Evel Knievel gained fame in the 1970s jumping rows of cars, lines of buses, and tanks of sharks on a modified Harley-Davidson XR-750. His attempt to jump Idaho’s Snake River Canyon was his most outlandish stunt and most spectacular failure. After months of build-up, the parachute deployed on launch and the Skycycle floated to the canyon floor.
With three wheels and wings, the Skycycle was a “cycle” in name only. The state of Idaho actually certified it as an aircraft. Rocket engineer Bob Truax designed the steam-powered machine, and built the body around a Navy bomber fuel tank. Water, which Evel claimed came from the same artesian well Olympia Beer was made from, was heated to around 900°F for the launch.