DeHavilland CP-121 Tracker Royal Canadian Navy Forces Patrol

Royal Canadian Navy - Marine Royale Canadienne
Grumman/DeHavilland CP-121 Tracker

01/22

Description + Specifications:

The Grumman S-2 Tracker (S2F prior to 1962) was the first purpose-built, single airframe anti-submarine warfare (ASW) aircraft to enter service with the United States Navy. Designed and initially built by Grumman, the Tracker was of conventional design - propeller-driven with twin radial engines, a high wing that could be folded for storage on aircraft carriers, and tricycle undercarriage. The type was exported to a number of navies around the world. Introduced in 1952, the Tracker and its E-1 Tracer derivative saw service in the U.S. Navy until the mid-1970s, and its C-1 Trader derivative until the mid-1980s, with a few aircraft remaining in service with other air arms into the 21st century.

Design and development:
The Tracker was intended as a replacement for the Grumman AF Guardian, which was the first purpose-built aircraft system for ASW, using two airframes for two versions, one with the detection gear, and the other with the weapon systems. The Tracker combined both functions in one aircraft. 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. Both the two XS2F-1 prototypes and 15 S2F-1 production aircraft were ordered at the same time, on 30 June 1950. The first flight was conducted on 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 Grumman E-1 Tracer and Grumman 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 colloquially called the "stoof with a roof.".

Grumman produced 1,185 Trackers and 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, Turkey and Taiwan.

The Tracker had an internal torpedo bay capable of carrying two lightweight aerial torpedoes or one nuclear depth charge. There were six underwing hard points for rocket pods and conventional depth charges or up to four additional torpedoes. A ventrally-mounted retractable radome for AN/APS-38 radar and a Magnetic Anomaly Detector (MAD) AN/ASQ-8 mounted on an extendable rear mounted boom were also fitted. 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. Later S-2s had the sniffer removed and had the ESM antennae moved to four rounded extensions on the wingtips. A 70-million-candlepower searchlight was mounted on the starboard wing. The engine nacelles carried JEZEBEL sonobuoys in the rear (16 in early marks, 32 in the S-2E/G). 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. Smoke dispensers were mounted on the port ventral surface of the nacelles in groups of three each.

Canadian service:
In 1954, de Havilland Canada (DHC) entered into a contract to build Trackers under license to replace the outmoded Grumman TBM-3E Avengers being used by the Royal Canadian Navy (RCN). 99 Trackers were built by DHC, with the first Canadian-built aircraft flying on 31 May 1956. From 1957 onwards, these aircraft operated from the newly deployed aircraft carrier HMCS Bonaventure and various shore bases. All the Canadian Trackers were built to the earlier "A" model airframe design with a length of 42 feet (13 m) (c.f. 43 ft 6 in (13.26 m) for later model Trackers) in order to fit in Bonaventure's hangar. In 1960-1961, 17 CS2F-1 aircraft, which had been relegated to training and utility duties by the CS2F-2, were transferred to the Royal Netherlands Navy. From 1964, 45 CS2F-2s were upgraded by fitting revised electronic equipment and sensors, becoming CS2F-3s. 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. 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 gradually all but 20 were placed in storage and the remainder were stripped of their ASW gear. The remaining active-duty Trackers served until 1990 on 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.

Variants:

CS2F-1 Tracker
Initial production run of anti-submarine warfare aircraft for Canada based on S2F-1. A total of 42 built by De Havilland Canada.

CS2F-2 Tracker
Improved version of CS2F-1 with Litton Industries tactical navigation equipment. A total of 57 were built by De Havilland Canada.

CS2F-3 Tracker
New designation given to 43 CS2F-2 aircraft upgraded with additional electronics.

CP-121 Tracker
New designation given to all CS2F-1, -2, and -3 aircraft following unification of Canadian military in 1968.

Operators:

Royal Canadian Navy:
99 units / 42 CSF-1 and 57 CSF-2 - 43 converted to CSF-3 (1956-1968)

Canadian Forces:
99 CP-121 Tracker (1968-1990)

Specifications (S-2F):
Crew: 4
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 sq ft (45.1 m2)
Empty weight: 18,315 lb (8,308 kg)
Gross weight: 23,435 lb (10,630 kg)
Max takeoff weight: 26,147 lb (11,860 kg)
Powerplant: 2 x Wright R-1820-82WA 9-cylinder air-cooled radial piston engines, 1,525 hp (1,137 kW) each
Maximum speed: 243 kn (280 mph, 450 km/h) at sea level
Cruise speed: 130 kn (150 mph, 240 km/h)
Range: 1,173 nmi (1,350 mi, 2,172 km)
Endurance: 9 hours
Service ceiling: 22,000 ft (6,700 m)
Wing loading: 48.3 lb/sq ft (236 kg/m2)

Armament:
4,800 lb (2,200 kg) of payload could be carried in the internal bomb bay and on 6 x under-wing hardpoints
Mk.41, Mk.43, Mk.34, Mk.44, or Mk.46 Torpedoes
Mk.54 depth charges or naval mines

source: wikipedia

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