Leonardo da Vinci’s rotating-blade flying-machine concept is commonly called the aerial screw.
Leonardo drew the aerial screw around 1489, describing a helical device intended to rise by “screwing” into the air. The design used a large spiral surface supported by a framework. His notes suggest that linen, reeds, and wire could form the structure, although the sketch does not provide a complete working power system.
The aerial screw is often described as a distant ancestor of the helicopter, but it was not a helicopter in the modern engineering sense. Modern helicopters use powered rotors with carefully shaped blades, while Leonardo’s concept depended on a broad helical surface and lacked an adequate engine.
The drawing is significant because it identifies the basic idea that rotation can produce vertical lift. Leonardo’s machine could not have carried a person with the technology available in Renaissance Italy, yet its visual logic has made it one of his best-known aviation inventions.