Heritage: Grumman Tracker

In 1967 the Grumman Tracker S-2E/G replaced the Fairey Gannet AS-1 as the Royal Australian Navy’s long-range fixed-wing Anti-Submarine Warfare (ASW) aircraft. The Tracker was an outstanding aircraft, designed specifically for carrier operations. Sturdy and reliable, the Trackers were well suited to their ASW role, serving on the carrier HMAS Melbourne (II) and at RANAS Nowra. Other duties included coastal surveillance and fishery patrols from 1975 to December 1980. After 17 years of exceptional service, the RAN retired the Trackers in 1984.  

The Replacement Problem

During the late 1950s Royal Australian Navy (RAN) began searching for replacements for its dated Fairey Gannet and DH Sea Venom aircraft. Because the next generation of naval aircraft had increased in size and weight, the view was HMAS Melbourne was too small and that a larger aircraft carrier was needed – requiring a significant financial outlay. As the Government was heavily committed to Army and Air Force re-equipment programs the outlook was not favourable.

In November 1959, the Defence Minister announced that the RAN Fleet Air Arm (FAA) would be disbanded in 1963, when the Gannets and Sea Venoms were due to retire. However, with mounting ‘Cold War’ tensions, SEATO commitments and concerns with Soviet influence in the region, that plan changed in 1961 when the Government decided to equip the FAA with Westland Wessex anti-submarine helicopters, and to operate HMAS Melbourne as an ASW helicopter carrier.

RAN FAA Renewal 

In 1963, with the Indonesian ‘Confrontation’ and communist aggression in South East Asia creating instability, the life of the Gannets and Sea Venoms was extended for four years. Repeated efforts by the Naval Board to restore the FAA’s offensive and defensive capabilities began to attract attention. But the idea of equipping the FAA with a larger aircraft carrier was vetoed due to costs and manpower shortages. Meanwhile, the search for replacement aircraft suitable for Melbourne continued, with two USN aircraft shortlisted. One was the Grumman Tracker which had operated from Melbourne’s Majestic-class sister ship HMCS Bonaventure since 1957. The other was the A4 Skyhawk. 

In May 1958, a Tracker S-2F from USS Philippine Sea completed a proving trial on HMAS Melbourne. This was repeated on 7 July 1964 with two S-2E Trackers from Subic Bay. In November 1964 Cabinet approved the purchase of the Trackers, including modifications to Melbourne. Then, following a USN Skyhawk A4 proving trial on our carrier in May 1965 the Skyhawks were approved, together with the up-grading of the Westland Wessex helicopters to Mk 31B standard.     

The Pilot Shortage

The purchase of the S2Es and the A4s secured the future of fixed-wing operations in the RAN FAA but exposed a shortage of pilots, caused by the 1959 decision to disband the RAN FAA.

Because the RAN did not have an entry-level pilot training school, trainees had previously been sent to the RAAF at Point Cook for a Basic Flying Training Course. However, in mid-1960s, the RAAF was over-stretched training pilots for Vietnam and the F-111s, and unable to handle the number of pilots the RAN required. The solution was to engage a leading aero club with highly qualified ex-service instructors to conduct the RAN’s introductory fixed-wing training. 

In 1966, the first (non-RAAF) group of RAN midshipman trainee pilots began a three-week Primary Flying Training Course with the Royal Victorian Aero Club, at Moorabbin Airport, south of Melbourne. The course involved 25 hours of ground instruction and 15 hours of flying training in DHC Chipmunk two-seat, single engine, primary trainers – with graduates ‘graded’ for further training. Those who did not pass the pilot test had the opportunity to become Observers.

Pilots who qualified were sent to the US Navy Air Station at Pensacola, Florida, for Basic Flying Training with T-28 and T-34 aircraft, and then to Corpus Christi, Texas, to fly Trackers (some pilots switched to A4 Skyhawks; others returned to Nowra for helicopter training). The USN training lasted about 18-months covering basic instruction through to carrier deck qualifications (at San Diego). The RAN pilots and aircrews were well regarded and set a high standard.    

