LOCKHEED AP-2H NEPTUNE

Designed as a long-range anti-submarine patrol plane the Neptune first flew on May 17, 1945 and P2V-1s and -2s entered service with the U. S. Navy in March 1947. Steady technological upgrades and new orders kept the Neptune in production until April 1962. The final production version, the P2V-7 (later P-2H), began coming off the assembly line in 1954 and was the first version built with underling jet engines. The AP-2H designation was applied to four heavily modified SP-2H aircraft for a special program during the Vietnam War. This program, the Trails Roads Interdiction Multisensor (TRIM) Project was designed to use then new technologies such as FLIR (Forward Looking Infra-Red) and LLLTV (Low Light Level Television) to track and attack North Vietnamese supplies and troops along the Ho Chi Minh Trail.