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Old 13th Dec 2011, 00:51
  #636 (permalink)  
Machinbird
 
Join Date: Jul 2009
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Lyman, your constant restating of your theory is somewhat annoying to me. Saying the same thing many times does not make it correct. Flying at night, in turbulence, should not be overly challenging. If the aircraft needed a bit of nose up at AP disconnect, then 1/2 to 3/4 seconds of aft stick would have been sufficient. What PF was doing must have been quite different.

From the control position graphs of the first 10 seconds, PF was badly over-controlling the aircraft in roll. The energy and force required to make these lateral control inputs were likely substantial.

The Airbus stick is angled forward in its neutral position (to discourage cross channel inputs I understand). I suspect that with the drag from the roll channel viscous damper, PF could not get adequate leverage on the stick to keep up with his perceived need for fast lateral input. Once the stick is canted back towards vertical, there is higher mechanical advantage available. Please note, I am only discussing the control inputs up to the stall. Afterwards, there were different reasons for his aft stick input.

If someone (perhaps A33Zab) could come up with the force/velocity characteristic for the lateral channel viscous damper, then we could look at the energy and force required to make those lateral inputs. It might be very educational when looked at in terms of human energy expenditure.
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