Preliminary Report on Free Flight Tests
This is a 1920 NACA-era technical report on preliminary free-flight glide and control-force tests of aircraft, drawn from the NASA Technical Reports Server collection, written for aeronautical engineers and researchers. Its pictures are plain line graphs of elevator angles, control forces against indicated airspeed, and one top-down aircraft drawing with control linkages, all in black ink on white paper. A designer could borrow the clean graph layouts and hand-drawn linework as examples of early engineering documentation.
