Leonardo da Vinci studied an ornithopter, a wing-flapping aircraft intended as a possible form of human flight.
The word ornithopter comes from Greek roots meaning bird-winged. Leonardo examined bird and bat anatomy, wing motion, balance, and the mechanics needed to imitate powered flapping flight. His notebooks contain several related proposals, including designs with wings operated by a person’s arms and legs.
Leonardo understood that human muscles alone would probably not provide enough power for a large flapping aircraft. Some drawings therefore use mechanical assistance or place the pilot in a framework that transfers muscular effort to the wings. None of these machines is known to have flown successfully.
An ornithopter is different from Leonardo’s aerial screw, which used a rotating helical surface rather than flapping wings. It is also different from a glider, which produces lift while moving forward without repeatedly flapping its wings.