View source for Vickers Valiant

{{Short description|British four-jet high-altitude bomber}}
{{About||the 1920s biplane|Vickers 131 Valiant|the 1977 tank|Vickers Main Battle Tank Mark 4}}
{{Use dmy dates|date=September 2020}}
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. -->
{{Infobox aircraft
  |name = Valiant
  |image = File:Vickers Valiant B(K).1 1962.png
  |image_caption = Valiant XD873 in 1962
  |aircraft_type = [[Strategic bomber]] or [[aerial refueling]] tanker
  |manufacturer =[[Vickers-Armstrongs]]
  |designer =[[George Edwards (aviation)|George Edwards]]
  |first_flight =18 May 1951
  |introduction =1955
  |retired =January 1965
  |status = Retired
  |primary_user =[[Royal Air Force]]
  |more_users =
  |produced = 1951–1957
  |number_built =107
  |variants =
}}

The '''Vickers Valiant''' was a British high-altitude jet [[bomber]] designed to carry nuclear weapons, and in the 1950s and 1960s was part of the [[Royal Air Force]]'s "[[V bomber]]" strategic deterrent force. It was developed by [[Vickers-Armstrongs]] in response to [[Air Ministry specification|Specification B.35/46]] issued by the [[Air Ministry]] for a [[nuclear weapon|nuclear-armed]] jet-powered bomber. The Valiant was the first of the V bombers to become operational, and was followed by the [[Handley Page Victor]] and the [[Avro Vulcan]]. The Valiant is the only V bomber to have dropped live nuclear weapons (for test purposes).<ref name="black wright 33">Blackman and Wright 2015, p. 33.</ref>

In 1956, Valiants operating from Malta flew conventional bombing missions over [[Egypt]] for [[Operation Musketeer (1956)|Operation Musketeer]] during the [[Suez Crisis]]. From 1956 until early 1966 the main Valiant force was used in the [[nuclear deterrence]] role in the confrontation between NATO and the Warsaw Pact powers.  Other squadrons undertook [[aerial refuelling]], [[aerial reconnaissance]] and Electronic Warfare.

In 1962, in response to advances in Soviet Union [[surface-to-air missile]] (SAM) technology, the V-force fleet including the Valiant changed from high-level flying to flying at low-level to avoid high altitude SAM attacks. In 1964 it was found that Valiants showed fatigue and crystalline corrosion in wing rear spar attachment forgings.{{#tag:ref|The rapid development of aircraft during World War II led to a demand for very high strength aluminium alloy, especially for use in highly loaded tension and compression members. One result was a zinc/magnesium based alloy given the identification DTD 683. It was ideal for such applications as wing spar caps providing, as was the case with wartime operations, the life of the aircraft was short. Use in early post-War transport aircraft showed that DTD 683 was very crack-sensitive and hence prone to fatigue failure. In many cases it had to be replaced by steel components. DTD 683 is an example of a material developed to meet a particular need, but whose wider characteristics were not investigated until too late.
D.Howe 1998|group=N}} In late 1964 a repair programme was underway, but a change of Government led to the new Minister of Defence [[Denis Healey]] deciding that the Valiant should be retired from service, and this happened in early 1965.  The Victor and Vulcan V-bombers remained in service until the 1980s.

==Development==
===Background and origins===
In November 1944, the Joint Technical Warfare Committee, along with a separate committee chaired by Sir [[Henry Tizard]], examined the future potential of "weapons of war" and the accompanying Tizard Report published on 3 July 1945 made specific policy directions for the [[Royal Air Force]] (RAF) [[RAF Bomber Command|Bomber Command]].<ref name="Turpin p. 71">Turpin 2002, p. 71.</ref> After the [[World War II|Second World War]], the policy of using heavy four-engined bombers for massed raids continued into the immediate postwar period; the [[Avro Lincoln]], an updated version of the [[Avro Lancaster]], became the RAF's standard bomber.<ref>McLelland 2013, p. 18.</ref> In 1946, the [[Air Staff (United Kingdom)|Air Staff]] issued Operational Requirements OR229 and OR230 for the development of [[jet aircraft|turbojet]]-powered heavy bombers capable of carrying [[nuclear weapon]]s at high altitude and speed, without defensive armament, to act as a deterrent to hostile powers and, if deterrence failed, to perform a nuclear strike.<ref name="Turpin p. 71"/> In conjunction with this ambition, Britain set about developing its own [[nuclear weapons and the United Kingdom|atomic weapons]].<ref name = "flint 131"/>

In January 1947, the British [[Air Ministry]] issued [[Air Ministry specification|Specification B.35/46]] for an advanced jet bomber intended to carry nuclear weapons and to fly near the speed of sound at altitudes of {{cvt|50000|ft|m}}.<ref name = 'Rose 52'/> Three firms: [[Avro|A.V. Roe]], [[Handley-Page Aircraft Company|Handley-Page]] and [[Vickers-Armstrongs]] submitted advanced designs intended to meet the stringent requirements.<ref name="Aero Aug80 p397">Burnet and Morgan  ''Aeroplane Monthly'' August 1980, p. 397.</ref> While [[Short Brothers]] submitted a design, by [[Geoffrey T. R. Hill]],<ref>{{cite web|url=http://www.aerocinema.com/product/the-lost-v-bomber-2.html|title=Aerocinema-The Lost V Bomber|work=aerocinema.com|url-status=dead|archive-url=https://web.archive.org/web/20141124185209/http://aerocinema.com/product/the-lost-v-bomber-2.html|archive-date=24 November 2014}}</ref> that was judged too ambitious, the Air Staff accepted another submission from the company for a separate requirement, B.14/46, as "insurance" in case the advanced B.35/46 effort ran into trouble. Aviation authors Bill Gunston and Peter Gilchrist described Specification B.14/46 as "calling for little more than a traditional aircraft fitted with jet engines"<ref name = "bomber 72">Gunston and Gilchrist 1993, p. 72.</ref> Short submitted a conservative design to meet B.14/46, which became the [[Short Sperrin|S.A.4 Sperrin]].<ref name = 'Rose 52'/> Two prototypes were completed, the first conducting its [[maiden flight]] in 1951, but the Sperrin was ultimately relegated to research and development purposes only.<ref name="Aero Aug80 p397"/><ref name = "flint 131"/>

Vickers had emerged from World War II as one of the world's pre-eminent companies in the field of aeronautical manufacturing and development. The company operated its own secretive [[Skunk Works]]-like development organisation based at Weybridge, Surrey, which had been involved in several secret wartime development projects. It was this secretive division where the early development of the Valiant took place, including the later assembly of the initial two prototypes.<ref name = "bomber 72 73">Gunston and Gilchrist 1993, pp. 72–73.</ref> Vickers initially produced a six-engine jet bomber design proposal to meet Specification B.35/46. As progress in the development of more powerful jet engines was made, this was re-worked to a four-engine proposal in 1948.<ref name = "bomber 73">Gunston and Gilchrist 1993, p. 73.</ref> The proposed design submitted by Vickers was relatively straightforward, being less aerodynamically advanced in comparison to competing bids made by rival firms.<ref name = "bomber 72"/><ref name = "black wright 17">Blackman and Wright 2015, p. 17.</ref>

Both Handley-Page and Avro had produced advanced designs for the bomber competition. These were produced as the [[Handley Page Victor|Victor]] and the [[Avro Vulcan|Vulcan]] respectively. The Air Staff decided to award contracts to each company as a form of insurance in case one of the designs failed. The submissions became known as the [[V bomber]]s, or V-class, with the aircraft given names that started with the letter "V".<ref>Downey 1985, p. 5.</ref> Vickers' submission had initially been rejected as not being as advanced as the Victor and the Vulcan,<ref name = 'Rose 52'>Rosemeyer 2009, p. 52.</ref><ref name = "bomber 72"/> but Vickers' chief designer [[George Edwards (aviation)|George Edwards]] lobbied the Air Ministry on the basis that it would be available much sooner than the competition, going so far as to promise that a prototype would be flown by the end of 1951, that subsequent production aircraft would be flown prior to the end of 1953, and that serial deliveries would commence during early 1955. Gaining the bomber contract was considered of crucial importance to the future of aircraft manufacturing at Vickers.<ref name = "bomber 73"/> "Edwards was supremely confident that Weybridge could deliver the aircraft as specified .. " and "..committed to the brochure performance figures and dates because he thought they knew how to do it". He resisted being pushed to try to more closely match the Victor and Vulcan height and speed requirements or to change equipment from that originally specified as these distractions would jeopardize his promised delivery dates.<ref>Gardner 2006, p. 92.</ref>

Although developing three different aircraft types in response to a single Operational Requirement (OR) was costly, events such as the [[Berlin Blockade]] had led to a sense of urgency in providing a deterrent to the Soviet Union from possible acts of aggression in Western Europe.<ref>Rosemeyer 2009, pp. 52–53.</ref><ref name = "bomber 72"/>

In April 1948, the Air Staff issued a specification with the designation B.9/48 written around the Type 660 Vickers design; and an 'Instruction to Proceed' was received by Vickers on 16 April 1948.<ref name = "bomber 73"/>

