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Old 4th Aug 2011, 00:07
  #1476 (permalink)  
takata
 
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Hi HazelNuts39,
Originally Posted by HazelNuts39
Correct, but don't forget that static pressures are affected also, reading high. Pitot minus static can become negative in extreme cases, as mentioned in one of the BEA reports.
Yes Sir! ... high alpha affects every probes, including, static and alpha probes!
Hence, airspeed is twice affected (did you try to derivate aircraft actual airspeed from ground speed and other parameters to see at which estimated (true) value airspeed was reading under 60 kt ?)
And V/S is also affected (obvious from graph)... and somewhat baro altitude...

This limitation of +60 KCAS for alpha validity would be due to good reasons, but I don't know which one... it seems to me easier to inhibit this alarm during specific phases when you don't need it (ground, rolling...) than doing it this way in relation with airspeed.
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