in terms of available thrust to maintain cruise flight. Why go higher where the available thrust would not maintain level flight let alone a zoom-climb? That would be a detail. The climb happened versus not: Why?
In Phase 3 when the "stall, stall" with Master Warning and audible warnings were heard why was the stall warning not respected as per the UAS QRH checklist? A number of ideas have been posited and discussed and may explain this but the key point is, it happened, vice not. Why?
What is going to be very complicated is understanding the human dynamics and factors which led to certain behaviours and not others. We already know that training regimes, simulator scripts, awareness of high altitude flight dynamics and swept-wing transport behaviours as well as system behaviours are being taught everywhere but we may only be able to make guesses at the psychology of the flight deck in this accident and this is where we must be extremely cautious and respectful of the crew and of our lack of knowledge.