§ Mrs. Bainasked the Secretary of State for Trade if he will consider changing 523W the use of NNI measures as criteria for measuring noise at low density airports; and if he will make a statement.
§ Mr. Clinton DavisThe NNI measure is based on a formula which takes account of aircraft noise levels and the number of aircraft heard. It has been found to be a valid measure of disturbance at quite low levels of aircraft movements and has been reviewed several times since its introduction. I do not, therefore, propose making any change, although I am always prepared to consider any alternative.
§ Mrs. Bainasked the Secretary of State for Trade whether soundproofing compensation at Heathrow Airport was automatic at the level of 45NNI or 60NNI.
§ Mr. Clinton DavisThe noise insulation grants scheme at Heathrow is based on two areas with different levels of grant—higher in the inner than the outer area. The boundary of the inner area is fixed in relation to roads and waterways in such a way as to enclose all the dwellings lying within the 60NNI contour. The boundary of the outer area is fixed in relation to the boundary of all those wards or parishes around the airport of which any part is cut by the 55NNI contour.
§ Mrs. Bainasked the Secretary of State for Trade if he will list in the Official Report the level of Government grants to sound-proofing schemes at each British airport in each of the last five years.
§ Mr. Clinton DavisThere are no Government grants to schemes for insulation against aircraft noise.
§ Mrs. Bainasked the Secretary of State for Trade if he will make arrangements to allow local authorities to conduct their own NNI tests in order to check those issued by the British Airways Authority.
§ Mr. Clinton DavisThis is a matter for the local authorities concerned, some of which commission noise consultants for such a purpose.
§ Mr. Hayhoeasked the Secretary of State for Trade what progress is being made with landing techniques which would reduce the levels of noise experienced by those living under the flight paths to Heathrow.
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§ Mr. Clinton DavisInvestigations are continuing of new flight management techniques to reduce noise levels on the ground, but it is too early to say whether the complex problems involved can be satisfactorily solved.
§ Mr. Hayhoeasked the Secretary of State for Trade whether action will be taken to reduce the noise of the Trident aircraft by encouraging the use of quieter engines and the fitting of hush kits.
§ Mr. Clinton DavisThe older types of jet aircraft, such as the Trident now in service, are at present exempt from the provisions of the United Kingdom Air Navigation (Noise Certification) Order 1970, although any new production of these older types of jet aircraft will, after 1st January 1976, also be required to meet the noise regulations. Following consultations with manufacturers and operators during the last year, my Department is examining the extent to which older aircraft can also be brought to comply with the noise certification regulations. However, there are important international implications and complex questions of cost and timing, and I am not yet able to say what the outcome will be, but a conclusion will be reached as soon as possible.
§ Mr. Hayhoeasked the Secretary of State for Trade whether he is satisfied that full account is taken of the larger numbers of people, adversely affected by the noise of aircraft movements, living to the east of Heathrow in determining preferential systems of runway use.
§ Mr. Clinton DavisI believe that within the constraints imposed by weather and safety considerations, the existing system of runway usage takes full account of the distribution of population around the airport.