Editing V bomber (section)

==Nuclear mission==
The British government was well aware of the devastation that a nuclear war would bring. A 1953 report estimated that an attack on the UK with 132 fission weapons would generate 2 million casualties. A follow-on study, which considered the possible effect of hydrogen bombs, estimated that as few as ten could reduce the entire UK to a radioactive ruin.{{sfn|Young|2007b|pp=8–9}} Given that defence was impractical, the UK turned to a policy of [[Deterrence theory|deterrence]], by targeting the population and administrative centres of the Soviet Union.{{sfn|Young|2007b|pp=11–12}} In 1957, the Air Ministry drew up a list of 131 Soviet cities with populations of 100,000 or more. Of these, 98 were within {{convert|2100|nmi|km}} of the UK.{{sfn|Wynn|1997|p=276}} Of these, 44 were selected. It was estimated that their destruction would kill about thirty per cent of the urban population of the Soviet Union, about 38 million people.{{sfn|Baylis|2005|pp=55–56}}

It was almost inconceivable that a war with the Soviet Union would not involve the United States, and as early as 1946,{{sfn|Young|2007a|pp=119–120}} American defence planning envisaged using the UK as a base for nuclear strikes on the Soviet Union, as the United States Air Force (USAF) had not yet developed long-range bombers that could attack key targets in the Soviet Union from bases in the United States. But the United States strategy was that attacks on population centres would have little value once a war had actually begun, and prioritised military targets, particularly those from which nuclear weapons could be launched or deployed.{{sfn|Young|2007b|pp=24–25}}

Coordination of war plans between RAF Bomber Command and the USAF [[Strategic Air Command]] (SAC) was clearly desirable, and a joint war plan was negotiated between 1954 and 1958.{{sfn|Wynn|1997|pp=270–274}} The RAF's nuclear force was capable of destroying key targets before bomber aircraft from the United States had entered Soviet airspace, "taking into account Bomber Command’s ability to be on target in the first wave several hours in advance of the main SAC force operating from bases in the United States."{{sfn|Wynn|1997|p=275}} Based on the assumption that RAF Bomber Command would have about 100 V bombers in operations by 1959, the SAC/RAF agreement assigned 106 targets to the UK: 69 cities, 17 long-range aviation bases, and 20 air-defence sites. Attacks on the air-defence installations would clear the way for waves of SAC bombers to follow. The plan was updated annually; as Soviet capabilities improved, more emphasis was placed on attacking airfields and missile bases.{{sfn|Young|2007b|pp=24–27}}

===Nuclear testing===
[[File:Buffalo R3 002.jpg|thumb|On 11 October 1956, Valiant B.1 WZ366 of [[No. 49 Squadron RAF|No. 49 Squadron]] became the first British aircraft to drop a live atomic bomb during the [[Operation Buffalo (1956)|Buffalo R3/Kite]] test]]
[[File:Wikivaliant.jpg|thumb|right|Vickers Valiant B1 XD818, flown by [[Kenneth Hubbard]] during [[Operation Grapple]], at [[Royal Air Force Museum Midlands]] in 2006]]
Special Valiant unit [[No. 1321 Flight RAF|No. 1321 Flight]] was formed at RAF Wittering on 3 August 1954{{sfn|Wynn|1997|p=598}} which conducted ballistic test trials with Blue Danube practice bombs. It became C Flight of No. 138 Squadron in March 1956, and No. 49 Squadron on 1 May 1956.

Valiants WZ366 and WZ367 were then flown to [[Maralinga]], South Australia for [[British nuclear tests at Maralinga#Operation Buffalo|Operation Buffalo]]. Valiant B.1 WZ366 of No. 49 Squadron became the first RAF aircraft to drop an operational atomic bomb when it performed a test drop of a down-rated 3-kt Blue Danube at Maralinga on 11 October 1956. The bomb landed about {{convert|100|yd}} left and {{convert|60|yd}} short of the target. The pilot was Squadron Leader [[Edwin Flavell (Royal Air Force officer)|Edwin Flavell]], and the bomb aimer was Flight Lieutenant Eric Stacey, and both were awarded the [[Air Force Cross (United Kingdom)|Air Force Cross]]{{sfn|Brookes|1982|p=74}}{{sfn|Wynn|1997|pp=170–173}}<ref>{{London Gazette |date=28 December 1956 |issue=40960 |supp=1 |page=36}}</ref> in the [[1957 New Year Honours]].

