London Airport (Noise) 37. Mr. Spearing asked the Secretary of State for Trade and Industry what are the technical arrangements for monitoring noise levels of aircraft approaching or leaving London Airport from the east. Mr. Noble Noise levels of aircraft taking off are measured at specified points related to the first community overflown. Noise levels on the ground of aircraft on approach are a function of aircraft height, and heights of a sample of approaching aircraft are therefore checked by radar. Mr. Spearing But does not the right hon. Gentleman agree that the question was about aircraft approaching London Airport over London and not those taking off? Would he not agree that the Parliamentary Commissioner's Report No. 47 showed that no effective noise monitoring took place? In view of that, would he not make a further statement on how he intends to make noise monitoring effective to the east of London Airport? Mr. Noble The hon. Gentleman probably realises that the problem of aircraft approaching is different from that of aircraft taking off because of the pilot being forced to fly on a glide path, and according to the performance of his engine, which may vary from type of plane to type of plane, he is no longer in control of the noise that the engine may be giving off, although there are limits to which he is expected to keep. Therefore, monitoring on approach is much less likely to have a satisfactory and safe result than when taking off. Mr. Hugh Jenkins Is it not the case that if the right hon. Gentleman would monitor or instruct that monitoring should be done under approaching aircraft, he would at least know the levels of noise? As it is, is he not depriving himself of essential information? Will he not think about this again? Mr. Noble As I said in my answer, a sample of approaching aircraft are checked and the noise levels are not in excess—or only very slightly in excess—of the limits. Mr. Geoffrey Finsberg Would my right hon. Friend not agree that one of the problems for many of our constituents is that they are given the most fatuous answers by his Department—and were by his predecessor's Department as well—and are asked to send details? Would he ask his officials how ordinary people can be excepted to be able to give the details required before prosecution can take place? Mr. Noble I fully accept my hon. Friend's feeling about some of the replies which one has to send. Not having had one from the right hon. Member for Barnsley (Mr. Mason) when he was President of the Board of Trade, I cannot express any view on that. But the fact which the House has to realise is that the problem of aircraft noise is perhaps the most difficult single subject which anyone could attempt to solve. It cannot at the moment be solved. The frustration people get on receiving official letters is perhaps a perfectly fair result of the difficulties of giving clear-cut answers and making promises which one knows one can keep. Mr. Michael Foot Does not the right hon. Gentleman think that it would assist in overcoming the sense of frustration if he could invent some simple mark which would tell recipients of his letters which of them he thought were fatuous? Mr. Noble I did not suggest that any letter sent by my predecessor or myself was fatuous: I merely said that they were at times disappointing, because there are no direct easy answers. If there were, I would be only too delighted to send some letters which would cheer people up a great deal. The difficulty is that if one moves the noise from one area to another to give relief, all one does is get another 50,000 or 20,000 complaints.