Leonardo da Vinci’s aerial screw was a spiral flying-machine concept often described as an early helicopter idea.
Leonardo drew the design around 1489. It showed a large helical surface made from reeds and linen, supported by a circular frame. His notes suggested that if the screw were turned rapidly, the spiral surface might bite into the air and lift the machine.
The aerial screw was not a working helicopter. Leonardo had no lightweight engine capable of supplying the necessary power, and the design lacked the aerodynamic understanding and control systems required for practical flight. Modern helicopters lift themselves with rotating airfoils rather than a continuous cloth-covered spiral.
The sketch is historically significant because it identified rotation as a possible way to generate lift centuries before powered rotorcraft existed. It is also commonly confused with Leonardo’s flapping-wing ornithopter, but the two machines use entirely different flight principles.