Torsional rigidity of cantilever wings with constant spar and rib sections
This is a 1929 NACA technical memorandum from the NASA Technical Reports Server, produced by the National Advisory Committee for Aeronautics for aircraft engineers and researchers studying wing structures. The pictures are plain engineering graphs of dimensionless curves plotted on gridded axes, with labelled families of lines marked a, b, c and so on, and a few with fitted dashed reference lines. A designer might take from them only the restrained grid-and-curve vocabulary of early technical charts, useful for diagram-style layouts.
