sentences:  The three rotor configuration was foreseen by Belgian helicopter experimenter Nicolas Florine in his patent of 1926 which presented the aforementioned means for balancing the reaction on the fuselage of two or more torque driven lifting rotors turning in the same direction.Work on the W.11 commenced in 1945.The original W.11 configuration used two rotors transversely mounted either side at the front of the fuselage and a single rotor mounted on the centerline at the tail.