Leonardo da Vinci designed an ornithopter as a winged aircraft inspired by birds.
An ornithopter is an aircraft that generates lift by flapping wings, rather than using fixed wings or a powered rotor. Leonardo’s sketches show a human pilot lying or standing inside a framework while operating large wings through pedals, levers, and other mechanical linkages.
The design was based on Leonardo’s close observations of bird flight, especially the movement of wings and the role of air. His machine was never built as a practical flying aircraft, because human muscles cannot provide enough power for a craft of that size.
An ornithopter is not the same as Leonardo’s aerial screw, which used a rotating helical surface. Modern experimental ornithopters have flown, but Leonardo’s design remains primarily a Renaissance engineering concept preserved in his notebooks.