Aircraft noise is the most significant cause of adverse community reaction related to the operation and expansion of airports. This is expected to remain the case in most regions of the world for the foreseeable future. Limiting or reducing the number of people affected by significant aircraft noise is therefore one of ICAO’s main priorities and one of the Organization’s key environmental goals.

The main overarching ICAO policy on aircraft noise is the Balanced Approach to Aircraft Noise Management, adopted by the ICAO Assembly in its 33rd Session (2011) and reaffirmed in all the subsequent Assembly Sessions (reference: ICAO Resolution A39-1 Appendix C). Detailed guidance on the application of the Balanced Approach is provided in  the ICAO Doc 9829, Guidance on the Balanced Approach to Aircraft Noise Management. 

The Balanced Approach consists of identifying the noise problem at a specific airport and analyzing various measures available to reduce noise through the exploration of various measures which can be classified into four principal elements, described in Figure 1. The goal is to address noise problems on an individual airport basis and to identify the noise-related measures that achieve maximum environmental benefit most cost-effectively using objective and measurable criteria.

ICAO Current initiatives on Aircraft Noise

Continuous work is being conducted by ICAO to ensure the currency of the technical basis underpinning the ICAO Standards, guidance and policies associated with reducing aircraft noise. This work includes, among several topics, investigations into emerging noise reduction technologies, noise impacts from new aircraft concepts (e.g. Unmanned Air Vehicles), and the development of SARPs for future supersonic aeroplanes. ICAO is also working on the environmental aspects of airport land-use planning, and good practices on airport community engagement.

As part of the ICAO Global Environmental Trends, ICAO has been assessing trends in global exposure to aircraft noise which provide a basis for sound discussion and decision-making on aircraft noise policies. Additionally, noise technology goals have been developed, in a with the purpose of providing stretch yet reasonable targets for industry R&D to aim at, in cooperation with States. More details on these ICAO initiatives on aircraft noise are provided in the following pages:

• Noise Trends

• Technology Goals

• Noise Reduction Technologies​​

• Community engagement for aviation environmental management​

• Supersonic Aircraft Noise Standards Development​

• CAEP WG1 Work

• New aircraft concepts (Remotely piloted aircraft, urban air mobility, drones)

  Local Air Quality

  One of ICAO’s environmental goals is to limit or reduce the impact of aviation emissions on local air quality (LAQ). Starting during the late 1970s, ICAO has been developing measures to address emissions from aircraft engines in the vicinity of the airport and from relevant airport sources. Volume II of Annex 16 to the Convention on International Civil Aviation contains Standards for aircraft engine emissions and is accompanied by related guidance material and technical documentation.

  Following the latest successful adoption of the CAEP/10 nvPM Standard based on visibility criterion, CAEP/11 agreed on nvPM mass and number Standard, which will be considered for adoption by the ICAO Council in the next year.

  ICAO provisions on LAQ also address liquid fuel venting, smoke (which is expected to be superseded by the nvPM Standard), and the main gaseous exhaust emissions from jet engines, namely: hydrocarbons (HC), oxides of nitrogen (NOx), carbon monoxide (CO).

  More details on the ICAO initiatives on LAQ are provided in the following pages:

  • Technology Standards
  • Technology Goals
  • Trends in Local Air Quality
  • Guidance on Airport Air Quality