Leonardo da Vinci sketched an aerial screw as a rotating aircraft concept in 1489.
The design appears in Leonardo’s notebooks as a large helical structure intended to rise by turning. Its shape resembles a screw or modern rotor, which is why historians commonly call it the aerial screw.
Leonardo did not build a working aircraft from the drawing, and the design lacked a practical power source and a lightweight framework. Modern helicopters use powered rotors, but they do not directly reproduce Leonardo’s proposed mechanism.
The aerial screw is often described as an early helicopter idea, although it was a conceptual study rather than a flight-tested invention. Leonardo’s interest in it formed part of his broader investigation of air resistance, wings, and mechanical motion.