(Photo: US Navy)
Gilbert Magill called his invention the Pinwheel. At 150 pounds, it was not quite up to Inspector Gadget's standards, but it was a start in the right direction.
The aircraft was a tip jet helicopter, meaning that there were little rockets at the ends of the rotor blades. They shot our a mixture of hydrogen peroxide, which instantly turned into steam and oxygen. Here's a video showing the Pinwheel in flight.
-via The Presurfer