Ratified by the International Civil Aviation Organisation's Assembly in 2001, the "balanced approach" to the reduction of aircraft noise is a world-wide standard. It is based on the concept that all possibilities for improving the noise environment near airports should be exhausted before consideration is given to imposing local restrictions at specific airports. The policy recommendation has four main components:

Reduction of noise at source: this refers to ICAO-sanctioned standards for the noise that may be produced by aircraft. New Chapter 4 standards apply only to aircraft coming off the production line from 1 January 2006. Land-use planning and management: this is a proposed local planning policy that should ensure that "activities nearby airports are compatible with aviation. Its main goal is to minimise the population affected by aircraft noise by introducing land-use zoning around airports." ICAO urges that environmental gains in noise reduction from the latest generation of aircraft should not be allowed to encourage domestic development to creep closer to airports. Noise abatement operational procedures: these include the introduction of improvements to noise abatement procedures where they do not exist, and more stringent ones where they do. These can include procedures such as limited flap take-offs and payload reduction for aircraft that only marginally meet Chapter 3 standards, and the use of runways that are not operationally ideal but have flight paths over less populous areas. Operating restrictions: this is the final sanction that can be used only after all the former three have been carried out, and can only be imposed on an airport-by-airport basis. Noise charging for specific aircraft types or operations can only be used by an airport facing stringent environmental considerations, and may only be used to cover the cost of applying local noise nuisance alleviation measures.

Source: Flight International