FAIL 1: Environmental self-assessment

What Airservices is required to do


To comply with its obligations under the Environment Protection, Biodiversity and Conservation Act 1999, Airservices Australia is required to determine whether its actions will have a significant impact on the environment.

This includes deciding whether:

"there is a real chance or possibility that the action will ... affect the health, safety, welfare or quality of life of the members of a community, through factors such as noise, odours, fumes, smoke, or other pollutants"

If it concludes that a proposed action, such as a flight path change, is likely to have a significant impact it is required to refer the matter to the relevant Minister for advice.


Airservices conducted a brief environmental self-assessment, which included very simple noise modelling.

The report concluded that the new routes "are not likely to result in any significant environmental impact within the meaning of the Environmental Protection and Biodiversity Conservation Act 1999 [which includes noise impact]" (p 18)

As a result, Airservices gave itself permission to go ahead with the flight path.

We believe this conclusion should not have been made because:

  1. The self-assessment failed to apply an appropriate standard for noise assessment
  2. The self-assessment failed to consider the nature of the communities newly overflown
  3. The modelling used the impact of past air traffic levels not future

Had Airservices taken the time to conduct a proper noise assessment and a simple Google search about the newly overflown areas, it would have realised the path would be likely to have a significant impact on residents. See more below.


Airservices's environmental self-assessment was sloppy, self-serving and irresponsible. As a consequence of its negligence, residents and businesses are now suffering significant impact from the new flight path.

1. The self-assessment failed to apply an appropriate standard for noise assessment


We believe that inappropriate noise modelling seriously undermines the self-assessment, calling into question its conclusions.

The report uses a computer model known as the INM, developed by the US-based Federal Aviation Administration (and superseded in 2015) to estimate the noise made by different types of planes at various point along their arrival and departure paths. It compares these noise levels with parameters derived from Australian Standard 2021-2015 Acoustics Aircraft Noise Intrusion Building Siting and Construction, used for construction of new buildings - not changes to flight paths. The preface to the Standard states:

Some experience has shown that communities that are newly-exposed to aircraft noise (e.g. as a result of the construction of new runways, or the redesign of flight paths near an aerodrome) tend to be more sensitive to such noise than communities that are accustomed to it. Land use planning must by necessity use a long-term horizon, and the building siting acceptability recommendations in this Standard are based on the reactions of noise-accustomed communities. Regulatory authorities are cautioned that a transient heightened reaction could result from substantial new noise exposure.

Airservices failed to heed the warning in the noise model standard it applied.

This Standard specifies that a noise level of 60 dB(A) is 'the sound pressure level of a noise event that is likely to interfere with conversation or with listening to the radio or the television'.

The model makes a blanket assumption that any noise event lower than 60dB is acceptable, irrespective of background noise (p 9). For example, it assumes that noise from an aircraft flying over Melbourne's Bourke Street Mall will have a similar noise impact as the same aircraft flying over a quiet rural area. Using the INM, Airservices estimated that an arriving 737-800 jet would create noise of 58dB(A) on the ground at Dunalley Primary School, 35km from the airport. Therefore Airservices deems this to be an acceptable level of noise, irrespective of frequency.

Airservices disregarded the real impact of noise the new flight path would have on newly overflown communities.

2. The self-assessment failed to consider the nature of the communities newly overflown

The Commonwealth government's Significant Impact Guidelines 1.2  requires that agencies whose actions may have an impact on the environment should consider whether the proposed action will affect 'the health, safety, welfare or quality of life of the members of a community, through factors such as noise, odours, fumes, smoke, or other pollutants'.


In determining this, the Guidelines require that agencies should take into account:

  • the components or features of the environment in the area where the action will take place
  • whether the environment, or elements of it, are sensitive or vulnerable to impacts - this can include the location of schools and hospitals, and whether the area has cultural or tourism values
  • the area's history, current use and condition

The communities in the affected areas - Kellevie, Copping, Bream Creak, Marion Bay, Boomer Bay, Dunalley, Murdunna and Connelly's Marsh -  are still in recovery from the 2013 bushfires, and are sensitive to factors such as environmental noise from jets.

The area also has 'special value' as a tourist area of the kind mentioned in the Guidelines, due to its quiet coastal environment, and the presence of tourism businesses and activities (Bream Creek Show, Falls Festival, plus several wineries and B&Bs). Since the destruction of the timber mill in the fires, the area increasingly relies on tourism for its economic sustainability. Dunalley Primary School, which has only recently reopened, is the heart of the community - and yet it is now directly overflown at low altitude by up to 30 flights per day.

The Guidelines say that the self-assessment should 'seek further information about the environmental context to increase your understanding of the likely impacts'.

A simple Google search would have revealed information about the fires, the school and about the area's tourism values, eg:




Given the scale of the change - arguably the largest to airspace around Hobart in 60 years - it was incumbent on Airservices to seek further information about the communities its actions were to affect.

Instead, Airservices completely disregarded the Commonwealth Guidelines, and the impact the flight paths would have on newly overflown communities.

3. The model looked at the impact of past air traffic not future air traffic

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Airservices said that the change was made, in part, because of predicted increases in air traffic at Hobart Airport. However, its modelling was based on a single day sample taken on Hobart Airport's quietest time of year.  on a single day Tuesday, 3 May 2016, on which there were 24 arrivals and 23 departures in total. It is unclear why this day was chosen, however it is in Tasmania's off-peak tourist season when there generally are less flights, and smaller aircraft in use.

By contrast, the the Commonwealth Guidelines state that agencies should 'Make conservative conclusions (that is, assume that the effect is more rather than less adverse)'.

During the Spring and Summer months, there are over 30 commercial jets scheduled to arrive each day, plus general aviation traffic including Air Ambulance, freight and Antarctic flights. On 27 December 2017, Hobart Airport recorded one of its busiest day ever, and is predicting further increases in future, including larger cargo and international passenger planes, which can arrive at any time of the day or night.

Airservices should have used predicted traffic to determine noise impact (similar to the noise modelling carried out for the Hobart Airport Masterplan), not past traffic.

Instead, Airservices deliberately underestimated the volume of air traffic in order to minimise the predicted noise impact.