The Effect of Small Angles of Yaw and Pitch on the Characteristics of Airplane Propellers

This report presents the results of wind tunnel tests to determine the effect on the characteristics of a propeller of inclining the propeller axis at small angles to the relative wind. Tests were made of a full-scale propeller and fuselage combination at four angles of yaw (0 degree, +5 degrees, +10 degrees, +15 degrees), and of a model propeller, nacelle, and wing combination of five angles of pitch (-5 degrees, 0 degree, +5 degrees, +10 degrees and +15 degrees). The results of the full-scale tests of a propeller and fuselage, without a wing, show that the effect on the propeller performance is small. Similar results are shown by the model test data except that where the propeller is directly in front of the wing there is an appreciable decrease in effective thrust and propulsive efficiency with increase of angle of pitch.