The forces and moments on airplane engine mounts
A 1936 NASA technical report on the forces and moments acting on airplane engine mounts, prepared for aeronautical engineers and researchers. The pictures are plain technical charts: one plots polar moment of inertia against diameter-squared for propeller blades with labelled curves and data points, and the other plots load factor against airspeed-style measurements for abrupt and mild pull-outs, with a legend of symbols and two straight reference lines. A designer could take their clean grid layouts, sparse linear plotting and legend-keyed marker symbols as a model for minimal data graphics.
