Engineering Acoustics

15Aircraft and Airport Transportation Noise Sources and Control

15.1 Introduction

The number of aircraft used for civilian and military air transportation has increased steadily during the last decades. Thus, aircraft noise has been a problem for people living in the vicinity of airports for many years. In the case of aircraft and helicopters, similar power plant and motion‐related noise sources as in surface transportation vehicles exist. Some small aircraft are powered by internal combustion engines. Nowadays many general aviation and all medium‐size airliners and helicopters are powered by turboprop power plants. Aircraft propeller and helicopter rotors are major noise sources that are difficult to control. All large civilian aircraft are now powered by jet engines in which the high‐speed (HS) exhaust and turbomachinery are significant noise sources. Although the latest passenger jets with their bypass turbofan engines are significantly quieter than the first generation of jet airliners, which used pure turbojet engines, the noise of passenger jet aircraft remains a serious problem, particularly near airports. The noisiest pure jet passenger aircraft have been or will soon be retired in most countries. Airport noise, however, is likely to remain a difficult problem since in many countries the frequency of aircraft operations continues to increase and because of the public opposition to noise voiced by some citizens living near airports. This opposition has prevented runway ...