Automatic stabilization
A 1936 NASA Technical Reports Server record titled Automatic stabilization, a technical report of aircraft stability and control theory held by the NASA technical library and written for aeronautical engineers and researchers. The pictures are line drawings of an aeroplane in three-quarter perspective with labelled body axes, rolling and yawing arrows, and force vectors, plus a hydraulic control schematic with a gyroscope, oil pressure feed and a graph of coefficients; a designer could take from them the clean diagram conventions of axis arrows, dashed projection lines and labelled vectors.
