AIrcraft Noise Measurement Impact and Control

Unfortunately, wherever aircraft fly hear people some level of annoyance from noise will result.The degree of annoyance can be estimated from the noise exposure thus enabling measures to be determined which can contain noise nuisance within reasonable bounds.Aircraft noise certification has been very successful in encouraging the development of quieter aircraft.but additionalsite related noise limits are also necessary to meet local needs.Day to day measurement at sensitive locations around an airport offers a means of ensuring that agreed noise control policies are effective. WHY MEASURE NOISE?Use of Noise Data Many people seem to think that just by mountinga noise monitoring programme, noise nuisance can somehow be alleviated.Nothing could be further from the truth.Measurement of noise only provides data iwhich can then be used either to assess the scale of the problem, determine how the environment is changing or to assess the success.or failure.on the ground of technical changes made to aircraft, or their operation, for noise control purposes.The data are, of course, also useful for planning future environmental noise control measures at the airport.Several kinds of measurement are possibleI each developed for a specific purpose and often using its own noise units.Noise monitoring is an effective tool which can give assistance in minimising the detrimental effect of airport development but only if an adequate framework of noise controls are set up and it is clear how the noise data are to be incorporated. Noise Certificationin November 1959, the the United States Government were the first to adopt Regulations which made noise emission control part of the airworthiness requirements for new aircraft.United Kingdom Regulations soon followed, based on criteria agreed through the international Civil Aviation Organisation.Noise Certification limits have steadily widened in scope and have generally reduced permitted noise levels as technology advanced.New provisions in the most recent Regulation, the Air Navigation Order 1986 ), included helicopters and now excludes Only certain STOI, aircraft and Concorde from noise certification requirements.Certification noise limits are dependant on the weight of the aircraft (Figl gives as an example the rules for helicopters), consequently an unacceptably wide range of noise emission values are to be expected If noise certification alone is to be relied upon to control the airport environment.For certification purposes noise from new helicopters will be measured for "Take Off" at two symmetrical points located 150m to the side of the ground projection of the fiightpath