Leonardo da Vinci designed an ornithopter as a bird-inspired flying machine powered by a pilot’s muscles.
An ornithopter is an aircraft that flies by flapping wings rather than using propellers or jet engines. Leonardo studied birds and bats, then filled notebooks with sketches of wing structures, control systems, and human-powered mechanisms.
His designs usually placed a person inside or beneath a large wing framework. The pilot would operate pedals, levers, or other linkages to move the wings. The central problem was that human muscles could not provide enough power for sustained flight with such a heavy machine.
Leonardo’s ornithopter was never built into a proven flying aircraft. It is also different from his helical aerial-screw concept, which used a rotating surface rather than flapping wings. Modern ornithopters exist as experimental aircraft and small models, but Leonardo’s design remained a Renaissance study of natural flight.