Leonardo da Vinci’s spiral device designed to lift into the air is called the aerial screw.
Leonardo sketched the aerial screw around 1489. Its large spiral sail was intended to be turned by people inside a platform, forcing air downward and theoretically raising the machine. The design is often described as an early helicopter concept, although it could not have flown with the materials and human power available in Renaissance Italy.
The aerial screw was a paper design rather than a completed working aircraft. Leonardo’s notes show that he was studying air as a medium and comparing the action of a screw in air with the action of a screw in water. That analogy helped him imagine vertical flight centuries before powered helicopters became practical.
The device is sometimes incorrectly called Leonardo’s helicopter. “Aerial screw” is the more precise historical name, while “helicopter” describes the later aircraft type it resembles. The sketch is preserved among Leonardo’s Codex Atlanticus drawings.