Leonardo da Vinci’s ornithopter design used a winged frame and flapping motion to imitate bird flight.
An ornithopter is an aircraft that generates lift by flapping wings rather than by using fixed wings or a helicopter rotor. Leonardo studied birds, bats, and the mechanics of flight, then sketched machines in which a person would operate wings through pedals, levers, and other linkages.
His proposed human-powered ornithopters were not practical aircraft. A human could not supply enough power for a machine of the illustrated size to take off and remain airborne. Leonardo’s observations were important, but he did not yet have the aerodynamic theory or lightweight engines needed for powered flight.
The word comes from Greek roots meaning “bird” and “wing.” Modern experimental ornithopters can fly with motors, but they are distinct from Leonardo’s human-powered concepts.