Relative Economy of Different Methods of Airplane Construction
A 1931 NACA Technical Memorandum (No. 618) issued by the National Advisory Committee for Aeronautics, a US government research body, covering airplane wing construction economy for aeronautical engineers. Its pictures are engineering line drawings of wing spar moment diagrams, plan views and cross-sections of aircraft such as the Caspar and U 12 Flamingo, with rulers, dimension lines and handwritten-style notation. A designer could draw from their sparse technical linework, dimension annotations and clean schematic layouts for minimalist diagrams.
