Leonardo da Vinci designed an ornithopter, a flying machine intended to rise by flapping wings like a bird.
Leonardo studied birds closely and filled his notebooks with observations about wing movement, balance, feathers, and air currents. His proposed human-powered machines generally used large wings moved by mechanical linkages, with the pilot providing power through pedals, handles, or both.
The word ornithopter combines Greek roots meaning “bird” and “wing.” It describes any aircraft that flies by flapping wings, whether powered by a person, an engine, or another mechanism. Leonardo’s designs were therefore ornithopters rather than helicopters or fixed-wing airplanes.
His machines were not practical aircraft because human muscles cannot supply enough power for a person-sized flapping aircraft. Nevertheless, the studies were important in the history of aeronautical ideas. Leonardo’s notes also show that he understood flight as a problem involving weight, thrust, lift, and control.