Leonardo da Vinci designed an ornithopter as a human-powered flying machine with flapping wings modeled on birds and bats.
His notebooks contain several studies of wings, feathers, air resistance, and the anatomy of birds. The designs generally placed a person inside or beneath a frame, using pedals, levers, or other mechanisms to move the wings.
An ornithopter is different from a glider, which flies with fixed wings, and from a helicopter, which uses rotating blades. Leonardo’s designs were exploratory drawings rather than proven aircraft, because human muscles cannot provide enough power for a practical flapping-wing machine of the proposed scale.
The term ornithopter comes from Greek words meaning “bird” and “wing.” Modern ornithopters have been built as small experimental aircraft and model machines, but Leonardo’s work remains one of the best-known early studies of powered flight.