John Stack graduated from MIT in 1928 and joined the Langley Aeronautical Laboratory as an aeronautical engineer. In 1939 he became director of all the high-speed wind tunnels and high-velocity airflow research at Langley. Three years later he was named chief of the compressibility research division there. He was promoted to assistant chief of research in 1947 and subsequently had that title changed to assistant director of the research center. He guided much of the research that paved the way for transonic aircraft, and in 1947 he was awarded the Collier Trophy together with the pilot of the X-1 who broke the sound barrier, (by then) Major Charles E. Yeager. He won the award again in 1952 and later won the Wright Brothers Memorial Trophy among other awards. From 1961-1962 he was director of aeronautical research at NASA Headquarters before retiring to become vice president for engineering at Republic Aircraft Corp (later part of Fairchild Industries) from which he retired in 1971.