Eric,

I should have been more precise in my comment. AoA,
as shown by a piece of yarn will be much quicker than
an ASI. The ASI will respond quickly, as you say,
but it will not arrive at a steady-state indication
for a few moments if the AoA change is considerable
and abrupt. I have no opinion about AoA instruments,
for I have never used one.

In my youth, I saw one used on an inboard strut between
the wings of a bi-plane; it was a blade type that floated
in the air. The pilot swore by it.

At 06:42 22 December 2007, Eric Greenwell wrote:
Nyal Williams wrote:
The inside wing; it travels a lesser distance while
sinking the same amount as the outside wing.

No one seems to have observed that the AoA is instantaneous
whereas the ASI indicates what the aircraft was doing
moments ago.

I don't think this is true: all the ASI I've had or
checked seemed to
respond in less than a second. Surely that's fast enough
to keep up with
the glider? Just try blowing gently into a pitot and
see how quick the
needle is. If takes 'moments' to respond, you should
check the indicator
and the pitot line.

The reason we are told to 'fly attitude and don't chase
the airspeed' is
it takes the glider a while settle down to a steady
speed, not because
the ASI is slow.


--
Eric Greenwell - Washington State, USA
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