Leonardo da Vinci studied the ornithopter, an aircraft designed to fly with flapping wings.
Leonardo made many sketches of bird flight and proposed machines whose wings would imitate the movement of birds or bats. His ornithopter concepts generally placed a human operator inside or beneath a frame, with mechanical linkages intended to move the wings.
The designs were not successful aircraft. Human muscles cannot provide the sustained power needed to flap wings large enough to lift a person, and Leonardo's machines lacked an independent power source. Some of his later studies shifted toward gliding and other ways of using air rather than copying flapping flight directly.
An ornithopter is defined by its method of producing lift through wing motion. The word therefore describes a category of aircraft, not one single Leonardo model. Modern experimental ornithopters have flown, but Leonardo's human-powered proposals were never demonstrated as practical man-carrying machines.