On Dec 13, 2:16 am, "Bert Willing" bw_no_spam_ple...@tango-
whisky.com wrote:

... Nose attitude is the onboard AoA, and it works...

Apologies for the dogpile, but I think that's wrong and wrong. I
believe that thinking like that is exactly what leads to the types of
insidious stall/spin entries that most often become accidents.

That's not to say that nose angle isn't a useful tool. In straight-and-
level flight, and in stable coordinated turns, nose angle and nose
angle rate are key indicators of speed and acceleration.

However, straight-and-level flight and stable coordinated turns
constitute a very small subset of the available flight regimes, and
are among those least likely to offer unanticipated stall spin
entries.

Also, in flapped ships, and especially in glidepath-flapped ships,
nose angle is virtually useless as a speed reference independent of
flap deflection. In a good old HP glider, you can have your toes on
the horizon and be tearing along at a stable 80 kts. Or you can be
going almost straight down at a stable 80 kts and viewing the horizon
through the crown of the canopy.

So far as soaring and sailplanes go, I'm basically an anti-
gadgetarian. For years, the most complicated device in my ship was the
digital clock. However, I think that a simple, effective AOA indicator
with an intuitive display would be a real asset. And, it would be
useful not only for stall/spin protection but also for cruise and
thermal optimization.

Thanks, Bob K.