Boeing EC-97G StratocruiserFrom the late 1950’s through to 1976, the 7407th Operation Squadron based at Wiesbaden, West Germany, was equipped with a number of EC-97C Stratocruisers to perform SIGINT operations. The aircraft generally operated to and from Berlin-Tempelhof, flying over East Germany within the protected airspace of the Berlin Air Corridor.
As part of Project Pie Face, the gathering of photographic intelligence by mounting cameras of passenger carrying and transport aircraft, another C-97 (Serial No: 22687) was equipped with the 3.25-ton ‘Big Bertha’ or ‘Daisy Mae’ camera. 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 by an RB-36 would probably be too provocative, it would be better if a transport aircraft was equipped with this huge camera. The work to remove the camera from the RB-36 and install it in the C-97 was conducted in a secure hanger at Convair, Fort Worth.
The camera took 18 x 36 inch negatives exposed at 0.0025 seconds and could be positioned to take vertical or left or right oblique photographs through a large window which was hidden by covert doors. Flown by the 7405th Support Sqn, the C-97 flew regular sorties along the Berlin air corridor and often declared an emergency so that it didn't land, but returned to Wiesbaden. However, on other occasions this aircraft, together with the other C-97 aircraft operated by the 7405th Support Sqn, did land at Tempelhof, so much so that they were sometimes referred to as the 'Berlin for lunch bunch'.
These venerable aircraft were eventually replaced by the Lockheed C-130E-II Hercules.