The fastest speed the XB-1 had reached prior to the January 28 flight was Mach 0.95, just below the supersonic threshold of Mach 1, which it hit during its last test flight on ... years since the 002 ...

The fastest speed the XB-1 had reached prior to the January 28 flight was Mach 0.95, just below the supersonic threshold of Mach 1, which it hit during its last ... for Concorde first flew at ...

The XB-1 demonstrator aircraft is the first civil aircraft to break the sound barrier since the Concorde ... which it hit during its last test flight on January 10. A livestream documented ...