Flap Gear for Airplanes : A New Scheme in Which Variation is Automatic
A 1927 NASA technical report, published as a NACA memorandum for aeronautical engineers, on an automatic flap gear scheme for aircraft. Its pictures are mechanical plates and drawings of linkages, operating cams, hinged flaps and wing sections, with a lift-to-drag chart; a designer could take from them the precise, schematic line style of early engineering diagrams and their clear, labelled layouts.
