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Supersonic flight over the United States has been effectively illegal since 1973, and the government has just taken its clearest step yet toward changing that. The Federal Aviation Administration has proposed replacing the decades old ban on civil overland supersonic flight with a noise based standard, a rule that would let aircraft fly faster than the speed of sound across the country as long as no audible sonic boom reaches the ground. It is a proposal rather than a done deal, but it is the concrete regulatory move that supersonic hopefuls have been waiting on for years.
The old rule was about noise, not speed. When regulators barred overland civil supersonic flight in 1973, the problem was the sonic boom, the sharp crack a plane makes when it pushes through the sound barrier, which can startle people and rattle windows across a wide corridor beneath the flight path. Rather than try to measure and manage that noise, the government simply banned civilian aircraft from going supersonic over land at all. That blanket prohibition has stood for more than half a century, and it is the single biggest reason there has been no successor to Concorde flying across America.
What has changed is the technology and the politics around it. The proposal follows an executive order issued in 2025 that directed the FAA to repeal the overland speed limit and set an interim noise standard, and it arrives after the US House passed the Supersonic Aviation Modernization Act earlier this year, a bill that would require the agency to rewrite its rules to allow faster than sound flight over land without special authorization as long as no boom hits the ground. That legislation still needs the Senate, but the FAA’s proposed rule can move on its own track, and together they mark a clear shift from prohibition toward regulation by noise.
The company most eager to fly through that opening is Boom Supersonic, which has been building its case in the air. Its XB-1 demonstrator has broken the sound barrier and, the company says, done so without producing a boom that reaches the ground, an effect it attributes to a phenomenon called Mach cutoff, where the shockwaves bend and lose their energy in the atmosphere before they hit the surface. That boomless flight is the whole premise of the new regulatory approach, because a noise standard only makes sense if aircraft can actually go supersonic quietly. Boom says it has already booked around 130 orders and pre-orders from carriers including United Airlines, American Airlines, and Japan Airlines, a sign that airlines are betting the rules will eventually catch up to the hardware.
The caution worth keeping is that a proposed rule is the start of a process, not the finish. An FAA notice of proposed rulemaking opens a 45 day public comment period and has to be turned into a final rule, and the details of exactly how quiet is quiet enough will matter enormously. The proposal puts that bar in concrete terms, a sonic boom overpressure no greater than 0.11 pounds per square foot at the ground. The original ban existed because people on the ground did not want to be startled by aircraft they would never board, and any new standard will have to satisfy communities as well as manufacturers. Turning a boomless demonstration into a fleet of certified airliners flying revenue routes is also a long, expensive road that has humbled supersonic ventures before.
Even so, the significance is hard to overstate for anyone who has watched supersonic travel sit frozen for a generation. For fifty years the barrier to flying fast over land was not physics but a line in the regulations, and the government is now proposing to redraw that line around noise instead of speed. If the rule is finalized and the boomless claims hold up in practice, it would reopen a door that has been shut since Concorde, and give companies like Boom a real runway to build toward. The era of quiet supersonic travel is not here yet, but for the first time in half a century, the rules are being written to allow it.
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