The Avro Vulcan (officially Hawker Siddeley Vulcan[2] from July 1963)[3] is a jet-powered delta wingstrategic bomber, which was operated by ...
The Avro Vulcan (officially Hawker Siddeley Vulcan[2] from July 1963)[3] is a jet-powered delta wingstrategic bomber, which was operated by the Royal Air Force (RAF) from 1956 until 1984. Aircraft manufacturer A.V. Roe and Company (Avro) designed the Vulcan in response to Specification B.35/46. Of the three V bombers produced, the Vulcan was considered the most technically advanced and hence the riskiest option. Several scale aircraft, designated Avro 707, were produced to test and refine the delta wing design principles. The Vulcan B.1 was first delivered to the RAF in 1956; deliveries of the improved Vulcan B.2 started in 1960. The B.2 featured more powerful engines, a larger wing, an improved electrical system and electronic countermeasures (ECM); many were modified to accept the Blue Steel missile. As a part of the V-force, the Vulcan was the backbone of the United Kingdom’s airborne nuclear deterrent during much of the Cold War. Although the Vulcan was typically armed with nuclear weapons, it was capable of conventional bombing missions, a capability which was used in Operation Black Buck during the Falklands War between the United Kingdom and Argentina in 1982. The Vulcan had no defensive weaponry, initially relying upon high-speed high-altitude flight to evade interception. Electronic countermeasures were employed by the B.1 (designated B.1A) and B.2 from circa 1960. A change to low-level tactics was made in the mid-1960s. In the mid-1970s nine Vulcans were adapted for maritime radar reconnaissance operations, redesignated as B.2 (MRR). In the final years of service six Vulcans were converted to the K.2 tanker configuration for aerial refuelling. Since retirement by the RAF one example, B.2 XH558, named "The Spirit of Great Britain" has been restored for use in display flights and air shows, whilst two other B.2s, XL426 and XM655, are kept in taxiable condition for ground runs and demonstrations at London Southend Airport and Wellesbourne Mountford Airfield respectively. The origin of the Vulcan and the other V bombers is linked with early British atomic weapon programme and nuclear deterrent policies. Britain's atom bomb programme began with Air Staff Operational Requirement OR.1001 issued in August 1946. This anticipated a government decision in January 1947 to authorise research and development work on atomic weapons, the U.S. Atomic Energy Act of 1946 (McMahon Act) having prohibited exporting atomic knowledge, even to countries that had collaborated on the Manhattan Project.[4] OR.1001 envisaged a weapon not to exceed 24 ft 2 in (7.37 m) in length, 5 ft (1.5 m) in diameter and 10,000 lb (4,500 kg) in weight. The weapon had to be suitable for release from 20,000 ft (6,100 m) to 50,000 ft (15,000 m).[5] In January 1947, the Ministry of Supply distributed Specification B.35/46 to UK aviation companies to satisfy Air Staff Operational Requirement OR.229 for "a medium range bomber landplane capable of carrying one 10,000 lb (4,500 kg) bomb to a target 1,500 nautical miles (1,700 mi; 2,800 km) from a base which may be anywhere in the world." A cruising speed of 500 knots (580 mph; 930 km/h) at heights between 35,000 ft (11,000 m) and 50,000 ft (15,000 m) was specified. The maximum weight when fully loaded ought not to exceed 100,000 lb (45,000 kg). In addition to a "Special" (i.e., atomic) bomb, the aircraft was to be capable of alternatively carrying a conventional bomb load of 20,000 lb (9,100 kg). The similar OR.230 required a "long range bomber" with a 2,000 nautical miles (2,300 mi; 3,700 km) radius of action with a maximum weight of 200,000 lb (91,000 kg) when fully loaded; this requirement was considered too exacting.[6] A total of six companies would submit technical brochures to this specification, including Avro.[7] Required to tender by the end of April 1947, work began on receipt of Specification B.35/46 at Avro, led by technical director Roy Chadwick and chief designer Stuart Davies; the type designation was Avro 698. It was obvious to the design team that conventional aircraft could not satisfy the Specification; knowing little about high-speed flight and unable to glean much from the Royal Aircraft Establishment or the US, they investigated German Second World War swept wingresearch. The team estimated that an otherwise conventional aircraft, with a swept wing of 45°, would have doubled the weight requirement. Realising that swept wings increase longitudinal stability, the team deleted the tail (empennage) and the supporting fuselage, it thus became a swept-back flying wing with only a rudimentary forward fuselage and a fin (vertical stabilizer) at each wingtip. The estimated weight was now only 50% over the requirement; a delta shape resulted from reducing the wingspan and maintaining the wing area by filling in the space between the wingtips, which enabled the specification to be met.[8] Though Dr Alexander Lippisch is generally credited as the pioneer of the delta wing, Chadwick’s team had followed its own logical design process.[9]The initial design submission had four large turbojets stacked in pairs buried in the wing either side of the centreline. Outboard of the engines were two bomb-bays.