John Barron McKay was an American naval officer, World War IIpilot, aeronautical engineer, and test pilot. He was one of twelve pilots who flew the North American X-15, an experimental spaceplane jointly operated by the United States Air Force and NASA. On September 28, 1965, he flew the X-15 to an altitude above 50 miles, thereby qualifying as an astronaut according to the United States definition of the boundary of space. However, this altitude did not surpass the Kármán line, the internationally accepted boundary of 100 kilometers. On November 9, 1962, McKay was injured when forced to make an emergency landing in the X-15-2, the second of three planes in the X-15 fleet. The craft rolled over, and McKay suffered crushed vertebrae. Subsequently, the damaged plane was refurbished to become the X-15A-2, a modified variant. Although McKay returned to flight as an X-15 pilot, his injuries contributed to an early death. He died on April 27, 1975.
On 9 November 1962, McKay undertook Flight 74 of the X-15 program on the X-15 56-6671 which was the Number-Two X-15 on its 31st flight. The X-15 was attached to its mothership the Boeing NB-52B Stratofortress 53-008, nicknamed Balls 8. McKay's mission was to reach an altitude of 125,000 feet at Mach 5.5 and to fly the aircraft without the lower part of its ventral fin. Further, the mission was to determine the flight response and stability of the aircraft and the characteristics of its flight boundary layer. The X-15 was released from the Stratofortress on schedule at 45,000 feet over Mud Lake, Nevada at 10:23:07.0 local time with a launch speed of 450 knots. Upon release, McKay was unable to attain the full power of the rocket engine which became stuck at 30% power and unresponsive to throttle control. Due to the lack of throttle response it was decided to make a forced landing at Mud Lake instead of landing at Edwards Air Force Base due to concerns about the reliability of the engine. McKay was at an altitude of 53,950 feet having attained a speed of Mach 1.49 when he started his descent for landing at Mud Lake. The motor was kept operating for 70.5 seconds to burn excess fuel and to reduce weight. The flaps failed to activate during landing and the aircraft speed at touchdown was higher than normal. Due to the excess speed and weight the aircraft experienced failures because of the increased dynamic loading which eventually led to its overturning.
Death
John B. McKay died on April 27, 1975 in Lancaster, California at the age of 52. The injuries he had sustained during his X-15 crash were major contributing factors. McKay, who also suffered from diabetes, turned to alcohol to numb the pain of his accident injuries. Liver disease was a contributing factor to his death. In 1996, he was inducted into the Aerospace Walk of Honor, and in 2005 he was posthumously awarded Astronaut Wings.
