Leonardo da Vinci sketched an ornithopter, a machine intended to fly with 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 inspire a human-powered aircraft. His drawings show frameworks, wings, pedals, and mechanisms designed to transfer movement from a pilot’s limbs to the wings.
Leonardo’s ornithopter was never built into a proven flying aircraft. Human muscles cannot generally produce enough sustained power to flap wings of the required size, so the design faced a fundamental engineering problem. Modern ornithopters have flown using engines or remote-control systems, but they are not evidence that Leonardo’s machine worked.
An ornithopter differs from a glider, whose wings remain fixed, and from a helicopter, whose rotating blades generate lift. Leonardo investigated all three broad ideas, but his flapping-wing concept belongs specifically to the ornithopter category.