Performing its maiden flight on 28 June 1954, the aircraft was introduced to USAF service during 1956. The standard model, designated B-66, was a bomber model that was procured to replace the aging Douglas A-26 Invader; in parallel, a dedicated photo reconnaissance model, designated "RB-66", was also produced alongside. Later on, further variants of the type were developed, leading to the aircraft's use in signals intelligence, electronic countermeasures and weather reconnaissance roles. Aircraft would commonly be forward deployed to bases in Europe, where they could more easily approach the airspace of the Soviet Union. Multiple variants would be deployed around Cuba during the Cuban Missile Crisis. They would also see use during the American intervention in the Vietnam War, typically operating as support aircraft for other assets that were active over the skies of North Vietnam. The last examples of the type were withdrawn during 1975.