Leonardo da Vinci’s machine concept with a screw-shaped rotor intended to rise vertically was the aerial screw.
Leonardo sketched the aerial screw around 1489. The machine used a large helical surface made from reeds and linen, supported by a framework. His notes suggested that rotating the screw would force air downward and lift the structure upward, anticipating the basic idea of a helicopter rotor.
The design was not a working helicopter. It had no practical engine, and its materials and human-powered mechanism could not provide enough thrust for sustained flight. The drawing was a conceptual study of air resistance and vertical motion.
The aerial screw is sometimes called Leonardo’s helicopter, but that label is retrospective. Modern helicopters use powered rotors, aerodynamic blades, and control systems. Leonardo’s design is historically important because it clearly explored rotary lift centuries before powered helicopters appeared.