ICAO to adopt new supersonic aircraft noise standards
March 21, 2025
The International Civil Aviation Organisation (ICAO) is continuing its evaluation of supersonic commercial aircraft noise standards, with Boom Supersonic revealing that member countries met in February to “support new recommendations”. The US-based supersonic aircraft designer is optimistic that this legislative consensus represents a significant step towards “clearing the path for commercial supersonic flight”.
During the February 2025 meeting of ICAO’s Committee on Aviation Environmental Protection (CAEP), 33 member countries gathered to discuss recommendations – or as Boom stated, “coming to agreement on new global supersonic aircraft noise standards”. Specifically, this included a “recommended new standard for landing and takeoff noise that recognises the unique physics and opportunities for noise reduction of supersonic aircraft” – something Boom is actively investigating in the design and development of its upcoming clean-sheet supersonic airliner, Overture. Boom provided data to support the FAA’s analysis.
Boom has recently achieved what it terms ‘boomless cruise’ with its subscale XB-1 flight test demonstrator campaign, during which no audible sonic boom reached the ground. Regarding the takeoff and landing portion of the flight, Overture’s ‘Variable Noise Reduction System’ promises to “automatically [manage] thrust to reduce noise at takeoff,” further quietening its medium bypass ratio turbofan engines (comparatively quieter than Concorde’s afterburning turbojets). Additionally, unlike Concorde, Overture will not use afterburner for takeoff; resulting in in a noise footprint it likens as akin to that of today’s subsonic long-haul aircraft.
The work builds the FAA Reauthorisation Act passed in Congress in 2024, “directing the FAA to continue its work to develop international standards, which has now come to fruition at the CAEP meeting,” wrote Boom.
However, with its US coast-to-coast routes targeting flight times 20% less than that of today’s subsonic airliners, Boom is still looking to challenge the existing federal ban on aircraft exceeding Mach 1 overland. “As currently written, the regulation addresses only supersonic speed, without taking into account that it is possible today for aircraft to fly faster than Mach 1 without creating a boom that is heard on the ground,” Boom explained.
Founder and CEO Blake Scholl added on Twitter: “XB-1 broke the sound barrier… boomlessly… but the real sound barrier is 14CFR 91.817 which says thou shalt not exceed Mach One. Next job is to break the regulatory sound barrier. It should always have been a noise limit, not a speed limit.”
ICAO states on its website that it “continues its efforts towards developing a standard for future supersonic aircraft,” although the page appears to be somewhat out of date as it estimates that “the certification of a supersonic aeroplane could occur in the 2020-2035 timeframe”. Boom is targeting the entry into service of Overture before the end of the decade.
