Investigation of a Flight Test Method for the Measurement of Propeller Thrust

A full scale wind tunnel test was performed with a general aviation aircraft to investigate the use of the slipstream momentum survey method as a means of measuring propeller thrust in flight. Aircraft angle of attack is shown to have significant influence on the momentum measurements. Thrust values obtained from the slipstream momentum correlated well with overall aircraft force measurements; however, insufficient data regarding the slipstream static pressure variation resulted in a systematic error in the results. The need for detail static pressure measurements in the slipstream is demonstrated.