War tensions with the Soviet Union in Europe began as early as 1946. In November, President Harry S. Truman ordered Strategic Air Command (SAC) B-29 Superfortress bombers to Europe. Truman decided to realign United States Air Force Europe (USAFE) into a permanent combat-capable force. In July, B-29s of the SAC 2nd Bombardment Group were deployed to Lakenheath. The first USAFE host unit at Lakenheath was the 7504th Base Completion Squadron, being activated in 1949. The 3909th moved to RAF Greenham Common in Berkshire during 1954, and was replaced by the 3910th Air Base Group in 1955. On 30 April 1956, two Lockheed U-2s were airlifted to Lakenheath to form CIA Detachment A. The first flight of the U-2 was on 21 May. The Central Intelligence Agency unit did not remain long, moving to Wiesbaden Air Base, West Germany in June 1956. On 10 October 1956, a United States Navy Douglas R6D-1 Liftmaster disappeared over the Atlantic Ocean after departure from RAF Lakenheath for a flight to Lajes Field in the Azores. The aircraft was on a Military Air Transport Service flight carrying 50 members of the 307th Bombardment Wing, on their way home to the United States after a temporary duty assignment and a U.S. Navy crew of nine. All 59 personnel on board were lost. 48th Tactical Fighter Wing Following French president Charles de Gaulle's insistence in 1959 that all non-French nuclear-capable forces should be withdrawn from his country, the USAF began a redeployment of its North American F-100-equipped units from France. The 48th Fighter Wing left its base at Chaumont-Semoutiers Air Base, France on 15 January 1960, its aircraft arriving at Lakenheath that afternoon. The tactical components of the 48th TFW upon arrival at Lakenheath were: 492d Tactical Fighter Squadron (LR, blue colours) 493d Tactical Fighter Squadron (LS, yellow colours) 494th Tactical Fighter Squadron (LT, red colours) The period between 1972 and 1977 can be described as a five-year aircraft conversion. Beginning in late 1971, the 48th TFW started its conversion to the McDonnell Douglas F-4D Phantom II. The conversion to the F-4D took several years, with initial operational capability being achieved on 1 July 1975. The F-4's service with the 48th Tactical Fighter Wing was short, as operation "Ready Switch" resulted in 48th Tactical Fighter Wing receiving General Dynamics F-111s Mountain Home AFB, Idaho in October 1976. Strike Eagle Lakenheath received its first McDonnell Douglas F-15E Strike