SR-71 Reconnaissance Operations at RAF Mildenhall were from April 1976 to 1990. Prior to Det 4 being established, UK permission was required for each sortie flown. The SR's stay was to be no longer than 20 days for each visit.

On 05 April of 1982 Prime Minister Margaret Thatcher announced that Det 4 would be a permanent SR-71 Detachment with two aircraft assigned. The United Kingdom remained in control of the more sensitive missions. The two aircraft Detachment ceased operations on 22 November 1989. The last aircraft departed the UK on 18 January 1990.

The U.S. Government has given the United Kingdom an SR-71 #962 for public display at Duxford Imperial War Museum for it's contribution to ending the Cold War.