Leonardo da Vinci designed an ornithopter, a bird-inspired flying-machine concept built around flapping wings.
The word ornithopter comes from Greek roots meaning “bird” and “wing.” Leonardo studied birds and bats because he believed their wing movements could reveal how humans might achieve powered flight. His notebooks contain several sketches of wings, frames, pedals, and lever systems intended to transfer human muscular effort into flapping motion.
Leonardo’s machines were not successful aircraft. Human muscles cannot generate enough sustained power to lift a person using the proposed mechanism, and the structures would also have been heavy. Modern ornithopters exist as small experimental or model aircraft, but they do not prove that Leonardo’s full-scale designs were practical.
The ornithopter is sometimes confused with Leonardo’s aerial screw. The aerial screw aims at vertical lift through a helical rotor, while an ornithopter imitates the repeated up-and-down wing motion of a bird or bat.