Vickers Valiant

Vickers Valiant
RAF Valiant in anti-flash white
RoleStrategic bomber
ManufacturerVickers-Armstrongs
First flight18 May 1951
Introduced1955
RetiredJanuary 1965
Primary userRoyal Air Force
Number built107

The Vickers-Armstrongs Valiant was a British four-jet bomber, once part of the Royal Air Force's V bomber force.

The Valiant was originally developed for use as high-level strategic bomber. When the other V-bombers came into use it was also used as a tanker. However, when the RAF moved to low-level attacks, low-level flying in the Valiant caused premature fatiguing. Rather than repair or rebuild the fleet, it was grounded and the Handley Page Victor took over the tanker role.

Development

V-Bomber origins: B.35/46 and Sperrin

The British Royal Air Force (RAF) Bomber Command left World War II with a policy of using heavy bombers with four piston-engines for massed raids. It remained committed to this policy in the immediate postwar period, adopting the Avro Lincoln, an updated version of the Avro Lancaster, as its standard bomber.

The development of jet aircraft and nuclear weapons soon made this policy obsolete. The future appeared to belong to jet bombers that could fly at high altitude and speed, without defensive armament, to act as a deterrent particularly to a Soviet attack and, if deterrence failed, to perform a nuclear strike.

After considering various specifications for such an advanced jet bomber in late 1946, in January 1947 the British Air Ministry issued a request in the form of Specification B.35/46 for an advanced jet bomber that would be at least the equal of anything the US or the USSR had. The request went to most of the UK's major aircraft manufacturers. While Short Brothers submitted a design that was judged too ambitious, the Air Staff accepted another submission from the company for a separate requirement, B.14/46, to provide a very conservative bomber design as "insurance" in case the advanced B.35/46 effort ran into trouble.

Short's conservative design became the S.A.4 Sperrin. A prototype Sperrin was completed and flew in 1951, but its design was too conservative when compared with the contemporary Vickers Valiant with swept wings and a much superior performance. The Sperrin engine fit was unusual, with nacelles with twin Rolls-Royce Avon turbojets arranged one above the other. Although a second prototype was built and flown, further development of the type was abandoned and it was retained as an engine testbed.

Short's also pursued their earlier, more ambitious bomber concept on a private basis, resulting in a small test aircraft, the Short S.B.4. Sherpa. The Sherpa was basically a tailless glider with two small jet engines and long, sweptback wings, giving something of the appearance of a boomerang with a fuselage. The Sherpa was intended to test the "aero-isoclinic" wing concept. In this scheme, the outer sections of the wings were pivoted, allowing them to maintain the same incidence even as the wing flexed. However, this line of investigation proved to be a dead end as well.

Design

Valiant details and variants

The Valiant was a conservative design, with a shoulder-mounted wing and four Avon RA.3 turbojets, each of 6,500 lbf (29 kN) thrust, two in each wing root. The design gave an overall impression of a plain and clean aircraft with simple aerodynamics. George Edwards described it appropriately as an "unfunny" aircraft.

The root chord thickness ratio (ratio of wing thickness to length at the root) was 12% and allowed the Avon engines to be within the wing rather than on pods as in the contemporary Boeing B-47. This "buried engine" fit contributed to the aircraft's aerodynamic cleanliness. However, it made engine access for maintenance and repair difficult and increased the risk that the failure of one engine would contribute to the failure of its pair due to flying debris such as turbine blades. It also increased the complexity of the design of the main spar which had to be routed round the engines. For these reasons the buried engine layout is not used nowadays and the podded layout pioneered by the Boeing B-47 is often employed. This also has the advantage of reducing wing root bending moment in flight because the podded engines can be mounted more outboard than in the "buried engine" layout (or engines mounted on the fuselage, for that matter).

The Valiant wing had a "compound sweep" configuration, devised by Vickers aerodynamicist Elfyn Richards. It had a 45 angle of sweepback in the inner third of the wing, reducing to an angle of about 24 at the tips. This was because the thickness/chord ratio could be reduced closer to the tips, balancing this against the sweep reduction in postponement of Mach effects such as buffeting and drag rise. Limiting in-service speed was Mach 0.82 and a typical cruise of Mach 0.76 at heights up to 55,000 ft when light. A "clean" Valiant (one without underwing tanks) could climb straight to 50,000 ft after takeoff unless it had heavy stores in the large bomb bay.

