Leonardo da Vinci’s bird-wing flight device powered by a pilot’s arms was an ornithopter.
An ornithopter is an aircraft designed to fly by flapping wings, imitating birds, bats, or insects. Leonardo studied birds extensively and drew several flying-machine designs in the late 15th and early 16th centuries. His sketches explored how a person might use mechanical linkages, pedals, and hand controls to move large wings.
Leonardo’s designs were ingenious but could not have lifted a person with human muscle power alone. The wings were too heavy, and the available materials and mechanisms were not strong or light enough. This design is often confused with Leonardo’s helical aerial screw, which used a rotating spiral surface rather than flapping wings. Modern ornithopters use motors or engines, although some small experimental models have flown with other power sources.