De Havilland DH.110 Sea Vixen

Sea Vixens at Play - Photo Chris Lord

The de Havilland DH.110 Sea Vixen was a twin boom 1950s–1960s British two-seat jet fighter of the Fleet Air Arm designed by de Havilland. Developed from an earlier first generation jet fighter, the Sea Vixen was a capable carrier-based fleet defence fighter that served into the 1970s. Initially produced by de Havilland it was later known as the Hawker Siddeley Sea Vixen when de Havilland became a part of the Hawker Siddeley group.

The aircraft was originally known as the DH.110; a twin-engined all-weather fighter, development of which started in 1946 following discussions with the Admiralty of its requirements for jet all-weather fighters. De Havilland's design shared the twin-boom layout of the de Havilland Vampire, had an all-metal structure and featured swept wings. It was to be powered by two Rolls-Royce Avon engines, each capable of 7,500 lbf (33 kN) of thrust, which would allow the aircraft to be supersonic in a shallow dive. Armament was to be four 30 mm ADEN cannons. In January 1947, specifications N.40/46 and F.44/46 were issued by the British Air Ministry for similar night-fighters to equip the Fleet Air Arm (FAA) and Royal Air Force (RAF), with nine prototypes being ordered for the RAF (together with four of the competing Gloster Javelin) and four prototypes for the Fleet Air Arm. In 1949, however, the Royal Navy decided to buy the de Havilland Sea Venom, which as a development of an existing type was cheaper and available quickly to meet its immediate needs for a jet-powered night fighter to replace its piston-engined de Havilland Sea Hornets, while the RAF cut its order back to two prototypes. Despite this, de Havilland continued with the project.

The prototype took to the skies on 26 September 1951 piloted by John Cunningham; the aircraft's performance exceeded expectations, and by the following year it was regularly flying faster than the speed of sound. However, tragedy struck while the aircraft was being demonstrated at the Farnborough Airshow on 6 September 1952. Following a demonstration of its ability to break the sound barrier, the aircraft disintegrated, killing 31 people, including the crew of two: test pilot and record breaker John Derry and Tony Richards. The failure was traced to faulty design of the end sections of the main spar, which resulted in the outer ends of the wings shearing off during a high-rate turn. The subsequent shift in the DH.110's centre of gravity caused the aircraft to lurch violently, creating forces of over 12 g, resulting in the cockpit and tail sections breaking away and the engines being torn from the airframe. One of the engines hit an area crowded with spectators at the end of the runway, causing the majority of casualties. Other spectators were injured by debris from the cockpit landing close to the main spectator enclosures alongside the runway. This incident led to a major restructuring of the safety regulations for air shows in the UK and since this crash no member of the public has died as a result of an airshow accident in the UK.

Owing to this incident, modifications were made to the second prototype, including the fitting of an all-moving tailplane, the modified aircraft not flying again until July 1954. By this time, the RAF had abandoned its interest in the DH.110, choosing instead the Javelin but the Fleet Air Arm decided to adopt the DH.110 to replace its interim Sea Venoms. The Sea Vixen became the definitive aircraft to dispense with guns, being armed with de Havilland Firestreak air-to-air missiles as apart of an integrated weapon system. In 1955, a semi-navalised variant was produced as a prototype, including changes of the leading edge profile and strengthening of the wings, making its first flight that same year. The following year, the aircraft made its first arrested deck landing on the fleet aircraft carrier HMS Ark Royal. The first true Sea Vixen, the Sea Vixen FAW.20 (fighter all-weather, later redesignated FAW.1), first flew on 20 March 1957; and on 2 July 1959, the first Sea Vixen equipped squadron formed.

The Sea Vixen had a twin-boom tail, as used on the de Havilland Sea Vampire and Sea Venom. The Sea Vixen became the first British aircraft to be solely armed with missiles, rockets and bombs. The Sea Vixen FAW.1 was armed with four de Havilland Firestreak air-to-air missiles, two Microcell unguided 2 inch (51 mm) rocket packs and had a capacity for four 500 lb (227 kg) or two 1,000 lb (454 kg) bombs. It was powered by two 11,230 lbf (50.0 kN) thrust Rolls-Royce Avon 208 turbojet engines; had a speed of 690 mph (1,110 km/h) and a range of 600 mi (1,000 km). The original DH.110 design as offered to the RAF had cannons fitted; however the cannons were soon removed and an all-missile armament was developed.

The pilot's canopy is offset to the left hand side. The observer is housed to the right completely within the fuselage, gaining access through a flush-fitting top hatch into his position.