In February 1949, two prototypes of the Vickers 660 series were ordered. The first was to be fitted with four [[Rolls-Royce Limited|Rolls-Royce]] [[Rolls-Royce Avon|RA.3 Avon]] [[turbojet]] engines, while the second was to be fitted with four [[Armstrong Siddeley Sapphire]] engines and was designated the Type 667.<ref name="Andrews Vickers p438">Andrews and Morgan 1988, p. 438.</ref>

===Prototypes===
[[File:Vickers Valiant Farnborough 1951.jpg|thumb|First prototype at the [[Farnborough Airshow]], 1951]]
On 18 May 1951, the first prototype, [[United Kingdom military aircraft serials|serial number]] WB210 took to the air for its maiden flight,<ref name="Andrews Vickers p439">Andrews and Morgan 1988, p. 439.</ref> within the deadline that George Edwards had promised, only 27 months since the contract had been issued. This was several months before the competing Short Sperrin; the Sperrin had straight (not swept) wings and was not ordered.  The Valiant pilot was [[Joseph Summers|Captain Joseph "Mutt" Summers]], who had also been the original test pilot on the [[Supermarine Spitfire]], and wanted to add another "first" to his record before he retired. His co-pilot on the first flight was Gabe "Jock" Bryce, who succeeded Summers as Vickers' chief test pilot upon his retirement shortly after.<ref name="Turpin p. 72">Turpin 2002, p. 72.</ref><ref name = "black wright 10">Blackman and Wright 2015, p. 10.</ref><ref>McLelland 2013, p. 68.</ref> The next month, the Vickers Type 660 was given the official name of "Valiant", reusing the name given to the [[Vickers 131 Valiant|Vickers Type 131]] general-purpose biplane of 1931.{{#tag:ref|Traditionally, RAF bombers had been named after towns and cities, for example Lancaster, [[Handley Page Halifax|Halifax]] and [[English Electric Canberra|Canberra]], but new jet aircraft technology reflected a new tradition. The name also fitted in with a tradition of alliteration in aircraft names.|group=N}} The name Valiant had been selected by a survey of Vickers employees.<ref name="Jones p31,3">Jones 2007, pp. 31, 33.</ref>

On 11 January 1952, the first Valiant prototype was lost while making internal noise measurements for the [[Vickers V-1000|V.1000]] programme. Testing included engine shutdowns and re-lights,<ref>Andrews 1965, p. 4.</ref> one of which caused a fire in the starboard wing; most of the crew managed to escape the aircraft safely, except for the co-pilot, who struck the tail after ejecting.<ref name="Flight p13">''Flight'' 4 July 1958, p. 13.</ref><ref>Blackman and Wright 2015, pp. 11–16.</ref>

On 11 April 1952, the second prototype WB215 made its maiden flight, after modifications to the fuel system.<ref name="Andrews Vickers p440">Andrews and Morgan 1988, p. 440.</ref> It was fitted with more powerful RA.7 Avon engines with {{convert|7500|lbf|kN}} thrust each, rather than the originally planned Sapphires. It also featured more rounded [[Components of jet engines#Air intakes|air inlet]]s, replacing the narrow slot-type intakes of the first prototype, to feed sufficient air to the more powerful engines. The short delay until the second prototype became available meant that loss of the prototype did not compromise the development schedule.<ref name="Turpin p74">Turpin 2002, p. 74.</ref><ref name="Jones p34">Jones 2007, p. 34.</ref><ref name = "black wright 17"/>

===The Valiant B2===
One of the three prototypes was the B.2 version.<ref name="Jones p26">Jones 2007, p. 26.</ref> The B.2 was intended to serve as a [[Pathfinder (RAF)|Pathfinder]] aircraft, flying at low level to mark targets for the main bomber force. To cope with increased air turbulence at low level, the B.2 had a strengthened airframe. In particular, the wing was strengthened with the removal of the cut-outs in the wing structure into which the main wheels retracted, allowing the wing torsion box structure to be uninterrupted and giving more room for internal fuel storage. Instead, the main landing gear, which had four wheels instead of the two wheels of the B.1, retracted backwards into large [[Aircraft fairing|fairing]]s set into the rear of the wings.<ref name = "bomber 77 78">Gunston and Gilchrist 1993, pp. 77–78.</ref> The B.2 had a lengthened fuselage with a total length of {{convert|112|ft|9|in|m|abbr=on}}, in contrast to a length of {{convert|108|ft|3|in|abbr=on}} for the Valiant B.1, with the extra length giving room for more avionics.<ref name="Jones p32,6">Jones 2007, pp. 32, 36.</ref>

The prototype B.2, serial number WJ954 first flew on 4 September 1953.<ref name="AndrewsVickers p445">Andrews and Morgan 1988, p. 445.</ref> Finished in a gloss black night operations paint scheme, it became known as the "Black Bomber". Its performance at low level was superior to that of the B.1 (or any other V-bomber), particularly at [[sea level#Aviation|sea level]],<ref name = "bomber 77"/> with the aircraft being cleared for {{convert|580|mph|abbr=on}} at low level (with speeds of up to {{convert|640|mph|abbr=on}} being reached in testing). This was compared to the B.1 sea-level limit of {{convert|414|mph|abbr=on|round=5}}. The Air Ministry ordered 17 production B.2 aircraft, which were to be powered by [[Rolls-Royce Conway]] [[turbofan]]s. Although the Valiant B.2 low-level capabilities were significant, the programme was terminated because the World War 2 "Pathfinder concept" was considered obsolete in the nuclear era.<ref name = "bomber 78">Gunston and Gilchrist 1993, p. 78.</ref> The B.2 prototype was used for tests for a few years, including the clearance of rocket-assisted take-offs, for the Valiant B.1 at hot or high airfields, using two Super-Sprite rocket motors. It also did extensive taxiing tests to investigate the cause of brake judder which caused a fatigue failure of the landing gear. It was scrapped in 1958.<ref>Trubshaw and Edmondson 1998, p. 37.</ref><ref name="Jones p36-7">Jones 2007, pp. 36–37.</ref><ref name="Osprey p83-4">Brookes 2012, pp. 83–84.</ref><ref name = "black wright 20"/>

===Production===
[[File:Vickers Valian B.1 WZ393 90 Sqn SGT 10.06.57.jpg|thumb|Valiant B(PR)K.1 WZ393 of 90 Squadron in original all-metal finish displaying at Blackpool Squires Gate airport in 1957]]
In April 1951, an initial production order for 25 Valiant B.1 (Bomber Mark 1) aircraft was placed by the Ministry of Supply on behalf of the RAF.<ref name="Aero Aug80 p400">Burnet and Morgan ''Aeroplane Monthly'' August 1980, p. 400.</ref> The timing of this order was key to establishing production quickly. Due to shortages of [[steel]] and other materials while setting up an assembly line at Brooklands, substantial portions of the production [[Jig (tool)|jigs]] for the Valiant were made from [[concrete]].<ref name = "bomber 77">Gunston and Gilchrist 1993, p. 77.</ref> The first five Valiants produced were completed to a pre-production standard, the first being WP199. On 21 December 1953, the production aircraft conducted its first flight; this had again occurred within the schedule that Edwards had promised.<ref name="Jones p37">Jones 2007, p. 37.</ref><ref name = "bomber 77"/>

On 8 February 1955, this first production Valiant was delivered to the RAF.<ref name="Osprey p12">Brookes 2012, p. 12.</ref><ref name = "flint 131">Flintham 2008, p. 131.</ref> Britain's "V-bomber" force, as it had been nicknamed in October 1952, formally entered operational service on that day. The Victor and Vulcan would soon follow the Valiant into service, for a total of three types of nuclear-armed strategic bombers in RAF service. In September 1957, the final Valiant was delivered.<ref name = "hub and sim 26"/> All production aircraft had been delivered on time and below budget.<ref name = "bomber 78"/>

A total of 108 Valiants were manufactured, including the sole B.2 prototype. In addition to its principal role as part of Britain's [[nuclear deterrent]], the Valiant bomber also dropped high explosive bombs. The bombers were followed into service by a strategic reconnaissance version and a multi-purpose version capable conventional bombing, [[aerial reconnaissance]] and [[aerial refueling|aerial refuelling]]. 18 squadron operated 6 Valiants with [[electronic countermeasure]]s equipment.<ref name = "black wright 19 20">Blackman and Wright 2015, pp. 19–20.</ref> Valiants of 90 and 214 squadrons were used for air refuelling through the addition of a Hose Drum Unit (HDU) in the bomb bay, mounted on the same suspension units that were also used for bombs.  This meant that for refuelling, the bomb-bay doors had to be opened so that the refuelling hose could be streamed (unlike later tankers where the HDU was flush with the under fuselage rather than inside a bomb bay). Several Valiants were also used for testing and development purposes, such as its use as a flying testbed during trials of the [[Blue Steel (missile)|Blue Steel]] nuclear-armed [[standoff missile]], which was later added to the arsenal of munitions the other V-bombers were equipped with.<ref name = "black wright 24 26">Blackman and Wright 2015, pp. 24–26.</ref><ref name = "flint 133">Flintham 2008, p. 133.</ref>

