The Grumman S-2 Tracker (S2F prior to 1962) is the first purpose-built, single airframe anti-submarine warfare (ASW) aircraft to enter service with the United States Navy.

The Tracker was intended as a replacement for the Grumman AF Guardian,[1] which was the first purpose-built aircraft system for anti-submarine warfare.

[2] The Tracker combined both functions in one aircraft, saving deck space aboard carriers and making for more efficient operations.

[1] Grumman's design (model G-89) was for a large high-wing monoplane with twin Wright Cyclone R-1820 nine cylinder radial engines, a yoke type arrestor hook and a crew of four.

Early model Trackers had an Electronic Support Measures (ESM) pod mounted dorsally just aft of the front seat overhead hatches and were also fitted with a smoke particle detector or "sniffer" for detecting exhaust particles from diesel-electric submarines running on snorkel.

Early Trackers also carried 60 explosive charges, dispensed ventrally from the rear of the fuselage and used to create sound pulses for semi-active sonar (JULIE) with the AN/AQA-3 and later AQA-4 detection sets, whereas the introduction of active sonobuoys (pingers) and AN/AQA-7 with the S-2G conversion saw these removed.

[citation needed] A number of Trackers live on as firefighting aircraft while the design also continued to provide excellent service with the naval forces of other countries for years after the U.S. retired them.

They were extensively used in the 1982 Falklands War, first from Veinticinco de Mayo, from where they detected the British task force, and then from the mainland[11] when the carrier returned to port after the sinking of the cruiser ARA General Belgrano.

[14][15] Between 1967 and 1984 the Royal Australian Navy operated two Squadrons of S-2E and S-2G variants, based at NAS Nowra (HMAS Albatross).

[16] However, on 4 December 1976, a deliberately lit fire in a hangar at Nowra destroyed or badly damaged a large proportion of the RAN's complement of Trackers.

At the end of its service in Brazilian Air Force, one S-2T Turbo Tracker was evaluated as a possible upgrade, but due high costs the program was canceled.

However, in 2010 the Brazilian Navy contracted Marsh Aviation to convert four S-2Ts[19] to Airborne Early Warning configuration and upgrade four additional Grumman C-1 Traders for tanking and carrier onboard delivery transport duties.

The latter were scheduled to be back in service by 2015 and were expected to operate from the successor of Minas Gerais, NAe São Paulo.

[20] Following the bankruptcy of Marsh Aviation in 2009 the program suffered delays and the upgrade of the airframes was resumed in partnership with Elbit Systems's subsidiary, M7 Aerospace.

[citation needed] In 1954, de Havilland Canada (DHC) entered into a contract to build 100 Trackers under license to replace the outmoded Grumman TBM-3E Avengers being used by the Royal Canadian Navy (RCN).

Also in 1964, a pair of CS2F-1 aircraft were stripped of armament and ASW electronics, converted to transports, and subsequently used for carrier onboard delivery.

An additional 17[33] Canadian-built CS-2A (CS2F-1) aircraft formerly operated by the Royal Canadian Navy were delivered between December 1960 and September 1961 after being overhauled by Fairey Canada.

The conversion involved the installation of two Garrett/Honeywell TPE-331-15AW turboprop engines, each rated at 1,227 kW (1,645 shp), with four-blade propellers This resulted in a payload increase of 500 kg.

[37] From the late 1970s until the mid-1990s Conair Aviation of Abbotsford, British Columbia, Canada took possession of retired Canadian and U.S. Trackers and converted them into Firecats, with a four-door fire retardant tank replacing the weapons bay and adjacent mid-fuselage section.

[citation needed] In 1958, CAL FIRE, then CDF, contracted with a private air tanker service for the use of their converted World War II aircraft.

[42] After re-engining with Honeywell TPE331 turboprop engines, at a cost of about $3 million per aircraft, it was expected to provide at least twenty years of service.

[39] Following its conversion in 1999, the aircraft was used during the 1999 Antalya wildfires and the Tüpraş Izmit Oil Refinery fire, started after the 1999 İzmit earthquake.

[39] TAI's Flight Test Engineering Group flew the lone converted aircraft as a testbed for new technology until the mid-2010s.

Although still in active service in South America, numbers of Trackers are on public display, mainly in countries that formerly operated the type.