DECISION MAKING BASED ON COMMUNITY NOISE ANNOYANCE IN THE MULTI-OBJECTIVE OPTIMIZA- TION OF A COMMERCIAL AIRCRAFT

The present paper deals with an innovative decision making approach for the selection of air- craft design concepts and operational procedures aimed at the reduction of the community noise annoyance. Specifically, the least annoying solutions pertaining to the Pareto front re- sulting from a multidisciplinary, multi-objective design and procedure optimization process, are selected on the basis of psychoacoustic requirements. The need of such an approach stems from the fact that the environmental requirements imposed to the commercial aviation are be- coming stricter and stricter, as the trend of the traffic increase is rapidly growing following the market demand. The fulfillment of these requirements often leads to design decisions that can be conflicting, thus forcing the designer to look for trade-off solutions since the early con- ceptual phase of the design process. The multi-objective optimization is the methodological approach most suited to cope with this kind of problems. Using this approach, the Pareto optimality is achieved as the set of non-dominated solutions (the Pareto front), i.e., the solu- tions such that none of the objectives can be improved without deteriorate at least one of the others. The criterion used to select one of the non-dominated solutions along the Pareto front represents a key point. Within the EC-funded project COSMA, the outcomes of an extensive campaign of psychometric tests aimed at the identification of the most annoying characteristics of the aircraft noise are used to rank the points on the Pareto fronts with respect to the level of annoyance produced on the residential community. The approach is highly innovative, being the first time that psychoacoustic considerations are directly used in the design and procedural optimization process. The results obtained for different classes of aircraft in several operating conditions are presented.