In 1965, a group of RAN pilots and observers (experienced Fairey Gannet and Sea Venom aircrew) were sent to HMCS Shearwater, Nova Scotia, for a two-year training course on Royal Canadian Navy (RCN) Trackers. On return to NAS Nowra they formed the RAN Tracker Training Unit, complete with simulator and weapons system trainer. The unit was attached to 851 Squadron (recommissioned in September 1968) training Tracker pilots, observers, and aircrew. [Note: The last aircrew intake trained by the RAAF also went to Canada for Tracker training. Before departing they gained some twin-engine experience flying the RAN Dakotas at Nowra.]  

Right: The decision to use a civilian Aero Club in Victoria to provide ab-initio training in 1966 was a novel departure from the norm, born of necessity. Only one intake used this stream, who subsequently went on to the US (Pensacola and Corpus Christi) for more advanced training in a military environment and on military aircraft (far right).

In the meantime experienced aircrew had been sent to Nova Scotia for a two year training course on RCN Trackers. On return they formed the RAN Tracker Training Unit. (All newspaper clippings courtesy of Trove). (Click on images to enlarge).

Maintainer Instruction  

Early in 1966 a group of senior maintainers from Nowra arrived at the USN North Island Naval Air Station, at San Diego, California. The task was to learn about the Trackers systems, in readiness to become instructors on return to Australia. The aim being to build a high level of maintainer expertise at RANAS Nowra – ready for the arrival of the Trackers and Skyhawks. 

The main body of RAN maintainers arrived in the US in mid-1966 for detailed Tracker and Skyhawk instruction; including ‘hands-on’ experience attached to USN squadrons. There was much to learn about these aircraft – apart from new airframes and engines, the advanced avionics and ASW equipment required fresh skill sets. Because the USN aircraft stores and supply system was entirely different to that in the RAN, it took time to adjust to. Most of the maintainers returned to Australia on Melbourne – embarking at San Diego on 27-31 October 1967, together with the new aircraft. The training assistance provided by the USN and company instructors was comprehensive, and the friendly cooperation was much appreciated.

The Trackers Arrive

On 20 September 1967 Melbourne departed Sydney Harbour to collect the Trackers and Skyhawks from the USA. Sailing via Pearl Harbour, Vancouver, Los Angeles, and San Francisco. Melbourne berthed at San Diego where the aircraft were embarked on 27 and 30 October 1967.

On the 31st Melbourne sailed for Australia via Pearl Harbour and Suva, arriving at Jervis Bay on 21 November where 10 Skyhawk A4Gs were disembarked. On arrival at Sydney the following day, the 14 Tracker S-2Es were taken by road to Mascot for servicing, then flown to Nowra.  

With the arrival of the Trackers at Nowra, the process of forming the squadrons began. The primary Tracker unit, VS816 Squadron, was recommissioned on 10 January 1968 and immediately began exercises to bring the unit up to front-line standard. Melbourne was undergoing an extended refit over this period so it gave the squadron the opportunity to work-up with some  serious training off the NSW south coast.   

One of the issues the squadron had to deal with was flying the Tracker with one pilot (five to six hours was not unusual). Whereas the USN and RCN Trackers operated with a pilot and co-pilot in the cockpit, the RAN opted to have a TACCO (Tactical Coordinator) in the co-pilot’s seat. Although the Tracker had an effective autopilot to ease the pressure, lengthy day/night missions were not unusual, often flying in poor weather at a low level, placing a lot of pressure on the pilot. The up-side was the TACCO was in close contact with the pilot. This system worked well – demonstrating the high standard of training and cooperation in the cockpit.

