What was Leonardo da Vinci’s rotating-air machine called?

Leonardo da Vinci’s rotating-air machine was called the aerial screw.

Leonardo sketched the aerial screw in the Codex Atlanticus around 1489. The design used a helical surface made from reeds, linen, and wire around a central mast. He reasoned that if the screw were turned rapidly, its spiral surface might “screw” upward through the air. The drawing is frequently described as an early conceptual ancestor of the helicopter.

The aerial screw was not a working helicopter and Leonardo did not demonstrate powered vertical flight with it. Its proposed mechanism also lacked a practical engine capable of providing enough continuous power. Historians therefore distinguish between the idea’s visual similarity to a helicopter rotor and the engineering requirements of a true helicopter, including lift, stability, and control. Modern helicopters use rotating airfoils rather than a single rigid spiral surface, but Leonardo’s sketch remains one of the best-known Renaissance studies of vertical flight.