The Sea Vixen FAW.2 was the successor to the FAW.1 and included many improvements. As well as Firestreak missiles, it could carry the Red Top AAM, four SNEB rocket pods and the air-to-ground Bullpup missile. An enlarged tail boom allowed for additional fuel tanks in the "pinion" extensions above and before the wing leading edge, and there was an improved escape system along with additional room for more electronic counter-measures equipment. However, the changes in aerodynamics meant that the 1,000 lb bomb was no longer able to be carried. Visually the FAW.1 and FAW.2 may be distinguished by the tail booms which extend forward over the leading edge of the wing on the FAW.2.

The FAW.2 first flew in 1962 and entered service with front line squadrons in 1964, with 29 being built and a further 67 FAW.1s being upgraded to FAW.2 standard. The FAW.1 began phasing out in 1966. In 1972, the career of the Sea Vixen FAW.2 came to an end. It was planned to replace the Sea Vixen with the F-4 Phantom II, with both HMS Ark Royal and Eagle to be refitted to take the new aircraft. In the event, due to defence cuts and following the decommissioning of HMS Eagle, only Ark Royal was converted to take the new aircraft.

A small number of Sea Vixen subsequently saw service in the less glamorous roles of drone, being redesignated Sea Vixen D.3. Only four were converted to the D.3 standard. Three more were sent to Farnborough for conversion but not converted. The last remaining airworthy Sea Vixen (XP924) was a D3 conversion. Some other Sea Vixens became target tugs and were redesignated as TT.2.

The aircraft did not take part in any true wars during its career with the Fleet Air Arm though it took part in many operations. In 1961, President Abdul Karim Kassem of Iraq threatened to annex the neighbouring oil-rich state of Kuwait. In response to Kuwait's appeal for external help, the United Kingdom dispatched a number of ships to the region, including two fleet carriers. Sea Vixens aboard the fleet carriers flew patrols in the region, and Kassem's aggressive actions wilted in the face of the strong naval presence, thus averting a Gulf War over Kuwait.

In January 1964, trouble flared in the East African state of Tanganyika after the 1st and 2nd Tanganyika Rifles mutinied against the British officers and NCOs who, despite Tanganyika being independent, still commanded the regiment. The mutineers also seized the British High Commissioner and the airport at the capital Dar-es-Salaam. The UK responded by sending the light fleet carrier HMS Centaur, accompanied by 45 Commando, Royal Marines. The Sea Vixens, flying off Centaur, performed a number of duties including the providing of cover for the Royal Marines who were landed in Tanganyika by helicopters. The operation "to restore Tanganyika to stability" ended in success. That same year, Sea Vixens of HMS Centaur saw service once again in the Persian Gulf, including the launch of air-strikes against rebel forces, this time supporting British forces fighting against locals disgruntled by the loss of tolls in the Radfan. Later in 1964, HMS Centaur's 892 Squadron Sea Vixens stationed off Indonesia, helped to prevent an escalation of President Sukarno's Indonesia–Malaysia confrontation.

Sea Vixens saw further service during the 1960s, performing duties on Beira Patrol, a Royal Navy operation designed to prevent oil reaching landlocked Rhodesia via the then Portuguese colony of Mozambique. The Sea Vixen also saw service in the Far East. In 1967, once again in the Persian Gulf, Sea Vixens helped cover the withdrawal from Aden. There were a number of Royal Navy warships involved, including the carriers HMS Albion, Bulwark and Eagle (carrying the Sea Vixens) and the LPD (Landing Platform Dock) HMS Fearless.

Fairey Swordfish II LS326

Fairey Swordfish II LS326 - Photo Chris Lord

The Fairey Swordfish was a torpedo bomber built by the Fairey Aviation Company and used by the Fleet Air Arm of the Royal Navy during the Second World War. Affectionately known as the "Stringbag" by its crews, it was outdated by 1939, but achieved some spectacular successes during the war, notably the sinking of one and damaging two battleships of the Regia Marina (the Italian Navy) in the Battle of Taranto and the famous crippling of the Bismarck. It was operated primarily as a fleet attack aircraft; however, during its later years, it was also used as an anti-submarine and training craft. Designed in the 1930s, the Swordfish outlived several types intended to replace it, and remained in front line service until VE Day.

The Swordfish was based on a Fairey Private Venture (PV) design; a proposed solution to the Air Ministry requirements for a spotter-reconnaissance plane, spotter referring to observing the fall of a warship's gunfire. A subsequent Air Ministry Specification S.15/33, added the torpedo bomber role. The "Torpedo-Spotter-Reconnaissance" prototype TSR II (the PV was the TSR I) first flew on 17 April 1934. It was a large biplane with a metal frame covered in fabric, and utilized folding wings as a space-saving feature for aircraft carrier use. An order was placed in 1935 and the aircraft entered service in 1936 with the Fleet Air Arm (then part of the RAF), replacing the Seal in the torpedo bomber role.

