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S-2 Tracker



ASW aircraft



First flight

4 December 1952


February 1954


1976, USN


active with Argentine Navy

Primary users

US Navy
Royal Canadian Navy
Royal Australian Navy
Argentine Navy

Number built



C-1 Trader
E-1 Tracer


The Grumman S-2 Tracker (previously S2F) was the first purpose-built, single airframe anti-submarine warfare (ASW) aircraft to enter service with the US Navy.

Its predecessor, the AF-2 Guardian was the first purpose-built aircraft system for ASW, using two airframes, one with the detection gear, and the other with the weapons.

Design and development

Grumman's design (model G-89) was for a large high-wing monoplane with twin Wright Cyclone radial engines. Both the two prototypes XS2F-1 and 15 production aircraft, S2F-1 were ordered at the same time, on 30 June 1950. First flight was 4 December 1952, and production aircraft entered service, with VS-26, in February 1954.

Follow-on versions included the WF Tracer and TF Trader, which became the E-1 Tracer and C-1 Trader in the tri-service designation standardization of 1962. The S-2 carried the nickname "Stoof" (S-two-F) throughout its military career; and the E-1 Tracer variant with the large overhead radome was called the "stoof with a roof.".

Grumman produced 1,185 Trackers. Another 99 aircraft carrying the CS2F designation were manufactured in Canada under license by de Havilland Canada. U.S.-built versions of the Tracker were sold to various nations, including Australia, Japan and Taiwan.

Operational history

The Tracker was eventually superseded for U.S. military use by the S-3 Viking — the last USN Tracker squadron (VS-37 with S-2G models) was disestablished in 1976, but a number live on as firefighting aircraft. Trackers continued to provide excellent service with the naval forces of other countries for years after the U.S. discontinued them. For example, the Royal Australian Navy continued to use Trackers as front line ASW assets until the mid 1980s.


The Argentine Navy received its first S-2A models on the 1960s and later the improved S-2E. They were embarked on the ARA 25 de Mayo aircraft carrier and used in the COD, Maritime Patrol and ASW roles. In the 1990s, six remaining airframes where refurbished by Israel Aerospace Industries with turboprop engines as S-2T Turbo Trackers. 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.


The Royal Australian Navy operated two Squadrons of S-2E and S-2G variants from 1967 until 1984. VS-816 front line squadron, although based at Nowra, frequently embarked the Majestic class aircraft carrier HMAS Melbourne, as part of the 21st Carrier Air Group whenever that ship was deployed. VC-851 training squadron was based at NAS Nowra, HMAS Albatross.

During about 20 years of operation of the Tracker, the RAN lost only one S-2 during aircraft operations due to an accident at sea. However, in the mid 1970s a deliberately lit fire in a hangar at Nowra destroyed or badly damaged a large proportion of the RAN's complement of Trackers. These were subsequently replaced with ex-USN aircraft. The replacement aircraft were all S-2Gs, including the original aircraft modified by the USN to that status. This saw the introduction of AQA-7 acoustic gear into RAN service and all RAN operational Trackers were subsequently modified to this standard. The AQA-7 significantly enhanced the RAN's ASW capability.


In 1954, de Havilland Canada entered into a contract to build Trackers under license to replace the outmoded TBM-3E Avengers being used by the Royal Canadian Navy. A total of 99 Canadian-built Trackers would enter service starting in 1956. From 1957 onwards, these aircraft operated from the newly-deployed aircraft carrier HMCS Bonaventure and various shore bases. In order to fit aboard Bonaventure, the Canadian Trackers had their length reduced from the standard S2F length of 43 ft, 6 in (13.26 m) to an even 42 feet (12.80 m), and due to the reduced yaw moment of the shorter fuselage, an additional hydraulic booster was added in the tail assembly to reduce rudder effort in the case of an engine-out situation. In 1960, 17 active-duty CS2F-1 aircraft were transferred to the Royal Netherlands Navy. 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. The CS2F-1, -2, and -3 were redesignated as the CP-121 Mk.1, Mk. 2, and Mk. 3 respectively following the unification of Canadian forces in 1968.

