The Mayor's Ambient Noise Strategy - Greater London Authority

The Mayor’s Ambient Noise Strategy Mayor of London 125
policy 40
The Mayor supports review of the aircraft noise index currently used at
Heathrow and other airports in the UK. The index should be reviewed,
normally at five-yearly intervals or as appropriate in the light of
developing scientific understanding. Research should encompass issues
related to getting to sleep and getting back to sleep once woken, as well
as being woken once asleep.
Noise abatement operational procedures
4C.14 Operational procedures applied at Heathrow and other designated
airports to abate noise include maximum permitted noise levels for
departure; noise preferential routes for departure; minimum altitudes for
joining the final approach glidepath (Instrument Landing System, ILS);
low power/low drag procedures, and continuous descent approach.
4C.15 Take-off noise has traditionally been seen as of greater concern than
landing noise. Take-off has been where the main improvements in aircraft
technology, principally from reducing engine noise, have been made. The
‘noise footprint’ at take-off has been significantly reduced, as modern
aircraft are able to climb much more steeply. At Heathrow, complaints
about departure noise have fallen considerably.
4C.16 At Heathrow, noise monitoring and noise limits for departing aircraft have
been in place since 1959. The airport operator undertakes monitoring for
noise infringements at take off. Airlines are surcharged, and the income
distributed by a Noise Fund Panel to community projects. Infringements
have tended to be by older aircraft. New lower departure noise limits were
introduced by the Government in December 2000, enforced from
February and March 2001. The departure noise limits (L Amax
see glossary)
are: daytime 94 dB(A); night 87 dB(A); and 89 dB(A) for the ‘shoulder
periods’ between day and night (2300-2330 and 0600-0700 hours).