Delayed Deceleration Approach Noise Impact and Modeling Validation

Abstract

A validation methodology and evaluation of delayed deceleration approach performance and noise-impact modeling using noise measurements and radar data are presented. Advanced procedures such as delayed deceleration approaches, where aircraft maintain higher speeds and therefore remain cleanly configured and at lower thrust levels for longer flight periods, can be used for airport noise abatement. Delayed deceleration approaches have been shown in modeling to offer noise reductions before the stabilization point compared to procedures that decelerate early. The delayed deceleration approach validation methodology is demonstrated through monitoring of operational radar data with varying velocity profiles from Boeing 737, Airbus A320, and Embraer E190 flights and comparing modeled sound exposure levels of these procedures with available ground-noise-monitor data at two major airports. Thrust from radar flights was modeled based on weight predicted from final approach speed and assumed configuration. When corrected for atmospheric conditions, modeled noise is shown to be consistent with noise-monitor readings under reasonable flap-deployment schedule assumptions during observed early, intermediate, and delayed deceleration approaches. In addition, delayed deceleration approaches correlated with monitor readings with lower noise levels of an average of 3–6 dB compared to early deceleration approaches across different aircraft types.