In the past three decades, noise footprints at many major airports around the world have decreased significantly. This has been achieved mostly by improvements in aircraft technology, i.e. by the introduction of quieter high bypass ratio engines and improved air frames, and improved operational procedures such as continuous decent.
Airports have also mitigated the impact of aircraft noise on the ground through extensive programmes to provide noise insulation to homes, schools and hospitals.
Aircraft noise is the most significant cause of adverse community reaction related to airports’ license to operate and grow. And as airports around the world prepare to accommodate growth in air service demand, limiting or reducing the number of people affected by significant aircraft noise is a shared priority for airports, the aviation industry and regulators, including the International Civil Aviation Organization (ICAO).
In fact, ICAO’s Annex 16 Volume 1 has 246 pages several chapters dedicated to noise Standards. The continued introduction of aircraft certified to the new Chapter 14 noise standard is expected to reduce the number of people affected by significant aircraft noise and that more than one million people could be removed from Day Night average sound Level (DNL) of 55 dB affected areas between 2020 and 2036.
However, new challenges are arising. Recently, progress on aircraft noise at source has been offset by increases in traffic and the introduction of larger aircraft. It has also become more difficult to identify new ways of improving the noise performance of aircraft and therefor aircraft noise technology advancements have slowed down. The result has been increases in cumulative noise levels at some airports.
In addition, the implementation of Performance-Based Navigation (PBN) has brought an additional layer of complexity to aircraft noise management. PBN offers several benefits including, fuel efficiency, capacity, flexibility in routings, safety, predictability as well as the possibility for noise improvement. However, it also presents challenges, since while it can reduce the number of people affected by noise since the concentration of noise over a smaller area increases the intensity, and thus the negative perception of aviation.
ACI and our airport members are aware of the developments concerning the manufacturing and eventual use of supersonic aircraft for business jets and commercial aeroplanes. ACI supports the development of new technology, but the noise and emissions standards for supersonics must be stringent enough that they do not compromise the work we have been doing for decades.
Properly assessing the noise impact of supersonics on communities will be important to support States in defining their policies regarding public acceptability of supersonics and facilitate their decision regarding Standards and Recommended Practices.
Community annoyance is a complex issue. The way residents perceive noise includes a level of subjectivity that cannot be fully explained based solely on acoustic factors. Non-acoustic factors include the level of trust residents have in the airport or authorities in general, as well as their attitude towards aviation. Research shows that acoustic factors are responsible for only about 30% of annoyance.
Despite this, government policy and aircraft noise management have mostly focused on measures to reduce noise exposure. ACI advocates that in order to properly address aircraft noise annoyance, it is necessary to study the remaining 70% of variables responsible for community annoyance.
As the aviation industry grows and evolves, it must also provide effective noise management with workable solutions for all stakeholders. While we have come a long way as an industry in this regard, new challenges are demanding a new and broader perspective that has communities at the heart of the matter.
While we continue to improve our technology and provide effective noise insulation, we must also strengthen our community engagement. This includes beginning early in the process of new projects, having transparent communication, knowing the community, developing a tailored engagement plan, and going well beyond the minimum requirements.
London Gatwick Airport, through their Noise Management Board, serves as a prominent example of going above and beyond. It was set up with the purpose to develop, agree, oversee and maintain a coordinated noise management vision and subsequent strategies for the airport on behalf of stakeholder organizations, with the main aim of reducing the impact of noise on the local community.
Managing our noise impact is vital to safeguarding airports as drivers of economic and social benefits for the local, regional, and national communities they serve, particularly in the face of forecast growth. The continued sustainability of airports will in large part depend on this.