Leonardo da Vinci’s spiral design intended to rise through the air is commonly called the aerial screw.
Leonardo sketched the aerial screw around 1489, describing a structure with a spiral surface wrapped around a central mast. The concept is often compared with a modern helicopter rotor because it proposed pushing against air to generate upward motion. Leonardo’s drawing suggests a frame covered with reeds and cloth or another lightweight material.
The design was not a working helicopter and was never demonstrated as a flying machine by Leonardo. Its proposed mechanism would have required a powerful, lightweight source of rotation that did not exist in Renaissance technology. Human operators would not have been able to supply enough power through the methods available at the time.
Modern reproductions are useful for studying the idea, but they should not be treated as proof that the original design would have flown. The aerial screw is distinct from Leonardo’s ornithopter, which attempted flight through flapping wings rather than a spiral rotor.