The Fairey Swordfish is a retired biplane torpedo bomber, designed by the Fairey Aviation Company. Originating in the early 1930s, the Swordfish, nicknamed "Stringbag", was principally operated by the Fleet Air Arm of the Royal Navy. It was also used by the Royal Air Force (RAF), as well as several overseas operators, including the Royal Canadian Air Force (RCAF) and the Royal Netherlands Navy. It was initially operated primarily as a fleet attack aircraft. During its later years, the Swordfish was increasingly used for anti-submarine and training duties. The type was in frontline service throughout the Second World War.
The Swordfish achieved some spectacular successes during the war, including sinking one battleship and damaging two others belonging to the Regia Marina (the Italian navy) during the Battle of Taranto, and the famous attack on the German battleship Bismarck, which contributed to her eventually being sunk. Swordfish sank a greater tonnage of Axis shipping than any other Allied aircraft during the war. The Swordfish remained in front-line service until V-E Day, having outlasted some of the aircraft intended to replace it.
Development
Origins In 1933 Fairey, who were experienced in the design and construction of naval aircraft, began development of an entirely new three-seat naval aircraft, intended for the twin roles of aerial reconnaissance and torpedo bomber.Stott 1971, p. 21. Receiving the internal designation of T.S.R. I, standing for "Torpedo-Spotter-Reconnaissance I", the proposed design was a biplane powered by a single 645 hp Bristol Pegasus IIM air-cooled radial engine. The company initially chose to pursue the project as a self-financed private venture while both customers and applicable requirements for the type were sought. Development of the T.S.R. I was in parallel to Fairey's activities upon Air Ministry Specification S.9/30, for which the company was at one point developing a separate but broadly similar aircraft, but powered by a Rolls-Royce Kestrel inline engine and having a different fin and rudder configuration.Stott 1971, pp. 21–22.
Significant contributions to the T.S.R.I's development came from Fairey's independent design work on a proposed aircraft for the Greek Naval Air Service, which had asked for a replacement for the Fairey IIIF Mk.IIIB, and from British Air Ministry specifications M.1/30 and S.9/30.Stott 1971, p. 22. Fairey promptly informed the Air Ministry of its work for the Greeks, whose interest had waned, and proposed its solution to the requirements for a spotter-reconnaissance plane ("spotter" referring to the activity of observing and directing a warship's fall of shot). In 1934 the Air Ministry issued the more advanced Specification S.15/33, which added the torpedo bomber role.
The prototype, F1875, made its maiden flight from Great West Aerodrome, Heathrow on 21 March 1933, flown by Chris Staniland. F1875 made various flights, including several while re-engined with an Armstrong Siddeley Tiger radial engine before it was refitted with the Pegasus engine. On 11 September 1933, F1875 was lost during a series of spinning tests in which it became unable to recover; the pilot survived the incident. Prior to this, the prototype had exhibited favourable performance, which contributed to the subsequent decision to proceed with the more advanced T.S.R II prototype, which had been specifically developed to conform with the newly issued Specification S.15/33.
On 17 April 1934, the prototype T.S.R II, K4190, made its first flight, flown by Staniland. Compared to the previous prototype, K4190 had a more powerful version of the Pegasus, an additional bay in the rear fuselage to counteract spin tendencies, and the upper wing was slightly swept back to account for the increased length of the fuselage. During the ensuing flight test programme, K4190 was transferred to Fairey's factory in Hamble-le-Rice, Hampshire, where it was fitted with a twin-float undercarriage in place of its original land-only counterpart; on 10 November 1934, the first flight of K4190 in this new configuration was performed. Following successful water-handling trials, K4190 conducted a series of aircraft catapult and recovery tests aboard the battlecruiser HMS Repulse. K4190 was later restored to its wheeled undercarriage prior to an extensive evaluation process by the Aeroplane and Armament Experimental Establishment at RAF Martlesham Heath.Stott 1971, pp. 22–23.
In 1935, following the successful completion of testing at Martlesham, an initial pre-production order for three aircraft was placed by the Air Ministry; it was at this point that the T.S.R II received the service name 'Swordfish'.Stott 1971, p. 23. All three pre-production aircraft were powered by the Pegasus IIIM3 engine, but had a three-bladed Fairey-Reed propeller in place of the two-bladed propeller used on the prototype. On 31 December 1935 the first pre-production Swordfish, K5660, made its maiden flight. On 19 February 1936, the second pre-production aircraft, K5661, became the first to be delivered; the final pre-production aircraft, K5662, was completed as a floatplane configuration and underwent water-based service trials at the Marine Aircraft Experimental Establishment at Felixstowe, Suffolk.
Production and further development
In early 1936 a production contract for 68 aircraft was received, as the Swordfish I. Manufactured at Fairey's factory in Hayes, West London, the first production aircraft was completed in early 1936 and the type entered service with the Fleet Air Arm (FAA) in July 1936. By early 1940, Fairey was busy with the Swordfish and other types such as the new Fairey Albacore torpedo bomber.Stott 1971, p. 24. The Admiralty approached Blackburn Aircraft with a proposal that manufacture of the Swordfish be transferred to them; Blackburn then set up a new fabrication and assembly facility in Sherburn-in-Elmet, North Yorkshire.Stott 1971, pp. 24–25. Less than a year later, the first Blackburn-built Swordfish made its first flight. During 1941 the Sherburn factory assumed primary responsibility for the fuselage, along with final assembly and testing of finished aircraft.Stott 1971, p. 25. Blackburn-built Swordfish were nicknamed 'Blackfish'.
