Leonardo da Vinci sketched an ornithopter as a flying-machine concept with flapping wings modeled on birds.
The word ornithopter comes from Greek roots meaning “bird” and “wing.” Leonardo’s surviving drawings show a human-powered machine in which the pilot would operate large wings through pedals, levers, and connecting rods. The design reflects his close study of bird anatomy and flight.
Leonardo understood that a person could not simply flap wings with human arms. His machine therefore tried to amplify leg and body power mechanically, although it would not have generated enough lift for practical flight. No evidence shows that Leonardo built or successfully tested a full-scale ornithopter.
The concept is often confused with Leonardo’s aerial screw, which used a helical rotor rather than flapping wings. Modern ornithopters are experimental aircraft or model machines, and some use engines instead of human power.