Lockheed AP-2H Neptune

The Lockheed AP‑2H Neptune was a specialized maritime patrol and anti‑submarine warfare variant of the original P‑2 Neptune series. Developed in the early 1960s, the AP‑2H resulted from a conversion program undertaken by Lockheed Corporation that upgraded existing P‑2H airframes with advanced electronic and weapons systems. The aircraft first entered service with the United States Navy in 1965, and later saw limited export to allied navies. Its airframe retained the twin‑engine, high‑mounted wing and robust landing gear of the P‑2, but incorporated a dorsal radome housing the APS‑15 radar, a magnetic anomaly detector, and upgraded fire‑control computers. The AP‑2H could carry torpedoes, depth charges, AGM‑84 Harpoons and sonobuoys, giving it a versatile payload for both anti‑submarine and surface‑search missions. The addition of a modernized navigation suite and autopilot extended its endurance to over 12 hours, crucial for long‑range Atlantic and Pacific patrols. Though only a few dozen were built, the AP‑2H represented the transition from piston‑powered patrol aircraft to the jet‑driven P‑3 Orion, influencing subsequent maritime patrol design. Its operational legacy underscored the value of adaptable airframes in Cold‑War naval strategy, cementing its place in aviation history.