The aerodynamic analysis of the gyroplane rotating-wing system
A 1934 NASA technical report on gyroplane rotating-wing aerodynamics, issued as a government research document for aeronautical engineers. Its single picture is a technical graph of propeller thrust coefficients against resultant and translational velocity, with a rounded curve splitting into windmill-decelerating and vortex-ring branches on a fine grid with labelled axes. A designer might take from it the clean, minimal chart style: thin black curves, dotted leader arrows, and plain serif labels on white.
