In October, as an additional duty, he was designated commander, Air Task Group 7.4, Joint Task Force Seven, for the overseas atomic test, Operation Castle. He relinquished command of the 12th Air Division in July 1953 and took active command of Air Task Group 7.4. During the operational phase of Operation Castle in 1954, he spent four months at the Pacific Proving Grounds on Eniwetok Atoll. Estes was assigned as director of weapon systems operations, Wright Air Development Center of the Air Research and Development Command (ARDC), Wright-Patterson Air Force Base, Ohio, in July 1954. This directorate was transferred to the Office of the Deputy Commander for Weapon Systems, ARDC in August 1955, and became known as Detachment 1, at which time Estes became assistant deputy commander for weapon systems, Headquarters ARDC and commander, Detachment 1. Estes was transferred to Headquarters U.S. Air Force, Washington, D.C., as the Assistant Chief of Staff, Air Defense Systems, in August 1957, and was reassigned as Assistant Deputy Chief of Staff, Operations, in June 1958. In April 1961, Estes became the deputy commander for aerospace systems, Air Force Systems Command (AFSC), in Los Angeles, California, and in October 1962, he became vice commander of AFSC at Andrews Air Force Base, Maryland. In July 1964, Estes became commander of the Military Airlift Command (then the Military Air Transport Service) with headquarters at Scott Air Force Base, Illinois. Estes was presented the General H.H. Arnold Trophy, the highest military honor given by the Arnold Air Society, on April 26, 1967, for outstanding contributions to military aviation and aerospace programs. He died at his Bethesda, Maryland home in 2007. Education 1931 Graduate Hampton High School, Virginia 1936 Graduate U.S. Military Academy, West Point, N.Y. 1940 Primary and Advanced Flying Schools, Randolph and Kelly fields, Texas 1949 Air War College, Maxwell Air Force Base, Ala. Assignments June 1936 – June 1939: Various duties, 7th Cavalry and 1st Cavalry Division, Fort Bliss, Texas June 1939 – April 1940: Flying school, Love, Randolph and Kelly fields, Texas April 1940 – February 1944: Commanding officer, 23d Pursuit Squadron; commandant of flying cadets; and then director of training, Brooks Field, Texas February 1944 – June 1944: Commander, Blackland Army Air Base, Waco, Texas July 1944 – December 1945: Commander, Lubbock Army Air Force Base, Lubbock, Texas January 1946 – July 1948: Chief, Plans and Policy Branch; chief, Plans Section; deputy assistant chief