[8] In August 1947, Roy Chadwick was killed in the crash of the Avro Tudor 2 prototype and was succeeded by Sir William Farren.[10] Reductions in wing thickness made it impossible to incorporate the split bomb bays and stacked engines, thus the engines were placed side-by-side in pairs either side of a single bomb-bay, the fuselage growing somewhat. The wingtip fins gave way to a single fin on the aircraft's centreline.[8] Rival manufacturer Handley Page received a prototype contract for its crescent-winged HP.80 B.35/46 tender in November 1947.[10] Though considered the best option, contract placement for Avro's design was delayed whilst its technical strength was established.[11] Instructions to proceed with the construction of two Avro 698 prototypes was received in January 1948.[10] As an insurance measure against both radical designs failing, Short Brothers received a contract for the prototype SA.4 to the less-stringent Specification B.14/46; the SA.4, later named Sperrin, was not required. In April 1948, Vickers also received authority to proceed with their Type 660 which, although falling short of the B.35/46 Specification, being of a more conventional design would be available sooner; this plane entered service as the Valiant.[12] The decision to proceed with the B.2 versions of the Vulcan was made in May 1956. It was anticipated that the first B.2 would be around the 45th aircraft of the 99 then on order.[34] As well as being able to achieve greater heights over targets, it was believed that operational flexibility could be extended by the provision of in-flight refuelling equipment and tanker aircraft.[35] The increasing sophistication of Soviet air defences required the fitting of electronic countermeasure (ECM) equipment and vulnerability could be reduced by the introduction of the Avro Blue Steel stand-off missile, then in development.[36] In order to develop these proposals, the second Vulcan prototype VX777 was rebuilt with the larger and thinner Phase 2C wing, improved flying control surfaces and Olympus 102 engines, first flying in this configuration in August 1957.[37] Plans were in hand to equip all Vulcans from the 16th aircraft onwards with in-flight refuelling receiving equipment.[38] A B.1, XA903, was allocated for Blue Steel development work. Other B.1s were used for the development of the BOl.6 (later Olympus 200), XA891; a new AC electrical system, XA893; and ECM including jammers within a bulged tail-cone and a tail warning radar, XA895.[39] The first Avro Vulcan B.2, XH533, flying at Farnborough, 1958.The 46th production aircraft and first B.2, XH533, first flew in September 1958 fitted with Olympus 200 engines of 16,000 lbf (71 kN) thrust, six months before the last B.1 XH532 was delivered in March 1959.[40] Rebuilding B.1s as B.2s was considered but rejected over cost. Nevertheless, to extend the B.1's service life, 28 were upgraded by Armstrong Whitworth between 1959 and 1963 to the B.1A standard, including features of the B.2 such as ECM equipment,[41] in-flight refuelling receiving equipment,[42] and UHF radio.[43] The second B.2, XH534, flew in January 1959. Powered by production Olympus 201 of 17,000 lbf (76 kN) thrust, it was more representative of a production aircraft, being fitted with an in-flight refuelling probe and a bulged ECM tail cone. Some subsequent B.2s were initially lacking probes and ECM tail cones, but these were fitted retrospectively. The first 10 B.2s outwardly showed their B.1 ancestry, retaining narrow engine air intakes. Anticipating even more powerful engines, the air intakes were deepened on the 11th (XH557) and subsequent aircraft. Many of the early aircraft were retained for trials and it was the 12th B.2, XH558, that was the first to be delivered to the RAF in July 1960.[44] The 26th B.2, XL317, the first of a production batch ordered in February 1956, was the first Vulcan, apart from development aircraft, capable of carrying the Blue Steel missile; 33 aircraft were delivered to the RAF with these modifications.[45] When the Mk.2 version of Blue Steel was cancelled in favour of the Douglas GAM-87 Skybolt air-launched ballistic missile in December 1959,[46] fittings were changed in anticipation of the new missile, one under each wing. Though Skybolt was cancelled in November 1962, many aircraft were delivered or retrofitted with "Skybolt" blisters.[47] Later aircraft (XL391 and XM574onwards) were delivered with Olympus 301 engines of 20,000 lbf (89 kN) thrust. Two earlier aircraft were re-engined (XH557 and XJ784) for trials and development work; another seven aircraft (XL384-XL390) were converted circa 1963.[48] The last B.2 was delivered in 1965 and the type served till 1984. Whilst in service the B.2 was continuously updated with modifications including rapid engine starting, bomb-bay fuel tanks, wing strengthening to give the fatigue life to enable the aircraft to fly at low level (a tactic introduced in the mid-60s), upgraded navigation equipment, Terrain Following Radar (TFR), standardisation on a common nuclear weapon (WE.117) and improved ECM equipment.[49] The B.1As were not strengthened, thus all were withdrawn by 1968.[50] Nine B.2s were modified for the Maritime Radar Reconnaissance (MRR) role[51] and six for the airborne tanker role.[52] Less