Grumman Tracker Basics

Tracker Basics

Manufacturer: Grumman Aircraft Corp., USA
Type: All weather carrier ASW & Surveillance
Engines: 2 Wright Cyclone R-1820-82WA 9-cylinder radials
Max speed: 243 knots
Cruising speed: 130 knots
Service ceiling: 6,700 m (22,000 ft)
Range: 1,173 nm, or about 9 hrs duration.
Wingspan: 22.12 m (72 ft 7 in.)
Height: 5.33 m (17 ft 6 in)
Length: 13.26 m, (43 ft 6 in)
Empty weight: 8,319 kg (18,315 lbs)
Loaded: 10,630 kg (23,435 lbs)
MTOW: 11,860 kg (26,147 lbs)
Note: Performance figures subject to conditions

Naval aircraft manufacturer Grumman Aircraft Engineering Corporation, of Bethpage NY, was awarded a US Navy contract in 1950 to develop a purpose-built ‘hunter-killer’ anti-submarine warfare (ASW) aircraft. The prototype was the G-89 – a twin engine design capability of carrying weapons, surveillance and detection equipment and a search radar. This evolved into the XS2F Tracker which became designated as the S2-F, known throughout its life as the ‘Stoof’ (S-two-F).

The S2 first flew in 1952 and commenced service with the USN in 1954. It was an immediate success with variants produced until 1967. In all, more than 1,200 Trackers were built, including 99 built under licence by the De Havilland Canada for the Royal Canadian Navy. Orders for the Tracker came from 14 other countries.      

The Tracker was a high-wing monoplane, powered by two Wright R-1820-82, 9-cylinder, air-cooled, radial piston engines, each producing 1,525 hp; fitted with Hamilton Standard 3-blade variable pitch propellers. The wings had large Fowler-type flaps, spoilers, outer wing leading-edge slots; and a searchlight under the starboard wing. The wings folded over the fuselage to assist flight deck and hangar stowage. The Tracker’s heavy-duty tricycle undercarriage and tail-mounted arrestor hook were essential for carrier operations.

The S2 was primarily an ASW aircraft. Above: A Tracker as seen from the periscope of HMAS Onslow. Below: Overflying an Australian Oberon Class boat.

Designed for ASW and surveillance work, the Tracker included AN/APS-88 search radar in a retractable radome, aft of the bomb bay. To sense underwater objects a Magnetic Anomaly Detector (MAD) boom was extend from the tail. The S-2E/G had a AQA4/AQA7 sonics system and carried up to 32 SSQ41 (passive) and/or SSQ47 (active) acoustic sonobuoys – ejected from the rear of the engine nacelles. ECM radar direction finders were located in the wing tips. The bomb bay variously carried homing torpedoes or depth charges. Underwing hardpoints carried depth charges, rockets, or other munitions.    

The S-2E/G Variants

RAN Trackers had a crew of four: Pilot and Observer/TACCO in the cockpit; plus two electronic operators in the rear cabin. The S-2E/G incorporated several modifications that made them larger and heavier than the earlier S-2A models. This including a 45.7 cm (18 inch) fuselage extension aft of the cockpit, increased fuel capacity, streamlined engine nacelles, upgraded avionics and ASW gear, slightly wider wings, and increased tail surfaces. There was little variation between the S2E, with which the RAN was initially equipped, and the S2G (that came later), other than internal equipment fit. Trackers were the largest fixed-wing aircraft to operate from Melbourne.

The RAN’s Trackers were distributed over two Squadrons: VS816 was the front-line unit operating from RANAS Nowra or at sea on Melbourne, whilst VC851 concerned itself with shore-based training.  

Purpose Built & Dependable

The Tracker was light and responsive on the controls, and able to manoeuvre safely at low level and speeds – essential in ASW work. The two Wright Cyclone engines, although based on a

1930/50s design, were powerful and reliable. Trackers could fly on one engine – to counter the asymmetric thrust of one engine, a ‘single engine rudder assist’ (SERA) facility was built-in. This consisted of two parts: at the rear was the ‘main rudder’ and trim tab; forward was the ‘auxiliary rudder’ attached to the vertical fin. When the SERA was activated both rudders worked together to double to size of the rudder. As a rule, the SERA was switched on for take-off and landings, and off for cruising. Forward vision in the cockpit was good and the bubble side windows provided side and downwards vision. Rear vision was limited by the engines. An early concern during landings on HMAS Melbourne was the short distance between the starboard wingtip and the flight deck island, but precision landings and care avoided any problems.

