The machine commonly called Leonardo da Vinci’s aerial screw was a rotating design intended to rise vertically through the air.
Leonardo drew the aerial screw in a manuscript usually dated to about 1489. The design has a large helical surface made from reeds, linen, and other lightweight materials, supported by a circular frame. He suggested that turning the structure could make it “screw” upward through the air, an idea resembling the principle of a modern helicopter rotor.
The aerial screw was not a working helicopter. Its proposed materials and human-powered mechanism could not generate enough lift, and the large rotating surface would have been difficult to control. Historians therefore treat it as an important conceptual study rather than a successful aircraft.
The design is often called a helicopter in popular accounts, but that label can cause confusion. Modern helicopters use powered rotors that generate lift through carefully shaped blades and controlled rotation. Leonardo’s sketch anticipated vertical-flight thinking, yet it lacked the propulsion, materials, and control systems needed for practical flight.