Accuracy of airspeed an altitude

[MCRider]

Hi,

Yesterday I had a check of airspeed and altitude accuracy for my SkyView and my analog backup instruments.

The SkyView was always spot-on, max. airspeed error 1 knot, max. altitude error 20 feet. The steam gauges were less accurate but within allowed tolerances...

Well done, Dynon!

MCRider

 

[ggerhardt]

I've had some issues (that I think I've worked out now) getting my airspeed calibrated. The issue has been obtaining an accurate static measurement at high-speed (~180ktas). I think I have now found a good static port location that is insensitive to airspeed. The way I check this is watch my indicated altitude relative to my GPS altitude as I increase my speed. If I keep my GPS altitude flat and my indicated altitude moves up/down as I go faster, I know I have an issue with my static port location.

I realize this is not the issue you were trying to measure, but I'm curious - what gold standard airspeed measurement did you use to verify the Dynon and check your steam gauges? Did you fly a triangle or box and average your ground and TAS?

Thanks.

Geoff

 

[MCRider]

The measurement was done on the ground using a test kit that applies pressure to the static and pitot lines and by comparing the measurements with calibrated instruments in the test kit. It was part of getting the final airworthiness certificate (after flying with a "permit to fly" for a while).

Of course this measurement only checks the quality of the pressure sensors in the ADAHRS - problems with the static port location are out of the equation...