1. What is WARRP?
The Western Australia Route Review Project (WARRP) was a comprehensive review of airspace use, flight routes and aviation procedures across Western Australia. The review was undertaken by Airservices between 2006 and 2008. Changes were implemented in November 2008.
2. Why were changes needed?
Air traffic in WA, and particularly around Perth, has experienced massive growth since 2000, mainly as a result of the mining boom. There has been a 60% growth in air traffic in the past five years alone at Perth Airport.
In addition, airspace around Perth is extremely complex. Large areas close to the metropolitan area are used by the military for flight training and other exercises. Military use of this restricted airspace has increased over the past decade, reducing its availability for civilian air traffic.
Perth’s second airport, Jandakot, is one of the busiest airports in Australia, with more aircraft movements than Perth Airport. Virtually all of this traffic is light aircraft. There has been a significant increase in flight training activities at Jandakot in recent years.
These factors resulted in congested airspace and complex air navigation procedures which had the potential to impact on safety.
Large and small aircraft were also sharing two-way approach and departure routes, at times heading towards each other but at different heights.
3. Why was WARRP implemented?
Australia’s aviation safety regulator, the Civil Aviation Safety Authority, conducted an audit of airspace use in WA in 2003. As a result of the audit, changes were needed to maintain safety, reduce complexity, and to effectively manage the increased demand for air travel, other aviation services and military flying.
Airservices completed a project to co-locate military and civilian air traffic controllers in the same facility at Perth airport in 2005.
As the nation’s air navigation services provider, Airservices was then required to review and change procedures and flight routes across WA to ensure the ongoing safety of aircraft operations.
4. What benefits has WARRP delivered?
- Aircraft are operating more safely in the Perth area. The changes separated jets from slower turbo-prop and light aircraft, and removed two-way routes on which aircraft arrived and departed simultaneously, creating the potential for conflict
- Airspace has been configured to safely manage the ongoing, increased levels of air traffic in WA and around Perth in particular
- Aircraft using the new procedures are using less fuel, reducing CO2 emissions
- Heavily populated areas to the west of the airport have less exposure to aircraft noise than previously
5. Are there new flight paths? Where are they?
Most changes took place well outside the Perth greater metropolitan area, in rural WA.
Closer to Perth airport, aircraft arriving from the north and intending to land on Runways 03 and 06 (also to the north) now follow a new route to the east of the airport before turning to land.
There were aircraft flying in this area before, but less frequently. These aircraft are now flying more precise routes due to improvements in navigation technology and performance.
Traffic has increased on some approach and departure routes around Perth and decreased on others. Some routes have also been eliminated altogether and are no longer used.
For an overall comparison of new, old and unchanged flight routes for various runway use configurations at Perth airport, refer to these maps.
As with all flight routes, variations do occur based on weather (including seasonal winds), operational needs, the time of day and the availability of military airspace.
6. How have the changes affected aircraft noise distribution?
Heavily populated areas to the west of the airport are now receiving less overflights than before November 2008. A number of flight paths in these areas are no longer used.
Some areas which were previously overflown regularly by jet traffic on arrival and departure now have less exposure to aircraft noise due to the introduction of more precise flight paths. There has also been an overall reduction in the number of flight paths over the city and surrounding metropolitan area.
The introduction of one-way routes also allows aircraft to use constant climb or descent profiles, reducing the overall noise exposure compared to previous operations.
For a visual comparison of areas affected by aircraft traffic, before and after November 2008, refer to these maps below.
They provide an indication of the flight paths taken by approaching and departing jets. Each line on the map represents an individual flight. The colours represent the height of the aircraft at different points on its track.
- Jet Departures: December 2007 v December 2008
- Jet Arrivals: December 2007 v December 2008
- Jet Departures: March 2008 v March 2009
- Jet Arrivals: March 2008 v March 2009
Airservices also publishes quarterly Noise and Flight Path Monitoring System reports for Perth. These provide more detailed information on runway use and air traffic.
7. Why are more aircraft flying over my area constantly?
The air traffic ‘density’ (the number of aircraft flying a particular route) is not permanent – it will change over a period of days, weeks, and months. This depends on which runways are in use at the airport – itself a product of the time of day, weather, seasonal and other operational factors such as when military airspace around Perth is unavailable to civilian traffic.
For example, between January and March 2009, 80% of aircraft movements in and out of Perth used routes that were in place before November 2008. 20% of arrivals and departures used new procedures and routes.
The proportion of flights using the new routes is expected to increase during winter months due to changes in prevailing winds. However, it should decrease again in the warmer months.
Aircraft are also able to depart and arrive at Perth Airport at any time, day or night. The scheduling of flights is the responsibility of the airport and airlines as they seek to meet consumer demand and is not a matter for Airservices.
8. Are aircraft flying lower over my area?
No aircraft are flying lower as a result of the changes. In many cases, aircraft are flying higher over a given area due to improvements in aircraft navigation performance which allow a faster descent to the runway from closer to the airport.
