What was Leonardo da Vinci’s rotating aircraft concept called?

Leonardo da Vinci’s rotating aircraft concept was called the aerial screw.

Leonardo drew the design around 1489, describing a helical structure that would press against the air and rise if rotated quickly enough. The concept is often compared with a modern helicopter because both use rotating lifting surfaces, although Leonardo’s machine was not a practical helicopter and lacked a workable power source.

The drawing is usually interpreted as an early attempt to reason about vertical flight. Its frame was to be covered with a lightweight material, and the spiral form was intended to act like a screw moving through air. Historians debate how directly the design could have worked, especially given the weight of the proposed structure and the limited engines available in the Renaissance.

The aerial screw should not be confused with Leonardo’s ornithopter. The ornithopter depended on flapping wings, while the aerial screw depended on rotation. Both belonged to Leonardo’s broader investigations into mechanical flight.