Leonardo da Vinci designed ornithopters, flying machines based on the flapping motion of birds’ wings.
The word ornithopter comes from Greek roots meaning “bird” and “wing.” Leonardo studied bird anatomy, wing movement, and the mechanics of flight while developing machines intended to imitate flapping wings. Some sketches show a pilot lying or standing inside a framework and using pedals, levers, or other controls to move the wings.
Leonardo recognized that human muscle power alone would probably not be enough for a large flapping aircraft. His notebooks therefore include many investigations of lift, balance, wind, and gliding. None of his ornithopter designs is known to have flown successfully.
An ornithopter is different from a glider: a glider relies on fixed wings and air currents, while an ornithopter generates thrust by flapping wings. Leonardo’s studies helped make flight a subject of systematic mechanical analysis, even though powered aviation remained centuries away.