Tests for determining the effect of a rotating cylinder fitted into the leading edge of an airplane wing
This NASA technical report from 1926 sets out wind-tunnel tests on whether a rotating cylinder built into an aircraft wing's leading edge changes its lift. The pictures are engineering line drawings and plots: a rotated wing section sketch with dimensioned model views, and a lift coefficient graph with several plotted test series. A designer could take from them the clean technical diagram style of labelled dimension lines, hatched cross-sections and gridded data plots.
