Will Fraser:
Since it is a flight controls issue relative to the computer, and involved similarities with ACARS from 447, I'm not convinced it doesn't obtain.
All we have in AF447 case is "F/CTL PRIM 1 FAULT" @ 0213
It's a bit fast to talk about "similarities" when at this point (ALT2), pitch was only protected to g-loads, and the flight control computer only ability was to correct any pitch imput in excess off structural limits.
See "PRIM1" specifically. Inop or selected off, the chain is interesting relative to HS movement and the possibility of overspeed leading to upset.
I'm trying to give credit to the engineers here, and as well, I'm trying to give credit to the pilots: what would be the pitch setting at FL350? something like +2.5 deg and, even if (very unlikely) the pitch was unexpectidly reseted to 0 (whilch system would do that in Alternate 2?), this would hardly introduce a critical upset outside the pilots skills to recover from. The speed margin would be about Mach 0.04-0.06 under overspeed, and such an overspeed would still be far from the real structural limits (more than 50+ kts). By the way, if an overspeed really occured at one point, I guess that it will show some traces on the tailfin leading edge; then, the BEA will tell us about it but even so, it won't tell us if an overspeed was due to any computer or crew action.
Last, I'm hardly an authority you have to defer in any way. We are only exchanging personnal point of views in a public forum.
augustusjeremy:
I beg to differ. I think this is at least controversial.
And I remeber you saying something about failed engines. Maybe that's why Will Fraser is coming up with that AD now.
Sorry if I may have induced some of us in error, but the possibility of a (double) engine failures seems totally excluded until the ACARS stopped. And by this point, everything would be in direct law (manual) due to the limited power supply. So, it is very difficult to add any computer mis-behavoir after a situation like that would have developped.
I just don't believe in the scenario: "fast fall from FL350 in one piece and four minutes" I may be wrong, but it looks to me like a false lead to follow until we'll get much more facts to explain it.
S~
Olivier