The effect of flight path inclination on airplane velocity
This is a 1927 NACA technical report from the NASA Technical Reports Server, giving engineers graphs for calculating how the inclination of an aircraft's flight path changes its velocity. The three charts plot flight path angle against the ratio of lift to drag, with families of curves labelled by initial lift-to-drag values from 2 to 10, and altitude change per mile against change in maximum speed. A designer could take from them the clean, hand-ruled grid plotting style and the dense, evenly spaced family of radiating curves on a gridded field.
