Leonardo da Vinci’s ornithopter was a flying-machine concept designed to imitate the flapping wings of a bird.
Leonardo studied birds and bats extensively, believing that human flight might be achieved through mechanical wings. His ornithopter sketches show a pilot lying or standing in a frame and operating large wings through pedals, levers, or other mechanical linkages.
An ornithopter differs from an airplane, whose wings remain mostly fixed, and from a helicopter, which uses rotating blades. The word means “bird-like” and refers specifically to flight produced by flapping wings.
Leonardo created several winged-machine designs, but none was built and flown successfully during his lifetime. Human muscle power is not sufficient to lift a practical aircraft of the required size, which helped make the concept impractical.
His studies nevertheless influenced later thinking about aerodynamics and biological flight. Modern ornithopters have been built, including small aircraft powered by engines or motors rather than by a pilot’s muscles.