P2V-4 Neptune

The Lockheed P2V-4 Neptune was a maritime patrol and anti‑submarine aircraft developed in the late 1940s to replace the aging PB‑1 and PB‑2 flying boats. First flown in 1946, the P2V‑4 entered service with the United States Navy in 1949 as the first production model equipped with the new Wright R‑2600‑13 radial engines and a pair of Allison J33‑19 turbo‑jets mounted in nacelles under the wings. This hybrid propulsion gave the Neptune a cruising speed of over 300 knots and a remarkable range of more than 4,000 nautical miles, allowing it to patrol vast ocean areas. Its airframe featured a deep, low‑wing monoplane design with a large internal bomb bay that could carry depth charges, torpedoes, sonobuoys and later, nuclear depth bombs. Advanced radar, magnetic anomaly detection equipment and electronic support measures gave the P2V‑4 unprecedented ASW capability during the early Cold War. The aircraft proved decisive in early carrier‑based patrol operations, contributed to the detection of Soviet submarines, and later served in reconnaissance and weather‑sampling roles during the Korean and Vietnam conflicts. The P2V‑4 established the Neptune lineage that evolved into the iconic P‑2 and P‑3 families, shaping modern maritime patrol doctrine.

Lockheed Corporation

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