Leonardo da Vinci’s aerial screw used a helical blade to suggest a way of rising through the air.
Leonardo drew the aerial screw around 1489. The design featured a large spiral surface, or helical screw, mounted on a frame. He proposed that if the spiral could be made to rotate rapidly, it might “screw” upward through the air in a way analogous to a screw moving through wood.
The concept is often described as an ancestor of the helicopter, but it was not a workable helicopter. The drawing does not provide a practical power source capable of turning the rotor fast enough, and the proposed materials would have made the machine extremely heavy. Modern helicopters use powered rotors, aerodynamic blades, and precise control systems.
Leonardo’s aerial screw remains historically important because it recognized that rotary motion could generate lift. It was one of several flight studies in his notebooks, alongside parachutes, wings, and ornithopters.