The Besler Steam Plane, circa 1933
Steam powered flight! From the YouTube description:
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.
[via Make: Online]
