D6 IAS started reading high

[dico]

Hello,

I have a D6 EFIS in our Lancair as a backup unit and it's airspeed always matched that of the Garmin EFIS. However, after not flying it for a couple months over the winter (but being stored in a heated hangar), I now notice that the airspeed displayed on the D6 is 30kts higher than that of the Garmin. I know the Garmin is correct. We have only 1 pitot tube on the plane and it supplies both the Garmin and Dynon units for airspeed.

Can anyone suggest where I can begin to look? I would think it if was a leek in the hose, that we'd see an equal issue with the Garmin unit.

Thanks,

Dico

 

[Dynon]

Are you seeing 30 knots on the ground too? If there were water in the pitot line aft of your split between the pitot and the Garmin/Dynon tee, that could presurize the Dynon side of things. How does altitude look on the Dynon? If it's reading low, that might point to a static-side issue.