The Lockheed P-3 Orion is a four-engine turboprop anti-submarine and maritime surveillance aircraft developed for the United States Navy introduced in the 1960s. It was developed by Lockheed based on their L-188 Electra commercial airliner. The aircraft is easily recognizable by its distinct tail stinger, used for the magnetic detection of submarines. Over the years, the aircraft has seen numerous design advancements, most notably to the electronic packages the aircraft carries. The P-3 Orion is still in used by numerous navies and air forces around the world, primarily for maritime patrol, reconnaissance, anti-surface warfare and anti-submarine warfare.