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

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

Leonardo drew the design in a manuscript dated about 1489. It consisted of a large helical rotor made from a reed framework covered with linen. He proposed that people could turn the mechanism, causing the screw to “screw” upward through the air in a way compared with a screw moving through wood.

The aerial screw is often described as an early helicopter concept, but it was not a helicopter in the modern engineering sense. Its proposed human-powered mechanism would not have supplied enough lift, and Leonardo’s drawing did not include the control systems, lightweight engine, or aerodynamic rotor design required for practical flight.

The design remains historically significant because it identified a rotating lifting surface as a possible route to vertical flight. Modern helicopters use powered rotors, while Leonardo’s aerial screw was a speculative Renaissance machine and was never built by its designer.