Howard Hughes in front of his huge XH-17 crane helicopter. It was actually a Kellett design. Hughes converted the original test rig into flyable prototype using parts from other aircraft, including the cockpit section of a Waco CG-15. The XH-17 had two jet engines feeding compressed air to compressed air burners at the tips of the giant rotor blades. It first flew on 16 September 1952 but the media were led to believe they witnessed the first flight on 23 October. The US Air Force cancelled the impractical XH-17 and the planned H-28 development in 1953. Photo by: Loomis Dean / Life