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Old 26th August 2011 | 23:11
  #505 (permalink)  
airtren
 
Joined: Jul 2011
Posts: 195
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From: Northern Hemisphere
Hello QwainGlyndwr,

What I had in mind is the 'g load factor' involved in the pitch control (elevators and auto-trim) that may be an impediment to a very quick, but very short (time wise) set of actions, that involve also Elevators and possibly (tbd) THS, which a successful Stall Recovery may require.

"rudderrudderrat" had a quite similar perspective:
Originally Posted by rudderrudderrat
Hi Henra,

Originally Posted by henra
I'm quite confident this aircraft would have dropped the Nose upon stall if this hadn't been so vigorously countered by the massive NU inputs and subsequent THS following.
In Direct Law - I agree.
In ALT LAW - when stick free, the FBW computers would maintain the same attitude and probably apply more nose up elevator and trim in an attempt to maintain 1g during the stall.
Originally Posted by Owain Glyndwr
airtren

Originally Posted by airtren
Without having a Normal Acceleration in the picture, is there any indication that in order to being able to quickly and effectively react and have full control of the control surfaces at Stall, would have been better achieved by being in Direct Law?
Again, I would have to defer to proper pilots, but from a strictly aerodynamic point of view I can't see any advantage in being in Direct Law other than the obvious fact that there would not have been any autotrim deflection of the THS - something that IMHO needs sorting anyway.
It depends a bit on where you consider 'Stall' to be. By the time the stall was fully developed the actual details of how the system would respond to control inputs are far less important than the fact that there were no control inputs. If you are considering the actual entry to stall in the first place then the better pitch damping given by Alternate might have been a factor for good.

I don't think much of the harmonisation of roll and pitch given by Alt2, but I suspect that a 'double whammy' of direct law in both axes might have led to even worse results. But I trespass into pilot territory

Last edited by airtren; 27th August 2011 at 03:41.
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