The effect of weight and drag on the sinking speed and lift/drag ratio of gliders
A NASA technical report from 1934 on glider performance, catalogued from the NASA Technical Reports Server and aimed at aeronautical engineers. Its pictures are plain line graphs plotting sinking speed and lift/drag ratio against wingspan in metres at two airspeeds, with dashed and solid curves and labelled axes, offering a designer little beyond the clean chart conventions of the period.
