On 31 March 1956, the Skywarrior entered squadron service with the Navy. Initially used in the nuclear-armed strategic bomber role, the emergence of effective ballistic missiles led to this mission being deprioritised by the early 1960s. Throughout the majority of its later service life, the Skywarrior was tasked with various secondary missions, which included use as an electronic warfare platform, tactical reconnaissance aircraft, and high capacity aerial refueling tanker. It was among the longest serving carrier-based aircraft in history, having entered service during the mid-1950s and withdrawn from use in 1991. Throughout its service, the Skywarrior was the heaviest operational aircraft to operate from an aircraft carrier, which contributed to its nickname of "Whale".