Framework for Analyzing Aircraft Community Noise Impacts of Advanced Operational Flight Procedures

Abstract

A framework for analyzing the aircraft community noise impacts of advanced operational approach and departure procedures was developed. In this framework, the altitude, position, velocity, thrust, and configuration profiles of procedures to be assessed are specified by aircraft performance. These profiles are input to the NASA Aircraft NOise Prediction Program, which requires aerodynamic performance and engine state parameters, as well as generates airframe and engine noise throughout each procedure. Generated single-event surface noise grids are combined with population census data to estimate population noise exposure. The framework’s noise estimates agree to within effective perceived noise level of available certification noise data from six aircraft types. Use of the framework was demonstrated on example departure and approach cases to show how it can be used to assess the performance and noise impacts of varying the altitude, velocity, thrust, and configuration for various aircraft. One example shows the evaluation of the noise impacts of an increased thrust departure, in which the thrust and associated altitude were increased on departure. The second example analyzed the noise impacts of altered vertical path and configuration management approaches. These included altering conventional step-down approaches to continuous descent approaches at glide slopes of 3.0–3.2 deg, as well as delayed gear approaches.