NASA research pilot Jack McKay was injured in a crash landing of the X-15 #2 on November 9, 1962. Following the launch from the B-52 to begin flight 2-31-52, he started the X-15's rocket engine, only to discover that it produced just 30 percent of its maximum thrust. He had to make a high-speed emergency landing on Mud Lake, NV, without flaps but with a significant amount of fuel still in the aircraft. As the X-15 slid across the lakebed, the left skid collapsed; the aircraft turned sideways and flipped onto its back. McKay suffered back injuries but was eventually able to resume X-15 pilot duties, making 22 more flights. The X-15 was sent back to North American Aviation and rebuilt into the X-15A-2.