The Mayor's Ambient Noise Strategy - Greater London Authority

250 Mayor of London
The Mayor’s Ambient Noise Strategy
Chapters 2, 3, and 4 Noise standards for aircraft agreed internationally
through the International Civil Aviation Organisation (ICAO), a specialist
agency of the United Nations. Noise standards for aircraft were first
introduced in Volume I of Annex 16 to the Convention on International
Civil Aviation, 1944 (the ‘Chicago Convention’). The reference is to the
relevant Chapter of Volume 1 of Annex 16. Chapter 2 refers to the first
standards developed for subsonic jet aircraft. New Chapters have been
inserted. Chapter 4 standards were agreed in 2001, through ICAO’s
Committee on Aviation Environmental Protection (CAEP). The noise
reduction agreed was 10 dB ‘cumulatively’, while many European
Governments, airport operators through the Airports Council International,
and others had been arguing for 14 dB. These reductions refer to the sum
of three measured reductions used for noise certification. Noise levels are
measured during:
a take off at maximum power with a subsequent power cutback, where
the noise is measured under the flight path at 6.5 kilometres from start
of roll;
b a maximum power/no-power cutback climb flight, where the maximum
sideline noise is measured at a lateral distance of 450 metres, and
c a 3 degree slope landing approach, where the noise under the flight
path is measured 2000 metres before touch-down.
In the new Chapter 4, some trading off is allowed between the different
elements of the agreed 10 dB total reduction.
Clear Zone Area in which traffic is reduced and streets made more
pedestrian-friendly.
Continuous Descent Approach (CDA) is defined as a noise abatement
technique for arriving aircraft in which the pilot, when given clearance
below the transition altitude by air traffic control (ATC), will descend at
the rate which (s)he judges will be best suited to the achievement of
continuous descent whilst meeting the ATC speed control requirements.
The objective is to join the glide path at the appropriate height for the
distance without recourse to level flight. Low engine power settings
during CDA reduce overall sound energy emitted, as well as saving fuel. A
Code of Practice has been developed to reduce noise from each aircraft
arrival. ‘Low power-low drag’ is defined as a noise abatement technique
for arriving aircraft in which the pilot delays the extension of wing flaps
and undercarriage until the final stages of the approach, subject to
compliance with ATC speed control requirements and the safe control of
the aircraft.