From Fürstenfeldbruck, the 7499th continued to fly frequent missions in the West Berlin Air Corridors. As the Soviets modernised their units and increased their presence, it was vital to gain as much information on them as possible. For better management of this covert outfit as well as to bring it closer to the major USAFE photo and ELINT interpretation centres, the 7499th moved in August 1950 to Wiesbaden AB, within a few miles of USAFE Headquarters. Beginning in 1950, the unit upgraded to C-54 Skymasters to do both photo reconnaissance and ELINT work, replacing the B-17s. The C-54 boasted better collection capability, and had the additional advantage of actually being a transport, thus attracting much less attention at Tempelhof. C-47s also replaced the RB-26s, the C-47s also being less visible to the Soviets than the Invader bomber overflying East Germany. In 1955, in response to increasing collection requirements and the pending inactivation of the MATS intelligence units, USAFE upgraded its reconnaissance effort, creating the 7499th Support Group at Wiesbaden with three squadrons. The former 7499th Squadron became the 7405th Support Squadron, remaining at Wiesbaden as the only unit to conduct corridor collection. The 7405th had been openly tasked with the courier mission to West Berlin, meaning it was to conduct daily flights to and from Tempelhof Air Base carrying passengers and priority cargo. It was known as the "Berlin for Lunch Bunch". Under this cover the newer aircraft were to continue their collection using better sensors, including the first infrared imagery sensors. Its C-47s and RB-26s soldiered on into the late 1950s, and some C-54s until 1963. In 1959 the C-47s were supplanted by four Convair T-29s, navigator trainers converted for courier work and vertical photography, but another generation was about to arrive. A new aircraft, a specially modified Boeing EC-97G Stratofreighter, made its appearance in 1953. This aircraft (serial 49-2952), covertly carrying a 240-inch focal length camera, was codenamed PIE FACE and was mostly used along the periphery of the satellite nations. This camera, with a 20-foot focal length, was developed by Boston University and was installed initially in an RB-36. However, it was later decided that because an overflight though the corridor to Tempelhof by an RB-36 would probably be too provocative, it would be better if a transport aircraft was equipped with this huge camera.