Leonardo da Vinci studied the ornithopter, a flying-machine concept designed to fly by flapping wings like a bird.
The word “ornithopter” comes from Greek roots meaning “bird” and “wing.” Leonardo examined how birds generate lift and propulsion, then sketched machines with mechanical wings intended to imitate their movement. Some designs placed a person inside or beneath a winged frame, with pedals, levers, and cables transferring muscular effort to the wings.
Leonardo’s ornithopters were engineering studies, not proven aircraft. Human muscles cannot provide the sustained power needed to flap wings of the scale he imagined, and the designs lacked the lightweight engines later aviation required. His work nevertheless helped connect observation of animal flight with mechanical design. The ornithopter should not be confused with his aerial screw, which used a rotating helical surface rather than flapping wings.