The Lockheed P-2 Neptune is a maritime patrol and antisubmarine warfare (ASW) aircraft. It was developed for the USN by Lockheed to replace the Lockheed PV-1 Ventura and PV-2 Harpoon and was replaced, in turn, by the Lockheed P-3 Orion. Designed as a land-based aircraft, the Neptune never made a carrier landing, but a few were converted and deployed as carrier-launched, stop-gap nuclear bombers that would have to land on shore or ditch. The type was successful in export and saw service with several armed forces.