Abstract
This work introduces a noise abatement procedure for reducing aircraft community noise during departures based on the control of climb profiles via procedural level-offs. The proposed procedure consists of enforcing an altitude restriction along a departure path such that aircraft maintain level flight when overflying strategically selected regions. During this level segment, thrust demand is lower than during climbing flight, which results in lower engine noise. However, this effect must be balanced with the lower aircraft altitude in the level segment, which may reduce the distance between aircraft and observers. Thus, a systematic analysis methodology is needed to design an effective noise abatement procedure based on this technique, which has been developed and is presented in this paper. Modeling results show potential undertrack peak A-weighted noise level reductions of 2–4 decibels for both narrowbody and widebody aircraft in the level-off area depending on the level-off altitude and an associated increase of 1.5–6 decibels in the region where the climb is resumed. An example application of this procedure is demonstrated at Boston Logan Airport, with cumulative changes in noise impacts being assessed for one full day of operations. In this example application, fuel burn penalties are estimated at 37 pounds for a representative narrowbody operation and 142 pounds for a representative widebody operation.