After Bonaventure was decommissioned in 1970, all remaining Canadian Trackers were transferred to shore bases. This limited their usefulness for ASW patrols, and between 1974 and 1981, all but 20 were gradually placed in storage and the remainder were stripped of their ASW gear. The remaining active-duty Trackers served until 1990 doing fisheries protection and maritime patrol duties. A handful of Trackers were kept in flying condition until the late 1990s but were no longer used for active service.

A single Grumman-built S2F-1, serial number X-500, was sold to the RCN before Canadian production commenced. It was initially used for quality control purposes during Canadian production, and was later given a new RCN serial number, upgraded to CS2F-1 standards, and used to train RCN ground and maintenance personnel. This aircraft was placed in storage in 1972 and was undergoing restoration in March 2008.

Civilian use

In the late 1980s and early 90s Conair Aviation of Abbotsford, British Columbia, Canada took possession of retired U.S. and Canadian Trackers and converted them into Firecats, with a retardant tank replacing the torpedo bay. The Firecats were made in two variants, a piston engine Firecat and a turboprop-powered Turbo Firecat.


Two prototype anti-submarine warfare aircraft powered by 1,450 hp R-1820-76WA engines.
Designation of the first 15 production aircraft used for development, redesignated YS-2A in 1962.
Initial production variant with two 1,525 hp R-1820-82WA engines, re-designated S-2A in 1962, 740 built.
Trainer conversion of S2F-1, redesignated TS-2A in 1962.
Utility conversion of S2F-1, redesignated US-2A in 1962.
S2F-1 conversion with Julie/Jezebel detection equipment, redesignated S-2B in 1962. Survivors converted to US-2B after removal of ASW gear.
S2F-1S fitted with updated Julie/Jezebel equipment, redesignated S-2F in 1962.
As S2F-1 with asymmetrical (port-side) extension of bomb bay, slightly enlarged tail surfaces, 77 built, most redesignated S-2C in 1962.
Photo reconnaissance conversion of S2F-2, redesignated RS-2C in 1962.
Utility conversion of S2F-2/S-2C, redesignated US-2C in 1962. Some were used as target tugs.
Enlarged forward fuselage, enlarged tail surfaces, additional fuel capacity, and enlarged engine nacelles bays for 32 sonobouoys, redesignated S-2D in 1962, 100 built.
As S2F-3 but with Julie/Jezebel equipment, redesignated S-2E in 1962, 252 built.
YS2F-1 redesignated in 1962.
S2F-1 redesignated in 1962.
S2F-1T training version redesignated in 1962 and 207 conversion from S-2A.
S-2A converted as light transports/target tugs, 51 conversions.
S2F-1S redesignated in 1962.
Utility and target tug conversions of S-2A and S-2B, Most S-2Bs were converted and 66 S-2As.
S2F-2 redesignated in 1962.
S2F-2P photo-reconnaissance version redesignated in 1962.
S2F-2U utility version redesignated in 1962.
S2F-3 redesignated in 1962.
Proposed self-contained night attack aircraft to be developed under Operation Shed Light; none produced.
Electronic trainer conversion of the S-2D.
Utility conversion of the S-2D.
S2F-3S redesignated in 1962.
S2F-1S1 redesignated in 1962.
Transport conversion of S-2F.
S-2E conversions with updated electronics.
Initial production run of anti-submarine warfare aircraft for Canada based on S2F-1. 42 built by De Havilland Canada.
Improved version of CS2F-1 with Litto Industries tactical navigation equipment. 57 built by De Havilland Canada.
New designation given to 43 CS2F-2 aircraft upgraded with additional electronics.
New designation given to all CS2F-1, -2, and -3 aircraft following unification of Canadian military in 1968.
S-2T Turbo Tracker
Civil conversion
Civil firefighter conversion.
Civil conversion.
Marsh S-2F3AT Turbo Tracker
Turboprop conversion, powered by two Garrett TPE331 engines; 22 operated by the CDF
Conair Firecat or Turbo Firecat
Civil conversion as a single-seat firefighting aircraft.
  • For the crew trainer/transport version based on the Tracker refer to C-1 Trader
  • For the Airborne Early Warning version based on the Trader refer to E-1 Tracer


