Leonardo da Vinci sketched an ornithopter, an aircraft intended to fly with birdlike flapping wings.
The word ornithopter comes from Greek roots meaning “bird” and “wing.” Leonardo studied birds, bats, and the mechanics of flight, then drew machines with large wings that a human pilot might operate through pedals, levers, or other mechanical linkages.
Leonardo’s ornithopter designs were not powered aircraft that he successfully tested. Human muscles cannot generally provide enough sustained power for a full-sized flapping aircraft, and the proposed mechanisms also presented major engineering difficulties.
The sketches remain important because they show Leonardo reasoning from anatomy and observation toward mechanical flight. They belong to a broader group of flying-machine studies that also included gliding surfaces and rotary concepts, rather than representing a single completed aircraft.