Leonardo da Vinci’s birdlike flapping-wing aircraft designs are called ornithopters.
The word ornithopter combines Greek roots meaning “bird” and “wing.” Leonardo studied bird anatomy and flight, then developed sketches in which a human operator would move wing mechanisms. Some designs placed the pilot below or inside a framework connected to large wings.
Leonardo understood that birds generate lift and propulsion through complex wing movements, but human muscles could not provide enough power to fly a heavy mechanical craft. His ornithopters therefore remained studies and models rather than practical aircraft.
An ornithopter is not the same as a helicopter or an airplane. It produces thrust by flapping wings, while a helicopter uses powered rotary blades and a fixed-wing airplane uses forward motion over airfoils. Modern experimental ornithopters exist, especially at small scale, but Leonardo’s Renaissance designs were primarily investigations based on natural observation.