Editing Avro Vulcan (section)

===Into service===

====Vulcan B.1 and B1A====
The first 15 production B.1s were powered by the Olympus 101. Many of these early examples in a metallic finish remained the property of the Ministry of Supply, being retained for trials and development purposes. Those entering RAF service were delivered to [[No. 230 Operational Conversion Unit RAF|No 230 Operational Conversion Unit]] (OCU), the first in July 1956.<ref>Laming 2002, pp. 217–219.</ref> Later aircraft, painted in [[anti-flash white]] and powered by the Olympus 102 with {{convert|12000|lbf|kN|abbr=on}} thrust, began to enter squadron service in July 1957.<ref>Wynn 1997, p. 145.</ref> The Olympus 102s were modified during overhaul to the Olympus 104 standard, ultimately rated at {{convert|13500|lbf|kN|abbr=on}} thrust.<ref>Baxter 1990, p. 46.</ref>

Rebuilding B.1s as B.2s was considered but rejected over cost. Nevertheless, to extend the B.1's service life, 28 (the surviving B1 aircraft fitted with Olympus 102/104 engines) were upgraded by [[Armstrong Whitworth]] between 1959 and 1963 to the B.1A standard, including features of the B.2 such as ECM equipment,<ref>Brookes and Davey, 2009, p. 12.</ref> in-flight refuelling receiving equipment,<ref>''Pilot's Notes'' intro. Para. 1.</ref> and UHF radio.<ref name="PilotNotes">''Pilot's Notes'' pt. 1, ch. 16, para. 5.</ref>  However, the B.1As were not strengthened for low-level operations and all were withdrawn by 1968.<ref>Laming 2002, pp. 217–220.</ref>

====Vulcan B.2====
As far back as 1952, Bristol Aero Engines had begun development of the BOl.6 (Olympus 6) rated at {{convert|16000|lbf|kN|abbr=on}} thrust<ref>[http://www.flightglobal.com/pdfarchive/view/1957/1957%20-%200198.html?tracked=1 16,000 lb Thrust] ''Flight'' 15 February 1957 p 200</ref> but if fitted to the B.1, this would have reintroduced the buffet requiring further redesign of the wing.<ref name="laming p62">Laming 2002, p. 62.</ref>

The decision to proceed with the B.2 versions of the Vulcan was made in May 1956, being developed by Avro's chief designer [[Roy Ewans]]. The first B.2 was anticipated to be around the 45th aircraft of the 99 then on order.<ref>Wynn 1997, pp. 315, 316.</ref> As well as being able to achieve greater heights over targets, operational flexibility was believed to be extended by the provision of in-flight refuelling equipment and tanker aircraft.<ref>Wynn 1997, p. 154.</ref> 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 (missile)|Blue Steel]] [[stand-off missile]], then in development.<ref>Wynn 1997, p. 314.</ref> 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.<ref>Laming 2002, p. 82.</ref> Several Vulcan B.1s were used for the development of the B.2: development of the BOl.6 (later Olympus 200), XA891; a new AC electrical system, XA893; ECM including jammers within a bulged tail cone and a [[tail warning radar]], XA895: and for Blue Steel development work, XA903.<ref>Laming 2002, pp. 218, 219</ref>

[[File:SBAC58 Vulcan.jpg|thumb|left|Avro Vulcan B.2 XH533, the first B.2 Vulcan, flying at Farnborough in 1958]]
The 46th production aircraft and first B.2, XH533, first flew in September 1958 using Olympus 200 engines, six months before the last B.1 XH532 was delivered in March 1959.<ref>Laming 2002, p. 230.</ref> The second B.2, XH534, flew in January 1959. Powered by production Olympus 201s with {{convert|17000|lbf|kN|abbr=on}} 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 retrofitted. 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 the 12th B.2, XH558, was the first to be delivered to the RAF in July 1960. Coincidentally, XH558 was also the last Vulcan in service with the RAF, before being retired in 1992.<ref>Laming 2002, pp. 63, 64.</ref>

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.<ref>Bulman 2001, p. 152.</ref> When the Mk.2 version of Blue Steel was cancelled in favour of the [[Douglas Aircraft Company|Douglas]] [[GAM-87 Skybolt]] [[air-launched ballistic missile]] in December 1959,<ref>Wynn 1997, p. 401.</ref> 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.<ref>Bulman 2001, pp. 155–161.</ref> Later aircraft were delivered with Olympus 301 engines with {{convert|20000|lbf|kN|abbr=on}} thrust. Two earlier aircraft were re-engined (XH557 and XJ784) for trials and development work; another seven aircraft were converted around 1963.<ref>Bulman 2001, pp. 149, 150.</ref>

The last B.2 XM657 was delivered in 1965 and the type served until 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-1960s), upgraded navigation equipment, [[terrain-following radar]], standardisation on a common weapon ([[WE.177]]) and improved ECM equipment.<ref>Brookes and Davey 2009, pp. 21–23.</ref> Nine B.2s were modified for a maritime radar reconnaissance  role<ref name="Brookes83">Brookes and Davey 2009, p. 83.</ref> and six for an airborne tanker role.<ref>Darling 2007, p. 122.</ref> An updated bomb rack assembly allowing the carriage of 30 1,000&nbsp;lb bombs, up from 21 was demonstrated by Avro but was not introduced.<ref>{{Cite web|url=https://www.youtube.com/watch?v=eOmPJOT-wUg| archive-url=https://ghostarchive.org/varchive/youtube/20211115/eOmPJOT-wUg| archive-date=2021-11-15 | url-status=live|title=Vulcan Bomb loading procedure.| date=2 April 2015|via=www.youtube.com}}{{cbignore}}</ref> The updated wing profile increased range to 4,000&nbsp;nm (7,400&nbsp;km).<ref>{{Cite web | url=https://www.militaryfactory.com/aircraft/detail.asp?aircraft_id=239 |title = Avro Vulcan High-Altitude Long-Range Heavy Bomber - United Kingdom}}</ref>