The engine inlets were long rectangular slots in the first prototype, but later Valiants featured oval or "spectacle" shaped inlets to permit greater airflow for more powerful Avon engine variants. The jet exhausts emerged from fairings above the trailing edge of the wings. Water injection was fitted to some Valiants, for instance those in the tanker role, and increased takeoff thrust by about 1,000 lb (450 kg) per engine.

The tail surfaces were swept back, and the horizontal tailplane was mounted well up the vertical fin to keep it clear of the engines' exhaust.

The wing loading was low by modern standards and the Valiant was fitted with double-slotted flaps for takeoff (20 flap) and landing (40 or full flap, about 60). The aircraft featured tricycle landing gear, with twin-wheel nosegear and tandem-wheel main gear retracting outward into the wing. Most of the aircraft's systems were electric including flaps and undercarriage.

  • Electrics were based on 128 volt direct current generators for functions requiring large amounts of electrical power and a 28 V DC system provided a controlling voltage for other systems and the actuators that initiated the 128 V functions. Backup batteries were a bank of 24 V units for the 28 V low-voltage system and 112 V batteries (28 V in series) for the 128 V system. The brakes and steering gear were hydraulic, but its pumps were electrically driven.
  • The flight controls consisted of two channels of power control with full manual back-up. Practice flying in manual was allowed, even landings, under conditions of little turbulence and low crosswind. Landings in manual were limited to only 40 flap because it was difficult in manual to counter the trim change when full flap was lowered, resulting in a heavy landing. The controls were very heavy indeed when flown in manual and bank was limited to 20 degrees.

The Valiant was built around a massive backbone beam that supported the wing spars and the weight of bombs in the long bomb bay. The crew were contained in a pressurized "egg" and consisted of pilot, copilot, two navigators, and an electronics operator. Only the pilot and copilot had ejection seats. This was a concern for the other three crew members, who had to bail out of the crew door on the port side of the fuselage. The crew door was held partially open for bale-out to provide shielding from the airflow until the crew man had cleared the aircraft. Chute opening was automatic by a static line.

The main structural components, spars and beams etc were built with the zinc/magnesium/copper aluminium alloy designated as DTD683 in the U.K. and 7075-T6 in the U.S. system. The use of this alloy caused many problems in the manufacture of the prototypes and in the mass production of the Valiant. The main problem was the low fatigue resistance, but there were other problems, that resulted in new manufacturing and forging techniques in Aircraft manufacture.

The aircraft was designed with a 'Safe-Life' strategy.

This combination of 'Safe-Life' and DTD683 proved to be disastrous and it affected many of the early jet aircraft. This came to a head in around 1956, with the publication in the Journal of the Institute of Metals of a paper that condemned the material (DTD683) as being unstable, in that it could (and did) fail catastrophically in a rapid auto-catalytic process which could be initiated through stressing the airframe close to its design limits in turbulence or a heavy landing. The 'Safe-Life' design strategy was given the 'coup de grace' by an American engineer from Lockheed in a talk given to the RAeS also in 1956 because it could not guarantee safety in a catastrophic failure. The Valiant was designed with a method that could not guarantee safety in a catastrophic failure, with a material that was known to fail catastrophically and this was known by Vickers in at least 1956, 9 years before the Valiant was scrapped.

The Air Ministry had originally requested an escape system that would eject the entire crew compartment or, if that were not possible, ejection seats for all crew. Vickers engineers replied that this requirement was impractical. Experiments were later performed at the Bomber Command Development Unit (BCDU) at RAF Wittering that involved rear-crew ejections using instrumented dummies rather than live crew. This was not put into service due to the expense.

The Valiant B.1 could carry a single 10,000 lb (4,500 kg) nuclear weapon or up to 21 1,000 lb (450 kg) conventional bombs in its bomb bay. Large external fuel tanks under each wing with a capacity of 1,650 Imp gal (7,500 L), could be used to extend range. The aircraft had no defensive armament.

Initial Valiant production aircraft had four Rolls-Royce Avon 201 turbojet engines, with 9,500 lbf (42 kN) thrust each. Trials were performed with two underwing de Havilland Sprite and Super Sprite rocket booster engines. However, these were deemed unnecessary, due to the availability of more powerful Avon variants, as well as fear of accidents if one booster rocket failed on take-off, resulting in asymmetric thrust.

