Leonardo da Vinci sketched an aerial screw in 1489 as a possible rotor-powered flying machine.
The design shows a helical sail-like structure wrapped around a central mast. Leonardo reasoned that if the screw could be made to rotate rapidly, its surface might push against the air and lift the machine. The drawing is often described as an early conceptual ancestor of the helicopter, although it was never built or tested by Leonardo.
The aerial screw was part of Leonardo’s broader study of flight. He investigated bird wings, air resistance, balance, and mechanical motion in notebooks that combined artistic observation with engineering ideas. His proposal did not include a practical engine, so the machine could not have flown with Renaissance technology.
A common mistake is to call the sketch the first helicopter. It was a conceptual rotorcraft idea, not a working helicopter and not evidence that Leonardo built one. Modern reconstructions demonstrate the shape’s visual similarity to a rotor, but they do not turn the original design into a functional aircraft.