The Influence of Modern Noise-Simulation-Tools on the Design of Future Noise-Abatement-Procedures

Abstract

*† ‡ § ** Aircraft engines have been the predominant noise source in the past, inducing the development of noise abatement procedures. Enormous reductions in noise emission levels of turbine engines have been achieved during the last years, exposing airframe noise as an additional significant noise source during the approach and landing phase. In order to cope with these varying aircraft noise emission characteristics, new noise-simulation-tools have been developed, like the German Aerospace Center‘s SIMUL-Program. Now, being able to evaluate present Noise Abatement Procedures (NAPs) with state of the art simulation-tools, it is advisable to review these procedures and modify them with respect to present aircraft noise characteristics. This paper describes the results of a dedicated study on noise abatement approach procedures using the FAA’s Integrated Noise Model (INM) as a „conventional“ noise model, and DLRs simulation model SIMUL. Present procedures are evaluated and effects concerning engine and airframe noise are highlighted. Lessons learned, leading to new future (short- & medium-term) NAPs are presented. A brief outlook on future NAPs and their requirements for special equipment, both, airborne and groundbased, is given. Additionally, comparisons with the findings of other international studies are made.