This engine is for the class F3A aerobatic models completely new ways. Its revolutionary design combines the advantages of the outer rotor with the benefits of the internal rotor. The main advantage lies in the laminated rotor, whereby the operation is optimized at part load. By reversing the typical external rotor PLC Wicklungssytems potential advantages have been integrated into the propulsion system. An inner fan optimizes cooling of the rotor and the winding. The efficiency could be increased in comparison to conventional engines F3A significantly and is 91%! This at a weight of 565 g. A stable 12 mm hollow shaft provides excellent stiffness. The inner rotor can be easily mounted in the fuselage. A stroke of genius of the art: Advance - always one step ahead.