Leonardo da Vinci’s rotating-helical flying-machine design was called the aerial screw.
Leonardo sketched the aerial screw around 1489, during his studies of flight and the movement of air. The drawing shows a large helical surface made from reeds, linen, and wire, supported by a central mast. Leonardo reasoned that turning the screw could make it rise by pushing against the air, an idea often compared with the rotor of a modern helicopter.
The design was never built and tested by Leonardo, so it was not a working helicopter. Its importance lies in identifying a possible vertical-lift principle centuries before powered aviation. Modern helicopters use rotating airfoils and engines, not a single fabric-covered spiral.
The aerial screw is also sometimes called a helicopter in popular summaries, but “aerial screw” is the name associated with Leonardo’s specific drawing. It belongs to his Codex Atlanticus studies of flight and engineering.