Leonardo da Vinci sketched an ornithopter as a human-powered flying machine with flapping wings.
The term ornithopter comes from Greek words meaning “bird” and “wing.” Leonardo’s surviving studies explored how a person might imitate a bird’s flight by operating large wings through a system of levers, rods, and cranks. His drawings show several arrangements rather than one finished, buildable aircraft.
Leonardo understood that simply copying a bird would not be enough. He studied wings, airflow, balance, and the muscles of birds, but human muscles cannot produce the sustained power needed for flapping flight. The design therefore remained theoretical and was never demonstrated as a successful aircraft.
An ornithopter is not the same as Leonardo’s aerial screw, which used a rotating helical surface and is often compared with a helicopter. Modern experimental ornithopters do exist, but Leonardo’s proposed machine was centuries ahead of powered aviation.