When British and French gliding enthusiasts tested gliders propelled by small engines in 1922, they created a new type of low-cost "ultralight" airplane. The idea all but disappeared until a few hang glider pilots began experimenting with small engines they called "glide extenders" during the late 1960s.

Their work did not reach a wide audience until John K. Moody installed a 12½-horsepower engine on his Icarus II hang glider in 1975. The following August, as thousands of fellow flying enthusiasts watched, Moody ignited the modern ultralight movement in America by demonstrating running takeoffs and landings from level ground at the Experimental Aircraft Association’s fly-in convention in Oshkosh, Wisconsin.