Leonardo da Vinci designed an ornithopter, a flying machine intended to fly by flapping wings.
The word ornithopter comes from Greek roots meaning “bird” and “wing.” Leonardo studied birds closely and produced several drawings of machines whose wings would imitate the motion of a bird’s wings. Some concepts placed a person inside a frame and used pedals, levers, or other mechanical linkages to move the wings.
Leonardo understood that human muscle power would probably not be enough to make a person-sized flapping machine fly. His notebooks nevertheless contain important observations about lift, balance, wing shape, and the movement of air. These studies connected his artistic investigations of birds with his broader engineering work.
An ornithopter is not the same thing as a glider. A glider relies on fixed wings and forward motion, while an ornithopter produces thrust through flapping wings. Leonardo’s flying-machine sketches include both kinds of ideas, which is why the terms should not be treated as interchangeable.