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Old 24th Nov 2013, 19:55
  #917 (permalink)  
Bpalmer
 
Join Date: Dec 2012
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If someone could please explain how an A330 could ever have a CAS<60kts (at 1 g) whilst airborne - then I'll give up on this point.
If you are feeding "bad data" (intermittent / silent stall warning) onto the flight deck - then you'll probably get bad diagnosis out.
At extremely high angles of attack (e.g., 45°) the air striking the pitot tubes and the static ports (located well below the midline of the fuselage) approach the same angle. Indeed, at one point (at least), the error reported on the ISIS showed that the static pressure exceeded pitot pressure!
Since CAS is a measure of the difference between these two pressures, the airspeed indication will be erroneously low.
This happened as the stall deepened and the angle of attach exceeded 45°. You can easily correlate the periods of reduction in angle of attack during the descent with the stall warning sounding periodically.
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