Unlike the Vulcan and Victor, the Valiant did not see the production of a more capable mark 2 model.<ref name = "flint 131"/> In 1962 the Valiant bomber squadrons were switched to a low-level flight profile in order to avoid enemy Surface-to-Air (SAM) defence systems. In 1964 [[Fatigue (material)|fatigue]] was discovered due to the increased air turbulence in low level flying and led to the type's premature retirement. Vic Flintham observed that: "There is a fine irony to the situation, for Vickers had produced the Type 673 B Mk 2 version designed as a fast, low-level pathfinder... The Air Ministry was not interested..."<ref name = "flint 133"/> The Valiant was Vickers' last purpose-built military aircraft. It was followed by the [[Vickers Vanguard|Vanguard]], a passenger turboprop designed in 1959, and the [[Vickers VC10]], a jet passenger aircraft in 1962, also used as a military transport and tanker by the RAF.<ref name = "flint 131"/>

==Design==
[[File:Vickers Valiant (27363801724).jpg|thumb|Forward view of preserved Vickers Valiant XD818 at [[Royal Air Force Museum Midlands]] ]]
The Valiant was based on contemporary aeronautical knowledge with no advanced untried aerodynamics that required proving with scaled-down research aircraft or lengthy research and development. As a result George Edwards described the Valiant<ref>From Bouncing Bombs To Concorde-The Authorised Biography Of Aviation Pioneer Sir George Edwards OM, Robert Gardner 2006, {{ISBN|0 7509 4389 0}}, p.85</ref> as an "unfunny" aircraft.
The Valiant had a shoulder-mounted wing and four Rolls-Royce Avon RA.3 turbojet engines, each providing up to {{convert|6500|lbf|kN}} of thrust, installed in pairs in [[fireproof]] bays in each wing root.<ref name = "bomber 75"/> The design of the Valiant gave an overall impression of a clean aircraft with swept-wing aerodynamics.<ref name="Andrews Vickers p449">Andrews and Morgan 1988, p. 449.</ref> The root chord thickness ratio of 12% allowed the Avon engines to be within the wing rather than on pods as in the contemporary [[B-47 Stratojet|Boeing B-47]].<ref name="Andrews Vickers p442">Andrews and Morgan, p. 442.</ref> This "buried engine" installation contributed to the aircraft's aerodynamic cleanness, and was British practice at the time. It made engine access for maintenance and repair difficult and increased the risk that an uncontained failure of one engine would cause damage to the adjacent engine; it also increased the complexity of the design of the main spar which had to be routed around the engines.<ref name = "bomber 73 74">Gunston and Gilchrist 1993, pp. 73–74.</ref>

The wing of the Valiant used a "compound sweep" configuration, devised by Vickers [[aerodynamics|aerodynamicist]] Elfyn Richards.<ref name="Barfield p158">Barfield ''Air International'' September 1992, p. 158.</ref> Richards found that it was necessary to increase the sweep on the inboard section of the wing, a discovery which he later [[patent]]ed as "Improvements in Aeroplane Wing Formation" with an explanation that "the formation of the shockwaves be delayed to the same extent over the whole span of the wing";<ref>Patent Specification 631,785, Improvements in Aeroplane Wing Formation", Elfyn John Richards, Application Date Nov. 25,1947</ref> the Valiant wing had 37° sweepback for the inner third of the wing, and 21° for the remainder.<ref name="Aero Aug80 p398">Burnet and Morgan  ''Aeroplane Monthly'' August 1980, p. 398.</ref><ref name = "bomber 74">Gunston and Gilchrist 1993, p. 74.</ref> This was because the thickness/chord ratio could be reduced closer to the tips.<ref name="Barfield p158"/> The choice to have mild sweepback around the aerodynamic control surfaces meant that in-service speeds were limited to Mach 0.84 and a typical cruise of Mach 0.75 at heights up to {{convert|55000|ft}} when lightly loaded.<ref name="Profile p16">Andrews 1966, p. 16.</ref><ref name = "black wright 17 18">Blackman and Wright 2015, pp. 17–18.</ref> A [[drogue parachute]] was not necessary even operating from runways as short as {{Convert|6000|ft}}.<ref name = "bomber 77"/>

The wing was mounted high on the fuselage and the location of the engines and main [[landing gear]] within the wing limited the volume available for fuel.<ref name = "bomber 75"/> The [[trailing edge]] of the wing had two-section [[aileron]]s with [[trim tab]]s, and inboard of the ailerons were double-slotted [[Flap (aeronautics)|flap]]s.<ref>Gunston and Gilchrist 1993, pp. 75–76.</ref> Direct [[electric motor|electrical drive]]s were used to move the flaps and landing gear. The only hydraulically-operated equipment, the steering and brakes, was also powered by electric motors but driving hydraulic pumps instead of mechanical gearing.<ref name = "bomber 76">Gunston and Gilchrist 1993, p. 76.</ref>

[[File:Valiant 2 (3446560911).jpg|thumb|left|The wing root and air intakes]]
Production aircraft were powered by four Avon 201 turbojet engines, with {{convert|9500|lbf|kN}} thrust. The engines also provided [[bleed air]] for the [[pressurization]], [[ice protection system|ice protection]], and [[air conditioning]] systems. The aircraft's DC electrical [[Electric generator|generator]]s were also driven by the engines.<ref name = "bomber 76"/> [[Napier & Son|Napier Spraymat]] [[electric heating|electric heaters]] were installed in the engine inlets to prevent ice formation and subsequent shedding possibly causing engine damage. The shape of the engine inlets were long rectangular slots in the first prototype, whereas production Valiants had oval or "spectacle" shaped inlets designed to pass greater airflow for the more powerful engines that were installed.<ref name="Andrews Vickers p442"/> The jet exhausts emerged from fairings above the trailing edge of the wings.<ref name="Andrews Vickers p442"/>

For required takeoff performance from short tropical dispersal bases,<ref>Gunston 1973, p. 50.</ref> a [[jettison (aviation)|jettisonable]] [[RATO|rocket booster engine]]s pack was developed for the Valiant.<ref name = "bomber 78"/> Trials were performed with two underwing [[de Havilland Sprite]] boosters; they were no longer needed when more powerful variants of the Avon engine became available. Also, there was an increased risk of accidents if one booster rocket failed on takeoff, resulting in asymmetric thrust.<ref name = "black wright 20">Blackman and Wright 2015, p. 20.</ref> Some Valiant engines had [[water injection (engines)|water injection]], which increased takeoff thrust by about {{convert|1000|lbf|kN}} per engine.<ref name = "darling 41">Darling 2012, p. 41.</ref>

The crew were in a pressurized compartment in the forward fuselage and consisted of a pilot, co-pilot, two navigators, and air signaller (later called an air electronics officer (AEO)).<ref name = "black wright 28">Blackman and Wright 2015, p. 28.</ref> Manufacture of this pressurized section was subcontracted to [[Saunders-Roe]]. The pilot and co-pilot were located side by side on an upper level, the remaining three crew members sat at stations lower in the cockpit, and faced to the rear.<ref>Gunston and Gilchrist 1993, pp. 74–75.</ref> The crew was reduced to five with the deleted requirement for defensive [[gun turret]]s and [[air gunner]]s, an operational philosophy proved by the [[De Havilland Mosquito]] bomber of World War II.<ref name = "bomber 74"/>{{#tag:ref|Vickers had proposed the installation of a pair of 20 mm [[revolver cannon|cannon]] in the tailcone; this concept was never taken beyond the drawing stage.<ref name = "bomber 78"/>|group=N}} The pilot and copilot were provided with [[Martin-Baker Mk.3]] [[ejector seat]]s, while the rear crew had to bail out of the oval main entrance door on the port side of the fuselage.<ref name="Turpin p79-0">Turpin 2002, pp. 79–80.</ref> Safe escape using this exit was not considered likely.<ref name = "bomber 75"/>

[[File:Vickers Valiant B1 (3873562557).jpg|thumb|The entry door on the side of the forward fuselage, with the names of pilot [[Kenneth Hubbard]] and his crew]]
The fuselage area behind the pressurised crew section and forward of the wing was used to house much of the [[avionics]], and air conditioning equipment, and was sometimes called the "organ loft".<ref name = "bomber 75">Gunston and Gilchrist 1993, p. 75.</ref> The Valiant had twin-wheel nosegear and [[tandem]]-wheel main gear that retracted outwards into recesses in the underside of the wing. Each of the main gears were equipped with multipad [[anti-lock braking system|anti-skid]] [[disc brake]]s, and were [[telescoping (mechanics)|telescopic]]ally linked so that a single drive motor could pull them up into the wing recesses.<ref name = "bomber 75"/> Most of the aircraft systems were electric, including the flaps and undercarriage.<ref name = "darling 39">Darling 2012, p. 39.</ref> The brakes and steering gear were electrically powered, driving hydraulic pumps for actuation.<ref name="Flight p19"/><ref name = "black wright 18"/> The lower half of the aircraft nose contained the scanner for the [[H2S (radar)|H2S]] [[radar]] in a [[glass fiber]] [[radome]]; in addition, a visual [[bomb sight]] was located beneath the lower floor of the pressurised cockpit.<ref name = "bomber 75"/> The avionics bay was not accessible from the cockpit but could be accessed using an entrance at the base of the rear fuselage leading to an internal [[catwalk]] above the aft part of the [[bomb bay]].<ref name = "bomber 76 77">Gunston and Gilchrist 1993, pp. 76–77.</ref>

