Successful design work led to the first flight of the initial prototype on March 9, 1949, with Avro test pilot JH ‘Jimmy’ Orrell at the controls. The new aircraft was appropriately named after the polar explorer Sir Ernest Shackleton. This was not by any means simply the adopting of a suitable name for the type. Roy Chadwick knew Shackleton personally, and it was as much in tribute to the famous explorer and his long-range exploration under adverse conditions that the Shackleton aircraft received its name.The initial example to fly (the first of three prototypes) was allocated the British military serial number VW126, with the first production-standard version of the Shackleton being designated GR.Mk.1 (general reconnaissance), later amended to MR.Mk.1 (maritime reconnaissance). The initial production example flew in March 1950 and the type entered RAF service with 120 Squadron at RAF Kinloss in Scotland, which received its first examples from March/April 1951 onwards. A further early recipient was 224 Squadron at RAF Gibraltar, the latter being a significant British strategic base in the Mediterranean that was much-frequented by Shackletons in the coming years.
It soon became apparent however, that the MR.1 and the enhanced MR.1A could be improved upon, leading to the birth of a considerably more capable, improved and more powerful derivative. Designated MR.Mk.2, this new Shackleton model was pioneered by an aerodynamic trials aircraft, serial number VW126, which had been the first Shackleton to fly, and which now initially flew with intended MR.2 modifications during July 1951. Among the significant changes that were intended for the MR.2 were the installation of ASV Mk.13 air-to-surface search radar, the radome for this being relocated from the lower nose chin position of the MR.1 to a ventral location aft of the large bomb-bay; this radome was capable of being retracted when not in use. The radar had improved all-round coverage, and its lower fuselage position minimised the risk of bird-strikes.Both the nose and tail section of the MR.2 were lengthened compared to the blunter MR.1, with prominent look-out glazing in the extreme rear fuselage (the latter, apparently, a good place for a quiet nap during long patrol flights). Other changes included the strengthening of the undercarriage and twin-retractable tail wheels.
During the lifetime of the MR.2, the type underwent several major upgrades, with Phase I, II and III modifications introducing improved radar, weapons and other systems, as well as structural strengthening to increase fatigue life.Power for the MR.2 consisted of four mighty Rolls-Royce Griffon V12 piston engines. The Griffon 58 of 2,455hp with water/methanol boost was the preferred type for the later, fully uprated Phase III examples, all Shackletons having contra-rotating propeller units. Of all-metal construction, the Shackleton had a large wingspan of 120ft.
Armament comprised two forward-firing 20mm cannon in the nose, plus a dorsal turret (which was later dispensed with), and some 14,000lb of 1,000lb or 500lb bombs, mines, and/or depth charges. This represented a considerable war load and made the Shackleton MR.2 a potentially deadly foe for any hostile shipping or submarine threat. The capacious lower fuselage bomb-bay was capable of carrying a variety of contemporary ordnance and sonobuoys depending on the mission requirements of individual aircraft.There were typically ten crew members (two pilots, two navigators, a flight engineer, an air electronics officer, and four air electronics operators), however, this was open to revision depending on the mission flown and equipment fit, and sometimes a crew of at least 11 was carried.
WB833, originally ordered as an MR.1 (Avro’s paperwork actually says ‘MR.1A’) was reconfigured as the MR.2 prototype and first flew in this guise on June 17, 1952. The last ten MR.1As on Avro’s production line were completed as MR.2s, the first production example being WG530 which initially flew during August 1952. Orders for 80 further new-build aircraft were placed; the last 21 of these were completed as the later, considerably altered Shackleton MR.3, and therefore the total number of MR.2s built was 69.The Shackleton MR.2 was operated by RAF Coastal Command as part of the NATO requirement for patrols over the Atlantic during the Cold War, continuing the vital role the Command’s Consolidated Liberators had performed during the later stages of World War Two. The increasing number and capability of Soviet submarines posed a real threat to Britain in times of possible conflict, and the long-range Shackletons became the country’s guardians in the same way that Coastal Command had been vital to its survival in World War Two.
