Chapter 7—A Way Ahead—A Suggested Initial Approach

Index 1 2 3 4 5 6 7 References App A App B App C

Where do we go from here? Subject to the discussion generated and feedback received on this paper the Department is proposing that we now essentially put in place a new aircraft noise information regime in Australia. It is proposed that this regime be based on the principles discussed in Section 7.1 and that the actions identified in the subsequent Sections be initiated.

7.1 Broad principles

Examination of the issues raised by this paper has led us to conclude that we now need to work toward an aircraft noise information regime based on the following broad principles:


  • communicating in ‘everyday’ language
  • using information that can be easily verified by the layperson


  • not excluding people from information because the ‘Standard’ indicates noise is not a problem


  • placing the individual in a position where they can form their of the individual of the individual of the individual of the individual of the individual own view on the acceptability of future noise

There are four key areas that need to be balanced in publishing aircraft noise (and most other) information: completeness; accuracy; comprehensibility; and timeliness. In recent years it appears that the emphasis in providing aircraft noise information has been placed almost totally on trying to achieve technical accuracy/completeness (not geographic completeness) at the expense of the other factors.

Unfortunately the drive to get the ‘right’ answer inevitably leads to more complicated indicators which make them less comprehensible and less accessible to the layperson—this in effect is what appears to have happened as the ANEF has evolved.

It goes without saying that if any information is to be trusted by the community it must be accurate but by the same token it must be comprehensible to the audience it is intended for. Information may be totally accurate but it is likely to be very misleading if it cannot be fully understood.

In our experience public confidence in the ‘correctness’ of information can be improved if the indicator being used can be monitored by a member of the public without any special equipment or expertise to check its accuracy. The relational noise indicators in this paper lend themselves to this type of verification.

While the thrust of this paper has been toward making aircraft noise information more transparent and accessible to the general public the need to make aircraft noise information comprehensible to decision makers is equally important.

Decisions on the design of airspace arrangements on the location of airports or the orientation of runways are fundamental to the patterns of community noise exposure. However the persons charged with responsibilities for these decisions are rarely noise experts and have to largely rely on technical advice. Clearly if the decision maker has information like the relational indicators shown in this paper it enables him/her to gain a real ‘feel’ for what is the likely outcome of their decision. It places the decision maker in a much better position to ask the ‘right’ questions of their technical advisers.

back to top

7.2 Regular publication of area wide relational noise information

The Department considers that a constructive dialogue between airports and their surrounding communities would be facilitated by airports producing area wide regular transparent and widely distributed reports on aircraft operations and noise.

Implementation of this action would for example as argued in Chapter 6 lead in the long term to a lower number of noise sensitive people moving into areas where there is audible aircraft noise than would otherwise be the case. There would also be much less likelihood of persons feeling misled by airport information.

To date supplementary relational noise indicators such as those shown in this paper have been used on an ad hoc basis in Australia in response to circumstances where the interested parties have demanded information that goes beyond the ANEF.

Many Australian airports continue to only provide information on noise exposure patterns through the publication of ANEF contours. This may be a reflection of the fact that the production of an ANEF is formally required under the provisions of the Airports Act 1996 and State and Territory planning instruments. However this requirement relates to the use of the ANEF as a planning tool. In the context of the arguments presented in this paper about the use of the ANEF as an information tool an ANEF map is particularly deficient in that it provides no information on noise exposure patterns beyond the 20 ANEF. It is considered that this can only work against the long term interests of both the airport and those noise sensitive members of the community.

It is proposed to encourage and assist all airport operators to prepare and make available to as wide an audience as appropriate for each airport the types of information presented in this paper. The Department is happy to make available to all airport operators (and any other interested party) the routines developed to prepare the noise information described in this paper and to assist those bodies to establish systems for the preparation and publication of regular relational noise information reports.

back to top

7.3 Review and revision of Australian Standard AS2021

Australian Standard AS2021 needs to be reviewed and revised to incorporate recommendations for the production of area wide relational aircraft noise information. This would facilitate mandatory publication and dissemination of such information through relevant authorities picking up the Standard.

Australian Standard AS2021 clearly has a key role in the area under discussion in this paper. Unfortunately some of the messages it has conveyed have not been helpful and it is considered important that the Standard now be thoroughly reviewed so that the role of the ANEF as a land use planning system is clarified.

In the first instance it is considered important that the wording ‘acceptable’ and ‘unacceptable’ in the Standard be replaced by more objective terms such as ‘no building restrictions’ or ‘building not permitted/recommended’. As discussed at a number of points in this paper what is considered to be ‘acceptable’ by the Standard is not necessarily ‘acceptable’ to the individual.

It is considered essential that in a revised Standard a clear differentiation be made between ‘aircraft noise information’ and ‘land use planning controls’. Ideally the ANEF in future will be treated solely as a (noise based) land use planning line and it will no longer be used as a primary aircraft noise information tool. The best approach to achieve this goal may even ultimately be to produce two Standards—one for land use planning and one for aircraft noise information.

back to top

7.4 Further studies

The Department considers that it would be productive to carry out further specific work or studies directed at

  • the verification of N70s
  • the development of further relational noise indicators
  • the use of the Internet for disseminating aircraft noise information.

7.4.1 N70 verification study N70

The US FAA Integrated Noise Model does not allow direct computation of the N70 and therefore the Department has developed a system for computing these indirectly from the model (see Appendix B).

As far as is known no other country is routinely producing and publishing N70 contours. Very importantly a fundamental aim of the published N70s is to give information to communities relatively distant from an airport. Accuracy will drop off with distance from an airport. Given this it is not clear how much confidence can be placed on the contours and they are normally treated as being ‘indicative’.

While informal accuracy checks are very positive (see Appendix B) it would be beneficial if an independent study were carried out into the contours to ascertain the level of confidence that can be placed in them.

back to top

7.4.2 Development of other relational noise indicators

Clearly this paper does not represent the end of the road—it shows the current state of play. Undoubtedly significant improvements could be made to the presentations in this paper. For example there are many alternative ways in which the ‘average day’ and ‘sensitive times’ shortcomings of the current approaches could be addressed. The graphics in the flight path movements charts could be enhanced to indicate altitude or the density of flight path spreading.

There may therefore be merit in carrying out a special study involving consultation with all interested parties to ascertain whether the current range of relational indicators we have developed can be expanded and to decide on the best way to refine and enhance the indicators now in use.

back to top

7.4.3 The Internet

The Internet is largely an untapped tool for promulgating information on aircraft noise in Australia at the present time. There would appear to be a major potential for using the Internet to provide ongoing current aircraft noise exposure information using relational noise indicators for all major Australian airports.

By way of example the Department is now looking at ways to adapt the flight path movement charts shown in Chapter 2 for the Internet. It is proposed that the charts will include animation and will allow querying of information about movements on each of the flight paths.

Some airports have already moved to establish very good web sites and put relevant operational and noise information on the site for the community to access.

Clearly this is going to be a very fruitful area of further work.


Last Updated: 9 July, 2014