What name is given to Leonardo da Vinci’s flying machine with a helical rotor?

Leonardo da Vinci’s helical-rotor flying machine is commonly called the aerial screw.

Leonardo drew the design around 1489, showing a large spiral surface intended to push against the air as it rotated. The sketch is often described as an early helicopter concept because its central idea resembles the lift produced by a rotor.

The aerial screw was not a working helicopter. Leonardo did not provide a practical engine, and the materials and power available in the Renaissance could not have driven the proposed rotor effectively. The machine is therefore best understood as a speculative design based on an analogy between a screw moving through water and a rotor moving through air.

Modern helicopters use powered rotors, aerodynamic airfoils, and control systems. Leonardo’s drawing anticipated the broad rotor principle but not the complete engineering needed for sustained flight.