New innovative technologies and energy sources for aviation are under development in a fast pace, and ICAO is closely following up these developments to prepare for their timely environmental certification, as appropriate. In that regard, ICAO is maintaining the E-HAPI, a website with a non-extensive list of ongoing projects that have been identified globally.

Specifically on aircraft noise, ICAO is following up possible environmental issues from the operation of Emerging Technology Aircraft (ETA), including urban air mobility concepts, unmanned aircraft and remotely piloted aircraft. States and Stakeholders are invited to contact us at officeenv [at] icao.int (officeenv[at]icao[dot]int) and share experiences in responding to these aircraft noise issues. This information will be consolidated as a potential best practice guidance for States.

Related Events 

• QuietDrones 2022, June 27-30, 2022
   

States and Stakeholder experiences (click for details)
 

• Brazil - ANAC published an UAS regulatory roadmap, which foresees the discussion of noise requirements in 2023-2024.
• United States - The United States (U.S.) is investing in further understanding the acoustics of Emerging Technology Aircraft and expects to share some results in the CAEP/13 cycle. Additionally, the U.S. FAA is developing Rules of Particular Applicability (RPA) as the interim solution of noise certification for aircraft models of novel designs.  
• EASA - EASA is addressing noise requirements for UAM and Drone manufacturers on an individual basis until a general noise requirement scheme is available. Guidelines for the measurement of UAS noise are currently being developed and should be published for consultation in the last quarter of 2022.
• ACI
• ICCAIA - Manufacturers have recognized the need to design products substantially more quiet than current conventional helicopters, and are supporting the development of ETA noise certification procedures at CAEP.

Related material 

• On the prediction of noise generated by urban air mobility (UAM) vehicles. Physics of Fluids, 20 September 2022
• Urban Air Mobility Noise: Further Considerations on Indoor Space, Int. J. Environ. Res. Public Health 2022, 19(18), 11298
• Study on the societal acceptance of Urban Air Mobility in Europe, EASA, May 19th, 2021.
• Prediction of Urban Air Mobility Multirotor VTOL Broadband Noise Using UCD-QuietFly, Journal of the American Helicopter Society, Volume 66, Number 3, July 2021, pp. 1-13(13)
• Urban Air Mobility Noise: Current Practice, Gaps, and Recommendations, NASA/TP–2020-5007433, October 2020
• Psychoacoustic Measures for UAM Noise in the Context of Ambient Sound, Jun 12, 2020
• Vertical Flight Society eVTOL Workshop on Infrastructure - Noise and Acoustics, Apr 30, 2020
• Noise Measurement Report: Unconventional Aircraft - Choctaw Nation of Oklahoma; July 2019, FAA UAS National Airspace Integration Pilot Program, May 2020
• Initial Investigation into the Psychoacoustic Properties of Small Unmanned Aerial System Noise, Andrew Christian and Randolph Cabell, NASA Langley Research Center. June 05, 2017.
• Drone noise levels, Airborne drones. 
   

Useful references:

• ICAO Assembly resolution A40-17 Consolidated statement of continuing ICAO policies and practices related to environmental protection – General provisions, noise and local air quality
• A40-WP/625 - Report Of The Executive Committee On Agenda Item 15