Leonardo da Vinci studied an ornithopter, a human-powered aircraft intended to fly with flapping wings.
The word ornithopter means “bird-wing,” and Leonardo’s designs copied the basic motion of birds and bats rather than using a propeller. His notebooks contain studies of wing anatomy, bird flight, air currents, and mechanisms that could transfer human muscle power to wings.
Leonardo understood that a person’s muscles could not easily generate the power required for sustained flapping flight. Some of his proposed machines therefore relied on a pilot’s arms and legs together, but none was built into a successful aircraft. His work is best viewed as a combination of biological observation and mechanical experimentation.
The ornithopter idea remained influential after Leonardo. Modern ornithopters can fly as small radio-controlled models, but powered aircraft with fixed wings and propellers became the practical route to aviation.