Mitch. Just weeks ago I had unusual high readings on my ASI. Since I know what speeds to expect, I figured something's wrong with the ASI.
I took out the instrument, replaced it with a known good one - now the speed difference was even worse. It was showing a reliable 125 MPH in normal cruise, but landing at the advertised 60-70 MPH was not possible anymore, the plane would just sink like a stone at that indicated speed. So I looked for a problem with the line. Found it finally the static pipe had a crack that was allowing for extra air. I found it by checking the pipes(s) for looseness. While wiggeling at the lines, the static line suddenly broke. It broke right behind the attachment point to the ASI. The fix was easy , since the tube was just shortened by 1/2 inch. A new sealing insert and all is back to normal now. Hartmut ----- Original Message ----- From: Mitchell Williams To: [email protected] Sent: Wednesday, May 07, 2008 7:26 PM Subject: [ercoupe-tech] Re: Pitot Tube Calibration Ring Thanks to everyong for all the good information. "Checking me AherSpeed" that's why I'm here. When we bought the plane and flew it home, we were impressed by the cruise airspeed showing 105 to 110 mph. We flew loose formation with a Cessna 175 that we took to get the plane; he was showing 80mph with one notch of flaps just to rub it in. We've all noticed that if you fly the correct indicated airspeeds it gets too slow and drops in, so we've been adding about 10 mph. We installed a GPS in the panel, flew each cardinal heading at 100mph indicated, GPS four way average was 88 mph (77 knots). So we are looking for about 12 mph extra. I suspect the static system has a problem, probably beyond the "calibration ring". We'll look at it tonight. We set out last evening to check out the static system and got side tracked with the pitot ring thing, and a student preparing for a checkride. mitch - 99325
