Measurement of Altitude in Blind Flying
This is a 1934 NACA technical note on instruments for measuring altitude during blind flying, published by the National Advisory Committee for Aeronautics and preserved through the NASA Technical Reports Server for aviation engineers and instrument designers. Its pages are mostly line diagrams of altimeter mechanisms, plus graphs of instrument drift and recovery over time, and a designer could take from them the clean schematic style of early aeronautical technical drawing.
