Lockheed P-3 Orion

The Lockheed P-3 Orion is a four-engined, turboprop anti-submarine and maritime surveillance aircraft developed for the United States Navy and introduced in the 1960s. It is based on the L-188 Electra airliner and is easily told apart from it by the tail stinger used for magnetic anomaly detection of submarines. In August 1957 the Navy asked for a replacement for the piston-engined P2V Neptune and the P5M Marlin, Lockheed won the competition in April 1958 with a military development of the Electra, and the aerodynamic prototype first flew on 19 August 1958. Four Allison T56 turboprops give a top speed of 411 knots. The type became the P-3 Orion in the unified designation system of 18 September 1962. A total of 757 have been built, and many navies and air forces still use it for maritime patrol and reconnaissance, while the Boeing P-8 Poseidon is beginning to replace the Navy examples.