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Old 23rd September 2009 | 14:19
  #27 (permalink)  
Pugilistic Animus
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From: The No Transgression Zone
just to add a little,... it is important to remember a few circumscribing facts, since it is possible to encounter conditions outside of the part 25 gust envelope because
the theoretical model of the 'gust' considered is an alleviated sharp-edged gust modeled on a bell-shaped curve
it assumes that the gust steadily increases to a maximum then dies out likewise---however if a real sharp edged gust is encountered [severe CAT ] then a much higher load factor than computed will ensue possible leading to ultimate loading from the instantaneous increase in AoA without alleviation
and the value of the bell-shaped gust likewise decreases with with increased speed
going from Vb [max gust instensity] Vc [design cruise] Vd [design dive]
lastly, the the TAS value of the gust is rightly decreased with altitude [thinner air] but don't get a false sense of security from this fact either

so although far 25 offers a great deal of protections it does have its limitations the does not preclude the real possibility of structural failure if real life conditions are encountered beyonded the certificated envelope as is a very real possibility in real life even at the VTP/VRA

so always respect turbulence and slow down!

Last edited by Pugilistic Animus; 23rd September 2009 at 15:39.
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