XB-1 Boom breaks sound barrier on test flight from Mojave Air & Space Port

Evan Hawley.

Boom XB-1 takeoff from runway 30.

Boom Supersonic XB-1 flew over Mach One on Jan. 28, on the latest test flight at Mojave Air & Space Port, at Rutan Field.

Chase planes were a Northrop T-38 and Dassault Mirage F1, a French fighter.

According to a Jan. 28 press release from Boom Supersonic, "Boom Chief Test Pilot Tristan 'Geppetto' Brandenburg at the controls, the XB-1 demonstrator plane entered the supersonic corridor and reached an altitude of 35,290 feet before accelerating to Mach 1.12 (652 knots or 750 miles per hour)."

The XB-1 broke the sound barrier two more times before returning back to Mojave. The test flight took place in airspace known as the Bell X-1 Supersonic Corridor, named after the first plane to break the sound barrier with pilot Chuck Yeager. The XB-1's 12th test flight lasted approximately 34 minutes.

According to a http://www.space.com/ article, during the company's live stream on X, Boom advisor and former Chef Engineer Greg Krauland said, "I'm just to-the-moon excited about how well that went.... This is such a huge step, building the first civil supersonic jet, you know, right here in America," he said.

Krauland added, "This jet really does have much of the enabling technologies that are going to enable us to go ahead and to build a commercial supersonic airliner that is available to the masses."

Courtesy of Boom Supersonic.

Boom Chief Test Pilot Tristan "Geppetto" Brandenburg.

Crowds of excited aviation fans and news media gathered to welcome Boom's XB-1 back onto the ramp at Mojave Air & Space Port after the historic first civilian aircraft to break the sound barrier in America. Another first for Mojave Air & Space Port!

Boom CEO Blake Scholl wrote in a post on X, "XB-1's supersonic flight marks the first time a supersonic jet has come from something other than a nation-state." The only civilian supersonic aircraft was Concorde, which was retired in 2003. It was built jointly by the British and French governments.

Stated in a Jan. 10 press release from Boom Supersonic, "XB-1 started the New Year with a successful Flight 11 on Jan. 10, 2025 as it closes in on supersonic flight. In 2024, XB-1 completed 10 test flights at the Mojave Air & Space Port in Mojave, California.

"During the 44-minute flight, Boom Chief Test Pilot Tristan 'Geppetto' Brandenburg took XB-1 to an altitude of 29,481 feet. Flight 11 again reached a transonic top speed of Mach 0.95, faster than the cruising speed of today's airliners. An aircraft flies transonic when it reaches the range of speeds just below supersonic, which is Mach 1."

According to the press release, the primary objective for Flight 11 was expanding dynamic pressure to 383 KEAS (knots equivalent airspeed) ... a higher number than will be experienced during XB-1's first supersonic flight. This is the highest dynamic pressure the aircraft will ever experience ... pushing beyond the anticipated pressure the aircraft will experience at Mach 1.1.

The press release stated, as an aircraft approaches supersonic speeds, dynamic pressure becomes a key factor. It's essentially how hard the plane is pushing through the air. Dynamic pressure and Mach number work together to shape the aircraft's performance.

During flight testing, Boom pilots and flight test engineer's carefully expand one parameter at a time, either Mach number or dynamic pressure, in order to ensure safe and precise performance. The relationship between these two numbers changes with altitude ... the faster and lower you are, the higher the dynamic pressure, and vice versa.

The company believes that the XB-1 is on track to break the sound barrier in early 2025.

On the Boom Supersonic website, Nick Sheryka, XB-1 Chief Flight Test Engineer, speaks to Boom's progressive approach to flight testing, which is rooted in the company's philosophy that safety is the ultimate mission.

"Safety is our main priority," said Sheryka. "Like other aircraft test programs, we use a progressive approach to testing one new thing at a time." They planned around ten test flights before reaching Mach 1 or going supersonic speeds. The first flights were test systems, to make sure they worked as well in the air as they did in ground testing. "The second part of SB1's flight testing was all about expanding the envelope incrementally in airspeed, altitude and Mach number until we eventually make that sonic boom."

Supersonic air travel isn't a new technology. The sound barrier was broken in 1947 with the Bell X-1 and the commercial airliner Cocncorde first flew in 1969. Most of the supersonic technology has been applied to the most advanced military aircraft, where the costs were covered by government programs.

"The focus of the XB1 program is to demonstrate human rated supersonic vehicle technology at a price point that you and I can use for personal travel once scaled up to an airliner," Sheryka said in video.

Sheryka brings a decade of diverse subsystem design, build and test experience to Boom. As Chief Flight Test Engineer of XB-1, he is responsible for ensuring that all of the various aircraft systems work together to make a safe aircraft. Prior to working in aerospace he worked for the Department of Defense and holds qualifications to operate three types of naval nuclear reactor plants.

While working for Scaled Composites, Sheryka owned the clean-sheet design of several prototype experimental jet aircraft subsystems, served on bleeding-edge technology flight test teams and most recently led the subsystem team on the Stratolaunch program. In his free time, he fabricated and test flew his own experimental home-built Sonex aircraft.