PURPOSE: To make a further improvement in the performance of a rotational propeller because it is not only reducing the size of a propeller for aircraft and a rotor diameter for helicopters but also indispensable for a so-called VTOL plane flying vertically and horizontally by way of turning its propeller around.

CONSTITUTION: Two conical rotators 4 and 5 doubly rotating in an arrow A direction horizontally with a T-shaped turning shaft 1 as vertically rotating in an arrow B direction obtain a large thrust in an arrow C direction by means of a Magnus effect.