What powered Leonardo da Vinci’s proposed ornithopter?

Leonardo da Vinci’s proposed ornithopter was intended to use human muscle power to flap its wings.

Leonardo studied birds and bats while developing machines that might achieve flight by imitating natural wingbeats. His ornithopter designs included wings moved by pedals, levers, and other mechanical linkages. The pilot’s legs and arms would supply the force needed to operate the mechanism, transferring human effort to the wings.

The concept was not successful because human muscles cannot provide enough sustained power for a person-sized flapping aircraft with the materials and mechanisms available in Renaissance Italy. Leonardo’s flight studies therefore remained experimental designs rather than working aircraft. He also examined gliding and screw-based concepts, which should not be treated as the same machine.

An ornithopter is defined by flapping wings, not by its exact engine. Modern ornithopters may use motors, but Leonardo’s proposed version depended on the pilot’s physical effort. This distinction separates it from later powered aircraft using engines or propellers.