The Grumman S-2 Tracker (previously S2F prior to 1962) was the first purpose-built, single airframe anti-submarine warfare (ASW) aircraft to enter service with the U.S. Navy. The Tracker was of conventional design with twin engines, a high wing and tricycle undercarriage. The type was exported to a number of navies around the world. Introduced in 1952 the Tracker saw service in the USN until the mid-1970s with a few aircraft remaining in service with other air arms into the 21st century. The last operating fleet is maintained by Argentina and Brazil.
The Argentine Naval Aviation received seven S-2A in 1962, six S-2E in 1978 and three S-2G in 1990s. They were used from both aircraft carriers, the ARA Independencia and the ARA 25 de Mayo and used in the COD (US-2A conversions), Maritime Patrol and ASW roles. They were extensively used in the 1982 Falklands War, first from the 25 de Mayo, from where they detected the British Task Force and then from the mainland when the carrier returned to port after the sinking of the ARA General Belgrano cruiser. In the 1990s, six remaining airframes where refurbished by Israel Aerospace Industries with turboprop engines as S-2T Turbo Trackers. As of 2010, with the retirement of Argentina's only aircraft carrier, the Trackers are annually deployed on board Brazilian Navy NAe São Paulo during joint exercises ARAEX and TEMPEREX. and with U.S. Navy's aircraft carriers during Gringo-Gaucho maneuvers.
http://en.wikipedia.org/wiki/Grumman_S-2_Tracker