On 15 May 1957, Valiant B.1 XD818 flown by [[Wing commander (rank)|Wing Commander]] [[Kenneth Hubbard]] dropped the first British [[hydrogen bomb]] over the Pacific, the "Short Granite", as part of [[Operation Grapple]].<ref>{{cite web |url=http://www.rafmuseum.org.uk/documents/collections/1994-1352-A-Valiant-XD818.pdf|title=Individual History Vickers Valiant B (K) Mk.I XD818/7894M Museum Accession Number 1994/1352/A |publisher=Royal Air Force Museum |access-date=20 November 2015}}</ref> No. 49 Squadron was selected to perform the live weapon drop and was equipped with specially modified Valiants to conform with the scientific requirements of the tests and other precautionary measures to protect against heat and radiation.{{sfn|Hubbard|Simmons|2008|pp=61, 68}} The test was largely a failure, as the measured yield was less than a third of the maximum expected and the device failed to achieve a [[thermonuclear]] explosion as intended. The first British hydrogen bomb that detonated as planned was Grapple X Round A, dropped on 8 November 1957.{{sfn|Hubbard|Simmons|2008|p=157}} The Grapple series of tests continued into 1958, and the Grapple Y bomb exploded in April 1958 with ten times the yield of the original "Short Granite".{{sfn|Hubbard|Simmons|2008|p=167}} Testing was finally terminated in November 1958 when the British government decided to cease atmospheric testing.{{sfn|Arnold|Pyne|2001|pp=189–191}}

=== Project E ===
As V bomber production picked up, the number of bombers exceeded the number of available British nuclear weapons. Britain had only ten nuclear bombs in 1955, and just 14 in 1956.{{sfn|Young|2007b|pp=11–12}} To make up the difference, American nuclear weapons were obtained through [[Project E]]. Since they were in American custody, they were not available for the RAF to use as part of the UK's independent national nuclear deterrent; only British-owned weapons could be used for that purpose.{{sfn|McLelland|2013|pp=158–160}}{{sfn|Bronk|2014|pp=977–978}} The Vulcan and Victor were armed with British-built bombs [[Blue Danube (nuclear weapon)|Blue Danube]], [[Red Beard (nuclear weapon)|Red Beard]], [[Violet Club]], and [[Yellow Sun (nuclear weapon)|Yellow Sun]] of both the Mk 1 and Mk 2 versions.{{sfn|Finn|Berg|2004|p=55}} Project E modifications to Valiants commenced at RAE Farnborough in February 1956. Crew training was carried out with American instructors at [[RAF Boscombe Down]].{{sfn|Young|2016|p=212}}

[[File:YellowSunBomb1.JPG|thumb|left|A British [[Yellow Sun (nuclear weapon)|Yellow Sun]] nuclear bomb, photographed under the wing of Valiant XD818 at the [[Royal Air Force Museum Midlands]] ]]
The planned V bomber force was reduced to 144 aircraft, and it was planned to equip half of them with Project E weapons.{{sfn|Bronk|2014|p=980}} The first 28 Valiants were modified by October 1957; the remaining 20 Valiants, along with 24 Vulcans, were ready by January 1959.{{sfn|Young|2016|p=212}} Under the Project E Memorandum of Understanding, US personnel had custody of the weapons. That meant they performed all the tasks related to their storage, maintenance and readiness. While the bombs were at the same bases as the bombers, they were stored in Secure Storage Areas (SSAs) that British staff were not permitted to enter. It was therefore impossible to store British and American bombs together in the same SSA. Bomber Command designated RAF Marham, RAF Waddington and RAF Honington as bases with US SSAs. Another three sites had British SSAs.{{sfn|Bronk|2014|pp=978–980}} US custody created operational problems. The procedure for handing over the bombs added an extra ten minutes to the bombers' reaction time,{{sfn|Bronk|2014|p=985}} and the requirement that US personnel had guardianship of the weapons at all times meant that neither they nor the bombers could be relocated to dispersal airfields as the RAF desired.{{sfn|Wynn|1997|pp=262–263}}

