DEALING WITH THE WIND: AN ANALYSIS OF THE TURN REGRESSION AIRSPEED CALIBRATION TECHNIQUE

摘要

A simple project to determine position corrections for the author's Bearhawk morphed into an investigation of the assumptions and sources of uncertainty in two airspeed comparison flight test techniques. This investigation led to the realization that the "constant wind" assumption in the Cloverleaf flight test technique really meant time-invariant and location-invariant winds, which in practice is too idealistic. Continued investigation into how uncertainty in the wind had resulted in less than desirable results from the Cloverleaf technique in the past led directly to a justification for the structure of the Turn Regression technique. The robustness of the Turn Regression technique in the face of time-invariant but location-varying winds is demonstrated. The effects of sample size on the results are discussed, as is the importance of flying a complete turn. In the end, actual position corrections were determined.