The electrical systems used 112 volt [[direct current]] generators, one on each engine, for functions requiring large amounts of electrical power. A 28 V DC system was used for other uses including actuators that controlled the higher-voltage system functions. Backup power came from 24 V and 96 V batteries. 115 V [[alternating current]] was provided for the radar and the [[actuator]]s for the flight surfaces, flaps, [[Air brake (aeronautics)|air brake]]s and undercarriage.<ref name="Flight p19">''Flight'' 4 July 1958, p. 19.</ref><ref name="Turpin p78">Turpin 2002, p. 78.</ref><ref name = "black wright 18"/> It was decided during the design phase that as much of the aircraft would be electrically driven as was possible; the complete electrical system including high voltage generators and cabling, together with electric motors with mechanical drives, was lighter than the hydraulic equivalent consisting of pumps, tubing, actuators, fluid and storage tanks.<ref name = "bomber 76"/>

The [[aircraft flight control system|flight control]]s of the Valiant (ailerons, elevator and rudder) consisted of two channels of power control with full manual backup; flying in manual was practised during training as it would be required if a complete electrical failure occurred during a flight.<ref name="Flight p19"/> In "manual" the flight controls required considerable physical effort to operate.<ref name = "black wright 18">Blackman and Wright 2015, p. 18.</ref> The pilot's controls for elevators, ailerons and rudder had an [[Aircraft flight control system#Artificial feel devices|artificial feel]] system, the pressure for which was provided from a [[ram-air intake|ram-air inlet]].<ref name = "bomber 76"/>

A [[GE Aviation Systems|Smith Aerospace]] [[autopilot]] and [[instrument landing system]] (ILS) was installed along with various [[navigational aid]]s, such as the [[Marconi Company]]-built [[Green Satin radar|Green Satin]] [[doppler radar]], [[Gee (navigation)|Gee]] [[radio navigation]], [[Non-directional beacon|Automatic Direction Finder]] (ADF), [[VHF omnidirectional range|VOR]]/[[distance measuring equipment|Distance Measuring Equipment]] (DME), and [[radar altimeter]]s.<ref name = "bomber 77"/> Provisions for additional equipment and sensors, such as [[side looking airborne radar]], were also made.<ref name = "bomber 77"/>

[[File:Handley Page K2 (10024223034).jpg|thumb|Landing gear and wing]]
The centre fuselage of the Valiant had a main backbone beam to support the weight of the two widely-set [[Spar (aeronautics)|wing spar]]s and five [[fuel cell]]s in the upper fuselage. The bomb bay was also in the lower half of the centre fuselage.<ref name = "bomber 75"/><ref name="Flight p18">''Flight'' 4 July 1958, p. 18.</ref> The aft fuselage used a [[monocoque|semi-monocoque]] structure, being lighter than the centre fuselage; the [[Boulton Paul Aircraft|Boulton-Paul]]-produced electro-hydraulic power units for the ailerons, [[elevator (aeronautics)|elevator]]s, and [[rudder]] were contained within this space.<ref name = "bomber 76"/> The tail, which was attached to the rear fuselage was [[Cone|tapered]] rather than swept back,<ref name = "bomber 75"/> the [[horizontal stabilizer|horizontal tailplane]] was mounted well up the [[vertical stabilizer|vertical fin]] to keep it clear of the engines' exhaust.<ref name="Barfield p158"/> The tailcone contained an ARI 5800 Orange Putter [[tail warning radar]].<ref name = "bomber 78"/>

The main structural components, spars and beams of the Valiant had been constructed from a zinc/magnesium/copper aluminium alloy called DTD683 in the UK.<ref>''Flight'' 14 December 1951, p. 756.</ref><ref>''Flight'' 17 July 1953, p. 91.</ref> The Valiant had been designed with a '[[Safe-life design|Safe-Life]]' strategy;<ref>Brookes 2012, p. 83.</ref> this combination of 'Safe-Life' and DTD683 came to be viewed as a severe mistake. In 1956, a publication within the Journal of the Institute of Metals<ref>''The Journal of the Institute of Metals'' (JIM), Vol. 86, No. 1790, 1957–1958.</ref>{{#tag:ref|Structural Changes Caused by Plastic Strain and by fatigue in Aluminium-Zinc-Magnesium-Copper Alloys Corresponding to DTD.683 (Broom and Mezza)|group=N}} condemned the material DTD683 as being unstable and capable of catastrophic failure when stressing the airframe close to its design limits.  The "Safe-Life" design strategy was dismissed by a Lockheed engineer in a talk given to the [[Royal Aeronautical Society]] in 1956, because it did not guarantee safety from catastrophic failure.<ref>''Flight'' 6 April 1956, p. 394.</ref>

The Valiant B.1 could carry a {{convert|10000|lb|kg|adj=on}} nuclear weapon or up to 21 {{cvt|1000|lb|kg}} conventional [[bomb]]s in its bomb bay. It was designed for the early [[Nuclear fission|fission]]-based nuclear weapons and also the newer and larger [[thermonuclear]] [[hydrogen bomb]]s.<ref name = "bomber 75"/> A "clean" Valiant (one without underwing tanks) could climb straight to 50,000&nbsp;ft after takeoff unless it had heavy stores in the large bomb bay.{{Citation needed|date=May 2011}}

In the aerial reconnaissance role, a camera crate would be installed in the bomb bay, along with a pair of cameras set into the fuselage and larger rear fuel tanks to extend the aircraft's endurance.<ref name = "black wright 19">Blackman and Wright 2015, p. 19.</ref> Large external fuel tanks under each wing with a capacity of {{convert|1650|Impgal|L}}, could be used to extend range; an auxiliary fuel tank could also be installed in the forward area of the bomb bay; the external wing tanks were fitted as standard on Valiants that were operated as aerial refuelling tankers.<ref name = "black wright 19"/> For receiving fuel, a fixed [[aerial refueling#Probe-and-drogue 2|refuelling probe]] was fitted onto the aircraft's nose, this was connected to the fuel tanks via a pipe running along the outside of the canopy to avoid penetrating the pressure cabin.<ref name = "bomber 79">Gunston and Gilchrist 1993, p. 79.</ref>

==Operational history==

===Nuclear deterrent===
[[File:YellowSunBomb2.JPG|thumb|right|Side view of a [[Yellow Sun (nuclear weapon)|Yellow Sun]] nuclear bomb under the wing of Vickers Valiant XD818 at the [[RAF Cosford]] museum]]

The first squadron to be equipped with the Valiant was [[No. 138 Squadron RAF|138 Squadron]], which formed at [[RAF Gaydon]] on 1 January 1955, with 232 Operational Conversion Unit forming at Gaydon on 21 February 1955 to convert crews to the new bomber.<ref name = "darling 40"/> Since the Valiant was part of an entirely new class of bombers for the RAF, the crews for the new type were selected from experienced aircrew, with first pilots requiring 1,750 flying hours as an aircraft captain, with at least one tour flying the Canberra, with second pilots needing 700 hours in command and the remaining three crewmembers had to be recommended for posting to the Valiant by their commanding officers.<ref name="Jones p79-2">Jones 2007, pp. 79–82.</ref> Valiants were originally assigned to the strategic nuclear bombing role, as were the Vulcan and Victor B.1s when they became operational. At its peak, the Valiant equipped ten RAF squadrons.<ref name="Osprey p92"/><ref>Wynn, pp. 564-565.</ref>

According to Gunston and Gilchrist, the Valiant had performed "extremely well" during the annual bombing competition hosted by American [[Strategic Air Command]] (SAC).<ref name = "bomber 79"/> American interest in the Valiant resulted in a visit to Vickers by USAF generals [[Hoyt Vandenberg|Vandenberg]], Johnson and [[Curtis LeMay|LeMay]]. Vickers test-pilot Brian Trubshaw believed that George Edwards was put under some pressure to build the Boeing B-47 under license. The only result from the visit was Le May's insistence that the Valiant pilot side-by-side seating be incorporated in the B-52 instead of the tandem arrangement in the B-47 and prototype B-52.<ref>Brian Trubshaw Test Pilot, Brian Trubshaw and Sally Edmondson, Sutton Publishing Limited 1999, {{ISBN|0 7509 1838 1}}, p.35</ref>

[[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]]

On 11 October 1956, a Valiant B.1 (WZ366) of [[No. 49 Squadron RAF|No. 49 Squadron]] piloted by [[Edwin Flavell (Royal Air Force officer)|Edwin Flavell]] was the first British aircraft to drop an  atomic bomb when it performed a test drop of a down-rated [[Blue Danube bomb|Blue Danube]] weapon on [[Maralinga]], [[South Australia]].<ref name="Mason Bomber p378">Mason 1994, p. 378.</ref> This occurred as part of the [[Operation Buffalo (1956)|Operation Buffalo]] [[British nuclear tests at Maralinga|nuclear tests in that area]]. Windscreen blinds were fitted in advance of the test to protect the crew from the intense flash of light from the nuclear detonation. Following the landing of the aircraft after deploying the weapon, WZ366 was assessed for potential damage and for [[radioactive contamination]].<ref>Blackman and Wright 2015, pp. 33–36.</ref>

On 15 May 1957, a Valiant B(K).1 (XD818) piloted by [[Kenneth Hubbard]] dropped the first British hydrogen bomb, the Short Granite, over the Pacific as part of [[Operation Grapple]].<ref name="RAF">{{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 were equipped with specially-modified Valiants to conform with the scientific requirements of the tests and other precautionary measures to protect against heat and radiation.<ref>Hubbard and Simmons 2008, pp. 61, 68.</ref> However, the measured yield was less than a third of the maximum expected although achieving a thermonuclear explosion.

