The Avro Shackleton was a British long-range maritime patrol aircraft for use by the Royal Air Force (RAF) and the South African Air Force (SAAF). It was developed by Avro from the Avro Lincoln bomber, itself being a development of the famous wartime Avro Lancaster bomber. The type is named after the polar explorer Sir Ernest Shackleton.
Entering service with the RAF in 1951, the Shackleton was used primarily in the anti-submarine warfare and maritime patrol aircraft roles; it also became used as a search and rescue platform and for performing several other secondary roles such as being a troop-transport. In later life, a small number of the RAF’s Shackletons were subsequently adapted for airborne early warning duties, performing in this capacity until the type’s retirement in 1991. The Shackleton was also procured by South Africa, and would be operated by the SAAF between 1957 and 1984.
The Shackleton was a purpose-built aircraft for the maritime patrol role; however, the legacy of Avro’s preceding aircraft is present in many aspects of the overall design. The center section of the Shackleton’s wing originates from the Lincoln, while the outer wing and undercarriage were sourced from the Tudor outer wings; at one stage during development, the tail plane had closely resembled the Lincoln’s, but were enlarged and changed soon after. An entirely new fuselage was adopted, being wider and deeper to provide a large space in which to accommodate the crew, their equipment, and a large bomb-bay. Later variants of the Shackleton were substantially redesigned, adopting a new nose-wheel undercarriage, redesigned wings and center-section, and a larger fuel capacity for more range.
Various armaments and equipment was carried by the Shackleton in order to perform its missions. In ASW operations, the ASV Mk 13 radar was the primary detection tool; it could detect a destroyer at a range of 40 nautical miles, a surfaced submarine at 20 nautical miles, and a submarine’s conning tower at 8 nautical miles, although rough seas considerably reduced the radar’s effectiveness. Other equipment included droppable sonobuoys, electronic warfare support measures, an Autolycus diesel fume detection system and an magnetic anomaly detector (MAD) system. A special camera bay housed several reconnaissance cameras capable of medium altitude and night time vertical photography, and low-altitude oblique photography. The crew would also perform visual searches using various lookout positions that were provided for this purpose.
Weapons carried included up to nine bombs, three homing torpedoes or depth-charges; the aircraft also had two 20 mm cannon in a Bristol dorsal turret. An in-flight refueling receptacle could be accommodated, but was not fitted on production aircraft.
During the Second World War, the importance of securing the sea routes around the Cape of Good Hope had been made apparent, with over a hundred vessels being sunk in South African waters by enemy vessels between 1942 and 1945. In the post-war situation, the South African Air Force sought a large and capable platform to perform the maritime patrol role. After evaluating four RAF MR 2s in 1953, an order was placed for eight Shackletons as a replacement for the SAAF’s aging Short Sunderland maritime patrol aircraft. Modifications were required to fulfill South African conditions and requirements, such as the ability to operate over the Indian Ocean, the resulting aircraft was designated as the Shackleton MR 3.
On 18 August 1957, the first two Shackletons were delivered to D.F. Malan Airport, Cape Town. Two more followed on 13 October 1957 and the remainder arrived in February 1958. Delivered to the same basic standard as the RAF’s MR 3s, they were assigned single letter codes between “J” and “Q” and operated by 35 Squadron SAAF. The type typically patrolled the sea lanes around the Cape of Good Hope, often monitoring Soviet vessels traversing between the Indian and Atlantic oceans. The Shackleton was briefly used in low-level overland patrols along the Southern Rhodesian border, but these duties ended following concerns of the disturbance of wildlife.
Often, the Shackleton would be called into perform search and rescue operations in the treacherous waters around the cape. In March 1971, Shackletons successfully intervened in the SS Wafra oil spill, deliberately sinking the stricken oil tanker with depth charges in order to prevent an ecological disaster. The only operational loss incurred was 1718 K, which crashed into the Wemmershoek mountains at night time on 8 August 1963 with the loss of all 13 crew.
Due to an embargo imposed by the United Nations over South Africa’s policy of apartheid, acquiring components for the Shackleton fleet became increasingly difficult and thus the aircraft’s serviceability suffered. The fleet had been modified to Phase III standards prior to the implementation of the arms embargo, albeit without the auxiliary Viper engine. Two of the aircraft were re-sparred, 1716 J in the United Kingdom and 1717 O in South Africa by the SAAF, but the lack of engine spares and tyres, together with airframe fatigue, took a gradual toll. By November 1984, the fatigue lives of all but the two re-sparred aircraft had expired and the fleet was retired into storage.
Although the joke has been applied to several aircraft, the Shackleton was often described as “a hundred thousand rivets flying in close formation.”