Leonardo da Vinci designed an aerial screw, a flight-machine concept with a large spiral rotor.
The aerial screw appears in a drawing dated about 1489. Its helical surface was intended to press against the air and lift the structure, making it a conceptual ancestor of the helicopter rather than a functioning helicopter. Leonardo’s notes compare the action to a screw moving through a solid medium.
The design was not powered by an engine. It would have required people to turn internal mechanisms, and the materials and available human power were insufficient for practical flight. The drawing is therefore best understood as an exploration of a possible principle.
The aerial screw is separate from Leonardo’s wing-flapping ornithopter studies. It also differs from the later parachute concept, which addresses descent rather than powered ascent. These designs show Leonardo exploring several distinct ways humans might interact with air.