Airspeed indicates 22 knots in the hangar

[jbrady]

Whilst doing the calibration of the D-180 (see my other post), after maybe 20 minutes the IAS changed from zero to 22 kts and hunted about slightly. The ASI still read zero. Cannot fathom why this might be. Any clues please?

 

[Dynon]

Is the D180 new or just new to your aircraft? In any case, performing a zero pressure calibration should help calibrate the low IAS indications.

 

[jbrady]

OK thanks - that seems to have fixed it