The AF Guardian was developed as a replacement for the Navy"s TBF Avenger anti-submarine search & strike aircraft. The new plane was to be classified as “hunter-killer” carrier based anti-submarine (ASW) aircraft. The first prototype flew on 19 December 1945. Two variants of the Guardian were produced: The AF-2S for torpedo or bombing missions and the AF-2W with the large ventral radar. Designed to work in pairs, the AF-2W "hunter" member of the team had a crew of four and was unarmed, though it could carry underwing drop tanks, and had a large radome for the APS-20 search radar mounted on the belly under the cockpit. The AF-2S "killer" member of the team had a crew of three and could carry up to 1,800 kilograms (4,000 pounds) of munitions, including depth charges, bombs, or a homing torpedo in the bomb bay, plus 12.7 centimeter (5 inch) "high velocity air rockets (HVARs)" mounted on underwing pylons. The last Guardian was rolled out in March 1953, with a total of 389 of all variants built. By early 1953, Guardians began to be phased out of front line Navy squadrons in favor of the S2F-1 Tracker. Aug. 31, 1955 saw the end of the last operational active Navy squadron. The Guardians had slowly been transferred to U.S. Navy Reserve squadrons and mothballed. A number of Guardians ended up in civilian hands and were apparently used as "water bomber”s.