On 8 November 1957 a British hydrogen bomb detonated with its planned yield in the Grapple X test.<ref name = "hub and sim 157">Hubbard and Simmons 2008, p. 157.</ref> The Grapple series of tests continued into 1958, and in April 1958 the Grapple Y bomb exploded with ten times the yield of the original "Short Granite".<ref name = "hub and sim 167">Hubbard and Simmons 2008, p. 167.</ref> Testing was finally terminated in November 1958, when the British government decided it would perform no more air-delivered nuclear tests.<ref name = "bomber 79"/>

Originally the bombing role was to have been carried out at high altitude, but following the shooting down in 1960 of the [[Lockheed U-2]] flown by Gary Powers by an early Soviet [[SA-2]] Guideline missile, the SAM threat caused bomber squadrons to train for low-level attack as a means of avoiding radar detection when flying within hostile airspace. They were repainted in grey/green camouflage with normal markings, replacing their [[anti-flash white]] scheme.<ref name = "flint 133"/> By 1963, four Valiant squadrons (49, 148, 207 and 214) had been assigned to [[Supreme Headquarters Allied Powers Europe|SACEUR]] in the low-level tactical bombing role.<ref name = "bomber 79"/> By this point, there had been a noticeable decline in flying rates for the type.<ref name = "bomber 79"/>

===Conventional warfare===
[[File:vickers valiant camouflaged on ground arp.jpg|thumb|Camouflaged Valiant at [[Bristol Filton Airport|Filton]], [[England]]. Circa mid-1960s]]
Peacetime practice involved the dropping of small practice bombs on instrumented bombing ranges, and a system of predicted bombing using radio tones to mark the position of the bomb drop over non-range targets, the bomb error being calculated by a ground radar unit and passed either to the crew during flight or to a headquarters for analysis. Use of the Valiant's Navigational and Bombing System (NBS) and the high quality of assigned crews, who were typically veterans and often had been previously decorated for wartime service, meant a high level of bombing accuracy could be achieved, greater than that of aircraft during the Second World War. According to Gunston and Gilchrist, Valiant crews were able to place practice bombs from an altitude of {{convert|45000|ft}} within a few meters of their assigned target.<ref name = "bomber 79"/>

In October and November 1956 the Valiant was the first of the V-bombers to see combat, during the Anglo-French-Israeli Suez campaign. During [[Operation Musketeer (1956)|Operation Musketeer]], the British military operation in what became known as the [[Suez Crisis]], Valiants operating from the airfield at Luqa on Malta dropped conventional bombs on targets inside Egypt. Egyptian military airfields were the principal target; other targets included communications such as [[radio station]]s and transport hubs.<ref>Bowman 2016, p. 158</ref> On the first night of the operation, six Valiants were dispatched to bomb [[Cairo West Air Base]] (which was aborted in flight due to potential risk to US personnel in the vicinity) while six more attacked [[Almaza Air Base]] and a further five bombed [[Kibrit Air Base]] and Huckstep Barracks.<ref name = "black wright 42">Blackman and Wright 2015, p. 42.</ref><ref name = "darling 42">Darling 2012, p. 42.</ref>

Although the Egyptians did not oppose the attacks and there were no Valiant combat losses, the results of the raids were reported as disappointing. Although the Valiants dropped a total of {{convert|842|LT}} of bombs, only three of the seven airfields attacked were seriously damaged.{{#tag:ref|The Valiants had not yet been fitted with their operational Navigational and Bombing System (NBS) and were using Second World War bomb-aiming techniques.|group=N}} The Egyptian Air Force had been effectively destroyed in a wider series of multinational attacks of which the Valiant bombing missions had been a part.<ref>Bowman 2016, pp. 158, 161.</ref> It was the last time RAF V-bombers flew a live combat mission until Avro Vulcans bombed Port Stanley airfield in the Falkland Islands during the [[Falklands War]] in 1982.<ref>McClelland, pp.175–178.</ref>

===Tanker operations===
Valiant tankers were flown by No. 214 Squadron at [[RAF Marham]], operational in 1958, and No. 90 Squadron at Honington, operational in 1959.<ref name = "hub and sim 26"/> The two squadrons became dedicated tanker squadrons on 1 April 1962.<ref>Brookes 1982, p. 142</ref> Aircraft assigned to the tanker role were fitted with a Hose Drum Unit (HDU or "HooDoo") in the bomb bay. The HDU was mounted on bomb-mounting points and could be removed, so that the aircraft could be reverted to the bomber role if required;<ref>Tanner 2006, pp. 113–114.</ref> this arrangement meant that the bomb bay doors had to be opened in order to transfer fuel to a receiver aircraft. A control panel at the radar navigator station in the cockpit was used to operate the HDU.

Long-range demonstration flights were made with in-flight refuelling by other Valiant tankers that had been positioned at airfields along the route. In 1960, a Valiant bomber flew non-stop from Marham in the UK to Singapore and in 1961 a Vulcan flew non-stop from the UK to Australia.<ref name = "hub and sim 26">Hubbard and Simmons 2008, p. 26.</ref> The two tanker squadrons regularly made long range flights. These included non-stop flights from the UK to [[Nairobi]], [[RAF Gan]] and [[Singapore]].<ref>Brookes 1982, pp. 141–142</ref> Other aircraft refuelled by Valiants at this time included Victor and Vulcan bombers, [[English Electric Lightning]] fighters, and [[de Havilland Sea Vixen]] and [[Supermarine Scimitar]] fighters of the Royal Navy.<ref>Wynn 1994, p. 168.</ref>

===Countermeasures and reconnaissance roles===
Valiants of [[No. 18 Squadron RAF]] at [[RAF Finningley]] were modified to the "radio countermeasures" (RCM) role—now called "[[Electronic warfare support measures|electronic countermeasures]]" (ECM). These aircraft were ultimately fitted with American APT-16A and ALT-7 jamming transmitters, [[Airborne Cigar]] and Carpet [[Radar jamming and deception|jammers]], APR-4 and APR-9 "sniffing" receivers, and [[Chaff (countermeasure)|chaff]] dispensers. At least seven Valiants were configured to the RCM role.<ref>Brookes 2012, pp. 45–46.</ref>

Valiants of No. 543 Squadron at [[RAF Wyton]] were modified to serve in the photographic reconnaissance role. In one notable operation in 1965, Valiants of No. 543 Squadron photographed around {{convert|400000|sqmi}} of [[Rhodesia]] across an 11-week period.<ref name = "hub and sim 26"/>

===Fatigue failures and retirement===
In 1956, Vickers had performed a series of low level tests in WZ383 to assess the type for low level flight at high speed. Several modifications to the aircraft were made, including a metal radome, debris guards on the two inboard engines, and after six flights the aileron and elevator artificial feel was reduced by 50%. Pilots reported problems with cabin heating and condensation that would need remedying. The aircraft was fitted with data recording equipment and these data were used by Vickers to estimate the remaining safe life of the type under these flying conditions. Initially a safe life of 75 hours was recommended, which became "the real figure might be less than 200 hours".<ref>Morgan p. 66-68</ref> The number of hours flown by each Valiant in a year was an operational issue for the RAF.<ref>Valiant Units of the Cold War, Brookes p. 88.</ref>

[[File:15 Vickers Valiant WZ397 (15216077444).jpg|thumb|left|Vickers Valiant on display]]
Later the [[Royal Aircraft Establishment|RAE]] ran a similar series of tests that more closely resembled actual operational conditions including low level and taxiing; the corresponding report published in 1958 produced data that could be used to get a better grasp on which flight conditions produced the most damage, and enable a better projection of the future life span for the type.<ref>[http://naca.central.cranfield.ac.uk/reports/arc/cp/0521.pdf "Fatigue Loadings in Flight-Loads in the Nose Undercarriage and Wing of a Valiant."] E.W. Wells, ARC C.P. No. 521.</ref>

In May 1957 ''Flight'' reported an "incident at Boscombe Down, when the wing rear spar cracked after a rocket-assisted takeoff at overload weight (the reason for the rocket-assistance)"<ref>''Flight'' 17 May 1957, p. 651</ref> This aircraft was the second prototype WB 215 and had not been modified with the production fix for the known weakness in the rear spar;<ref>Properly to Test Book One "The Early Years", Noble 2003,{{ISBN|0 9544507 1 X}}, p.96</ref> the aircraft was subsequently broken up for wing fatigue testing after it had flown 489 hours.<ref>Morgan p. 44 & p. 89.</ref>

