Editing V bomber (section)

==Development==
In November 1946, the [[Air Ministry]] issued an [[operational requirement]] (OR230) for an advanced jet bomber capable of carrying a {{convert|10,000|lb|kg|adj=on}} bomb to a target {{convert|2,000|nmi|km|abbr=off}} from a base anywhere in the world with a cruising speed of {{convert|500|kn|kph}} and at an altitude of between {{convert|35000|and|50000|ft}}. The bomb weight arose from an earlier operational requirement for an atomic bomb (OR1001), which specified a maximum weight of {{convert|10,000|lb|kg}}. The speed and altitude requirements were based on what was thought necessary to penetrate enemy air defences. The aircraft itself was to weigh no more than {{convert|200000|lb}}. The [[Ministry of Supply]] baulked, and initially refused to accept OR230. Calculations showed that such an aircraft would require a runway {{convert|2000|yd}} long. Bomber Command's runways were built to handle the Lancaster, and extending them would be an expensive undertaking, involving not only additional construction, but land acquisition and demolition works. OR230 would never be fulfilled, and was ultimately cancelled on 17 September 1952.{{sfn|McLelland|2013|pp=52–53}}{{sfn|Wynn|1997|pp=44–45}}

The Operational Requirements Committee met to discuss OR230 on 17 December 1946. This committee was chaired by the [[Vice-Chief of the Air Staff (United Kingdom)|Vice-Chief of the Air Staff]], [[Air Marshal]] Sir [[William Dickson (RAF officer)|William Dickson]], with Stuart Scott-Hall, the Principal Director of Technical Development (Air) representing the Ministry of Supply. The result was a new Operational Requirement (OR229) on 7 January 1947. This was much the same as OR230, but the range was cut to {{convert|1,500|nmi|km}}, and the weight reduced to {{convert|100000|lb}}. OR229 formed the basis of an [[List of Air Ministry specifications|Air Ministry specification]], B.35/46. A request for designs went to most of the United Kingdom's major aircraft manufacturers: [[Handley Page Aircraft Company|Handley Page]], [[Armstrong Whitworth Aircraft|Armstrong Whitworth]], [[Avro]], [[Bristol Aeroplane Company|Bristol]], [[Short Brothers]] and [[English Electric]].{{sfn|McLelland|2013|p=54}}
[[File:Avro 707A WD280 in flight c1951.jpg|thumb|An [[Avro 707]] in flight during 1951; this type was developed to test the tailless thick delta wing configuration chosen for the Avro Vulcan]]

On 30 April 1947, Armstrong Whitworth, Avro, English Electric and Handley Page were invited to submit formal design tenders. A tender design conference was held on 28 July 1947, and decided to order the design submitted by Avro, along with a small flying model to test its [[delta wing]] design. The conference also decided to investigate the [[crescent wing]] concept as insurance against the favoured delta wing design being a failure. The Handley Page and Armstrong Whitworth designs were both considered. The Ministry of Supply gave financial cover in the form of an Intention to Proceed (ITP) order to Avro in November 1947. An advisory committee selected the Handley Page design on 23 December 1947, and it too was given an ITP.{{sfn|Wynn|1997|pp=46–48}}

The 17 December 1946 meeting that came up with OR230 also decided to solicit bids for a more conservative design that could be put into service more quickly, and could act as further insurance against the failure of both of the more advanced designs. This was expressed in another operational requirement (OR239), from which an Air Ministry specification, B.14/46, was generated, which was issued on 11 August 1947. This had lower cruising altitude and speed requirements than B.35/46, but was otherwise identical. A design was put forward by Shorts, which was given an ITP in November 1947.{{sfn|Wynn|1997|pp=46–48}} The result was an extremely conservative design with straight wings, the [[Short Sperrin]], which was in practice little more than a jet-powered Lincoln.{{sfn|McLelland|2013|pp=56–66}}

Meanwhile, Vickers-Armstrong had produced a [[swept wing]] design, the Vickers 660. This had been rejected because it did not meet the B.35/46 specification; but the estimated performance of the Sperrin caused officials at the Air Ministry to take another look. A new specification, B.9/48, was drawn up, based on the Vickers-Armstrong design,{{sfn|McLelland|2013|pp=66–68}} which was issued on 19 July 1948. An ITP was given to Vickers-Armstrong in April 1948, followed by a contract for two prototypes in February 1949, whereas Shorts was only awarded a contract for two prototypes in February 1949. The first prototype Vickers 660 flew on 18 May 1951,{{sfn|McLelland|2013|pp=56–66}} three months before the first prototype Sperrin, which first flew on 10 August 1951. No longer required, the Sperrin was cancelled; only the two prototypes were built.{{sfn|Wynn|1997|pp=50–53}}

Vickers-Armstrong named its aircraft the [[Vickers Valiant]]. Hitherto, bombers had been named after British or Commonwealth cities, but in October 1952 the Air Ministry decided to adopt alliterate names, with the other designs becoming the [[Avro Vulcan]] and the [[Handley-Page Victor]]. Henceforth, the three would be known as the V bombers.{{sfn|McLelland|2013|pp=66–68}}{{sfn|Wynn|1997|p=56}} While more expensive than the approach of building one bomber design per category, the RAF insisted on having choice. [[Air Chief Marshal]] Sir [[John Slessor]] believed that had the air force been forced to choose among the three British bombers under development in the late 1930s—the [[Avro Manchester]], [[Short Stirling]], and [[Handley Page Halifax]]—it would have chosen the wrong one.{{sfn|Brookes|1982|p=67}}

As a stop gap, the British announced on 27 January 1950 that it had agreed to acquire [[Boeing B-29 Superfortress]] bombers from the United States free under the recently passed American [[Mutual Defense Assistance Act]]. This allowed the Air Ministry to drop the development of the Sperrin. The B-29 served in the RAF under the name of the Washington B1.{{sfn|Brookes|1982|pp=32–33}}{{sfn|Suit|1995|pp=103–104}} The RAF received its first Washington on 22 March 1950, and the eighty-seventh was delivered in June 1952.{{sfn|Suit|1995|pp=105–106}} Like the Lincoln, it was a piston-engine aircraft, and while it did have the range to reach the Soviet Union from British bases, it was not nuclear-capable.{{sfn|Brookes|1982|pp=32–33}}{{sfn|Suit|1995|pp=103–104, 109–110}} The RAF planned to use them against Soviet bomber bases. The Washingtons suffered from maintenance problems due to a lack of spare parts, and most were returned to the US between July 1953 and July 1954; four remained in service until 1958.{{sfn|Suit|1995|pp=108–109}} Their role was assumed by the new jet-propelled [[English Electric Canberra]] bomber.{{sfn|Brookes|1982|pp=32–33}}