The Neptune was developed for the US Navy 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 small number 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. Beginning with the P2V-5F model, the Neptune became one of the first operational aircraft fitted with both piston and jet engines. Neptunes were operated by RAAF Squadrons 10 and 11 from RAAF Edinburgh, South Australia. For full details on the Neptune P-2 and its variants, click here.