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Old 12th Apr 2013, 19:29
  #11 (permalink)  
Join Date: Jun 2011
Location: France
Age: 39
Posts: 17
Drawing a conclusion from looking at 2s of SS input is pointless.
It took more than half a minute of predominantly NU input to initiate this condition. It is safe to assume getting the Trim and Elevator down again would have taken at least the same dedication in the opposite direction.
What the report says is that the full deflection of the elevator down was not achieved with this input, because of the alt2b law. While the same law gives the full deflection of elevator up when the pilot was pulling the stick.

And 2 seconds is not a lot, but in Quantas 72 that's exactly the time that was needed to flung the passengers up at -0.8g. 2 seconds (that's on the cvr). Granted it is not a stall and all, but the 2 seconds nose down input, at full authority would probably have improved things for them.

No Airliner is tested nor required to be recoverable in this attitude. Even the trusty old 737 might not be in certain conditions.
This is so far outside any tested and validated Flight Envelope and no one seems willing to sacrifice an airliner plus crew in order to find out during flight test.
Would you volunteer ?
I'm not a pilot anyway, but a 707 was crashed in the eighties for some fuel test, maybe they could do a similar test over an ocean with a remotely piloted airliner. After all, this might help calibrating models for simulations, and thus give an insight to all planes. It is not an A330 specific issue.
I hope in 2013 we have the capability of simulating the unsteady flow around wings, even in the transonic regime. What is lacking is probably just some experimental data to validate the computations.

Conclusion: Don't fly at AoA's of 45 !!!
Yes but all that is easier when you have an AoA indicator. As you mentioned in your post you are probably safe below 30 degrees, which is not that much.
predictorM9 is offline