Angle of Attack

On Friday, October 23, 2015 at 10:09:47 AM UTC-5, Jonathan St. Cloud wrote:
Didn't the SSA have a contest to develop a working AOA indicator for gliders? What ever happened to that project, has a practical AOA indicator ever been developed for gliders?

Easy to install, just put a yaw string on either side of the canopy, as low as possible. Works great EXCEPT if you have ANY yaw, then you will see a large difference! So, pretty useless in practice.

There was an interesting article in an old Soaring (mid 70s?) that describes how to build a pneumatic CLmax indicator; it had a pellet in a calibrated tube that would show when you got to CLmax - another way to get AOA info, really.

Seems it would be easy to build-in symmetrical pressure ports in the wings to get AOA info - nowadays you could even get the data via bluetooth to avoid leaky connectors. Hmm, maybe a little "blister" could be made, self-contained with pressure sensors, microprocessor, bluetooth, and battery, that could be slipped on the leading edge of each wing and provide the necessary data to a small display in the cockpit? External, or recessed flush with the leading edge (after cutting out a small chunk of leading edge?

Kirk
66

If it's on the side of the canopy is it still a yaw string?

Sorry - couldn't help myself.

On Friday, October 23, 2015 at 4:46:53 PM UTC-7, Dave Springford wrote:
If it's on the side of the canopy is it still a yaw string?

Sorry - couldn't help myself.

Nope, AOA-string.
Had a Mod-1 on the side of the DG-1000. Not very useful if you wanted to see where you are going and where the trouble might come from. Worse than any flight computer.
Heinz