Igor Sikorsky was not so much an inventor as a designer who made use of the best of all the currently available designs and melded them together into what was the basic 'mould' for the majority of his helicopter designs. The VS-300 was powered by a 75hp Lycoming engine and had two tail-rotors; one for anti-torque and directional control, the other to aid horizontal stability. Later versions of the VS-300 were powered by a 90 hp Franklin engine and the second tail-rotor was dispensed with. 1935-40