Originally Posted by
CONF iture
OK, so let's have a look:
Originally Posted by
CONF iture
It certainly won't efficiently as the elevators are commanded nose-down as a start.
And if the elevators are commanded nose-down to arrest the pitch-up tendency from the engines, as submitted by dozy, it is even a poorer concept.
Remember, we are still 2.5 deg short of alpha max.
Elevators don't effect an AoA, they effect a pitch attitude.
Therefore, if the pitch attitude is limited by AoA protection and the pitch-up moment from the increase in thrust is expected to exceed that attitude, then the systems will be correct in counteracting that tendency through the elevators. As Capt. Bechet stated, this is normal behaviour, and something that Capt. Asseline should have been aware of.
Nothing in the documentation or the video states that 17.5 degrees AoA is guaranteed upon application of full back-stick. The demonstration in the video was not performed with the engines spooled down, and that would have made a massive difference to systems behaviour.
It does not have to be, what matters is the intention, the intention to efficiently deliver.
Which, in the circumstances, the systems could be argued to have done just that.
The systems were designed to keep the aircraft flying and stable even at attitudes which would be considered extreme for a transport aircraft. I'd be prepared to bet money that the combination of Asseline's inputs, had the aircraft been in Direct Law, plus the pitch-up moment from the thrust increase would almost certainly have stalled the aircraft. I'd also be prepared to bet that no human pilot would have been able to take in all the flight parameters and keep the aircraft more stable than the EFCS did.
but a contributory factor for the crash it has to be.
Can you prove that the extra 2.5 degrees of pitch would have avoided the crash? I know I certainly wouldn't be able to.
If CONF 3 was the setting for the video demo, why alpha max was at 15 when it was at 17.5 for Habsheim ... ?
We don't know what the CONF setting was for either.