Originally Posted by
Owain Glyndwr
My point, not very clearly expressed, was really that 'forward speed' is an expression of Dozy's; I am sure that AB's engineers knew and know very well that it is the total air speed over the vanes that drives them not forward speed alone. [and so does Dozy I suspect, it was probably just loose wording]
Correct - a poor choice of words on my part. I'm a software guy, not an aero guy. My apologies.
The point I was trying to make stands, however. Whether you're building a system of an electro-mechanical, analogue electronic or digital electronic nature, excluding bad data is paramount, because you can always plan a system that will work predictably with an input missing or invalid, but if you allow bad data in, you'll get bad data - and feedback - out (GIGO principle).
@rudderrudderrat:
I said in this thread, and the other, that:
Originally Posted by
DozyWannabe
I'd be very interested in seeing how all currently operating commercial airliners' sensory, control and warning systems behave when subjected to a flight profile that extreme - the problem is that no simulator can accurately replicate the conditions, and no test pilot in his right mind would risk flying that profile for real!
Because while it's all very well to hypothesise that the Captain might have diagnosed a stall earlier if the warning had still been sounding consistently, the fact is that we don't know how the systems on other aircraft behave when the aircraft is taken so far outside the expected flight envelope. To focus on that disregards the fact that the stall warning had been sounding consistently for around a minute without being acknowledged or acted upon by either of the flight crew present at the time. It also disregards the fact that the Captain was presented with unstable pitch tending towards nose-up, a rapidly unwinding altimeter and unreliable speed indications - would not these factors alone be enough to deduce a stall?