Initially, 72 [[Mark 5 nuclear bomb]]s were supplied for the V bombers.{{sfn|Wynn|1997|pp=264–265}}{{sfn|Moore|2010|pp=114, 256}} They had a yield of up to {{convert|100|ktTNT}}.{{sfn|Moore|2010|p=114}} The successful [[British hydrogen bomb programme|British development of the hydrogen bomb]], and a favourable international relations climate caused by the [[Sputnik crisis]], led to the United States Atomic Energy Act being amended again in 1958, resulting in the long-sought resumption of the nuclear [[Special Relationship]] between Britain and the United States in the form of the [[1958 US–UK Mutual Defence Agreement]].{{sfn|Navias|1991|pp=193–198}} The United States now agreed to supply the V bombers with megaton weapons in place of the Mark 5,{{sfn|Young|2016|p=212}} in the form of [[Mark 15 nuclear bomb|Mark 15]] and [[Mark 39 nuclear bomb]]s.{{sfn|Wynn|1997|pp=264–265}} [[HM Treasury|The Treasury]] immediately inquired as to whether this meant that the British megaton bomb programme could be terminated.{{sfn|Young|2016|pp=213–214}} The answer was no; the operational restrictions imposed by Project E "effectively handed the US government a veto over the use of half of Britain's nuclear deterrent".{{sfn|Young|2007b|p=994}} With sufficient British bombs on hand, operational issues, and the concept of an [[independent nuclear deterrent]] came to the fore.{{sfn|Young|2016|pp=213–214}}

The [[Air Council]] decided on 7 July 1960 that Project E weapons would be phased out by December 1962, by which time it was anticipated that there would be sufficient British megaton weapons to equip the entire [[strategic bomber]] force.{{sfn|Wynn|1997|pp=266–267}} Project E weapons were replaced by British Yellow Sun bombs at RAF Honington on 1 July 1961 and Waddington on 30 March 1962.{{sfn|Moore|2010|pp=114, 210}} Problems encountered in the development of the Red Beard bomb meant that the replacement of kiloton weapons took longer.{{sfn|Young|2016|pp=213–214}} The UK-based Valiants at Honington and Wittering were withdrawn in April and October 1962,{{sfn|Moore|2010|p=214}} and the last Valiants were retired from the V bomber force in July 1965.{{sfn|Wynn|1997|pp=494–500}} The final practice loading at RAF Marham—with the Mark 43s—was in January 1965, and the last US personnel left the base in July.{{sfn|Wynn|1997|p=269}}

===Low level strike===
The prospect of bombers being able to avoid the Soviet air defences dimmed with the appearance of the [[Mikoyan-Gurevich MiG-21]], which [[Nigel Birch]], the [[Secretary of State for Air]] and senior RAF officers saw at [[Tushino Airfield]] on 24 June 1956. There was no immediate concern as Soviet designs often took several years to deploy; but its ceiling of {{convert|65610|ft}} posed a clear threat to the V bombers. So too did the new [[SA-2]] [[surface-to-air missile]]s, which appeared in 1957. One of them shot down an American [[Lockheed U-2]] piloted by [[Francis Gary Powers]] over the Soviet Union on 1 May 1960. In 1957, the supersonic [[Avro 730]] bomber was cancelled. This freed up funds for the [[Blue Streak missile]] programme,{{sfn|Brookes|1982|pp=88–90}} but it too was cancelled, on 24 February 1960.{{sfn|Wynn|1997|p=397}}{{sfn|Moore|2010|p=48}} To extend the effectiveness and operational life of the V bombers, an Operational Requirement (OR1132), was issued on 3 September 1954 for an air-launched, rocket-propelled [[standoff missile]] with a range of {{convert|100|nmi|km}} that could be launched from a V bomber. This became [[Blue Steel (missile)|Blue Steel]]. The Ministry of Supply placed a development contract with Avro in March 1956, and it entered service in December 1962.{{sfn|Wynn|1997|pp=186–191}}

