Airspeed Indicator Condensation

[Thumper]

My '68 Arrow still has the original airspeed indicator. I had to get it rebuilt last week because it failed the pitot/static system IFR certification and they isolated the "massive" leak to the airspeed indicator.

When I picked it up today, I flew about 20 minutes to the home drome and noticed by the time I got in the pattern there was slight/moderate condensation on the inside of the glass. It was about 90 degrees today with high humidity. DA was high for us sea level types.

Condensation normal, problem, it'll go away, all of the above.....?

I thought I'd ask here before calling the A&P back.

Thanks in advance for your input.

 

[kontiki]

There are pitot static system drains in the Arrow I rent. I believe that system should be dry.

Working as an A&P on 727s years ago, it was pretty common to pull all the equipment off the pitiot static manifold and flush the system with dry nitrogen. Of course that aircraft operated at very cold altitudes most of the time. You really don't want any moisture freezing in there.

I haven't done much GA work to know how frequently it comes up on a small aircraft.

 

[Captain]

I flew a B-727 and I don't recall the airspeed indicator getting particularly cold. I always wore short sleeves anyway...

 

[kontiki]

I flew a B-727 and I don't recall the airspeed indicator getting particularly cold. I always wore short sleeves anyway...

Noted; when I say "in there," the pitot-static manifold ran to drains in the NLG wheel well, drains in the E&E compartment, from cockpit to static ports across and on both sides of aircraft and all the way aft of aft pressure bulkhead to FDR. Many of the lines were in the lower cargo compartment sidewall close to the hull.

My point was that if moisture collected in a low cold part of the line it could have been a problem. That purge was scheduled for every D check at Eastern Airlines. Eastern, like D checks are all long gone now.

 

[Off In The Jungle]

We have the same issue in our Caravan. Ours happens to the turn coordinator. For us it is usually on a rainy, colder morning, and by the end of the day it gets better.

What was the weather like when you flew it home?

Did you get a new airspeed indicator, a servicable one or did your A & P open it up himself to fix the leak? The latter by the way is a no-no.

 

[timwinters]

We have the same issue in our Caravan. Ours happens to the turn coordinator. For us it is usually on a rainy, colder morning, and by the end of the day it gets better.

Mine too...always has, for the 8 years and 1000+ hours that I've owned my bird. Mine TC is actually a Britain auto pilot head.