Speed record set 50 years ago Published Oct. 3, 2017 By 412th Test Wing Public Affairs EDWARDS AIR FORCE BASE, Calif. -- Fifty years ago on Oct. 3, 1967, Maj. William J. “Pete” Knight flew the modified X-15A-2 to a speed of Mach 6.72. The aircraft was flown with its full ablative coating and external fuel tanks. A dummy ramjet mounted on the lower ventral stub stabilizer fell away during the flight as a result of severe heat damage to the fairing. The flight marked the highest speed achieved in the X-15 program and remains the highest speed ever reached by a manned airplane. The video below is from a 1999 production narrated by then Edwards historian Dr. Jim Young, which describes this historic event. 01:43 VIDEO | 01:43 | Speed Record Set 50 Years Ago Today