Leonardo da Vinci’s birdlike flying machine was an ornithopter.
An ornithopter is an aircraft that produces lift by flapping wings, copying the motion of birds, bats, or insects. Leonardo studied bird anatomy and flight in several notebooks and developed sketches for machines with large movable wings. Some designs placed a pilot inside a frame who would operate the wings with pedals, levers, or hand controls.
Leonardo understood that human muscle power would probably not be enough to lift a heavy machine in sustained flight. His studies nevertheless helped separate practical observations about air from purely mythical ideas of flight. The surviving drawings show several variations rather than one finalized aircraft.
An ornithopter is different from Leonardo’s aerial screw, which used a rotating helical surface. Neither concept became a working Renaissance aircraft, but both demonstrate his systematic investigation of lift, motion, and mechanical power.