[[File:Vickers valiant camouflaged on ground arp.jpg|thumb|A camouflaged Valiant during the 1960s]]
By this time, it was anticipated that even with Blue Steel, the air defences of the Soviet Union would soon improve to the extent that V bombers might find it difficult to attack their targets, and there were calls for the development of the Blue Steel Mark II with a range of at least {{convert|600|nmi|km}}.{{sfn|Wynn|1997|pp=197–199}} Despite the name, this was a whole new missile, and not a development of the Mark I.{{sfn|Moore|2010|p=107}} The [[Minister of Aviation]], [[Duncan Sandys]], insisted that priority be accorded to getting the Mark I into service,{{sfn|Wynn|1997|pp=197–199}} and the Mark II was cancelled at the end of 1959.{{sfn|Moore|2010|p=107}} Considerable modification was required to enable the Victors to carry Blue Steel. These included structural changes to the bomb bay. New {{convert|20600|lbf|kN|abbr=on|adj=on}} Conway RCo.17 engines were installed, along with a [[combustor]] ignition system to allow all four engines to be started simultaneously and reduce [[Scrambling (military)|scramble]] time to {{frac|1|1|2}} minutes per aircraft. A total of 23 Victor B.2 aircraft were upgraded to the new standard, known as B.2R (for retrofit), and two more were built as such.{{sfn|Brookes|1982|p=128}}

The British government then turned to [[AGM-48 Skybolt|Skybolt]], an American missile that combined the range of Blue Streak with the mobile basing of the Blue Steel, and was small enough that two could be carried on the Vulcan bomber.{{sfn|Moore|2010|pp=47–48}} Armed with a British [[Red Snow]] warhead, this would improve the capability of the UK's V bomber force, and extend its useful life into the late 1960s and early 1970s.{{sfn|Harrison|1982|p=27}} [[Cabinet of the United Kingdom|Cabinet]] Defence Committee approved the acquisition of Skybolt in February 1960.{{sfn|Young|2002|p=72}} The Vulcan B.2s were modified to carry a pair of Skybolt missiles. They were fitted with {{convert|20000|lbf|kN|abbr=on|adj=on}} Bristol Olympus 301 engines, strengthened wings and two special attachment points. A British warhead was designed to fit in Skybolt's nose cone, and dummy test firings were carried out at [[RAF West Freugh]] commencing on 9 December 1961.{{sfn|Brookes|1982|pp=117–118}}{{sfn|McLelland|2013|p=156}} It did not prove possible to modify the Victors.{{sfn|Brookes|1982|pp=117–118}}{{sfn|Young|2004|p=626}} The project came to an abrupt halt when the US government cancelled Skybolt on 31 December 1962,{{sfn|Roman|1995|p=218}} but the vestigial attachment points were used for [[AN/ALQ-101]] [[electronic countermeasure]] pods during the [[Falklands War]].{{sfn|White|2012|pp=148–149}} To replace Skybolt, the [[Prime Minister of the United Kingdom|Prime Minister]], [[Harold Macmillan]], negotiated the [[Nassau Agreement]] with the [[President of the United States]] [[John F. Kennedy]] on 3 January 1963, under which the US agreed to supply the UK with [[UGM-27 Polaris|Polaris]] [[submarine-launched ballistic missiles]] instead. This spelt the beginning of the end of the V bombers' nuclear deterrent, but six more years passed before the submarines were built and the Royal Navy was able to take over responsibility.{{sfn|McLelland|2013|pp=170–171}}

