The Ban on Supersonic Flight Is Ending. The Fight Over Noise Is Just Beginning.

A 53-year ban on supersonic flight over the U.S. is on its way out. But the FAA's proposed noise standard, conveniently based on one startup's tech, is already under fire for not actually measuring loudness.

The Federal Aviation Administration wants to end its 53-year-old ban on commercial supersonic flights over the United States. That rule, a relic from an era when military jets shattered windows over Oklahoma City, is what kept the Concorde confined to transoceanic routes. The new deal is simple: you can break the sound barrier over land, but you can’t make a scene. The proposal opens the door for a new generation of airliners promising to get you from New York to Los Angeles in under three hours. The dream is alive. The problem is that nobody agrees on what “quiet” actually means.

The newly proposed rule would cap sonic boom overpressure at 0.11 pounds per square foot (psf), a stark drop from the Concorde's 1.94 psf. This standard is no accident; it’s based on technology demonstrated by Colorado startup Boom Supersonic with its XB-1 aircraft. Their trick is called “Mach cutoff,” a technique that involves flying at specific altitudes and speeds where atmospheric conditions refract the shockwaves upward, away from the ground. It’s clever physics, but it’s not the only game in town. NASA, with its needle-nosed X-59 Quesst, is chasing a different metric entirely: a perceived level of 75 decibels, which it hopes will sound more like a distant car door slamming. One method games the atmosphere; the other redesigns the airplane. The regulator has picked a side before the debate is even over.

This proposed rule is a regulatory gift-wrap for Boom Supersonic, whose entire business model for its Overture airliner depends on opening up lucrative overland routes. With commercial agreements already signed, Boom needs this legal runway cleared for takeoff. But critics are sounding the alarm. Dan Rutherford, senior director at the nonprofit International Council on Clean Transportation, told Aviation Week that the FAA’s pressure-based standard is “weak,” pointing out that United Nations experts discarded the metric years ago because it fails to measure loudness or annoyance. It's a clash between a company that needs to ship hardware and watchdogs who argue the public is about to become an unwilling test audience for a flawed experiment. All a ghost of Concorde, an engineering marvel that died from brutal unit economics, hangs over the entire affair.

The FAA hopes to finalize its noise regulations by mid-2027, just two years before Boom plans to deliver its first Overture airliner in 2029. But NASA’s own quiet-supersonic flight tests, collecting real-world feedback on noise perception from communities across the country, are still ongoing. The data from those flights could fundamentally challenge the FAA’s chosen standard, potentially forcing a rewrite just as the first new supersonic jets are entering production. The coming years will be defined by a battle over metrics—Boom's atmospheric trick versus NASA's airframe-level acoustic design. The engineering problem of a quiet boom might be solvable. The real question is who gets to decide how much noise is an acceptable price for speed: the airline, or the people living under its flight path?