Leonardo da Vinci sketched an ornithopter, a flying machine intended to rise by flapping wings.
Leonardo studied birds extensively and tried to apply their wing movements to human flight. His notebooks contain drawings of frames, wings, joints, and control mechanisms based on bird anatomy. The proposed machine would have required a person to generate or control wing movement, but human muscles cannot provide enough power for a practical flapping aircraft of that size.
An ornithopter is not the same as a glider. A glider uses fixed wings and gains lift while moving through the air, whereas an ornithopter seeks lift through repeated wingbeats. Leonardo also sketched other airborne concepts, including a parachute and a screw-shaped aerial device, but those represent different approaches to flight.
No Leonardo ornithopter is known to have flown. The designs remain important because they show how observation of nature shaped Renaissance engineering ideas.