After years of front-line service, in July 1964, a cracked spar was found in one of the three Valiants (either WZ394 – Wynne, or WZ389 – Morgan) on Operation Pontifex.<ref>Wynn p. 469.</ref> This was followed on 6 August by a failure of the starboard wing rear spar at 30,000&nbsp;ft,<ref>Brookes, Victor Units of the Cold War, p. 67.</ref> in WP217, an OCU aircraft from Gaydon captained by Flight Lieutenant "Taffy" Foreman. The aircraft landed back at Gaydon but without flap deployment because damage to the starboard rear spar caused the flap rollers to come out of their guides so that the flap would not lower on that side. Later inspection of the aircraft also showed the fuselage skin below the starboard inner plane had buckled, popping the rivets; the engine door had cracked and the rivets had been pulled and the skin buckled on the top surface of the mainplane between the two engines.<ref name = "darling 39 40">Darling 2012, pp. 39–40.</ref> Both of these aircraft were PR variants.<ref>Morgan, App 2, Individual Valiant Histories pp. 89–94.</ref>

Inspections of the entire fleet showed that the wing spars were suffering from fatigue at between 35% and 75% of the assessed safe fatigue life, probably due to low level turbulence.<ref name = "darling 40">Darling 2012, p. 40.</ref> After this inspection, the aircraft were divided into three categories, Cat A aircraft continuing to fly, Cat B to fly to a repair base, and Cat C requiring repair before flying again. The tanker squadrons had the highest proportion of Cat A aircraft because their role had been mainly at high level.<ref name = "darling 40"/> This also caused the methods of assessing fatigue lives to be reviewed.<ref>Wynn 1996, p. 465.</ref> By the time the type was scrapped, only about 50 aircraft were still in service; the rest had been slowly accumulating at various RAF Maintenance Units designated as "Non effective Aircraft".<ref>Morgan App2, pp. 89–94.</ref>

Initially there was no question of retiring the type, or even a majority of affected aircraft. Repairs were actively taking place at Valiant bases such as Marham using working parties from Vickers plus RAF technicians from the base.  In January 1965, the Wilson government with [[Denis Healey]] as [[Secretary of State for Defence]] decided that the expense of the repairs could not be justified, given the short operational life left to the Valiant, and the fleet was permanently grounded as of 26 January 1965.<ref>[https://news.google.com/newspapers?id=wGNAAAAAIBAJ&sjid=nKMMAAAAIBAJ&pg=5895,4007485&dq=vickers+valiant&hl=en "Valiants to be Scrapped."] ''Glasgow Herald'', 27 January 1965.</ref> The QRA alert that had been in place for [[SACEUR]] was maintained until the final grounding.<ref>Wynn 1996, pp. 464–471, 500.</ref> When asked to make a statement regarding the Valiant's scrapping in the [[House of Commons of the United Kingdom|House of Commons]], Denis Healey stated that it "was not in any way connected with low-level flying" and that the "last Government took the decision to continue operating the Valiant force for another four years after its planned fatigue life was complete".<ref>{{citation |url=https://api.parliament.uk/historic-hansard/commons/1965/feb/01/royal-air-force-valiant-aircraft#column_725|title=ROYAL AIR FORCE (VALIANT AIRCRAFT) |work=[[Hansard|Parliamentary Debates (Hansard)]] |date=1 February 1965 |volume=705|at=cc723-7}}</ref>

Aviation author Barry Jones commented in his book that: "A question has to be asked. For two years before the demise of the Valiant, Handley Page at Radlett had 100 [[Handley Page Hastings|Hastings]] go through their shops. They were completely dismantled and rebuilt, having DTD683 components removed and replaced by new alloy sections. What was so special about the Hastings and why was the Valiant not treated similarly? Perhaps we will know one day – but I doubt it."<ref>"V-Bombers" Barry Jones p. 117.</ref> A ''Flight'' report about the scrapping states "Fatigue affected all Valiants ... not only those that had been used for some low flying".<ref>{{citation |url=http://www.flightglobal.com/pdfarchive/view/1965/1965%20-%200310.html|title=End of the Valiants|work=Flight International |date=4 February 1965 |page=184}}</ref>

On 9 December 1964, the last Valiant tanker sortie in XD812 of 214 Squadron was refuelling Lightning aircraft over the North Sea and was recalled to land back at Marham before the scheduled exercise was completed. On the same day, the last Valiant bomber sortie was carried out by XD818.{{#tag:ref|XD818 was also the aircraft which had dropped nuclear weapons during [[Operation Grapple]].|group=N}}

==Variants==
Including the three prototypes, a total of 107 Valiants were built.<ref>Brookes 2012, p. 45.</ref><ref name="Royal Air Force Museum">{{cite web |url=http://www.nationalcoldwarexhibition.org/research/collections/vickers-valiant-b1/ |title=Vickers Valiant B1 |publisher=Royal Air Force Museum  |access-date=19 May 2018 }}</ref>
* '''Valiant B.1''': 37 pure bomber variants, including five pre-production '''Type 600''', '''Type 667''' and '''Type 674'''s, which were powered by Avon RA.14 engines with the same {{convert|9500|lbf|kN}} thrust each as the earlier Avon 201 and 34 '''Type 706''' full-production aircraft, powered by Avon RA.28, 204 or 205 engines with {{convert|10500|lbf|kN}} thrust each, longer tailpipes and water-methanol injection for takeoff boost power.<ref name="Thunder and Lightnings">{{cite web |url=http://www.thunder-and-lightnings.co.uk/valiant/history.php |title=Vickers Valiant - History |website=thunder-and-lightnings.co.uk |access-date=19 May 2018 }}</ref>
* '''Type 710 Valiant B(PR).1''': eleven bomber/photo-reconnaissance aircraft. Edwards and his team had considered use of the Valiant for photo-reconnaissance from the start, and this particular type of aircraft could accommodate a removable "crate" in the bomb-bay, carrying up to eight narrow-view/high resolution cameras and four survey cameras.<ref name="Thunder and Lightnings" />
* '''Type 733 Valiant B(PR)K.1''': 14 bomber/photo-reconnaissance/tanker aircraft.<ref name="Thunder and Lightnings" />
* '''Type 758 Valiant B(K).1''': 44 bomber / tanker aircraft. Both tanker variants carried a removable tanker system in the bomb bay, featuring fuel tanks and a hose-and-drogue [[aerial refuelling]] system. A further 16 Valiant B(K).1s were ordered, but cancelled.<ref name="Thunder and Lightnings" />
* '''Valiant B.2''': 1 prototype.<ref name="Thunder and Lightnings" />
* Vickers also considered an air transport version of the Valiant, with a low-mounted wing, wingspan increased from {{convert|114|ft|4|in}} to {{convert|140|ft}}, fuselage lengthened to {{convert|146|ft}}, and uprated engines. Work on a prototype, designated the Type 1000, began in early 1953. The prototype was to lead to a military transport version, the Type 1002, and a civilian transport version, the Type 1004 or VC.7. The Type 1000 prototype was almost complete when it, too, was cancelled.<ref name="Thunder and Lightnings" />
Valiant production ended in August 1957.<ref name="Royal Air Force Museum" /> An order for 17 B.2 models was cancelled.<ref name="Thunder and Lightnings" />

==Operators==
[[File:Vickers Valiant B1 3-view silhouette.jpg|thumb|Silhouette of the Valiant B.1]]
;{{UK}}
* [[Royal Air Force]] operated Valiants from [[RAF Gaydon]], [[RAF Finningley]], [[RAF Honington]], [[RAF Marham]], [[RAF Wittering]] and [[RAF Wyton]] by:
** [[No. 7 Squadron RAF|No. 7 Squadron]] – Reformed at Honington on 1 November 1956, moving to Wittering on 26 July 1960 and disbanding 30 September 1962.<ref name="Osprey p92">Brookes 2012, p. 92.</ref>
** [[No. 18 Squadron RAF|No. 18 Squadron]] – Valiant equipped C Flight of 199 Squadron renumbered 18 Squadron at Finningley on 17 December 1958 and disbanded 31 March 1963.<ref name="Osprey p92"/>
** [[No. 49 Squadron RAF|No. 49 Squadron]] – Reformed Wittering 1 May 1956, moving to Marham 26 June 1961 and disbanding 1 May 1965.<ref name="Osprey p92"/>
** [[No. 90 Squadron RAF|No. 90 Squadron]] – Reformed at Honington on 1 January 1957 and disbanded on 1 March 1965 .<ref name="Osprey p92"/>
** [[No. 138 Squadron RAF|No. 138 Squadron]] – Reformed at Gaydon on 1 January 1955, moving to Wittering on 6 July 1955 and disbanding 1 April 1962.<ref name="Osprey p92"/>
** [[No. 148 Squadron RAF|No. 148 Squadron]] – Reformed Marham 1 July 1956 and disbanded 1 May 1965.<ref name="Osprey p92"/>
** [[No. 199 Squadron RAF|No. 199 Squadron]] – C Flight of 199 Squadron received Valiants on 29 May 1957 at Honington in the ECM training role, replacing [[Avro Lincoln]]s, with the rest of the Squadron operating the Canberra. 199 Squadron was disbanded in December 1958, with C Flight becoming 18 Squadron.<ref name="Osprey p92"/><ref name="Halley80 p203">Halley 1980, p. 203.</ref>
** [[No. 207 Squadron RAF|No. 207 Squadron]] – Reformed at Marham on 1 April 1956, disbanding on 1 May 1965.<ref name="Osprey p92"/>
** [[No. 214 Squadron RAF|No. 214 Squadron]] – Reformed at Marham on 21 January 1956 and disbanded on 1 March 1965.<ref name="Osprey p92"/>
** [[No. 543 Squadron RAF|No. 543 Squadron]] – Reformed at Gaydon on 1 April 1955 in the strategic reconnaissance role and moved to Wyton on 18 November 1955. It received Victor Mk 1s to replace its grounded Valiants in 1965.<ref name="Osprey p92"/><ref name="Halley80 p315">Halley 1980, p. 315.</ref>
** [[No. 232 Operational Conversion Unit RAF]] – Formed at Gaydon 21 February 1955 to train Valiant flight crews, with Victor training added in 1957. The Valiant equipped B flight disbanded in February 1965.<ref name="Osprey p92"/>
** [[No. 1321 (Valiant/Blue Danube Trials) Flight]]<ref name="Osprey p34-5">Brookes 2012, pp. 34–35.</ref>