The Tracker carried advanced avionics and ASW equipment which included the Jezebel sonar-buoys (hydrophones), a magnetic anomaly detector and radar; operated by two specialist crew members in the rear cabin. During ASW exercises excellent results were achieved when working together with the updated Westland Wessex HAS 31B helicopters, and later with the Sea King helicopters, both of which used dunking sonar. Working as a team to optimise performance, the Trackers flew the long-range ASW patrols with the helicopters providing close-in coverage – both performing day and night exercises in all weather. 

A bird’s eye view. Tracker on finals to HMAS Melbourne. Photo: Nick Thorne.

Flight Deck Drills & Embarkation

HMAS Melbourne completed her long-term refit early in 1969, which included numerous modifications for the Trackers and Skyhawks. In March, with the ship sailing off Jervis Bay, work-up exercises began on Melbourne with the Trackers from Nowra doing ‘touch and goes,’ arrested landings and catapult launches in an intensive program. Once the Air Group completed their flight deck qualifications the squadrons embarked and immediately began series of day and night time exercises; preparing for deployment to SE Asian waters and various coalition exercises.  

Tracker Tasks

Anti-submarine patrols and surveillance were key tasks for the Trackers. Although never used in combat, the Trackers were part of a strong deterrent policy during the ‘Cold War’ years. The RAN’s commitment to SEATO, FESR, ANZUK and ANZUS defence alliances involved regular exercises with allied navies. Due to Australia’s proximity to South East Asia and regional security threats, collective defence was an important aspect of Australia’s defence strategy – and a major reason behind the government’s decision to bolster the FAA’s defensive and strike capability. 

On patrol the Tracker’s rear mounted radar dome would be lowered to detect surface vessels and submarines (air scoops on the fuselage cut radome vibration). If a suspicious target was located a marker flare or a pattern of sonar-buoys (hydrophones) could be dropped to listen for submarine noises. The magnetic anomaly detector (MAD) could detect minor variations in the magnetic field created by a submerged submarine; enabling the operator to distinguish it from a whale or school of fish. 

While 816 Squadron was at sea embarked on HMAS Melbourne, Nowra-based 851 Squadron was busy training Tracker aircrews and conducted Fleet Requirement Unit (FRU) duties; assisting ships with radio and radar calibrations and gunnery exercises. In addition to coastal surveillance, search and rescue missions were conducted using a ‘G’ Dropper positioned under a wing (containing a large inflatable life-raft). Other coastal tasks involved patrolling the economically important Bass Strait oil fields; and further afield, fishery protection patrols covered Australia’s northern shores, operating variously from Broome and Darwin, March 1975 to December 1980.

 The Nowra Hangar Fire

At about midnight on 4 December 1976, a fire destroyed all but three of the RAN S-2E Trackers stored in ‘H’ hangar at RANAS Nowra, crippling both VS816 and VC851Tracker squadrons. Of the 12 Trackers in the hangar 6 were destroyed, three were damaged beyond repair, two were repaired and returned to service and one salvaged as a training aid. The only aircraft to escape the inferno was in Sydney being overhauled. The heat of the fire was so intense that a large part of the hangar roof collapsed. A court-marshal found the junior sailor who started the fire to be mentally unstable.  You can see an account of the police investigation here.


Earlier in October 1976 the had RAN ordered six surplus, low-mileage, S-2E Trackers from a USN storage facility. As delivery was being arranged at the time of the fire, a further ten airframes were added to the order – all sixteen the upgraded S2-G models. In less than four months they were selected, prepared to flight, flown to San Diego and transported to Australia aboard HMAS Melbourne. The RAN had not only restored its ASW/Surveillance capability in an astonishingly short time, but improved it as well.

