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Old 19th Jul 2012, 10:57
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HazelNuts39
 
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Originally Posted by AZR
Would you be so kind as to "translate" what impact will a different 'a' value have (in AF447 scenario, and/or in general)?
Again my understanding, and I may be wrong. With stick free the Nz law tends to maintain essentially the current trajectory at approximately 1 g (nz=0). If that trajectory is such that the airplane decelerates, it will have to pitch up to maintain approximately 1 g at decreasing airspeed. The pitch rate q depends on the rate of deceleration dV/dt. It will not quite maintain 1g but it will settle for nz = - q/a, i.e. an incremental load factor that is slightly negative, depending on the value of 'a'.

P.S.
For example, at FL350, M.6, 205t and decelerating at 2 kCAS/second, the pitch rate maintaining 1g is 0.27 degrees/second.

Last edited by HazelNuts39; 19th Jul 2012 at 20:52. Reason: P.S.
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