Leonardo da Vinci’s ornithopter was a flying-machine design that used flapping wings modeled on birds.
Leonardo studied birds, bats, and the mechanics of wing movement while developing several flying-machine concepts. His ornithopter drawings show a human pilot inside a frame who would operate wings through pedals, cranks, and other mechanical controls. The word ornithopter comes from Greek roots meaning bird and wing.
The machines were not successful aircraft. Human muscle could not provide enough power to lift the proposed structure and pilot, and the designs lacked the lightweight engines later needed for powered flight. Leonardo’s sketches nevertheless helped organize observations about lift, balance, and wing motion.
An ornithopter is distinct from a glider, which remains airborne by using fixed wings, and from a helicopter, which uses rotating blades. Leonardo explored all these broad flight ideas, but his flapping-wing machines were never demonstrated as practical aircraft.