Leonardo da Vinci called his screw-shaped vertical-flight concept the aerial screw.
Leonardo sketched the aerial screw in a manuscript usually dated to around 1489. The design featured a helical surface wrapped around a central mast. Leonardo reasoned that if the spiral structure rotated rapidly, it might screw itself upward through the air, much as a screw moves through a material.
The aerial screw is often described as a distant ancestor of the modern helicopter, but it was not a helicopter in the engineering sense. Leonardo did not provide a practical engine or a complete method for producing the required power. The machine’s large size and proposed materials would also have made sustained flight difficult.
The design remains significant because it shows Leonardo thinking about lift, rotation, and vertical flight several centuries before powered helicopters appeared. Modern helicopters use rotating blades that generate lift, but their aerodynamics and propulsion systems differ substantially from Leonardo’s proposed helical rotor.