"Now, to refine the question from a flight safety point of view: Is it safer
to rely on this AoA indication and alarm or avoid being on the edge of the
envelope by a good margin in the first place? "
Jos,
As Ron pointed out, the AOA is the only thing that will tell you how far you
are from the edge of the envelope. Under normal weight, density altitude, no
bank, 1g, you have a good idea of this from airspeed, but as Ron pointed out
with high weight, low density altitude, high bank angle and maybe leveling
out from a steep descent (so high g), the critical angle of attack (ie
incipient stall) will be reached at a very much higher airspeed. AOA allows
you to track how close you are to the stall under all these conditions, so
that you can maintain a good margin of safety. A stall warner only tells you
when you get too close to the stall. And in theory at least AOA can provide
other information about airspeed for best L/D ratio (best glide angle) under
these varying conditions as well.
Keith Hickling,
New Zealand.
|