==Accidents and incidents==
* 12 January 1952; the first Valiant prototype WB210 crashed near Bransgore following a midair fire.<ref>"Sole British Jet Atom Bomber Crashes." ''New York Times'', 13 January 1952.</ref>
* 29 July 1955; Valiant B1 WP222 of [[No. 138 Squadron RAF|No. 138 Squadron]] crashed on takeoff at [[RAF Wittering]] following aileron malfunction, killing all four crew.<ref name="WA100-95" /><ref name="times53289">"Valiant Crash Inquest Verdict." ''The Times,'' Issue 53289, August 1955, p. 11.</ref>
* 11 May 1956; Valiant B1 WP202 of the Royal Aircraft Establishment lost control and crashed attempting to land at Southwick Recreation Ground, near Hove in Sussex.<ref name="WA100-95" />
* 13 September 1957: Valiant B(PR)K1 WZ398 of [[No. 543 Squadron RAF|No. 543 Squadron]] caught fire in a hangar at [[RAF Wyton]], not repaired.<ref name="WA100-128" />
* 11 September 1959: Valiant BK1 XD869 of [[No. 214 Squadron RAF|No. 214 Squadron]] flew into the ground after a night takeoff from [[RAF Marham]].<ref name="XA100-20" />
* 12 August 1960: Valiant BK1 XD864 of [[No. 7 Squadron RAF|No. 7 Squadron]] nosewheel failed to retract on takeoff from [[RAF Wittering]], while sorting it out the aircraft stalled and crashed into the ground at [[RAF Spanhoe]] disused airfield.<ref name="XA100-20">Halley 2001, p. 20.</ref>
* 11 July 1961: Valiant B1 WP205 of the Aircraft and Armament Experimental Establishment overshot runway and hit control caravan at Boscombe Down.<ref name="WA100-95">Halley 2003, p. 95.</ref>
* 3 November 1961: Valiant B(PR)K1 WZ399 of [[No. 543 Squadron RAF|No. 543 Squadron]] abandoned takeoff at [[Offutt AFB]], Nebraska, United States, caught fire after overshooting runway onto a railway line.<ref name="WA100-128" />
* 14 March 1961 Valiant B. 1 WP200 at RRFU Pershore, failed to complete takeoff, written off.<ref name="WA100-95" /><ref>Morgan 1994, p. 32.</ref>
* 6 May 1964: Valiant B1 WZ363 of [[No. 148 Squadron RAF|No. 148 Squadron]] (although a 148 Sqn aircraft, it was on loan to, and crewed by, members of 207 Sqn) dived into the ground at night at [[Market Rasen]], Lincolnshire.<ref name="WA100-128">Halley 2003, p. 128.</ref>
* 23 May 1964: Valiant B(PR)K1 WZ396 of [[No. 543 Squadron RAF|No. 543 Squadron]] landed on foam with landing gear problems at [[RAF Manston]], not repaired.<ref name="WA100-128" />

==Surviving aircraft==
[[File:Wikivaliant.jpg|thumb|Vickers Valiant B1 ''XD818'', flown by [[Kenneth Hubbard]] during [[Operation Grapple]] – [[RAF Museum Cosford]] in 2006]]
* Vickers Valiant B1 XD818 – [[Royal Air Force Museum Midlands]] at [[RAF Cosford]], on display with the other two [[V bomber]]s, the [[Handley-Page Victor|Victor]] and [[Avro Vulcan|Vulcan]] in the National Cold War Exhibition. This is the only fully intact example in existence, and so Cosford is the only place where an example of all three V bombers can be seen together.<ref>[http://www.rafmuseum.org.uk/documents/press_releases/cosford/60th_Anniversary_of_Valiants_First_Flight.pdf "60th Anniversary of Valiant's First Flight."] Royal Air Force Museum, 17 May 2011.</ref>
* Cockpit sections surviving comprise XD816 at [[Brooklands Museum]] in Surrey<ref>[http://www.brooklandsmuseum.com/index.php?/explore/aircraft-gliders-cockpit-sections/ "Powered Aircraft, Gliders & Aircraft Cockpit Sections."] {{Webarchive|url=https://web.archive.org/web/20160428164504/http://www.brooklandsmuseum.com/index.php?/explore/aircraft-gliders-cockpit-sections/ |date=28 April 2016 }} Brooklands Museum, Retrieved: 19 August 2012.</ref> and XD875 at [[Morayvia]], [[RAF Kinloss|Kinloss]].<ref>[https://www.morayvia.org.uk/exhibits "Exhibits"] Morayvia, Retrieved: 20 July 2020.</ref> A third surviving section is the cockpit of XD826 which is part of the [[Imperial War Museum Duxford]] in Cambridgeshire<ref>[https://www.iwm.org.uk/events/conservation-in-action "Valiant cockpit now part of the IWM."] Imperial War Museum, 18 December 2022.</ref> and the flight deck of XD857 is displayed at the [[Norfolk and Suffolk Aviation Museum]] at Flixton, Suffolk.<ref>[http://www.aviationmuseum.net/our_aircraft.htm "Our Aircraft."] {{webarchive|url=https://web.archive.org/web/20131206184358/http://www.aviationmuseum.net/our_aircraft.htm |date=6 December 2013 }} Norfolk and Suffolk Aviation Museum, Retrieved: 19 August 2012.</ref>

==Specifications (Valiant B.1)==
[[File:Vickers Valiant.svg|thumb]]
{{Aircraft specs
| ref = ''Vickers Aircraft since 1908,''<ref name="Andrews vickers p450">Andrews and Morgan 1988, p. 450.</ref> ''Jet Bombers''<ref name = "bomber 80">Gunston and Gilchrist 1993, p. 80.</ref>
| prime units? = imp<!--        General characteristics-->
| genhide = 
| crew = five – two pilots, two navigators (one navigator plotter + one navigator radar), air electronics officer
| capacity = 
| length m = 
| length ft = 108
| length in = 3
| span m = 
| span ft = 114
| span in = 4
| height m = 
| height ft = 32
| height in = 2
| wing area sqm = 
| wing area sqft = 2362
| wing area note = 
| swept area sqm = <!-- swing-wings -->
| swept area sqft = <!-- swing-wings -->
| aspect ratio = <!-- sailplanes -->
| airfoil = 
| empty weight kg = 
| empty weight lb = 75881
| empty weight note = 
| gross weight kg = 
| max takeoff weight lb = 140000
| gross weight note = 
| fuel capacity = 
| more general = <!--
        Powerplant
-->
| eng1 number = 4
| eng1 name = [[Rolls-Royce Avon]] RA28 Mk 204
| eng1 type = [[turbojet]]s
| eng1 kn = <!-- jet/rocket engines -->
| eng1 lbf = 10000<!-- jet/rocket engines -->

<!--
        Performance
-->| perfhide = 
| max speed kmh = 
| max speed mph = 567
| max speed kts = 
| max speed note = at {{convert|30000|ft|m|abbr=on}}
| cruise speed kmh = <!-- if max speed unknown -->
| cruise speed mph = <!-- if max speed unknown -->
| cruise speed kts = 
| range km = 
| range miles = 4500
| range note = with underwing tanks
| endurance = <!-- if range unknown -->
| ceiling m = 
| ceiling ft = 54000
| g limits = <!-- aerobatic -->
| roll rate = <!-- aerobatic -->
| climb rate ms = 
| climb rate ftmin = 4000
| lift to drag = 
| wing loading kg/m2 = 
| wing loading lb/sqft = 
| wing loading note = 
| more performance = <!--
        Armament
-->
| bombs = ** 1 × {{convert|10000|lb|kg|abbr=on}} [[Blue Danube (nuclear weapon)|Blue Danube]] nuclear bomb <ref name="Mason bomber p379">Mason 1994, p. 379.</ref> ''or''
** 1 × [[Yellow Sun (nuclear weapon)|Yellow Sun]]<ref>McLelland 2013, p. 101.</ref> ''or''
** 21 × {{cvt|1000|lb}} bombs
| avionics = 
}}

