The most common operational measure in aviation to reduce the effect of environmental noise pollution is noise abatement procedures. Noise abatement procedures are recommended flying techniques based on noise optimal trajectories, which aim at reducing the noise impact on local communities as much as possible. Atmospheric conditions influence sound propagation, however the noise abatement procedures are often fixed and independent of weather conditions.

This research has been set up in order to analyse whether the implementation of weather-adaptive noise abatement procedures result in different noise optimal trajectories in different weather conditions. The research objective is to assess the influence of weather on optimised noise abatement departure procedures for one fly over, by developing an optimisation tool that allows for the synthesis of weather adaptive noise abatement procedures within the terminal manoeuvring area.

To analyse the influence of different atmospheric conditions on the noise optimal trajectories in various weather conditions, a sound propagation model has been developed with the inclusion of variable air temperature and lapse rate, relative humidity, wind profile and ground surface type. Together with an aircraft performance model enhanced with varied atmospheric conditions and a noise impact model, the noise optimal trajectories in different weather conditions are obtained using optimal control theory in GPOPS. The model can be adapted to various requirements and aircraft types.

The resulting trajectories are used to evaluate whether weather-adaptive noise abatement procedures should be implemented or not and to evaluate the performance of optimal control theory in this framework.