Avro Shackleton

The Avro Shackleton was a British long-range maritime patrol aircraft for use by the Royal Air Force. It was developed by Avro from the Avro Lincoln bomber with a new fuselage. It was originally used primarily in the anti-submarine warfare (ASW) and maritime patrol aircraft (MPA) roles, and was later adapted for airborne early warning (AEW), search and rescue (SAR) and other roles from 1951 until 1990. It also served in the South African Air Force from 1957 to 1984. The type is named after the polar explorer Sir Ernest Shackleton.

Design and development

Contra-rotating propellers

The aircraft was designed by Roy Chadwick as the Avro Type 696. It was based on the Avro Lincoln, itself a derivative of the successful wartime Avro Lancaster bomber, one of Chadwick's earlier designs which was the then current ASW aircraft. The design took the Lincoln's wings and landing gear and mated them with a new fuselage, and was initially referred-to during development as the Lincoln ASR.3. The engines were Rolls-Royce Griffons with 13-foot (4 m) contra-rotating propellors, creating a distinctive engine noise and adding high-tone deafness to the hazards of the pilots. The first test flight was in March 1949 and front-line aircraft were delivered to Coastal Command in April 1951 and had their operational debut during the Suez Crisis. In the ASW role, the Shackleton carried both types of sonobuoy, ESM, an Autolycus (diesel fume detection system) and for a short time an unreliable magnetic anomaly detector (MAD) system. Weapons were nine bombs, or three torpedoes or depth-charges, and 20 mm cannon.

The MR.2 was improved with feedback from operations and is considered by aficionados to be the definitive type. The radome was moved from the nose to a ventral position, to improve all-round coverage and minimise the risk of bird-strikes. Both the nose and tail sections were lengthened, the tail planes were redesigned and the weak undercarriage was strengthened.

The MR.3 was another redesign in response to crew complaints. A new tricycle undercarriage was introduced, the fuselage was increased in all main dimensions and had new wings with better ailerons and tip tanks. As a sop to the crews, on fifteen hour flights the sound deadening was improved and a proper galley and sleeping space were included. Total take-off weight had risen by over 30,000 lb (13,600 kg) (Ph. III) and assistance from Armstrong Siddeley Viper Mk.203 turbojets was needed on take-off (JATO). This extra strain took a toll on the airframe, and flight life of the Mk. IIIs was sufficiently reduced that they were outlived by the Mk. IIs.

Operational history

SAAF 1722, the last flying Shackleton.

A total of 185 Shackletons were built from 1951 to 1958: around twelve are still believed to be intact, with one still flying (SAAF 1722 based at AFB Ysterplaat).

Royal Air Force

All marks suffered from using the Griffon engines — thirsty for fuel and oil, noisy and temperamental with high-maintenance needs. In 1961 MR.2's engines needed top overhauls every 400 hours and went through a spate of ejecting spark plugs from their cylinderheads. It was not unusual to see an engine changed every day in a unit of 6 aircraft. They were constantly on the cusp of being replaced, but even the potentially beneficial Napier Nomad re-engine didn't quite happen.

The need to replace the Shackleton was first raised in the early 1960s. The arrival of the Hawker-Siddeley Nimrod in 1969 was the end for the Shackleton in most roles but it continued as the main SAR aircraft until 1972. The intention to retire the aircraft was then thwarted by the need for AEW coverage in the North Sea and northern Atlantic following the retirement of the Fairey Gannet. With a new design not due until the late 1970s the existing AN/APS-20 radar was installed in Mk. IIs as an interim measure, the AEW.2, from 1972. The disastrous Nimrod AEW replacement programme dragged on and on and the eventual successor to the Shackleton did not arrive until the RAF finally abandoned the Nimrod AEW and purchased the E-3 Sentry in 1991.

South African Air Force

After evaluating four RAF MR.2s in 1953, the South African Air Force ordered 8 aircraft to replace the Short Sunderland in maritime patrol duties. Some minor modifications were required for South African conditions and the resulting aircraft became the MK.3. These Shackleton's remained in maritime patrol service with 35 Squadron SAAF up to November 1984. The aircraft received SAAF designations 1716 to 1723.

Although the joke has been applied to several aircraft, the Shackleton has been described as "a hundred thousand rivets flying in loose formation"

Variants

A Shackleton AEW.2 on display at the Museum of Science and in Manchester

Shackleton GR.1

The first production model for the RAF, later redesignated Shackleton MR.1.

