Stall-proof Airplanes
This is a 1927 NACA technical report, issued by the National Advisory Committee for Aeronautics in the United States, written for aeronautical engineers and researchers studying airplane stall behaviour. The pictures are plain engineering charts and line drawings of aerofoil sections, with graphs of moment coefficients plotted against angle, and black-and-white smoke or flow photographs showing air streaming past slotted wings. A designer could take from them the stark, diagrammatic look of technical plots, the thin curved wing silhouettes, and the striped flow lines.
