Gents,

A temporary aoa sensor, in that case a yaw sensor I did design for my glider. Temporary because I only need it to calibrate a rudder mixer. After finishing that the vane sensor can be removed again,

I discovered that it isn't easy to prepare such a sensor for low speed and high accuracy for a pattern ship.
A dynamic pressure tube with several angled orifices is possible but need a lot of electronics to calculate the aoa an accurate way so in thr refrigerator for a while........................ next methode,

Null seeking method, using external energy, can be pneumatic, hydraulic, electric, to rotate the mechanism and a potentiometer. Sensor to detect the position and "airflow direction" for example, pneumatic slots, thermal sensors, differential pressure, whatever you want.
An example of such an instrument, in the picture, also present on the Northrop NF5 of the past so I know the ins- and outs of this system.

Result has to be something like I show on the video, it is one of three null seeking instruments "under test ".
Still to do: long term stability, testing of temperature dependency, vibrations etc.

http://www.youtube.com/watch?v=enLJP_97Jtc

Profit of this method is the low drag of the sensor element and nearly zero % hysterese while rotating a potentiometer for feed back of the angle.
For the Simla so when the plane is ready also the measurement requiments are available

Cees,