You might find the info on this site useful and interesting. http://www.airservicesaustralia.com/wp-content/uploads/Moorabbin-Airport-Noise-Information-Pack.pdf The impacts of aircraft noise Although the terms ‘noise’ and ‘sound’ are used interchangeably, the term noise is often used to refer to an unwanted sound which can impact on the quality of life. The term sound refers to pressure variations travelling through the air and is measured on a logarithmic scale with the decibel (dB(A)) as the unit of measure. The sound level of typical daytime urban-based activities can vary between 40dB(A) and 80dB(A). Residents living near the airport can be exposed to the impacts of aircraft noise and this can affect people in different ways. Aircraft noise is influenced by a number of different factors such as how far away an aircraft is, power of the engine and placement of exhaust (muffler) where fitted, humidity, air density and cloud cover. These factors can impact on how sound behaves, for example noise waves from an aircraft can travel up to 10km.
Generally, noise from departing aircraft is greater than that of an arriving aircraft. On departure, the noise level experienced on the ground is influenced by a range of aircraft factors such as the type and size, rate at which it climbs and the way it is flown by the pilot. Improvements in aircraft engine and airframe technologies have resulted in modern aircraft being more efficient and quieter. From an aircraft noise perspective, Australia has one of the most modern fleets of any country.
Noise Abatement Procedures Noise Abatement Procedures (NAPs) are designed to help reduce the impact of aircraft noise on the community. These procedures are comprised of preferred runways, preferred flight paths and noise abatement areas. NAPs are included in the Aeronautical Information Publication (AIP), a package of documents which provides all of the operational information necessary for the safe and efficient conduct of air navigation throughout Australia. NAPs are implemented by Air Traffic Control, however, their use is not mandatory and subject to factors such as extreme weather conditions, safety and pilot requirements. All aircraft are expected to observe the NAPs outside of tower hours of operation. Moorabbin Airport currently operates a Fly Friendly Programme (see attachment 1). The program encourages pilots to operate in a manner which is considerate of local residents and outlines a number of noise abatement procedures such as: - Delayed turns for departing aircraft to minimise noise intrusion over residential areas over Parkdale - Preferred runways outside of tower hours which are the least noise sensitive - Runway operation restrictions e.g. use of jet aircraft may be restricted to only certain runways - Restrictions on certain training procedures to avoid noise over residential areas - Procedures to minimise noise emissions from ground running