Dave,
Airspeed numbers on the ground can't be correlated with any reliability to numbers in the air. In the air, the wing is at a significant angle of attack and is developing lift. Do the in-the-air GPS airspeed calibration and go with that. A GPS calibration method for your airspeed indicator is to fly three sides of a square, recording certain data and enter it into a website calculator. http://www.reacomp.com/true_airspeed/index.html Ed Burkhead http://edburkhead.com/Ercoupe/index.htm ed -at- edbur???khead.yyy change -at- to @, remove the ??? and change yyy to com
