Why do aircraft fly where they do?

Flight paths

Flight paths can be considered ‘highways in the sky’. They define three-dimensional routes or corridors that aircraft use to arrive or depart from an airport.  Flight paths are often shown as a single line on a map, however, unlike a train on a railway line or a car on a highway, it is not always possible for aircraft to follow precisely along the line depicted.  In practice, a flight path can vary up to several kilometres or more.  This occurs for a range of reasons, including:

  • weather conditions,
  • requirement to keep a safe distance between aircraft in the sky, and
  • pilot and aircraft performance.

Variations in aircraft tracking within the corridor can lead to the perception, when viewed from the ground, that aircraft are flying on the ‘wrong’ or a ‘new’ flight path, which is rarely the case.  Over time, as navigation technology has improved, these corridors have generally been getting smaller.

Every runway at Perth Airport has a number of flight paths which are used depending on:

  • type of aircraft,
  • volume of traffic,
  • type of navigation aid being used, and
  • current weather conditions.

All flights paths are developed and implemented by Airservices as the national operator of civilian airspace management across Australia.  The airspace operated by Airservices however is approved and regulated by the Office of Airspace Regulation, which is part of the Commonwealth Civil Aviation Safety Authority (CASA).  In developing flight paths, consistent with International standards, Airservices takes into account:

  • safety and minimising the risk of aircraft conflicting in the sky,
  • minimising air track miles,
  • fuel consumption and associated carbon impact, and
  • noise impact on urban areas.

In developing the flight paths, Airservices will determine additional options to maintain and have approval, through the Office of Airspace Regulation, as many routes as possible to provide appropriate operational flexibility.

Take-off and landing

For safety, aircraft must take-off and approach into the wind as much as possible.  This assists the aircraft with producing lift, provides more control and reduces the amount of runway required. Therefore, the wind direction generally dictates which runways are used at Perth Airport.

Approaching the runway

For safety, it is important that the manner in which pilots approach a runway is similar around the world.  Arriving aircraft will generally approach a runway in a relatively straight line from around three to four kilometres from the runway end and at a three-degree angle.  This three-degree ‘glide path’ follows a line that descends about 100m every two kilometres.

Residential areas under these approaches will also be under the flight path of aircraft taking off.  There are no alternatives to this.

For further information click here.

Print a summary of noise in your area

Below you will find a printer friendly report that summaries the current and future noise exposure available in your area.

To set a specific street address rather than the suburb already selected, please click ‘Choose new location’.

Please note the property report is not currently compatible with Internet Explorer 11 and is best viewed using Google Chrome or Safari.

What are typical aircraft operating at Perth Airport?

The information below will help you identify the types of aircraft that regularly operate from Perth Airport.  These aircraft types represent over 80% of all aircraft movements at Perth Airport.

Bombardier
Dash 8
British Aerospace
146/RJ100

Fokker
100

Boeing
717-200

Airbus
A320

Boeing 737-800

Airbus A330

Boeing 787

Boeing 777
Airbus A380

What is noise?

Sounds are vibrations through the air or other medium that are received and interpreted or ‘heard’ by a person or animal. Whereas ‘noise’ can be simply defined as unwanted or unpleasant sound.
Sound is measured in decibels (dB) and is represented on a non-linear (logarithmic) scale. This means that a person would have difficulty noticing a change in 1 or 2 dB while a 10 dB change in noise levels effectively reflects a doubling or halving of loudness.
Sound sources that have similar intensities will generally sound equally loud. For example, it would be difficult for a person to distinguish between the sound levels of a loud cafe (70 dB) from that of a passing car (70 dB).
The human ear is less sensitive to low audio frequencies so instrument measured sound levels are typically ‘A-weighted’ to mimic the response of the human ear to sound. This is indicated by adding (A) to the dB unit and expressed as dB(A).
The majority of aircraft noise is generated by the engines and from aerodynamic drag on the airframe and wings. The amount of noise produced by an aircraft depends on a range of factors including:

  • aircraft size and weight,
  • number and type of engines,
  • thrust setting,
  • speed, and
  • altitude and distance.

Atmospheric conditions can also have a significant impact on the distance and intensity that sound can be transmitted through the air. Passenger aircraft are typically loudest on take-off when weight and thrust settings are high and during landing when thrust settings are varied and landing gear and other drag producing components are extended.

 

What are Perth Airport and industry doing to manage the impacts of aircraft noise?

Perth Airport has adopted the International Civil Aviation Organisation’s (ICAO) recommended ‘balanced approach’ to aircraft noise management for managing noise in the vicinity of the airport.  The balanced approach consists of identifying the noise issue at an airport and then analysing the various measures available to reduce noise.  The four principal elements of the ICAO balanced approach are:

  • reduction of noise at source,
  • land use planning and management,
  • noise abatement operational procedures, and
  • operating restrictions.

In collaboration with Airservices Australia, airlines, and other key stakeholders Perth Airport is developing a new comprehensive Aircraft Noise Management Strategy (ANMS) and action plan.  The new ANMS builds on the ICAO balanced approach to aircraft noise management.  In addition to a clear objective, the new plan is based on six key themes:

  • identifying opportunities for improvement,
  • community engagement,
  • working with industry to achieve better outcomes,
  • land use planning,
  • continuous improvement, and
  • new runway planning.

The themes establish the framework for the action plan which will outline individual actions and priorities for managing, and where possible, reducing aircraft noise as well as methods for monitoring and communicating performance.

Airservices has released their Commitment to Aircraft Noise Management document that outlines how Airservices intends to collaboratively address the impact of aircraft noise.