Describing aircraft noise
Accurately and comprehensively describing aircraft noise is essential to maintaining a proactive approach to informing the community on aircraft noise issues. There are several measures used to describe aircraft noise, none of which is singularly able to show every aspect of the impact of aircraft noise. We therefore outline a number of these measures so that the community can form a more complete understanding of the effects of aircraft noise.
- High Noise Corridor
- Actual Aircraft Tracks
- Single Event Contours
- Noise and Flight Path Monitoring System (NFPMS)
- Australian Noise Exposure Forecast (ANEF)
High Noise Corridor
The High Noise Corridor is an area of land around Canberra Airport subject to significant adverse aircraft noise exposure. Canberra Airport argues that this is the preferred measure to be used in determining the suitability of residential development, and within which no further residential development should be permitted. Areas throughout this Corridor will be subject to high noise exposure, which will increase as aviation traffic grows. Lesser amounts of noise may still be experienced outside the Corridor, as evidenced by actual aircraft tracks and single event noise contours.
More information on the High Noise Corridor.
Actual aircraft tracks
The following map shows the actual departure (green) and arrival (red) tracks for jet aircraft in April 2008.
The tracks represent actual jet aircraft tracks. Flight paths do change over time (although will be largely restricted within the High Noise Corridor), and as aviation grows into the future, more tracks will be observed. Examples of recent changes to flight paths include RNP offset approach procedures that curve around houses in the High Noise Corridor at Jerrabomberra, approximately halving the noise for those aircraft and new automated arrival and departure procedures which keep aircraft in the High Noise Corridor for longer and reduce high-level overflight of residents in Gungahlin and Tuggeranong.
However, the map does not show the noise impact of each aircraft, which can be better understood by examining single event noise exposure levels. The actual noise exposure levels vary by aircraft, and disperse over a far wider area than the actual tracks, as shown in the following section.
Single event noise exposure contours
Another valuable tool in visually representing the noise caused by aircraft is provided by single event contours. These contours represent the noise created by individual aircraft on a particular flight path. Below are two diagrams, which show the cumulative noise impact created by 737-400 and 767-300 aircraft operating in and out of Canberra Airport using current flight paths. These maps show clearly how high levels of aircraft noise are concentrated within the High Noise Corridor and why land within this area is inappropriate for residential development.
The Commonwealth Government has stated that 65 to 70dBA is the level at which noise becomes intrusive and that residents in these areas will therefore actively seek respite through operational changes as the Airport grows and the frequency of flights increases over time. At general aviation airports, noise can be a problem from 60dBA. In and around Canberra, some residents exposed to less than 60dBA are still calling for additional noise respite measures.
As a solution to the inherent uncertainty created by varying aircraft tracks and the differing noise made by different aircraft, following extensive consultation Canberra Airport has developed a High Noise Corridor within which no residential development should occur. The High Noise Corridor not only caters for current aircraft activity but looks to the future, protecting future residents from increased aircraft activity as Canberra Airport grows to meet future demand.
Noise and flight path monitoring system
Airservices Australia commenced operation of a Noise and Flight Path Monitoring System (NFPMS) at Canberra Airport in June 2002 following extensive public pressure to have the system installed. The pattern of aircraft flight tracks described by this System has been made available to the public and is published quarterly on the Airservices Australia website. Reports are made to meetings of the Canberra Airport Aircraft Noise Consultative Forum by Airservices Australia.
Australian Noise Exposure Forecast (ANEF)
Click here for more information on Australian Noise Exposure Forecast (ANEF)
