 Hiram Maxim adopted the idea for his steam-powered test rig, which lifted off but was held down by safety rails, in 1894.Otto Lilienthal designed and flew two different biplane hang gliders in 1895, though he is better known for his monoplanes.By 1896 a group of young men in the United States, led by Octave Chanute, were flying hang gliders including biplanes and concluded that the externally braced biplane offered better prospects for powered flight than the monoplane.