Contribution to the aerodynamics of rotating-wing aircraft
A 1939 NASA technical report on rotating-wing aircraft aerodynamics, issued through the NASA Technical Reports Server and aimed at engineers and researchers of the period. Its pictures are plain line work: one page of dense typeset equations numbered (77), and a schematic diagram of a rotor disc with azimuth angles, a flight direction arrow and labelled radii, which a designer might take as a clean, technical diagramming style with clear angle callouts and arrows.
