A Preliminary Study of the Prevention of Ice on Aircraft by the Use of Engine-exhaust Heat
A 1939 NASA technical report on preventing ice on aircraft wings by routing engine-exhaust heat through them, produced by the NACA-era research program for aeronautical engineers and engineering libraries. The pictures are engineering line charts of surface temperatures against chord position, a spray-diagram of an icing wind tunnel, and a hatched airfoil cross-section marked with ice thickness, giving a designer plain graph and diagram conventions in black, white and grey.
