Fifty years ago, the federal government banned all civilian supersonic flights over land. The rule prohibits non-military aircraft from flying faster than sound so their resulting sonic booms won't startle the public below or concern them about potential property damage.

Commercial supersonic flight has been banned over land in the United States since 1973 primarily due to the sonic boom—a startling, thunder-like noise created when an aircraft exceeds the speed of sound. These booms are not just loud; they can be physically disruptive, causing windows to shatter and distressing both people and livestock on the ground. During the era of the Concorde, these noise concerns restricted the aircraft to over-water routes (like London to New York), which severely limited its commercial viability. In 2026, the ban remains a major hurdle for the next generation of supersonic jets, though NASA is currently testing the X-59 Quesst, an experimental aircraft designed to turn a "boom" into a quiet "thump." Beyond noise, supersonic flight is also scrutinized for its high environmental impact, as flying at such high speeds and altitudes requires significantly more fuel and emits more carbon and nitrogen oxides per passenger than traditional subsonic travel. Until technology can silence the boom and green the fuel, the ban over populated landmasses is unlikely to be lifted.