The Dyle and Bacalan "D.B. 80" day mail airplane (French) : an all-metal high-wing monoplane
This is a 1930 technical circular from the NASA Technical Reports Server, an aircraft circular describing the Dyle and Bacalan D.B. 80 French day mail airplane, an all-metal high-wing monoplane, prepared for aeronautical engineers and researchers. The pictures are plain black-and-white line drawings and photographs: rotated photos of the aircraft in profile, a three-view plan with dimension figures, and numbered engineering details of structural joints and fittings, useful to a designer as clean diagrammatic reference for mechanical linework.


