Aircraft trajectories for reduced noise impact

A method has been developed for studying the feasibility of reducing annoyance due to aircraft noise by modifying the flight trajectories over a community. Numerical optimization is used to compute the optimum flight paths, based upon a parametric form of the trajectories that implicitly includes some of the problem restrictions. The other constraints are formulated as penalties in the performance measure that is to be minimized. Various aircraft on multiple trajectories (landing and takeoff) can be considered. It is found that significant reductions in community annoyance are possible through this approach. A reduction in the amount of searching for the absolute minimum of the performance measure has been achieved through the use of the known statistics of lateral dispersion in the flight paths. In addition, the population distribution is found not to have a dominant influence in determining the optimum set of flight paths when the mixture of aircraft on those paths changes; the optimum set may have to be recomputed for a change in the flight mix.