Evolution of modern air-transport powerplants

Abstract

The advance in the performance and economics of aircraft powerplants is a significant aspect of our technical history and points the way toward expansion of air transport. In the 1935-1964 period, aircraft engine cruise power has increased twentyfold, weight/horsepower ratio has improved by a factor of 5, and fuel consumption per pound of thrust horsepower of jet engines now approaches that of the best piston engines at twice the flight speed. With these gains have come substantial decreases in powerplant initial and maintenance costs and in-flight shutdown rates, and a great jump in engine earning capacity. Further, the turbofan engine compares most favorably with land and sea propulsion systems in initial, direct operating, and maintenance costs. Advances in engine technology and reliability over the past 30 years indicate the feasibility of attaining the supersonic transport goals, but only after a development program of great magnitude has been established. More immediately promising is an expansion in the air-cargo area, using present technology.