The first RAF unit to fly the Shackleton MR.2 was 42 Squadron at RAF St Eval in Cornwall, which received its initial examples in January 1953. Thereafter the type gradually replaced the Shackleton MR.1/MR.1A and Lockheed Neptune MR.Mk.1, becoming Coastal Command’s premier long-range watch over Britain’s waters and maritime interests. The 69th and final MR.2 was WR969, which first flew in May 1954, but the last to make its maiden flight was WR968 on June 17, 1954. Some 14 RAF squadrons eventually flew the MR.2 (there were no export customers for this Shackleton version, nor for the MR.1/MR.1A). The type served into the early 1970s, performing many tasks including maritime patrol, anti-submarine, reconnaissance and search and rescue, in addition to use as troop transports.Sadly, several Shackletons were lost in accidents. The prototype MR.2, WB833, was eventually passed into RAF service after various trials work. While flying from RAF Ballykelly, Northern Ireland, it tragically crashed in poor visibility during April 1968 on the Mull of Kintyre, all crew members losing their lives.In addition to their maritime roles with Coastal Command, RAF Shackletons also played an important part in Colonial Policing (ColPol), as related elsewhere in this issue.
An offshoot of the Shackleton MR.2 production was the T.2 trainer. Ten examples were converted from MR.2 airframes, the work commencing in the latter half of 1966 with MR.2 Phase II WL739 and ending with WR967 which was the final example to be converted. The work was carried out at Langar, Avro by then having become a part of Hawker Siddeley Aviation (HSA). The T.2 was unarmed and was fitted out for radar training, the main operator being the RAF’s Maritime Operational Training Unit (MOTU). The MOTU also operated examples of the Shackleton T.4, the trainer conversion of the MR.1A.Further refinement of the Shackleton’s basic design led to the uprated MR.Mk.3, which was visibly different to the Mk.1 and Mk.2 versions in having a tricycle undercarriage and prominent wing-tip fuel tanks for increased range and endurance. Many other changes were made, including revised cockpit glazing for improved visibility. Powered by the Griffon 58, like the MR.2 Phase III airframes, the new MR.3 flew in prototype form on September 2, 1955 at the manufacturer’s Woodford facility. Sadly that airframe, WR970, crashed fatally in December 1956.The MR.3 entered RAF service with 220 Squadron in the summer of 1957. Like the versions of Shackleton that preceded it, the MR.3 underwent several upgrades in equipment or avionics, the most radical being the installation of additional power. To give greater thrust in ‘hot and high’ environments, an auxiliary Armstrong Siddeley Viper turbojet was fitted in the rear of each outer engine nacelle, giving a much-needed boost to performance especially for take-off. The Viper was the same turbojet type as was installed in the BAC Jet Provost trainer.
The final MR.3s in RAF service were those of 42 Squadron at RAF St Mawgan in Cornwall, and 203 Squadron at RAF Luqa, Malta, both of which ended their operational flying of the type in 1971 while transitioning onto the Hawker Siddeley Nimrod MR.Mk.1.The Shackleton MR.2 itself received a new lease of life with the conversion of 12 examples to AEW.Mk.2 airborne early warning (AEW) platforms. With the phasing out of the Royal Navy’s Fairey Gannet AEW.3 airframes, the RAF took on the responsibility for AEW coverage of the RN’s maritime assets, as well as defending Britain’s airspace with these already venerable Shackletons. The prototype conversion was MR.2 Phase III WL745/O, which first flew on September 30, 1971. The most obvious alteration was the installation of AN/APS-20F airborne search radar in a large, bulged fairing below the forward fuselage, and the deletion of the MR.2’s usual sea search radar equipment from the lower fuselage aft of the wing.
The type was exclusively flown by 8 Squadron, which re-formed at RAF Kinloss on January 1, 1972 and received its first AEW.2 conversion during April of that year. Intended as an interim until the eventually-abandoned Nimrod AEW.Mk.3 became available, they served with the RAF in this very specialised role until 1991. Sadly one of their number, WR965/65 ‘Rosalie’, was lost on April 30, 1990, with her entire crew. The type was eventually replaced by the Boeing Sentry AEW.Mk.1 (E-3D).Despite the Shackleton’s undoubted success in British service, the type only gained one export customer – the South African Air Force (SAAF) which eventually operated eight Mk.3-series Shackletons. The first two examples were officially handed over at Woodford in May 1957.
In SAAF service the type was flown by 35 Squadron at D.F. Malan civil airport, which was sizeable enough to operate these large aircraft. They replaced Sunderlands which had flown from Durban’s Congella flying boat station.The Shackletons served the SAAF well, making vital coastal patrols and in particular watching over the sea lanes off the Cape of Good Hope and Cape Agulhas where the Soviet military presence was always a potential danger. The type underwent various local upgrades (but not the installation of auxiliary Viper turbojets) and was eventually officially withdrawn from service in November 1984.The total Shackleton production ran to at least 185 examples, including the eight export airframes, though 189 has also been quoted from allocated serial numbers.Acknowledgement: Grateful thanks to the Avro Heritage Museum, and particularly Harry Holmes, for assistance with this article.
