In September 1953, President
Dwight D. Eisenhower appointed Quarles Assistant Secretary of Defense for research and development. Subsequently, he was jointly selected by both the
Secretary of Defense and the
Secretary of Commerce to be the chairman of the Air Navigation Development Board. In March 1954, President Eisenhower appointed Quarles to the
National Advisory Committee for Aeronautics. On August 11, 1955,
President Eisenhower appointed Quarles as interim
Secretary of the Air Force, and he was sworn into office August 15, 1955. The
United States Senate confirmed his appointment on February 16, 1956. As Secretary, Quarles stressed the need to use cutting edge technology to maintain military superiority over the
Soviet Union. He supported expanded funding for research and development programs, and pressed for rapid fielding of
B-52 Stratofortress,
F-102 Delta Dagger, and
F-104 Starfighter aircraft. He resigned as Secretary of the Air Force on April 30, 1957, to accept a new Presidential appointment as
Deputy Secretary of Defense. He remained in that position until his sudden death from a heart attack in Washington, D.C., on May 8, 1959. ==Funeral==