The S-3B Viking first flew in September of 1984. It’s a four-seat, twin-engine turbofan-powered jet aircraft that used by the U.S. Navy to identify and track enemy submarines. In the late 1990s, the S-3B's mission focus shifted to surface warfare and aerial refueling. The B variant featured upgraded avionics, AN/APS-137 inverse synthetic aperture radar, the Joint Tactical Information Distribution System, and AGM-84 Harpoon launch capability. 119 were converted from S-3As.