What did Leonardo da Vinci’s flying machine use to imitate a bird’s wings?

Leonardo da Vinci’s flying machine used flapping wings to imitate a bird’s wings.

Leonardo studied birds and bats while developing ornithopter designs, especially in the late 15th century. An ornithopter is a machine intended to fly by flapping wings rather than by using fixed wings and a separate propeller.

His sketches show a pilot positioned inside or beneath a framework connected to large wings. Mechanical linkages were meant to transfer the pilot’s movements or the motion of pedals and handles to the wings. Leonardo understood that bird flight involved complex changes in wing shape, although the available human power was not sufficient for practical sustained flight.

The design is distinct from Leonardo’s separate aerial-screw concept, which used a rotating helical surface. Neither concept became a proven flying aircraft in his lifetime, but both reveal his effort to study flight through mechanics and close observation of nature.