Leonardo da Vinci studied an ornithopter, an aircraft intended to fly by flapping wings modeled partly on a bat.
Leonardo filled his notebooks with observations of birds, bats, and the mechanics of flight. His ornithopter concepts used wings that a human pilot would move through mechanical linkages, attempting to imitate the power stroke of a bird. He recognized that successful flight required more than simply copying a wing’s shape; weight, balance, lift, and muscle power were also crucial.
No Leonardo ornithopter achieved powered human flight. A person could not generate enough continuous power through the proposed mechanism, and the available materials were too heavy for the required strength. Leonardo also studied gliding and the possibility of using fixed wings, which are different from flapping-wing aircraft.
The term ornithopter comes from Greek words meaning bird and wing. Modern ornithopters have been built as small experimental aircraft and models, but Leonardo’s designs remained theoretical studies.