Leonardo da Vinci called his proposed vertical-flight device the aerial screw.
Leonardo drew the aerial screw in a manuscript dated to about 1489. The design showed a large helical surface wrapped around a central mast. He imagined that the rotating screw would “screw” itself upward through the air, using a concept related to the action of a screw moving through a solid material.
The sketch is often described as an ancestor of the helicopter, but it was not a working helicopter. Leonardo’s design had no practical engine, and the materials and human power available in his era could not have lifted the proposed structure effectively.
The aerial screw remains significant because it identified vertical lift as a separate engineering challenge from ordinary gliding or winged flight. Modern helicopters use powered rotors, not Leonardo’s continuous helical surface.