While the plane’s engines were still audible on the ground, surpassing the Mach cutoff ensured no one heard a disruptive sonic boom. According to the company’s February 10th announcement ...

and the company did it with no audible sonic booms on the ground. The Boom Supersonic XB-1 (pictured here in an earlier flight) flew Mach 1.122 in Boomless Cruise ... no one on the ground could ...

The aircraft, detailed in blueprints in a recent academic paper, is meant to reach Mach 1.6 and have a barely audible sonic boom when the project comes to fruition, according to the outlet.

"During its historic first supersonic flight on January 28, 2025, Boom’s demonstrator aircraft, XB-1, broke the sound barrier three times without generating a sonic boom that reached the ground ...