Leonardo da Vinci designed an ornithopter as a flying-machine concept with flapping wings modeled on bird anatomy.
The word ornithopter combines Greek roots meaning “bird” and “wing.” Leonardo studied birds, bats, and the mechanics of flight, then drew machines in which a human pilot would move wings through mechanical linkages. Some of his sketches show a pilot lying down or standing while using pedals and hand controls.
The designs were imaginative but not practical for human-powered flight. Human muscles cannot generate enough sustained power to lift the required machine and pilot using flapping wings alone. Leonardo’s work nevertheless helped connect close observation of animals with engineering design.
An ornithopter is not the same as Leonardo’s aerial screw, which used a helical rotating surface rather than flapping wings. Modern ornithopters have been built as small aircraft and model machines, but Leonardo’s famous drawings remained conceptual studies rather than successful aircraft.