Leonardo da Vinci designed an aerial screw with rotating blades above a central shaft.
Leonardo sketched the aerial screw in the 1480s, probably around 1489. The design shows a helical sail or screw intended to press against the air and lift the machine. It is commonly recognized as an early conceptual ancestor of the helicopter, although Leonardo’s device was not powered by an engine and could not have flown as drawn.
The sketch is sometimes called a helicopter prototype, but that wording can be misleading. Modern helicopters generate lift with powered rotors whose blades rotate continuously. Leonardo’s aerial screw instead relied on several people turning a mechanism, and the materials available in the fifteenth century would have made the proposed machine too heavy.
Its importance lies in the underlying idea: a rotating spiral surface might climb through air in the same way a screw advances through a solid material. The concept shows Leonardo applying mechanical analogies to a problem that later engineers solved with engines, lightweight structures, and aerodynamic rotor blades.