Shackleton MR.1A

Version powered by four Griffon 57A V12 piston engines, equipped with a chin mount radome. In service from April 1951.

Shackleton MR.2

Version with longer nose and radome moved to the ventral position.

Shackleton MR.2C

Number of Shackleton MR.2s, fitted with the navigation and offensive equipment of the Shackleton MR.3.

Shackleton MR.3

Maritime reconnaissance, anti-shipping aircraft. The tail wheel was replaced by a tricycle undercarriage configuration. Fitted with wingtip tanks. Eight exported to South Africa.

Shackleton MR.3 Phase 2

Similar to Shackleton MR.3 but fitted with two Viper turbojet engines for assisted take off.

Shackleton MR.4

Project of new maritime reconnaissance version, none built.

Shackleton AEW.2

Airborne early warning aircraft. MR.2s converted to take ex-Fairey Gannet airborne early warning radar.

Shackleton T.4

Navigation trainer conversion.

Operators

Retired Mk3, SAAF 1721, on permanent display at Swartkop, Tswane

South Africa

• South African Air Force
  • 35 Squadron SAAF received 8 aircraft.

United Kingdom

• Royal Air Force (Coastal Command)
  • No. 8 Squadron RAF
  • No. 37 Squadron RAF
  • No. 38 Squadron RAF
  • No. 42 Squadron RAF
  • No. 52 Squadron RAF - Two Shackletons used for transport duties.
  • No. 120 Squadron RAF
  • No. 201 Squadron RAF
  • No. 203 Squadron RAF
  • No. 204 Squadron RAF
  • No. 205 Squadron RAF
  • No. 206 Squadron RAF
  • No. 210 Squadron RAF
  • No. 220 Squadron RAF
  • No. 224 Squadron RAF
  • No. 228 Squadron RAF
  • No. 240 Squadron RAF
  • No. 269 Squadron RAF
  • No. 236 Operational Conversion Unit, RAF
  • Maritime Operational Training Unit, RAF
  • Air Sea Warfare Development Unit, RAF

Survivors

• MR2C WL795 on display at RAF St. Mawgan, England.
• AEW2 WR960 on display at the Museum of Science and Industry in Manchester, England.
• AEW2 WR963 owned by Air Atlantique Classic Flight, Coventry, England.
• MR3 WR971 on display at the Fenland & West Norfolk Aviation Museum, Wisbech, England.
• MR3 WR974 on display at the Gatwick Aviation Museum, England.
• MR3 WR977 on display at the Newark Air Museum, England.
• MR3 WR982 on display at the Gatwick Aviation Museum, England.
• MR3 WR985 privately owned at Long Marston, England.

• SAAF 1716 was restored to flight in 1994, but crash landed in the Sahara (22°37′59″N 1°30′58″W) in 1994 on her way to the UK. The crash did not result in any casualties, but the aircraft was abandoned in the desert.

• SAAF 1717 is on static display at the Transport museum in Stanger

• SAAF 1720 is on static display at AFB Ysterplaat.

• SAAF 1721 is on static display at the South African Air Force Museum in Swartkop.

• SAAF 1722 is the only remaining flying Shackleton, based at AFB Ysterplaat.

• SAAF 1723 is on static display at the Vic's Viking Garage (On the N1 highway next to Soweto) in Johannesburg.

Specifications

Armed with two 20 mm Hispano cannon in the nose

General characteristics

• Crew: 10
• Airfoil: modified NACA 23018 at root, NACA 23012 at wingtip

Performance Armament
Twin 20 mm Hispano cannon in the nose; bombs, torpedoes and depth charges as required.

See also

Related development

• Avro Lancaster
• Avro Lincoln

Aircraft of comparable role, configuration, and era

• Canadair CL-28
• P-2 Neptune
• Tupolev Tu-95

Related lists

• List of aircraft of the RAF
• List of aircraft of the South African Air Force

References

Bibliography

• Howard, Peter J. "Avro (Hawker Siddeley) Shackleton Mks. 1 to 4". Aircraft in Profile, Volume 13. Windsor, Berkshire, UK: Profile Publications Ltd., 1973, p. 193-217. ISBN 0-85383-022-3.

External links

• The Shackleton Association
• Aircraft.co.za - The Complete Aviation Reference
• Avro Shackleton Site
• David Gubbins Website with airframe histories
• The Shackleton Project, Ysterplaat AFB, South Africa
• FRIENDS OF WR963