The son of Percy Williamson and his wife Gertrude, Williamson was educated at
Bancroft's School and
Market Harborough Grammar School. He enlisted in the
Aircraft Apprentice Scheme at
RAF Halton in 1945. After passing-out from Cranwell as a
pilot officer, he was sent to the Advanced Flying School at
RAF Driffield, where he trained on
Meteors and
Vampires. He was then posted to
No. 112 Squadron in July 1951 flying Vampires initially from
RAF Fassberg and then from
RAF Jever in Germany. , a type flown by Williamson during the
Korean War In January 1953 he volunteered to join
No. 77 Squadron RAAF flying Meteors in a ground attack role in the
Korean War. He was promoted to
flight lieutenant on 13 June 1953. He returned home in late 1953 to become
aide-de-camp to Air Marshal
Sir Harold Lydford, the Air Officer Commanding-in-Chief,
RAF Home Command. After briefly returning to No. 112 Squadron in 1956, he joined
No. 20 Squadron at RAF Oldenburg in Germany as a flight commander flying
Hunters. that year he went to the
Central Flying School where he became a
Qualified Flying Instructor and then an examiner. He was given command of
No. 23 Squadron flying
Lightnings from
RAF Leuchars in 1966. and became Station Commander at
RAF Gütersloh in Germany. He was awarded the
Air Force Cross in the 1968
Birthday Honours. After this tour in Germany he returned to the UK and attended the
Royal College of Defence Studies in 1971. Promoted to
air vice marshal on 1 July 1975, he was appointed Commandant of the
RAF Staff College, Bracknell, on 16 August 1975. Williamson went on to be Assistant Chief of Staff (Plans and Policy) at
SHAPE on 10 March 1977 and then became Air Officer Commanding-in-Chief at
Support Command with the acting rank of
air marshal on 30 August 1978. He was promoted to the substantive rank of
air marshal on 1 January 1979. Williamson was made Commander-in-Chief
Strike Command with the acting rank of
air chief marshal on 15 September 1980. He was promoted to the substantive rank of
air chief marshal on 1 March 1981 and advanced to
Knight Grand Cross of the Order of the Bath in the 1982
Birthday Honours. He became
Chief of the Air Staff on 15 October 1982 and was appointed
Air Aide-de-Camp to
the Queen on the same day. As Chief of the Air Staff he persuaded the British Government to build a completely new airfield at
Mount Pleasant in the
Falkland Islands in the aftermath of the
Falklands War. He also implemented the emergency airlift of food and supplies to
Ethiopia in the wake of severe drought, famine and civil war there ("Operation Bushel") and advised on the international agreement to proceed with the
European Fighter programme. He was promoted to
Marshal of the Royal Air Force on 15 October 1985 and retired the same month. ==Later work==