Terry joined the Royal Air Force in the ranks as an
RAF Regiment aircraftman 2nd class on 17 July 1946. His potential for officer service was quickly recognised and Terry was commissioned as a
pilot officer in the
RAF Regiment on 29 May 1947. Spending the next nine years as a junior officer in the RAF Regiment, serving on Light Anti-Aircraft squadrons in
RAF Germany and as Personal Staff Officer to the
Commandant-General of the RAF Regiment. He transferred to the General Duties Branch in April 1956. During the later 1950s and 1960s, he worked his way up the officer ranks. As a group captain, Terry was station commander of
RAF El Adem,
Libya, from 1969 to 1970. He was there in September 1969 when
Colonel Gaddafi overthrew King
Idris of Libya in a coup. Terry oversaw withdrawal of British troops from
El Adem and
Tobruk in March 1970. Terry was appointed the Assistant Chief of Staff in the Plans and Policy Division of the
Supreme Headquarters Allied Powers Europe in 1975. On returning to the United Kingdom, he took up the post of
Vice-Chief of the Air Staff on 25 March 1977. On 30 April 1979, Terry was appointed Commander-in-Chief of
RAF Germany. Following promotion to
air chief marshal, he was appointed Deputy Supreme Allied Commander Europe at
SHAPE on 9 April 1981. Terry remained as Deputy SACEUR until 16 July 1984 and he retired from the RAF several months later. ==Governor of Gibraltar==