Landing and Braking of Airplanes
A 1929 NACA technical memorandum on the landing and braking of airplanes, issued by the National Advisory Committee for Aeronautics for engineers and aircraft designers. Its pictures are plain line diagrams: velocity vector triangles, force diagrams of a wheel and brake on a runway, and stress-strain graphs with labelled curves and axes. A designer could take from them the clean, labelled, monochrome convention of technical engineering drawing.
