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Civil Aviation Bill

I am sympathetic to the point that the hon. Lady makes. I am fairly sure that my hon. Friend the Member for Hayes and Harlington (John McDonnell) will refer to similar matters if he catches the Deputy Speaker’s eye. The problem in relation to noise is that there is no official noise index to show night noise in the UK, although Leq is recognised during the day period, between 7 am and 11 pm. However, the Government produce noise maps for airports at night using Leq contours. They argue that it is an adequate way of expressing aircraft noise levels, and they produced noise for London Heathrow airport for its recent consultation on the night noise regime, which the hon. Member for Richmond Park (Susan Kramer) mentioned. That method can be totally inadequate as a way of assessing the impact of a small number of noisy events distributed over an otherwise long and tranquil period. That is explicitly endorsed by the World Health Organisation in its guidelines for noise levels. It states:"““Where there are no clear reasons for using other measures, it is recommended that LAeq,T be used to evaluate more or less continuous environmental noises. However, when there are distinct events to the noise, as with aircraft or railway noise, measure of individual events such as the maximum noise level (LA Max) or the weighted sound exposure level (SEL) should also be obtained in addition to LAeq,T.””" As planes get marginally quieter, many more will be allowed to fly at night under a pure quota count regime. It is the frequency of noise events that can ruin a night’s sleep. If I am woken up, say, by all noise events over 90 dB, I will not be pleased to hear that twice as many, even if they are 92 dB rather than 95 dB, will be countenanced under a future regime. Therefore, it is essential that the numbers limit on noise on night-time movements is retained. One final weakness that I shall identify in the quota count system is that it is extremely dubious to equate a 3 dB reduction—