Multi-National Exercises

During their service life with the RAN the Trackers participated in regular naval exercises with the South East Asia Treaty Organisation (SEATO); the Far East Strategic Reserve (FESR); ANZUK; the biennial RIMPAC exercises, and ‘Kangaroo’ exercises – with other joint, multi-nation exercises taking place at various intervals. Generally, the ANZUS navies were the main participants, but other regional navies were often involved.   

Each year from the mid-1950s to the early 1970s the RAN participated in SEATO and FESR exercises conducted in South East Asian waters. From the late 1960s HMAS Melbourne’s Trackers and Westland Wessex helicopters featured in the ASW ‘war games’. Repeatedly the Trackers demonstrated their value when working in conjunction with the helicopters. These challenging and realistic multi-national exercises were especially important during the ‘Cold War’ years, when Soviet submarine activity was a serious concern.           

In 1971 HMAS Melbourne participated in the inaugural RIMPAC exercises hosted by the US Navy; reaching Pearl Harbour on 25 October, joining navy units from the USN, RN, RNZN, and Canada – where the Trackers reaffirmed their outstanding wide-area search qualities. Other manoeuvres in Australian waters, and multi-nation exercises in SE Asian and Pacific waters were regular events, building inter-service cooperation and experience.

But Melbourne did much more by ‘showing the flag’, visiting Hong Kong, Japan, and other South East Asian ports. Calls were also made at Manus Island and Rabaul, until 1975, when Papua New Guinea became independent. Much of Melbourne’s time at sea was spent testing the ships systems and aircraft in a constant round of intensive exercises, all designed to maintain a high level of efficiency in the ship’s crew and her Carrier Air Group.  

Proud Service Record

Despite the Grumman Tracker’s ‘retro’ appearance, pilots considered them pleasant to fly, and were highly valued as ASW aircraft; superior to the Fairey Gannets they replaced. The RAN Trackers were active during the latter part of ‘Cold War,’ ensuring Australia had an effective anti-submarine ‘seek and destroy’ capability in the event of hostilities. In home waters duties included coastal surveillance, illegal fishing patrols, and search and rescue missions. The Trackers were rugged, first-rate aircraft serving the RAN from 1967 until 1984 when fixed-wing flying in the FAA ended. At that point rotary-wing Westland Wessex and Sea King helicopters took over the ASW role, but the Trackers are remembered for their splendid service record. Several Trackers are on display at aviation museums, including the Fleet Air Arm Museum, at Nowra, NSW.

Postscript

On 25 February 1982, the Minister for Defence announced that HMAS Melbourne was to be placed in ‘contingent reserve’ and that the RAN would take delivery of HMS Invincible in 1983. But, when the April-June 1982 Falklands War intervened, the Invincible deal was cancelled. On 30 June 1982 Melbourne was decommissioned and moved to the dolphins at Athol Bight, Sydney Harbour – having worked long and hard since commissioning in 1955.

In March 1983 the incoming Labor Government announced it would not purchase a replacement aircraft carrier, putting an end to carrier-borne fixed-wing operations in the RAN. Since then various ships in the RAN fleet have been modified to embark ASW helicopters.  

NATOPS FLIGHT MANUAL
We have the full NATOPS Flight Manual for the S2 Tracker but it is a large file [82MB, 752 pages] so is not directly downloadable from this site. If you wish to obtain a copy please use the ‘Contact Us’ form below and we will send you a Dropbox link.  

References

HMAS Melbourne Reports of Proceedings
Australian Defence Review 1972
National Archives of Australia
Flying Stations, ANAM, Allen & Unwin
‘Wings Across The Sea’, Ross Gillett, Aerospace Publications
Wikipedia

Australian Aircraft Carriers 1929-1982, Vince Fazio
Flight International, 6 March 1982
Sea Power Navy News archive
816 & 851 Squadron histories
Air Enthusiast No 61, Willing Tracker
Horatio J Kookaburra, Flickr
ADF Serials
ANL Trove

If you enjoyed reading about the Tracker, why not visit our feature on the Fairey Gannet?  Filled with useful information and with a compendium of photos, we know you will love it!  Click on the image below.