Lockheed P-2 Neptune

The Lockheed P-2 Neptune, designated P2V by the United States Navy before September 1962, was a maritime patrol and antisubmarine warfare aircraft developed by Lockheed to replace the PV-1 Ventura and PV-2 Harpoon, and replaced in turn by the P-3 Orion. Design work began at Lockheed's Vega subsidiary as a private venture on 6 December 1941. The Navy signed a letter of intent for two XP2V prototypes on 19 February 1943, the first aircraft flew in May 1945, production began in 1946 and it entered service in 1947. Ease of manufacture and maintenance was a major design factor and probably helped its long life and export success. From the P2V-5F model it was one of the first operational aircraft fitted with both piston and jet engines, the Westinghouse J34 jets burning the same aviation gasoline as the piston engines. Designed as a land-based aircraft, it never made a carrier landing, though a few were converted into carrier-launched stop-gap nuclear bombers.