Leonardo da Vinci designed an aerial screw, a rotating-air device built around a vertical helical surface.
The drawing appears in Leonardo’s 15th-century studies of flight. It shows a large helical structure made from reeds, linen, and other materials, mounted on a framework. Leonardo reasoned that rotating the screw could make it rise by pushing against the air, much as a screw advances through a solid material.
The aerial screw is frequently called a helicopter ancestor, but it was not a working helicopter. Leonardo had no lightweight engine capable of supplying the necessary power, and the design lacked the controls and aerodynamic understanding needed for sustained flight. Its large rotor also required several people to turn it.
The concept nevertheless became an important historical reference for vertical-flight ideas. Modern helicopters use powered rotors with carefully shaped blades, while Leonardo’s aerial screw depended on a continuous helical surface and human or mechanical rotation.