Metal Construction Development. Part III : Strip Metal Construction - Wing Ribs
This is a 1929 NACA technical memorandum on metal construction, part III, covering strip-metal wing ribs, published by the National Advisory Committee for Aeronautics for aircraft engineers and researchers. The three pages show line drawings of rib cross-sections and sheet forms, a mechanical testing apparatus with labelled parts, and black-and-white photographs of test rigs, specimens and fittings. A designer could take from them the exacting technical diagram style, with lettered callouts, dimension lines and clean grey-scale photography of machinery.
