Departure Noise Limits and Monitoring Arrangements at Heathrow, Gatwick and Stansted Airports

This report describes a study that was undertaken on behalf of the Department for Transport as part of the review of departure noise limits. The study considered both the monitoring arrangements (numbers and positions of monitors) and the limits themselves. Some improvements to the monitor arrays are proposed where there are currently large lateral separations between monitors. The study found that the daytime limit could be reduced by 1dBA, but larger reductions would lead to a high rate of infringements for some of the older Chapter 3 aircraft types currently operating at the London airports. Similarly, the night limit could only be reduced, by 3dBA, if a ban on QC/4 departures were to be imposed. Differential limits, affecting quieter aircraft types, were also considered, and the report recommends a trial to assess their feasibility.