Deliveries to the Air Force began in 1956, with 145 of this model produced. RB-66s were used as the primary night photo-reconnaissance aircraft of the USAF during this time, many examples serving with tactical reconnaissance squadrons based in the United Kingdom and in West Germany. A total of 72 of the B-66B bomber version were built, 69 fewer than originally planned. A total of 13 B-66B aircraft later were modified into EB-66B electronic countermeasures aircraft for the cold war with Russia, and were stationed at RAF Chelveston with the 42nd Tactical Reconnaissance Squadron who did the conversion in the early 1960s. They would rotate out of an alert pad in Spain during the time that the 42nd had them. These and the RB-66Cs that the 42nd had would eventually be sent to Vietnam. Unlike the U.S. Navy's A-3 Skywarrior, which performed some bombing missions, the Destroyer was not used as a bomber in Vietnam.