Military Operators

  • Argentine Navy
  • Royal Australian Navy
  • Brazilian Air Force used Trackers on behalf of the navy until their retirement. They operated from the aircraft carrier NAeL Minas Gerais.
  • Royal Canadian Navy
  • Canadian Forces
  • Italian Air Force
  • Japan Maritime Self-Defense Force received 50 S2F-1 in 1957 from US, and operated until 1984. After received,6 S2F-1 are remodeled 4 S2F-U and 2 S2F-C. S2F-1 is nicknamed Aotaka(あおたか, Blue Hawk). A S2F-1 is displayed in Kanoya Air Base,Kanoya, Kagoshima.
 South Korea
  • Republic of Korea Navy
  • Royal Netherlands Navy received in 1960 17 CS2F-1 aircraft formerly used by the Royal Canadian Navy. These aircraft were operated from land bases as well as from the light carrier Karel Doorman until a fire in 1968 took that ship out of Dutch service.
  • Peruvian Navy operated with S-2E and S-2G from 1975 until 1989, they were assigned to Naval Aviation Squadron N°12 (Escuadron Aeronaval N°12). A total of 12 S-2E were bought from the US Navy in 1975 and 4 S-2G in 1983.
 Republic of China (Taiwan)
  • Republic of China Navy currently operate 2 S-2T (upgrade from S-2E and S-2G, 22 S-2T have been retired with the remaining to be replaced by 12 P-3C Orions).
  • Air Division of the Royal Thai Navy
  • Turkish Navy Aerial Wing
 United States
  • United States Navy operated their Trackers between 1954 and 1976.
  • United States Marine Corps operated some Trackers.
  • Uruguayan Navy received the first three S-2A Trackers on 10 April 1965 to the Capitan Curbelo Navy Base. On 15 September 1982 one S-2G arrived. On 2 February 1983, another two S-2Gs arrived. By September 2004 the remaining Uruguayan Trackers were not in flight condition.
  • Venezuelan Navy

Civil Operators

Many retired Trackers were sold to private owners for fire-fighting duties. Some were rebuilt and re-engined with turboprop engines.

  • Conair Group Inc. received TS-2A/Conair Firecat (G-89).
  • Saskatchewan Environment received TS-2A/Conair Firecat (G-89).
  • Sécurité Civile received US-2A/Conair Turbo Firecat (G-89).
  • KLM - Royal Dutch Airlines operated S-2 Tracker (G-89/G-121/S2F) - ex-Dutch Navy Tracker was used by KLM to train their mechanics.
 United States
  • California Department of Forestry & Fire Protection received S-2F3AT Turbo Tracker (G-121)
  • Hemet Valley Flying Service received TS-2A(FF) Tracker (G-89)
  • Marsh Aviation received S-2A(FF) Tracker (G-89)
  • Sis-Q Flying Service received TS-2A Tracker (G-89/S2F-1T)
  • Aero Union, in addition to being an operator, Aero Union devekioed the prototype S-2 tankers for the State of California in 1973.

Specifications (S-2F)

General characteristics

  • Crew: four (two pilots, two detection systems operators)
  • Length: 43 ft 6 in (13.26 m)
  • Wingspan: 72 ft 7 in (22.12 m)
  • Height: 17 ft 6 in (5.33 m)
  • Wing area: 485 ft² (45.06 m²)
  • Empty weight: 18,315 lb (8,310 kg)
  • Loaded weight: 23,435 lb (10,630 kg)
  • Max takeoff weight: 26,147 lb (11,860 kg)
  • Powerplant: 2× Wright R-1820-82WA radial engines, 1,525 hp (kW) each


  • Maximum speed: 280 mph (450 km/h) at sea level
  • Cruise speed: 150 mph (240 km/h)
  • Range: 1,350 mi (2,170 km) or 9 hours endurance
  • Service ceiling: 22,000 ft (6,700 m)


  • 2× homing torpedoes (Mk. 41, Mk. 43, or Mk. 34), depth charges (Mk. 54), or mines in the bomb bay
  • 6× underwing hardpoints for torpedoes, depth charges, or rockets