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Old 13th July 2011 | 22:12
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henra
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From: PLanet Earth
Originally Posted by HazelNuts39
Thx Henra, I wasn't aware of that. In the case of AF447, when the pilot 'maintained nose-up inputs' after 2:10:51, and continued that '15 seconds later', reaching a pitch attitude of 16 degrees, and supposing he released the stick at that point, would the FCS then maintain 16 degrees pitch?
Not necessarily. I don't know the exact implementation of the C* law by Airbus. If it were a straightforward pitch rate law below a certain speed this would be the case but I'm sure it is not exactly implemented this way all the way to Stall speed.
Unfortunately I don't know how exactly they factor in AoA in the very low speed regime but it would not be too difficult to overlay AoA thresholds over a pitch rate law and I cannot see them not factoring this in.

Edit:
If someone has got access to a good sim the exact behaviour of the 'bus should be rather easy to find out. Put it in Alt2 in a constant climb at 5-10° NU pitch and wait what happens.
Take notes of Speed, AoA, Pitch, Trim while speed reduces close to the apogee.

Last edited by henra; 13th July 2011 at 22:22.
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