The XB-70A #1 is seen taking off on a research flight, escorted by a TB-58 chase plane. The TB-58 (a prototype B-58 modified as a trainer) had a dash speed of Mach 2. This allowed it to stay close to the XB-70 as it conducted its research maneuvers. When the XB-70 was flying at or near Mach 3, the slower TB-58 could often keep up with it by flying lower and cutting inside the turns in the XB-70's flight path when these occurred.