Leonardo da Vinci designed an ornithopter to imitate a bird's flight. The term ornithopter comes from Greek words meaning “bird” and “wing,” and describes an aircraft that flies by flapping wings rather than by using fixed wings or a rotating rotor.
Leonardo studied birds, bats, and the movement of air while developing several flying-machine concepts in the late 15th and early 16th centuries. His proposed ornithopters used human-powered mechanisms to move large wings, but no surviving design shows that one was successfully built or flown.
An ornithopter is different from Leonardo’s separate aerial-screw concept, which is often described as an early helicopter idea. It is also different from a glider, whose wings remain still while the aircraft moves through the air. Modern experimental ornithopters are usually powered by engines or lightweight mechanisms rather than by a pilot’s muscles.
Leonardo’s flying studies were influential because they treated flight as a problem of anatomy, mechanics, balance, and aerodynamics rather than as a purely mythical idea.