Including three prototypes, a total of 107 Valiants were built, including:

  • 39 Valiant B.1 pure bomber variants, including five pre-production Type 674, which were powered by Avon RA.14 engines with the same 9,500 lbf (42 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 10,500 lbf (47 kN) thrust each, longer tailpipes, and water-methanol injection for take-off boost power.
  • 8 Type 710 Valiant B(PR).1 bomber/photo-reconnaissance aircraft. Edwards and his team had considered use of the Valiant for photo-reconnaissance from the start, and this particular batch of aircraft could accommodate a removable "crate" in the bomb-bay, carrying up to eight narrow-view/high resolution cameras and four survey cameras.
  • 13 Type 733 Valiant B(PR)K.1 bomber/photo-reconnaissance/tanker aircraft
  • 44 Type 758 Valiant B(K).1 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.

Valiant production ended in August 1957.

Valiant B(PR)K.1 WZ393 of 90 Squadron in original all-metal finish displaying at Blackpool Squires Gate airport in 1957

Valiant tankers were flown by 214 Squadron at RAF Marham, operational in 1958 and 90 Squadron at Honington, operational in 1959. These aircraft 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 if necessary. However, this arrangement meant that the bomb doors had to be opened in order to give fuel to a receiver aircraft.

With inflight refuelling probes fitted to Valiants, Vulcans and Victors and Valiant tankers available, the so-called "Medium Bomber Force" of the RAF could go beyond "medium range", and the RAF had a true strategic bombing capability. Long-range demonstration flights were made using Valiant tankers pre-deployed along the route. In 1960, a Valiant bomber flew non-stop from Marham in the UK to Singapore and in 1961 a Vulcan non-stop from the UK to Australia. The two tanker squadrons regularly practised long range missions, refuelled by other Valiant tankers on the way. In 1963 a squadron of Gloster Javelin All-weather interceptors was refuelled in stages from the UK to India, the tankers flying on to Butterworth near Penang in Malaysia (exercise "Shiksha"). Other aircraft refuelled at this time included Victor and Vulcan bombers and English Electric Lightning fighters, also the de Havilland Sea Vixen fighter of the Royal Navy.

Valiants of No. 18 Squadron RAF at RAF Finningley were modified to the "radio countermeasures" (RCM) role - RCM is now called "electronic countermeasures" (ECM). These aircraft were ultimately fitted with APT-16A and ALT-7 jamming transmitters, Airborne Cigar and Carpet jammers, APR-4 and APR-9 "sniffing" receivers, and chaff dispensers. At least seven Valiants were configured to the RCM role.

Valiants of number 543 Squadron at RAF Wyton were modified to the photographic reconnaissance role.

Originally, Valiants were finished in silver, but once equipped with nuclear weapons they were painted in anti-flash white to reflect some of the glare of a nuclear blast. However, the RAF roundels were left in solid red-white-blue. It was later realized that this insignia might be permanently burned into an aircraft by the flash of its dropped nuclear weapon detonating. In the other V-bombers the roundel became faded pink-white-violet, but the faded insignia was never applied to the Valiant.

Of the three prototypes, two were Mark 1s and one was for a developed version, the Valiant B.2, designed for low level attack. As such it had a strengthened airframe to cope with the rougher ride at low level. The B.2 had a lengthened fuselage with a total length of 114 ft (34.8 m), in contrast to a length of 108 ft 3 in (33 m) for the Valiant B.1. The strengthened wing entailed changes to the main landing gear. Each main undercarriage leg had four wheels instead of two and it retracted backwards into fairings to the rear of the wings. 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, 655 mph (1,054 km/h) at sea level compared to 414 mph (666 km/h).

The Air Ministry ordered 17 B.2s, including two prototypes and 15 operational aircraft, in April 1952. The prototype was completed, and flew for the first time in September 1953. However, although the Valiant B.2's low-level capabilities would later prove to be highly desirable, the B.2 program was cancelled in 1955. The B.2 prototype was used for tests for a few years, then incrementally destroyed by being used as a target for ground gunnery.

Vickers also considered an air transport version of the Valiant, with a low-mounted wing, wingspan increased to 140 ft (42.7 m) from 114 ft 4 in (34.8 m), fuselage lengthened to 146 ft (44.5 m), 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.

Operational history

Camouflaged Valiant at Filton, England. Date uncertain but probably the mid-1960s

As the Valiant was an entirely new class of aircraft for the RAF, 232 Operational Conversion Unit was established at RAF Gaydon. The first operational RAF unit to be equipped with the Valiant was 138 Squadron, also at RAF Gaydon, though it later moved to RAF Wittering. At its peak, the Valiant equipped at least seven RAF squadrons.

