On 5 November 1959, North American Aviation test pilot Scott Crossfield dropped away from the wing of the NB-52A mothership at about 45,000 feet and Mach 0.82, over Bouquet Canyon Reservoir, some 35 miles southwest of Edwards Air Force Base. He was in X-15 number two, 56-6671, on his fourth flight in the rocket plane and his third in this aircraft. Almost as soon as he lit the two Reaction Motors XLR11 engines, one of the four combustion chambers of the lower engine exploded, and fire broke out in the engine bay.

Eleven Seconds of Thrust

Crossfield shut both engines down after 11.7 seconds. The X-15 was not designed to land heavy, so he held it level for the 114 seconds it took to jettison the liquid oxygen and water-alcohol propellant. The tanks would not empty completely. When he turned for Rosamond Dry Lake, about ten miles southwest of Edwards, he was still roughly 1,000 pounds overweight. Major Robert M. White, in a chase F-104, called out his height above the lakebed as he came in.

Bent in Half

The X-15 landed on two tail skids and a nose wheel. Crossfield described the skids digging in gently, and then the nose slamming down hard as the aircraft ploughed across the lakebed. It stopped in about 1,500 feet, against the usual 5,000. When he climbed out, unhurt, he saw that the fuselage had buckled immediately behind the cockpit.

The flight had lasted 5 minutes 28 seconds. The investigation found that the nose-gear strut had extended rapidly and its oil had foamed, so it absorbed almost none of the impact. The landing checklist was changed so that pilots lowered the gear earlier. The aircraft went back to North American’s plant for repair and returned to flight about three months later.

Crossfield and the X-15

Crossfield already had his place in history: on 20 November 1953 he became the first pilot to fly at twice the speed of sound, in the Douglas D-558-II Skyrocket. He had made the X-15’s first powered flight on 17 September 1959, in this same aircraft. In June 1960 he was in the cockpit of X-15-3 during a ground run of the new XLR99 engine when an explosion destroyed the rear of the aircraft; he was unhurt. His 14th and last X-15 flight, on 6 December 1960, ended North American’s contractor test programme, and the aircraft passed to NASA and the Air Force. A NASA photograph shows him symbolically handing the keys to Air Force pilot Bob White and NASA pilot Neil Armstrong.

The Fastest Aircraft Ever Flown

56-6671 was damaged again on 9 November 1962, when NASA pilot John McKay was seriously injured in a landing accident. North American rebuilt it once more, this time as the X-15A-2, with a fuselage stretched by more than two feet and two external propellant tanks. On 3 October 1967, Air Force Major William J. “Pete” Knight flew it to Mach 6.70, or 4,520 mph. No winged, piloted vehicle went faster until Space Shuttle Columbia re-entered from orbit in 1981, and no aircraft has gone faster since. The X-15A-2 is now displayed at the National Museum of the United States Air Force in Dayton, Ohio. Crossfield died on 19 April 2006, aged 84.

What the Popular Version Gets Right

The account circulating online is accurate: the 45,000-foot launch, the exploding chamber in the lower engine, 11.7 seconds of thrust, the 114-second dump, the 1,000 pounds of extra weight, Bob White in the chase F-104, the 1,500-foot rollout and the 5-minute 28-second flight all match the record. One nuance: the handover of the keys to White and Armstrong was a symbolic photograph. The first government pilots to fly the X-15 after Crossfield were NASA’s Joe Walker and the Air Force’s Bob White in 1960; Armstrong made his first X-15 flight later that year.

Sources: Bryan Swopes, This Day in Aviation, “5 November 1959”; Air Force Test Center, “November 5, 1959: Test Pilot Scott Crossfield”; NASA, “X-15 Accident” (photo E-9543); NASA History, “65 Years Ago: First Factory Rollout of the X-15” and “65 Years Ago: First Powered Flight of the X-15”; A. Scott Crossfield with Clay Blair, Always Another Dawn (1960).