When the experimental XB-1 aircraft achieved supersonic speeds on a test flight, it did not create a disruptive sonic boom – thanks to a physics phenomenon called the Mach cutoff

US aerospace firm Boom Supersonic is expecting to reach design freeze on the Overture supersonic passenger aircraft in about a week, as flight-testing of its experimental XB-1 jet concludes. The XB-1 departed on its 13th and final flight on 10 February,

Boom Supersonic will attempt its second supersonic flight on Monday, nearly two weeks after its first successful foray through the sound barrier.