Efforts were made to disperse production and to use shadow factories to minimise the damage caused by Luftwaffe bombing raids. Major sub-assemblies were produced by four subcontractors based in neighbouring Leeds. Initial deliveries from Sherburn were completed to the Swordfish I standard; from 1943 onwards, the improved Swordfish II and Swordfish III came into production, at first supplementing, and then superseding the original model. The Swordfish II carried ASV Mk. II radar and the lower wings strengthened to allow the use of 3-inch rockets. Aircraft built from the summer of 1941 onwards had the more powerful Pegasus XXX engine. The Swordfish III was fitted with centimetric ASV Mk.XI radar mounted between the undercarriage legs, precluding carrying torpedoes, and retained the Pegasus XXX powerplant.
Production of the Swordfish ended on 18 August 1944.Stott 1971, p. 26. Almost 2,400 aircraft had been built, 692 having been constructed by Fairey and a further 1,699 by Blackburn at their Sherburn facility. Of the latter, 834 were Mark I, 545 Mark II and 320 Mark III.
Design The Fairey Swordfish was a medium-sized biplane torpedo bomber and reconnaissance aircraft with a fabric-covered metal airframe. It had folding wings. In service, it received the nickname Stringbag; this was not due to its profusion of struts, spars, and braces, but a reference to the seemingly endless variety of stores and equipment that the type was cleared to carry. Crews likened the aircraft to a housewife's string shopping bag, common at the time and which could accommodate contents of any shape.Lamb 2001
The primary weapon of the Swordfish was the aerial torpedo, but the low speed of the aircraft and the need for a long straight approach made it difficult to attack well-defended targets. Swordfish torpedo doctrine called for an approach at followed by a dive to torpedo release altitude of .Emmott, Norman W. "Airborne Torpedoes". United States Naval Institute Proceedings, August 1977. Maximum range of the early Mark XII torpedo was at and at .Campbell 1985, p. 87. The torpedo travelled forward from release to water impact, and needed another to stabilise at preset depth and arm itself. Ideal release distance was from the target.
The Swordfish could also be used as a dive-bomber. During 1939, Swordfish on board HMS Glorious participated in a series of dive-bombing trials, during which 439 practice bombs were dropped at dive angles of 60, 67 and 70 degrees, against the target ship HMS Centurion. Tests against a stationary target showed an average error of from a release height of and a dive angle of 70 degrees; tests against a manoeuvring target showed an average error of from a drop height of and a dive angle of 60 degrees.Smith, p. 66.
After more modern torpedo attack aircraft were developed, the Swordfish was redeployed successfully in an anti-submarine role, armed with depth charges or eight 60 lb (27 kg) RP-3 rockets and flying from the smaller escort carriers, or even merchant aircraft carriers (MACs) when equipped for rocket-assisted takeoff (RATO). Its low stall speed and inherently tough design made it ideal for operation from the MACs in the often severe mid-Atlantic weather. Indeed, its takeoff and landing speeds were so low that, unlike most carrier-based aircraft, it did not require the carrier to be steaming into the wind. On occasion, when the wind was right, Swordfish were flown from a carrier at anchor.Wragg 2003, p. 142.
Operational history
Introduction
In July 1936, the Swordfish entered service with the Fleet Air Arm (FAA), which was then part of the RAF; 825 Naval Air Squadron was the first squadron to receive the type. The Swordfish began replacing both the Fairey Seal in the spotter-reconnaissance role and the Blackburn Baffin in the torpedo bomber role, competing with the Blackburn Shark in the combined role. Initially, the Shark replaced the Seal in the spotter-reconnaissance squadrons and the Swordfish replaced the Baffin in torpedo squadron, after which the Shark was quickly replaced by the Swordfish. For nearly two years during the late 1930s, the Swordfish was the sole torpedo bomber aircraft used by the FAA.
By the eve of war in September 1939, the FAA, which had been transferred to Royal Navy control, had 13 operational squadrons equipped with the Swordfish I. There were also three flights of Swordfish equipped with floats, for use with catapult-equipped warships. After the outbreak of the Second World War, 26 FAA Squadrons were equipped with the Swordfish. More than 20 second-line squadrons also operated the Swordfish for training.Stott 1971, pp. 23–24. During the early months of the war, the Swordfish operated in mostly uneventful fleet protection and convoy escort missions.
Norwegian campaign
The Swordfish first saw combat on 11 April 1940, during the Norwegian campaign. Several Swordfish aircraft were launched from the aircraft carrier HMS Furious to torpedo several German vessels reported to be anchoring at Trondheim. The Swordfish found only two enemy destroyers at Trondheim, scoring one hit in the first attack of the war by torpedo-carrying aircraft.