Alternative noise certification concepts for air carrier aircraft

Abstract

This paper examines a number of general and specific concepts in noise certification. These include current takeoff and landing flight procedure requirements, and the potential role of static engine noise testing for noise certification. Effectiveness of existing noise certification concepts are briefly reviewed and alternative methods considered which stress measures of total community‐noise impact. The most interesting of the certification procedures considered consisted of two elements: (1) an initial static engine/nacelle test to certify an engine for the absence of significant pure‐tone components or to provide measured data, when required, to cover an acoustical change involving only the engine/nacelle combination, and (2) a level flyover test to certify an aircraft for noise after translation of the measured data to fixed measurement points on the ground under maximum noise flight conditions. For the latter tests, maximum gross weight is still recommended as the aircraft performance parameter to use for determining acceptable noise levels. However, the current two‐value takeoff certification requirement might be replaced by the average of these two quantities as a single takeoff noise certification value. [Work supported by FAA.]