Leonardo da Vinci sketched an ornithopter for human flight by flapping wings like a bird.
The word ornithopter combines Greek terms associated with bird and wing. An ornithopter is an aircraft that generates lift and propulsion by flapping its wings, rather than by relying on fixed wings or a powered propeller. Leonardo studied birds extensively and used their anatomy and movement as models for several flying-machine designs.
His ornithopter concepts generally placed a pilot inside a frame connected to large wings. Some drawings show the pilot using hands and feet to operate mechanical linkages. Leonardo recognized that human muscle power would probably not be sufficient to produce sustained flight with such a machine, but his studies still explored important questions about lift, balance, and wing movement.
An ornithopter is not the same as a helicopter, which uses rotating blades, or a glider, which uses fixed wings and needs forward motion through the air. Leonardo's flying-machine work included all of these broader ideas, but the flapping-wing machine has the specific name ornithopter.