Supersonic prototype jet breaks sound barrier on US test flight

Boom Supersonic’s XB-1 broke the sound barrier at an altitude of about 10,700 metres (35,000ft). Photograph: Boom

A US-made prototype jet has broken the sound barrier, in the first commercial venture to achieve supersonic speeds since Concorde.

Boom Supersonic, a startup that seeks to build the world’s fastest airliner, flew a test flight of its fighter jet-sized XB-1 demonstrator over the Mojave desert in California on Tuesday.