McKay was with the NACA and NASA from February 8,1951 until October 5, 1971 and specialized in high-speed flight research programs. He began as an NACA intern, but assumed pilot status on July 11, 1952. In addition to the X-l5, he flew such experimental aircraft as the D-558-1, D-558-2, X-lB, and the X-lE. He has also served as a research pilot on flight programs involving the F-100, F-102, F-104, and the F-107.

Born on December 8, 1922, in Portsmouth, Va., McKay graduated from Virginia Polytechnic Institute in 195O with a Bachelor of Science degree in Aeronautical Engineering. During World War II he served as a Navy pilot in the Pacific Theater, earning the Air Medal and Two Clusters, and a Presidential Unit Citation.

McKay wrote several technical papers, and was a member of the American Institute of Aeronautics and Astronautics, as well as the Society of Experimental Test Pilots.