 Inventors from Australia, France and England produced several successful microlight motor gliders in the early 1970s  and very few were portable wings.Surprisingly, what really launched the powered ultralight aviation movement in the United States was not the Rogallo flexible wing but a whole series of rigid-wing motorized hang gliders.The Icarus V flying wing appeared with its tip rudders and swept-back style wing was used as a base for some powered experiments.