Besler Aero Steam Engine
A Travel Air 2000 biplane made the world's first piloted flight under steam power over Oakland, California, on 12 April 1933. The strangest feature of the flight was its relative silence; spectators on the ground could hear the pilot when he called to them from mid-air. The aircraft, piloted by William Besler, had been fitted with a two-cylinder, 150 hp reciprocating engine.
An important contribution to its design was made by Nathan C. Price, a former Doble Steam Motors engineer. Price was working on high pressure compact engines for rail and road transport; the purpose of the flight was to obtain publicity for this work. Following its unexpectedly favourable reception Price went to Boeing and worked on various aviation projects, but Boeing dropped the idea of a steam aero engine in 1936. Price later worked for Lockheed where his experience with developing compact burners for steam boilers helped to design Lockheed's first jet engine.