About 35,000 feet (10,670 meters) over the Mojave Desert, northwest of Los Angeles, Boom Supersonic's XB-1 became the first privately funded airplane to break the sound barrier during a test flight on Tuesday.

Boom Supersonic's XB-1 made history on Tuesday by becoming the first civil aircraft to break the sound barrier. Before Tuesday, no civil private manufacturer had passed the sound barrier with an aircraft it had developed.

On its 12th test flight, the Boom XB-1 prototype broke the sound barrier three times and achieved a top speed of Mach 1.1.