By the end of the 1950s, it was becoming clear that the nuclear mission of the Skywarrior would be passed onto ballistic missiles; however, its high weight clearance and size meant that the aircraft would be useful in various other capacities. Accordingly, large numbers of Skywarriors were retrofitted as aerial refuelling tankers or as electronic warfare platforms; notably, the "EKA-3B" model could readily swing between performing strike, refuelling, and electronic warfare duties as required. Numerous other models of the type were developed, leading to the type being used for aerial reconnaissance and as a trainer aircraft as well. Production of the type ceased in 1961.