What Is the Boom XB-1? Civil Jet Makes History by Breaking Sound Barrier

Boom Supersonic's XB-1 made history on Tuesday by becoming the first civil aircraft to break the sound barrier.

Why It Matters

Before Tuesday, no civil private manufacturer had passed the sound barrier with an aircraft it had developed.

What To Know

During the XB-1's historic flight on Tuesday—its 12th test flight overall—the aircraft stayed supersonic for around four minutes before breaking the sound barrier two more times during the same outing.

The XB-1 reached Mach 1.122 when it broke the sound barrier for the first time after about 12 minutes into the flight.

What Is The Boom XB-1?

Boom Supersonic is an American startup company based in Colorado. Its XB-1 is a one-third-scale demonstrator of a 64-passenger supersonic airliner—dubbed "Overture"—that Boom wants to eventually build.

Boom Supersonic's XB-1 during its supersonic flight on January 28, 2025. Boom Supersonic

Where Did The Test Flight Take Off?

Tuesday's test flight took place from the Mojave Air & Space Port. The location was symbolic, as it was the same California airspace where Chuck Yeager broke the sound barrier for the first time in 1947 in the Bell X-1, a rocket engine–powered aircraft that was created jointly by the National Advisory Committee for Aeronautics, the U.S. Army Air Forces and the U.S. Air Force.

What Speed Is Supersonic?

According to the National Aviation Academy, "supersonic speed is the speed of an object that is faster than the speed of sound, measured at about 768 miles per hour at sea level."

Aircraft speed is measured by a Mach number, which is velocity relative to speed of sound, per the National Aviation Academy. Mach 1 is considered the speed of sound.

How Do Planes Break The Sound Barrier?

The sound barrier is the sudden increase in aerodynamic drag that occurs when an object approaches Mach 1. Aircraft that break this barrier not only have engines designed to reach this incredibly high speed but the planes are also aerodynamically shaped to withstand shock waves that come during such acceleration.

Could The Boom XB-1 Impact Air Travel?

Boom Supersonic has been very open about its ambitions to become the future of air travel and to fill the gap left after the Concorde made its final flight in 2003 with its Overture aircraft.

"XB-1's supersonic flight demonstrates that the technology for passenger supersonic flight has arrived," Boom founder and CEO Blake Scholl said in a statement released Tuesday.

He added, "A small band of talented and dedicated engineers has accomplished what previously took governments and billions of dollars. Next, we are scaling up the technology on XB-1 for the Overture supersonic airliner. Our ultimate goal is to bring the benefits of supersonic flight to everyone."