Review of the Departure Noise Limits at Heathrow, Gatwick and Stansted Airports: Additional Study of Boeing 747 Departures

This supplement describes analyses of Boeing 747 take-off noise, performance and weight data, undertaken to assess particular points raised in responses to the consultation on the review of noise limits at Heathrow, Gatwick and Stansted airports. The main topics addressed are Boeing 747 climb performance, seasonal variations in aircraft heights and noise levels, and noise abatement procedures. The accuracy of the model which was used to estimate numbers of infringements is also considered, and estimates are given of infringement rates under the proposed new monitoring regime.