| Topic: | Re:Re:Airplane noise | |
| Posted by: | Paul Clements | |
| Date/Time: | 23/10/11 10:33:00 |
| This information can be found on the following link. http://www.heathrowairport.com/portal/page/Heathrow+noise%5EGeneral%5ENoise+explained%5ENoise+today%5EMeasuring Measuring aircraft noise For many years, noise created by aircraft has been measured by averaging out the noise levels during the day (a 16-hour day) during the summer period. The amount of noise is given in decibels (dB). Averaging-out means that the day’s high and low levels of noise are levelled out to give a single figure. The Government calls this averaged-out decibel measurement “LAeq”. This is the most common international measure of aircraft noise. It means “equivalent continuous noise level”. In the UK the Government says people start to become significantly annoyed by aircraft noise at 57 dB LAeq. This figure is used as the starting point for policies on managing aircraft noise around airports. The Environmental Research and Consultancy Division (ERCD) of the Civil Aviation Authority produces maps annually on behalf of the Government which indicate which areas fall within the area subject to 57 dB LAeq. The maps for 2010 were published by the Government on 7 October 2011. The report below contains the published LAeq contours for 2010. These are based on the actual split of easterly and westerly operations during 2010. More noise is experienced at the end of the runways (where aircraft take off and land) than at the sides. View the full ERCD report relating to the 2010 Noise Exposure Contours (6.2MB PDF) Aircraft manufactured today are much quieter than they were 40, 30 or even 20 years ago, and these will be replaced by even quieter aircraft in the future. In fact, due to technological advances and improvements made in noise control methods, between 1980 and 2006 the number of people living within the 57dB LAeq contour has fallen from 2 million to around 252,000. This is despite the fact that during the same time runway movements have increased from around 273,000 to 477,000. The government was required to produce strategic noise maps for 2006 and airport operators were required Noise Action Plans based on these maps. The latest strategic noise maps produced are available on the Civil Aviation Authority's (CAA) website under ERCD report 0706. |