Upon reflection I think this device might be really helpful. It would allow
me to fly much closer to the stall without having to think too much when
thermalling and landing. I could just keep pulling until I feel the buzz.
Might still have a problem when I am doing a wing over after a high energy
inverted pass however.

Well trained and practised glider pilots are completely comfortable with
the stall and spin characteristics of their glider(s). Whenever I return to
base high I take the opportunity to stall / spin / and bat my glider to
improve my handling skill and my familiarity with its flight
characteristics. It is also great fun.

In the UK we train pilots to recognise and recover stalls, spins, and
spiral dives before they go solo. Solo pilots at my club are also
encouraged to learn aerobatics to improve their handling and awareness of
the aircraft. Like unclhank, I do not think we should replace training with
gadgets.

Jim

ps: I watched a chap in a brand new Mercedes back into a table yesterday
producing a huge and expensive dent. He had reversing sensors but they
clearly weren't pointing at the table and he new he could rely upon them
because that's what the salesman had said!



At 14:29 07 September 2011, Bill D wrote:

How do I know it works? Because it works and is therefore considered
essential in hundreds of thousands of airplanes.

So, what solution do you propose?

I'm trying to think of ways to save lives. What is your objective?

The "lets train them better" idea has been around 100 years with
generally dismal results. The stall warning device idea has been
around probably 50 years and works well enough it has been widely
adopted throughout the aviation world. Only the gliding world has
successfully resisted stall warning devices and we pay for it in our
accident record.

Stall sensors could be either airspeed or AoA based. A simple and
rugged sensor is a pair of pressure ports on the top and bottom of the
nose cone. The differential pressure between these ports is
proportional to AoA.

Would there be false warnings? Of course there would. It happens on
light airplanes but there's no confusion since a intermittent warning
in rough air has an obvious and benign cause. A steady warning at low
airspeed signals an impending stall. If an AoA display is part of the
system, a glance at it would show the cause of a warning.

It's also possible to set sensitivity depending on the phase of
flight. If the gear is down signaling an impending landing, the
warning could be more sensitive sounding at a lower AoA/higher
airspeed. Our computers detect thermalling and set themselves to that
mode automatically - they could also set the stall warning to be less
sensitive when thermalling.

If a stick vibrator isn't sufficient, adding a bright light to the
glare shield or audible warning would be easy. It could even be set
so the vibration starts early to be followed by a loud warning if the
dangerously high AoA condition persists. This could avoid annoying an
attentive pilot while providing an unmistakeable warning to the
distracted pilot.

It is so easy for people to set back and think of reasons why
something might not work while never putting forward one which would
work. They never have to prove an idea won't work, they just raise
doubts by suggesting it might not work perfectly every time. They're
called "Negative Experts".

A stall warning device doesn't have to work every time. If it saves a
life 10% of the time it would be worthwhile. Good research says it
will work far more often than that.