§ Sir R. Russellasked the President of the Board of Trade if he will publish in the OFFICIAL REPORT a list of types of aircraft which land and take off from London Airport in the order of the amount of noise they create, as measured in decibels.
§ Mr. Goronwy RobertsGround noise levels of a single aircraft type vary with height, climatic conditions, all up weight and operating procedures. An accurate comparison of the intrinsic noise of various types postulates standardised operating techniques and conditions and sophisticated measurement and correction procedures. These are in course of being developed for noise certification purposes but as a guide the noise levels in standard conditions of the major types using Heathrow are roughly assessed as follows:—
Lateral Flyover Approach DC8–50 111 117 119 Boeing 707–320 111 118 121 Super VC10 116.5 109.5 114 BAC 111–500 110 100 105.5 Trident 2 114 109.5 110 The unit of measurement is the Effective Perceived Noise Decibel.
§ Sir R. Russellasked the President of the Board of Trade what is the location of monitoring points around the area of London Airport to detect violation of noise regulations.
§ Mr. Goronwy RobertsI have placed in the Library copies of a map showing the location of noise monitoring points round Heathrow.
§ Sir R. Russellasked the President of the Board of Trade how many violations of noise regulations occurred in the area 77W around London Airport in 1969; how many of the offending aircraft have been identified; and what action has been taken against those infringing the noise abatement requirements.
§ Mr. Goronwy RobertsIn 1969 there were 426 infringements (or 0.5 per cent. of aircraft monitored) of the daytime (0700–2300) limit of 110 PNdB and 104 (or 2.1 per cent.) of the night limit of 102 PNdB. All offending aircraft were identified and each incident was referred to the airline concerned with a request for investigation and explanation in appropriate cases. There was no evidence of such systematic and serious infringement by any one airline as to justify denying the airline the use of Heathrow.