Leonardo da Vinci’s four-wing aerial screw design is commonly called the aerial screw.
Leonardo drew the concept around 1489, showing a large helical surface intended to press against the air as it rotated. The sketch is often discussed as an early helicopter concept because its central idea is vertical lift produced by a rotating screw-like structure.
The drawing does not demonstrate that Leonardo had a practical engine or a workable way to supply enough power. The proposed structure was also very large, and the materials and human power available in Renaissance Italy would not have made a full-scale flight machine feasible.
The aerial screw should not be confused with Leonardo’s ornithopter studies, which sought lift through flapping wings. Nor should it be called a helicopter in the modern technical sense: helicopters use powered rotors with aerodynamic blades, while Leonardo’s design remained a theoretical machine represented in a notebook.