Leonardo da Vinci’s aerial-screw design is often identified as a helicopter concept.
Leonardo drew the aerial screw around 1489. Its large spiral sail was intended to rotate and lift the machine if driven by people turning a central mechanism. The design was based on the idea that a screw moving through air could rise in much the same way that a screw moves through a solid material.
The aerial screw was not a working helicopter. Its materials, power source, and human-powered mechanism could not have produced enough lift for practical flight. Modern helicopters use powered rotors rather than a fabric-covered spiral rotor.
The sketch remains important because it shows Leonardo reasoning about vertical flight centuries before powered helicopters became possible. It is also commonly called the “helicopter,” although that modern name describes its resemblance rather than a completed machine.