Ratier Metal Propeller with Pitch Variable in Flight
A 1930 NASA technical report, issued as a technical memorandum by the NACA, on a metal propeller whose pitch can be varied in flight, aimed at aeronautical engineers. The pictures are black-and-white engineering drawings: perspective sketches of blade-bearing mechanisms with lettered callouts and a pair of sectional cutaway views of a propeller hub with its shaft and bearings, showing how mechanical parts fit and move, which suits a designer wanting technical line diagrams.
