Aircraft Propulsion

Abstract

Mechanical flight began just over 40 years ago, and the only system of propulsion in use until five years ago was the internal combustion piston engine driving a propeller. Quite suddenly, the internal combustion turbine has come very much to the fore, both with and without a propeller, giving an increase in speed from under 500 to over 600 m.p.h.—a result chiefly due to the great increase in thrust horse-power available from a given weight and bulk of power plant. In much the same way as Parsons's demonstration of the possibilities of the steam turbine in the launch Turbinia eventually established the steam turbine as the chief prime mover for large powers, so the record-making Meteor has begun a similar change-over in aircraft propulsion, and perhaps in power plant for locomotives, ships, and power stations. The piston engine, however, has taken 40 years to reach its present development from the rather crude early motor-car engine, and doubtless it will be a long time before it becomes obsolete. It seems a suitable time to put on record the progress in power to weight ratio, reliability, and thermal efficiency that has been made possible by intensive development and research.