The Pressure Jet Helicopter

Abstract

Before enlarging on the main subject of this paper, it will be helpful to clarify some fundamental conceptions of various rotor drive configurations.In the past the original shaft-driven helicopter presented two major problems to the designer. These were first: the necessity to choose between either some torque balancing device or a multi-rotor layout and, second: the necessity of a large reduction gear box, the weight of which seemed to become prohibitive with increasing all-up weight of the design. Big helicopters with either single rotor/tail rotor configuration or multi-rotor configuration, are flying successfully and prove that these afore-mentioned problems, although still in existence, were mastered in an admirable way. Nevertheless, in the old days the words “ tip. drive ” had a magic sound to the harassed designer.