From 2008 to 2009, up to 18% of turbo-prop aircraft regularly flying into and out of Perth have been replaced by jet aircraft as passenger numbers and demand for air travel has increased. The increase in flights, especially jets, may have made aircraft movements more noticeable as there are more larger aircraft in the skies.
It is possible to determine how high aircraft are over a particular location, house, or property using WebTrak.
9. What is WebTrak?
WebTrak is an Airservices initiative which allows you to observe, via the Internet, aircraft movements in near-real time at eight airports around Australia, including Perth. WebTrak provides information about individual aircraft such as aircraft type, altitude, destination and noise levels, and plots their position on a map.
10. My area seems to have recently had a large increase in aircraft with no warning – why?
Weather and seasonal factors play a large role in runway selection and arrival and departure patterns in Perth.
For example, in the winter months, prevailing winds mean most aircraft land from the south. This brings aircraft arriving from the north over the hills to the east of Perth before turning to land.
In summer, aircraft will land from the south during the hot northerly winds but in the afternoon and evening prevailing sea breezes mean more aircraft land from the north. This reduces the proportion of aircraft using the new arrival path to the east of the airport.
But as aviation is weather dependent, it is difficult to predict which route will be in use at a given time – weather and particularly wind can change at short notice, increasing traffic over certain areas while reducing it in others.
11. Why can’t aircraft fly over non-residential areas?
All capital city and busy regional airports have to balance the needs of nearby residents and the safe operation of aircraft.
Airspace around Perth is complex. In particular large areas close to Perth are controlled by the military, with access by civilian aircraft either restricted or completely prohibited. This means the air corridors available to access Perth Airport are limited.
Some flying over residential areas is unavoidable, but the flight path structure aims to minimise aircraft noise impacts on residents as much as practicable without compromising safety.
The changes introduced in Perth in November 2008 have moved a proportion of arriving aircraft from over more densely populated areas to the west of the airport to less populated areas to the east. In this situation, Airservices has made maximum use of airspace over national park and farmland within the constraints outlined above.
12. What consultation did Airservices undertake?
Airservices followed a consultation model we employ nationally for airspace reviews.
In Perth, this involved consultation with the Perth Airport Noise Management Consultative Committee. The committee includes representation from local Members of Parliament, councils, community representative groups and the Western Australia Government.
For more information about the committee and its role, visit the Perth Airport website.
Airservices also continually updated local councils in the Bayswater, Belmont, South Perth, Canning, Gosnells, Mundaring and Kalamunda areas throughout the review period.
13. Why were no other local councils involved?
Airservices consulted those councils whose residents could be most affected by the proposed changes. Under noise exposure guidelines, this is generally in areas close to the airport where residents are most likely to be affected by frequent, low-flying aircraft.
Further away, aircraft are flying at heights generally accepted not to cause significant noise (less than 70 decibels outdoors or less frequent overflights).
For example, on approach routes to the east of the airport, jet aircraft are generally at or above 5000ft (more than 1.5km high) before turning west and descending to land.
Noise impacts and their calculation and effects are explored in a study conducted by the Department of Transport and Regional Services in 2000, Expanding Ways to Describe and Assess Aircraft Noise (refer to pages 23-35).
14. What information did Airservices provide relating to the changes?
Airservices provided detailed information on new arrival and departure routes, and potential noise implications, to the Perth Airport noise committee in October 2006. We continued to update the committee on progress at meetings throughout 2007 and 2008.
Detailed maps were published on the Airservices website and comment sought from airlines, other airport and airspace users, Government and the community.
We also took submissions, questions and feedback and provided supplementary information via email and mail.
15. Why was there no public announcement of the changes?
Airservices is constantly reviewing airspace nationally to ensure procedures and routes are safe. Consultation occurs with airports, airlines, the wider aviation industry and other key stakeholder groups. This is an ongoing process – changes are discussed and made over time and implemented by publishing air navigation advisories and charts as required.
Airservices established a dedicated portal on its website containing information relating to the changes in WA in 2006.
We also issued a media release announcing the changes to all major newspapers, radio and television stations nationally, including those in Perth, on 21 November 2008.
16. Does Airservices have to minimise noise impacts?
Our first priority is the safety of aviation. According to the Air Services Act 1995:
“…in exercising its powers and performing its functions, Airservices Australia must regard the safety of air navigation as the most important consideration”.
This is clearly the community’s priority as well.
With safety as the highest priority, we work to minimise the environmental impacts of aviation. This includes reducing noise impacts where possible and introducing environmentally-friendly approach and departure paths to reduce noise, fuel consumption and CO2 emissions.
17. Where can I get more information?
Airservices is committed to providing information to the community.
We also monitor community concerns and complaints and work with all stakeholders to minimise noise impacts wherever possible.
Our Noise Complaints and Information Service can provide information or log complaints about specific incidents, aircraft and flight routes.
If you would like a response to your inquiry or complaint, please indicate this when contacting us and ensure you provide contact details.