A warning concerning the take-off with heavy load
This is a 1927 NACA technical note issued by the National Advisory Committee for Aeronautics, a government research body, aimed at aviators and engineers, and it warns pilots about take-off performance when an aircraft carries a heavy load. The pictures are plain engineering line charts on gridded paper: one plots effective horsepower against altitude curves for 7, 15 and 500 feet, and the other plots altitude in feet against time in minutes, comparing an indicated climb path with the actual one. A designer might take from them the clean, dense look of technical graphs and the flat, labelled style of mid-century aviation documentation.
