I previously posted about trying to use, with the D6, our homemade AOA probe that we had been using in a clone of the Alpha Systems AOA that I put together for much less that the $600 that Alpha Systems charges. There is nothing wrong with the system that they sell, but the spirit of homebuilding encourages one to "roll your own" and learn and save money. The AOA system uses a 2 port probe to convey differential pressure to a mechanical diff. pressure gauge. There is a patent that you can look up and get all the details, 4,559,822. although the geometry of the input holes in the patent is not the same as that used in the Alpha Systems probe. In the Alpha System probe, the configuration that I used, the input holes are drilled paralled to the horizontal, not perpendicular to the surfaces like in the patent. A drawing is attached. I used the system for several years driving a pressure gauge calibrated with a green, yellow, and red region and it was very accurate, but when I installed the D6 I wanted to use the included AOA software, display, and audio alarm. I have tee'd into the lower port of the AOA probe, the one which sees increased air pressure with increasing angle of attack and connected that to the AOA port on the Dynon D6. The upper hole from the probe is not used in the installation, only the lower hole.
After doing the stall calibration procedures in the D6 manual, I am very satisfied with the performance of the D6 using this probe. The alarm just starts to sputter when I nibble at the stall and comes on steady just as the plane enters the full stall.
After doing the stall calibration procedures in the D6 manual, I am very satisfied with the performance of the D6 using this probe. The alarm just starts to sputter when I nibble at the stall and comes on steady just as the plane enters the full stall.
