§ Mr. Jessel
asked the Secretary of State for Transport when he expects to commence consultations on the United Kingdom aircraft noise index study: main report (DR Report 8402); and what form he proposes these consultations should take.
§ Mr. Michael Spicer
I have today inititated this consultation process.
Following criticism of the noise and number index, which has been used since 1963 as an index of aircraft noise disturbance, a full study was commissioned by the Department of Trade, which then had responsibility for 598W civil aviation matters. The main aim of the study was either to substantiate the NNI or if necessary devise some better index.
The main conclusion reached by the authors of the study report, the directorate of research of the Civil Aviation Authority, is that there appears to be a case for replacing the NNI system of measurement by one based on the 24-hour Leq (equivalent continuous sound level) scale.
As indicated in the White Paper on "Airports Policy" (Cmnd. 9542), the Government are concerned that aircraft noise disturbance is monitored as accurately as possible, and by methods that fairly represent the level of annoyance experienced, and so command public confidence. I would, therefore, like those whom I am formally consulting, and others who may wish to play a part, to let me have their comments by the end of August. These comments will be carefully examined and will be taken into account in the development of future policy. A synopsis of the comments will be made generally available.
I have placed a copy of the study report in the Library of the House.