The Effect of the Slipstream on an Airplane Wing
A 1939 NASA technical report on how a propeller slipstream affects an airplane wing, written for aeronautical engineers and aerodynamics researchers. The three pictures are geometric diagrams of velocity vectors, a propeller force and jet-direction construction, and a contour plot of induced velocity fields around a wing, which a designer might use as a reference for flow-line and vector-arrow graphics.
