Gas Turbines For Helicopters

Abstract

Rapid developments in the use of the helicopter were made in the Korean War. These were taking place at the time when there was considerable urge to introduce the gas turbine engine into the civil aircraft market. It was also a time when much effort was being expended on various forms of reaction propulsion, mostly for missiles. A number of new helicopter projects were started, taking advantage of the new knowledge in propulsion engineering; some utilised new gas turbine designs and others various forms of tip jet reaction. Liquid fuel rockets, ram-jets, pulse-jets and air pressure jets were tried. However, the main line of development continued to be the gradual improvement of direct mechanical drive.Since Korea the natural trend has been first to convert existing helicopters to turbine engines. When new helicopters were designed wisdom dictated mechanical drive pending the gathering of sufficient experience with other forms of rotor power, and so far the accumulated knowledge of the mechanical drive has proved of greater value to helicopter progress than the potential advantages offered by the alternative engine forms.