Optimal departure trajectories with respect to sleep disturbance

Abstract This paper describes on-going research in the field of trajectory optimization with respect to noise. Recently, this resulted in a tool in which the Integrated Noise Model, a Geographic Information System and a dynamic trajectory optimization algorithm are combined. This tool has proved to be effective in analyzing noise abatement procedures for departure. With this tool, optimized departure trajectories were generated by using a composite performance index which incorporated a noise related and a fuel related parameter. This resulted in minimum-fuel trajectories that were locally adjusted for noise considerations. However, such a minimum-fuel trajectory is not very realistic from an operational point of view. Therefore, this study proposes a different composition of the performance index. The performance index that is used in the present study incorporates the deviation from a reference flight path instead of a fuel parameter. In this way, a reference flight can be selected that is more practical. A trajectory optimized using the modified performance index will deviate from the reference track only if this improves the noise impact. It is also shown that, depending on the scenario, two instruments, i.e., a thrust cutback or lateral movement, are employed to a different extent in order to achieve a noise reduction.