Got home from my UPS trip this morning and went up this afternoon to see how much my indicated airspeed was in error. First, I checked the pitot tube-- it was 3 1/4" from the lower surface of the wing, so I adjusted it gently to 3 7/8". It is not parallel to the lower surface of the wing, but canted slightly down after the adjustment. Next, I checked the pitot and static lines at the left wing joint. There is clear plastic tubing joining both lines secured with safety wire wrapped around the ends. I could not really access the tubing to check it, but it appears to be fairly new and in good condition. There is also a metal line coming from the center section that is no longer connected to anything and it is open on the end. After that, I went up and flew South, East and West at 75 MPH indicated and 100 MPH indicated and logged the groundspeeds I saw on the GPS for each leg. After feeding them into the web-based program linked from Ed's Coupe Site, I got a +23 MPH error at 75 MPH indicated and +27 MPH error at 100 MPH indicated. I ordered a new UMA airspeed indicator from Aircraft Spruce with proper range markings when I got home. Hope that fixes it!
Later, Dave
