Boom XB-1 Shatters The Sound Barrier, Reviving Civilian Supersonic Flight Hopes

Ever since the ahead-of-its-time Concorde jet was retired in 2003, aviation enthusiasts have eagerly awaited the return of a passenger aircraft capable of breaking the sound barrier. That dream is now inching closer to reality. On Jan. 28, 2025, American aviation company Boom Supersonic achieved a significant milestone toward civilian supersonic flight when its demonstrator aircraft, the Boom XB-1, broke the sound barrier for the first time.

The Boom XB-1 achieved this long-awaited feat during its 12th test flight, 35,290 feet above California's Mojave desert — the same airspace where in 1947, Charles E. "Chuck" Yeager became the first human to break the sound barrier, using the Bell X-1 "Glamorous Glennis" rocket plane. The XB-1, flown by Boom's chief test pilot, Tristan "Geppetto" Brandenburg, reached a maximum speed of Mach 1.12 (750 mph). Boom Supersonic livestreamed the entire event in remarkable clarity.

While it's common for military and fighter planes to travel faster than sound, the Boom XB-1's achievement is particularly noteworthy as it is the first privately built aircraft to achieve supersonic speeds. The Concorde, which remains the only passenger plane to break the sound barrier, had a lot of support from the French and British governments when it was jointly developed and manufactured by Sud Aviation (later Aérospatiale) and the British Aircraft Corporation. This successful test of the Boom XB-1 paves the way for the development of Boom Overture, the full-fledged supersonic passenger plane from Boom Supersonic.

While the Boom XB-1 might not look imposing on camera, at 71 feet long it isn't a small aircraft by any stretch. It has a delta-wing design, and like most modern planes, it is loaded with a lot of carbon-composite materials. Another unconventional technical aspect of the Boom XB-1 — making it markedly different from other planes — is the fact that it's a tri-jet, powered by three General Electric J85-15 turbojet engines, providing 12,000 pounds of thrust.

Boom also claims that the XB-1 has the most efficient civil supersonic engine intakes ever tested. These intakes — which feature variable geometry — also contribute to quieter operations. In fact, Boom expects the XB-1's successor — the Boom Overture — to be 30 times quieter than the Concorde with the help of these engine intakes.

The Boom XB-1 made its inaugural flight nearly a year ago — in March 2024. Its first flight was followed by 10 other Boom XB-1 subsonic flights, each testing the aircraft under challenging conditions.

The successful supersonic test of the Boom XB-1 is likely to stimulate the development of Boom's most important project — the Boom Overture, whose success was heavily dependent on that of the Boom XB-1 program. The Boom Overture is designed to carry 64 to 80 passengers at nearly twice the speed of sound. The aircraft is designed to hit a cruising speed of Mach 1.7, making it twice as fast as most current passenger aircraft.

Thanks to the progress Boom Supersonic has been making, the Boom Overture has attracted the attention of American Airlines, United Airlines, and Japan Airlines, all of them collectively placing 130 orders. In line with this vision, Boom in June of 2024 completed construction of the Overture Superfactory in Greensboro, North Carolina, where the company expects to manufacture 33 Overture planes a year at first, and then 66 after addition of a second assembly line. While Boom Aviation still has its work cut out in developing the Boom Overture, the successful test run of the XB-1 should ensure that public interest in civilian supersonic flights will remain high.