PPRuNe Forums - View Single Post - Concorde Paris crash, questions, facts, opinions
Old 15th Sep 2010, 05:49
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bjornhall
 
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There is a little too much misinformation on this thread by now... Let's not agree on things that are not factual. This is a rather straightforward event, and there is no need to confuse matters with misconceptions and false "facts".

Aircraft overweight a factor with an engine out? No. 0.5 % makes no difference, and that is not me saying that but the investigators who looked into that fact.

Out of trim? Where does the report say that? It talks about how much fuel would have to be pumped out of tank 11 during taxi before takeoff to be in trim, but that was not unusual, and where does it say that was not done? If you are talking about the 54.3 % CG indication observed on the pilots' CG indicator after the crash then that is also not significant; it is the load sheet values that matter as long as the CG indication is not off by more than 0.3 %. Also, 0.3% is not a large shift on that gauge; who can tell it did not move at all during the impact?

Again, we do not know if it took off downwind; some indications say it did, some say it didn't, but it is perhaps more likely it had a few knots tailwind. It was definitely within the flight manual limitation. I still do not see how it would make a difference; I suppose you are suggesting it would have been moving faster when the tyre failed and thus been able to climb better? But how would that allow it to land before the fire brought it down? It would not. If indeed it took off with the full 8 kt tailwind reported by the tower it would have been another couple tons overweight due to the tyre speed limitation, but since it rotated before Vr it was off the ground well before that limitation.

The aircraft most decidedly did not stall! Control was lost due to the effects of the fire, due to the combination of the number one engine surging and flight control damage. We know that by comparing aircraft behavior with control inputs from the FDR. Yes, they pulled back power on the good engines to reduce bank, in an effort to regain control. The bank was a result of the flight controls not being able to counteract the impact of two failed engines on one side, although the aircraft was well over VMCA-2.

And finally, according the the report there as ambiguity regarding when the fire drill should be executed; some generic Air France manual said after being established in the climb (citing some altitude figure if I remember correctly), whereas the Air France's Concorde manual said it should be done immediately (do not remember the exact names of the two manuals, look it up if it is important). The captain and the flight engineer apparently agreed on when the drill was to be executed, since the captain called for the drill at the same time when the flight engineer stated that engine 2 should be shut down (I can not tell from the translated transcript whether that was something the FE suggested should be done, said he was going to do or said he was already doing). Procedures are not to be changed during their execution in an actual emergency, Robert's "rule of life" notwithstanding.

Now, in case there is anything left to be said about this accident... Perhaps we could discuss what happened and why, rather than dwelling on things that never happened and facts that aren't true?
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