Leonardo da Vinci’s proposed flying machine with a large rotating screw was called the aerial screw.
Leonardo sketched the device around 1489–1490. Its design used a helical linen surface stretched over a reed frame, forming a shape similar to a giant screw. He reasoned that turning the screw could force air downward and lift the machine upward.
The drawing is often described as an early conceptual ancestor of the helicopter, but it could not have flown as drawn. Leonardo’s plan assumed human muscle power, while the combined weight of the frame and crew would have exceeded what people could generate through rotation.
The aerial screw is also sometimes called a “helicopter” in modern summaries. That label helps explain the concept, but Leonardo did not build a working helicopter, and powered vertical flight required much later engines and engineering.