By 1939, the Fleet Air Arm (now under Royal Navy control) had 13 squadrons equipped with the Swordfish Mark I. There were also three flights of Swordfish equipped with floats, for use off aircraft catapult-equipped warships. One - from HMS Warspite — spotted fall of shot (i.e., radioed gunnery corrections back to the ship) during the Second Battle of Narvik in 1940 and subsequently sank the U-boat U-64. The Swordfish pioneered the use of Air to Surface Vessel radar ( ASV ), by carrier borne aircraft to locate surface ship targets at night and/or through clouds.

Swordfish flew from merchant aircraft carriers ("MAC ships"), 20 civilian cargo or tanker ships modified to carry three or four aircraft each, on anti-submarine duties with convoys. Three of these ships were Dutch manned, flying Swordfish from 860 (Dutch) Naval Air Squadron. The rest were manned by pilots and aircrew from 836 Naval Air Squadron, at one time the largest squadron with 91 aircraft.

Almost 2,400 had been built, 692 by Fairey and 1,699 in Sherburn by the Blackburn Aircraft Company, which were sometimes dubbed the "Blackfish". The most numerous version was the Mark II, of which 1,080 were made.

The primary weapon was the aerial torpedo, but the low speed of the biplane and the need for a long straight approach made it difficult to deliver against well-defended targets. Swordfish torpedo doctrine called for an approach at 5,000 ft (1,500 m) followed by a dive to torpedo release altitude of 18 ft (5.5 m). Maximum range of the early Mark XII torpedo was 1,500 yd (1400 m) at 40 knots (74 km/h) and 3,500 yd (3200 m) at 27 knots (50 km/h). The torpedo travelled 200 yd (180 m) forward from release to water impact, and required another 300 yd (270 m) to stabilise at preset depth and arm itself. Ideal release distance was 1,000 yd (900 m) from target if the Swordfish survived to that distance. Swordfish — flying from the British aircraft carrier HMS Illustrious — made a very significant strike on 11 November 1940 against the Italian navy during the Battle of Taranto, Italy, sinking or disabling three Italian battleships and a cruiser lying at anchor. In the aftermath, Taranto was visited by the Japanese naval attache from Berlin, who later briefed the staff who planned the attack on Pearl Harbor. Swordfish also flew anti-shipping sorties from Malta. In May 1941, a Swordfish strike from HMS Ark Royal was vital in damaging the German battleship Bismarck, preventing it from escaping to France. The low speed of the attacking aircraft may have acted in their favour, as the planes were too slow for the fire-control predictors of the German gunners, whose shells exploded so far in front of the aircraft that the threat of shrapnel damage was greatly diminished as did the fact that some at least of the Swordfish flew so low that most of the Bismarck's flak weapons were unable to depress enough to hit them. The Swordfish aircraft scored two hits, one which did little damage but the other jammed Bismarck's rudders with 15° port helm on. making the warship unmanueverable and sealing its fate. The Bismarck was destroyed less than 13 hours later. 

The problems with the aircraft were starkly demonstrated in February 1942 when a strike on German battleships during the Channel Dash resulted in the loss of all attacking aircraft, partly because only ten of the promised eighty-four fighters turned up to escort the six Swordfish. With the development of new torpedo attack aircraft, the Swordfish was soon 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 (MAC) when equipped for rocket-assisted takeoff (RATO). Its low stall speed and inherently tough design made it ideal for operation from the MAC carriers in the often severe mid Atlantic weather. Indeed, its takeoff and landing speeds were so low that it did not require the carrier to be steaming into the wind, unlike most carrier-based aircraft. On occasion, when the wind was right, Swordfish were flown from a carrier at anchor.

Swordfish-equipped units accounted for 14 U-boats destroyed. The Swordfish was meant to be replaced by the Albacore, also a biplane, but actually outlived its intended successor. It was, finally, however, succeeded by the Fairey Barracuda monoplane torpedo bomber.

The last of 2,392 Swordfish aircraft was delivered in August 1944 and operational sorties continued in to January 1945 with anti-shipping operations off Norway (FAA Squadrons 835 and 813), where the Swordfish's manouvreability was essential. The last operational squadron was disbanded on 21 May 1945, after the fall of Germany; and the last training squadron was disbanded in the summer of 1946.

Origin of the Stringbag Nickname

The Swordfish received the Stringbag nickname not because of its construction, but because of the seemingly endless variety of stores and equipment that the aircraft was cleared to carry. Crews likened the aircraft to a housewife's string shopping bag which was common at the time and, which due to its having no fixed shape, could adjust to hold any shape of packages. Like the shopping bag, the crews felt that the Swordfish could carry anything.