FAA proposal: Supersonic airliners can fly over US cities if they’re quiet

“I’m honestly surprised that the FAA would propose a rule this weak,” Rutherford told the publication.

US lawmakers in Congress have also been pushing forward the Supersonic Aviation Modernization Act. That would require the FAA to allow for overland supersonic flights “so long as the aircraft is operated in such a manner that no sonic boom reaches the ground in the United States.” The bill passed the House on March 24, 2026, and is still awaiting a vote in the Senate.

Another way for quiet supersonic flight

Meanwhile, NASA has been testing a different approach to quieter supersonic flight with the Lockheed Martin X-59 Quesst—a needle-nosed experimental aircraft with an airframe designed to reduce the typical sonic boom to a sonic thump. NASA has relied on perceived levels of decibels (PldB) to evaluate sound levels, with the goal of consistently demonstrating sonic thumps around 75 PldB that would sound like a car door slamming about 20 feet away.

A NASA test pilot and mission integration manager previously told Ars that the X-59 aircraft’s future supersonic flight tests over US cities and towns nationwide would provide community feedback on perceived sound levels that could help inform regulations by civil aviation authorities.

The FAA still has time to further refine its proposed noise regulations for overland supersonic flights before attempting to finalize them by mid-2027. The agency also plans to propose another rule later this year that would set takeoff and landing noise standards for supersonic aircraft.

Legalization of quieter overland supersonic flights does not guarantee a successful comeback for commercial supersonic airliners. The Concorde supersonic airliner cut transatlantic flights between New York and London from seven hours to under three hours, but the aircraft’s massive fuel consumption made it difficult to sustain profitable operations—never mind recovering the more than $2.8 billion in development costs shared by the UK and French governments.

Boom Supersonic is developing a supersonic airliner called Overture with the goal of delivering the first aircraft to customers by 2029. The company has signed commercial agreements with American Airlines, Japan Airlines, and United Airlines that give the companies options to purchase the Overture aircraft.

But Boom has also pivoted away from its main goal in recent months to produce natural gas turbines to power AI data centers. Boom CEO Blake Scholl has suggested that revenue from this side venture would help pay for the development costs of the Overture supersonic airline. At the same time, United Airlines CEO Scott Kirby has said he gives Boom a “50/50” chance of getting its supersonic airliner flying.