Moisture in pitot

[8466]

I took off the other day just above freezing on a clear day and as I climbed the airspeed initially climbed then slowly decreased at the same pitch and power until it went to zero. I turned around and landed uneventfully. I went to my mechanic and explained what happened and he said sounds like moisture in the pitot tube and since there is no drain it has to evaporate naturally or get get blown out. He was right when I flew the next time on a warmer day the a/s indicator worked normally. What should I do to prevent this? Any suggestions?

Cloudancer

[6643]

Do you have a cover on the pitot tube? I've had that happen with the static system, but never the pitot system, which has a cover.

[8466]

No, because it has a built in cover that opens at aircraft movement, and I cannot find a pitot cover that fits. So since this has happened I am in the midst of making one.

[6643]

it has a built in cover that opens at aircraft movement

that's actually what I was thinking of. It'll work fine as long as you don't have a strong wind right on the nose. Get a girl's (gender neutral?) hair tie. Put it around the pitot tube behind the cover, give it a half twist, then put it around the cover and pitot tube. Repeat the half twist if it's too loose.

[8466]

I will do that.thank you