The Steady Spin
This is a technical report on aircraft spin mechanics, issued by NASA's technical reports series with a 1931 date, written for aeronautical engineers and researchers. The pictures are plain line graphs of curves plotted against angle of attack or spin parameters, with labelled families of dashed and solid lines, grey-beige paper, and axis ticks; a designer might take from them the restrained vocabulary of engineering charts for layout or background texture.