==See also==
{{Portal|UK|Aviation}}
{{aircontent
|related=<!-- related developments -->
|similar aircraft=
* [[Avro Vulcan]]
* [[Boeing B-47 Stratojet]]
* [[Handley Page Victor]]
|lists=<!-- related lists -->
* [[List of aircraft of the Royal Air Force]]
* [[List of V Bomber dispersal bases]]
|see also=<!-- other relevant information -->
}}

==References==

===Notes===
{{Reflist|group=N}}

===Citations===
{{Reflist|colwidth=30em}}

===Bibliography===
* Andrews, C.F. ''The Vickers Valiant (Aircraft in profile no. 66)''. Leatherhead, Surrey, UK: Profile Publications Ltd., 1965.
* Andrews, C.F. and Eric B. Morgan. ''Vickers Aircraft since 1908''. London: Putnam, 1988. {{ISBN|978-0851778150}} .
* Barfield, Norman. "Vickers Valiant: Precient programme management par excellence". ''[[Air International]]'', Vol. 43, No. 3, September 1992, pp.&nbsp;153–161. {{ISSN|0306-5634}}.
* Blackman, Tony and Anthony Wright. ''Valiant Boys: True Stories from the Operators of the UK's First Four-Jet Bomber''. Grub Street Publishing, 2015. {{ISBN|1-9106-9087-2}}.
* Bowman, Martin. ''Cold War Jet Combat: Air-to-Air Jet Fighter Operations 1950–1972''. Casemate Publishers, 2016. {{ISBN|1-4738-7463-7}}.
* Brookes, Andrew. ''Force V: The History of Britain's Airborne Deterrent''. London: Jane's Publishing Company Ltd., 1982. {{ISBN|0-7106-0238-3}}.
* Brookes, Andrew. ''Valiant Units of the Cold War (Osprey Combat Aircraft: 95)''. Oxford, UK: Osprey Publishing, 2012. {{ISBN|978-1-84908753-7}}.
* Burnet, Charles and Eric B. Morgan. "The V-Bombers: Vickers Valiant, Part 1." ''[[Aeroplane Monthly]],'' Volume 8, No. 8, August 1980.
* Burnet, Charles and Eric B. Morgan. "The V-Bombers: Vickers Valiant, Part 2." ''Aeroplane Monthly,'' Volume 8, No. 9, September 1980.
* {{cite journal |last1=Buttler|first1=Tony|title=Vital Bombers: Origins of the RAF's 'V-Bomber' Force |journal=Air Enthusiast |date=January–February 1999 |issue=79 |pages=28–41 |issn=0143-5450}}
* Darling, Kev. ''RAF Strike Command 1968 -2007: Aircraft, Men and Action'', Casemate Publishers, 2012. {{ISBN|1-8488-4898-6}}.
* Downey, Bob. ''V Bombers'' (Warbirds Illustrated No. 35). London: Arms and Armour Press, 1985. {{ISBN|0-85368-740-4}}.
* Ellis, Ken. ''Wrecks & Relics: 20th Edition''. Leicester, UK: Midland Publishing, 2006. {{ISBN|1-85780-235-7}}.
* Flintham, Vic. ''High Stakes: Britain's Air Arms in Action 1945–1990''. Pen and Sword, 2008. {{ISBN|1-8441-5815-2}}.
* Gardner, Robert. ''From Bouncing Bombs To Concorde-The Authorised Biography Of Aviation Pioneer Sir George Edwards OM'', Sutton Publishing, 2006. {{ISBN|0 7509 4389 0}}.
* Gunston, Bill. ''Bombers of the West''.  London: Ian Allan Ltd., 1973, pp 38–53. {{ISBN|0-7110-0456-0}}.
* Gunston, Bill and Peter Gilchrist. ''Jet Bombers: From the Messerschmitt Me 262 to the Stealth B-2''. Osprey, 1993. {{ISBN|1-85532-258-7}}.
* Halley, James. ''Royal Air Force Aircraft WA100 to WZ999.'' Tonbridge, Kent, UK: Air-Britain (Historians) Limited, 2003, First edition 2001. {{ISBN|0-85130-321-8}}.
* Halley, James J. ''The Squadrons of the Royal Air Force''. Tonbridge, Kent, UK: Air-Britain (Historians) Ltd, 1980. {{ISBN|0-85130-083-9}}.
* Hubbard, Kenneth and Michael Simmons. ''Dropping Britain s First H-Bomb: Story of Operation Grapple 1957.'' Pen and Sword, 2008. {{ISBN|1-7834-0336-5}}.
* Jackson, Robert. ''Modern Combat Aircraft: 11 – V-Bombers''. Shepperton, Surrey, UK: Ian Allan Ltd. {{ISBN|1-901945-03-0}}.
* Jones, Barry. ''V-Bombers: Valiant, Vulcan and Victor''. Ramsbury, Malborough, UK: The Crowood Press, Paperback edition, 2007. {{ISBN|978-1-86126-945-4}}.
* Laming, Tim. ''V-Bombers: Vulcan, Victor and Valiant – Britain's Airborne Nuclear Deterrent''. London: Patrick Stephens Limited, 1997. {{ISBN|978-1-85260-529-2}}.
* [http://www.flightglobal.com/pdfarchive/view/1953/1953%20-%200935.html "Light Alloys and Production Problems: Two Further Papers from the A.F.I.T.A. Congress."] ''Flight,'' 17 July 1953, pp.&nbsp;91–93.
* Mason, Francis K. ''The British Bomber since 1914''. London: Putnam, 1994. {{ISBN|0-85177-861-5}}.
* McBrearty, J. F. [http://www.flightglobal.com/pdfarchive/view/1956/1956%20-%200396.html "Fail-Safe airframe design: The Lockheed philosophy: 'Fail-Safe' preferred to 'Safe Life'."] ''Flight'', 6 April 1956, pp.&nbsp;394–397.
* McLelland, Tim. ''Britain's Cold War Bombers''. Stroud, Gloucestershire: Fonthill, 2013. {{ISBN|978-1-78155-052-6}}.
* Morgan, Eric B. ''Vickers Valiant: The First V-Bomber''. Leicester, UK: Midland Publishing, 2002. {{ISBN|1-85780-134-2}}.
* Rosemeyer, Maurice Patrick. ''Adventure in the Air: Memoirs of a Flight Test Engineer.'' London, Ontario, Canada: Insomniac Press, 2009. {{ISBN|1-926582-14-4}}.
* {{cite book |last= Spooner |first= Nigel |year= 2024 |title= A History of Aviation at Brooklands in 100 Objects |location= Barnsley, England |publisher= Pen & Sword Airworld |isbn= 978-1-52679-091-0}}.
* [http://www.flightglobal.com/pdfarchive/view/1951/1951%20-%202503.html "Structural Problems – and Some Suggested Solutions: a Digest of Mr H. H. Gardiner's R.Ae.S Lecture."] ''Flight'', 14 December 1951, pp.&nbsp;756–758.
* Tanner, Richard. ''History of Air-To-Air Refuelling''. Pen and Sword, 2006. {{ISBN|1-8441-5272-3}}.
* Trubshaw, Brian and Edmonson, Sally. ''Brian Trubshaw: Test Pilot''. Stroud, UK: Sutton Publishing, 1998. {{ISBN|0-7509-1838-1}}.
* Turpin, Brian. "Database: Vickers Valiant." ''Aeroplane,'' Volume 30, No. 2, Issue 346, February 2002.
* [http://www.flightglobal.com/pdfarchive/view/1958/1958-1-%20-%200011.html "Valiant: Last of the Vickers Bombers?"] ''[[Flight International|Flight]]'', 4 July 1958, pp.&nbsp;13–20.
* Wilson, Stewart. ''Combat Aircraft since 1945''. Fyshwick, Australia: Aerospace Publications, 2000. 1-875671-50-1.
* Wynn, Humphrey. ''RAF Nuclear Deterrent Forces.'' London: The Stationery Office. 1996. {{ISBN|0-11-772833-0}}.

==External links==
{{External media|topic= |width=22% |float=right |video1=[https://www.youtube.com/watch?v=pFC2aaY2rdc Newsreel footage of Valiant following 1955 Speed Record] |video2=[https://www.youtube.com/watch?v=jCbzOQwJfd4 Footage and Description of the Valiant B2] |video3=[https://www.youtube.com/watch?v=0pLQD-LuCho Period footage of RAF Valiant operations]|video4=[https://www.youtube.com/watch?v=Tbn5hulJCNM High Encounter]}}
{{Commons category|Vickers Valiant|position=left}}
* [https://www.rafmuseum.org.uk/research/collections/vickers-valiant-b1/ RAF Museum]
* [http://www.thunder-and-lightnings.co.uk/valiant/history.html Valiant History]

{{Vickers aircraft}}
{{British military aircraft since World War II}}
{{Strategic nuclear weapon systems of the United Kingdom}}
{{Portal bar|Aviation|Nuclear technology|United Kingdom}}
{{Authority control}}

{{Good article}}

[[Category:1950s British bomber aircraft]]
[[Category:Vickers aircraft|Valiant]]
[[Category:Quadjets]]
[[Category:High-wing aircraft]]
[[Category:Aircraft first flown in 1951]]
[[Category:Strategic bombers]]
[[Category:V bombers|Valiant]]
[[Category:Aircraft with retractable tricycle landing gear]]