What is Leonardo da Vinci’s rotating aerial-screw design commonly called?

Leonardo da Vinci’s rotating aerial-screw design is commonly called the aerial screw.

Leonardo drew the machine around 1489, describing a large helical surface wrapped around a frame. He suggested that if the screw were turned rapidly, it might “screw” its way upward through the air. The concept is often discussed as an early ancestor of the helicopter, although it was not a practical helicopter and was never demonstrated as a working aircraft.

The design probably relied on linen stretched over a reed or similar framework. Its large size and the limited power available from human muscles would have made sustained lift impossible. The drawing is therefore more useful as a conceptual step in the history of vertical flight than as an operable invention.

Leonardo’s aerial screw and his flapping-wing machines show that he explored more than one route to flight. Modern helicopters use powered rotors, aerodynamic blades, and controllable pitch rather than a single screw-shaped surface.