[[File:Avro 698 Vulcan B2, UK - Air Force AN0738495.jpg|thumb|left|[[Avro Vulcan XH558]] ]]
Although originally part of the V force, three squadrons of Valiants were assigned to [[SACEUR]] as part of the TBF (Tactical Bomber Force), while remaining part of Bomber Command for training and administration. As the new Victors and Vulcans became available, Valiants became surplus to the planned V force of 144 aircraft. It was proposed that 24 Valiants could replace 64 Canberra bombers. This represented a numerical reduction in the force available to SACEUR, but an improvement in capability due to the Valiants' all-weather strike capacity. The decision was taken by the Air Council on 15 May 1958. The first squadron to be assigned was No. 207 Squadron, on 1 January 1960. It was followed by No. 49 Squadron on 1 July, and No. 148 on 13 July. No. 49 Squadron moved to RAF Marham so that all three squadrons were concentrated there. They were each equipped with two [[Mark 28 nuclear bomb]]s provided by Project E.{{sfn|Wynn|1997|pp=363–367}} The three TBF squadrons eventually became the only Valiant bomber squadrons as all the others were disbanded or converted to tanker or strategic reconnaissance roles.{{sfn|Jackson|1981|p=35}} They adopted SACEUR's [[Quick Reaction Alert]], under which arrangements were made so that three armed aircraft were always ready to scramble within 15 minutes.{{sfn|Brookes|1982|p=130}} They were also the first V bombers to adopt a low-level strike role, with their white paintwork replaced by green camouflage.{{sfn|Jackson|1981|p=35}} During the [[Cuban Missile Crisis]], each V force squadron kept one fully armed aircraft and crew at 15 minutes' readiness.{{sfn|Woolven|2012|p=117}}

By 1963, the RAF was convinced that, to have any chance of survival, the V bombers would have to attack at low level. At altitudes below {{convert|3000|ft}}, radar was less effective due to ground-generated clutter. The three Vulcan B.1A squadrons at RAF Waddington and the four Victor B.1A squadrons at RAF Honington and RAF Cottesmore were ordered to switch to low-level operations in March 1963. The Vulcan B.2 and Victor B.2 squadrons followed on 1 May 1964. A sign of the new doctrine was the replacement of their white paintwork with green camouflage on their upper surfaces, starting with Vulcan XH505 on 24 March 1964. They were also outfitted with new ECMs, ground positioning equipment and terrain-following radar. Tests performed in the UK and at [[RAAF Woomera Range Complex|Woomera]] demonstrated that Blue Steel could be launched from low level. The Yellow Sun Mark 2 free-fall bomb was a different story, and V bombers equipped with it would have had to climb to medium altitude to release it. A new bomb, the [[WE.177]] was developed. Deliveries of the {{convert|450|ktTNT|adj=on}} WE.177B commenced in September 1966.{{sfn|McLelland|2013|pp=173–175}}{{sfn|Baylis|1995|pp=350–351}} Through Project E and the introduction of the smaller, lighter Red Beard bomb, which entered service in 1960, by the mid-1960s Canberras and the [[Royal Navy]]'s [[Fleet Air Arm]] were able to deliver nuclear weapons,{{sfn|Moore|2010|pp=113–116}} but their power was insignificant compared with that of the 109 Victor and Vulcan bombers.{{sfn|Brown|1964|p=293}}
[[File:Handley Page HP-80 Victor K1A, UK - Air Force AN2256553.jpg|thumb|right|Victor XH649]]
The V bombers were formally relieved of their role as the deliverer of the UK strategic nuclear deterrent, which officially passed to the Polaris ballistic missile submarines of the Royal Navy on 1 July 1969.{{sfn|Wynn|1997|p=630}} The last Blue Steel mission was flown on 21 December 1970. Five Vulcan squadrons continued to serve with the WE.177B weapon in a tactical role in Europe with SACEUR. Nos 9 and 35 Squadrons moved to [[RAF Akrotiri]] in Cyprus, where they replaced Canberra bombers in support of [[CENTO]] and operations on NATO's southern flank. They were withdrawn in 1975 in the wake of the [[Turkish invasion of Cyprus]]. Six squadrons of Vulcans were still assigned this role with the WE.177 weapon in 1981. The last four remaining squadrons were about to disband in 1982 when called upon to assist in the Falklands War.{{sfn|Brookes|1982|pp=163–165}}{{sfn|McLelland|2013|pp=175–177}}