A Valiant B.1 (WZ366) of No 49 Squadron (captained by Squadron Leader E.J.G. Flavell AFC) was the first RAF aircraft to drop a British operational atomic bomb when it performed a test drop of a down-rated Blue Danube weapon on Maralinga, South Australia, on 11 October 1956.

The Valiant was the first of the V-bombers to see combat, during the Anglo-French-Israeli Suez intervention in October and November 1956. During Operation Musketeer, Valiants operating from the airfield at Luqa on Malta dropped conventional HE bombs on Egyptian targets. It was the last time the V-bombers flew a war mission until Avro Vulcans bombed Port Stanley airfield in the Falkland Islands during the Falklands War in 1982.

Although the Egyptians did not oppose the attacks and there were no Valiant combat losses, the results of the raids were disappointing. Their primary targets were seven Egyptian airfields. Although the Valiants dropped a total of 842 tonss (856 tonnes) of bombs, only three of the seven airfields were seriously damaged. Note that the Valiants had not yet been fitted with their operational Navigational and Bombing System (NBS) and were dropping largely using Second World War techniques. When NBS was fitted and crews well-practised, bombing accuracies became typical of other aircraft of the time and from high level (say, 40,000 ft/12,190 m) a 100 yd (90 m) error was not uncommon. Peacetime practice involved the dropping of small practice bombs on instrumented bombing ranges, also a system of predicted bombing using radio tones to mark the position of 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.

On May 15, 1957 a 49 Squadron Valiant B(K).1 (captained by Wing Commander K.G. Hubbard OBE DFC AFC) dropped the first British hydrogen bomb, the "Short Granite" (AKA "Green Granite Small"), over the Pacific as part of Operation Grapple. The blast was impressive, but the test was largely a failure, as the measured yield was less than a third of the maximum expected and while achieving the desired thermonuclear explosion the device had failed to operate as intended. The first British hydrogen bomb that detonated as planned (or actually with a higher yield than planned), "Grapple X Round A" (AKA "Round C1"), was dropped on November 8, 1957.

The Grapple series of tests continued into 1958, and the first really satisfactory drop occurred in April 1958, with the "Grapple Y" bomb exploding with ten times the yield of the original "Short Granite" (the November 1957 bomb was considered unsuitable for mass production). Further tests followed, but testing was finally terminated in November 1958, when the British government decided it would perform no more air-delivered nuclear tests. Eventually Britain renounced such tests completely.

Valiants were originally assigned to the strategic nuclear bombing role as were the Vulcan and Victor B.1s when they became operational. By the early 1960s, these aircraft were joined by the Victor B.2 and Vulcan B.2. Originally the bombing role was at high level but with the shooting down of the Lockheed U-2 flown by Gary Powers by an early SA-2 Guideline missile, the SAM threat caused the V-force to train for low-level attack. They were repainted in grey/green camouflage, replacing their anti-flash white scheme. The Valiant did not carry the Blue Steel nuclear-tipped stand-off missile that was carried by the Victor and Vulcan.

Three squadrons of Valiants were assigned to the low-level tactical bombing role (49, 148, 207) and two more squadrons (90 and 214) served as tankers. They also continued to serve in the strategic photo-reconnaissance role (543 Squadron).

Low-level operations proved too much for the Valiant. On 6 August 1964, there was a failure of a rear spar in WP217, an OCU aircraft from Gaydon flown by Flight Lieutenant "Taffy" Foreman. This was fortunately without loss, the aircraft being landed back at Gaydon but without flap because of damage in the rear of one wing. Later inspection of the aircraft showed the fuselage skin below the starboard inner plane had buckled, popping the rivets; the engine door had cracked and on the top surface of the mainplane between the two engines the rivets had been pulled and the skin buckled. 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. 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. This also caused the methods of assessing fatigue lives to be reviewed.

Under this plan, repairs were taking place by Vickers teams at a number of bases and Valiant crews were retained pending the aircraft coming back on line. However, in early 1965 the Wilson government with Denis Healey as Secretary of State for Defence decided that the expense could not be justified and the fleet was permanently grounded as of 26 January 1965. The QRA alert that had been in place for SACEUR was maintained until the final grounding and was then allowed to lapse. The deterrent bomber role continued with the Victor and Vulcan but the UK air tanker force ceased to exist, and it was over a year before the first of the Victor tankers became operational.

The last known Valiant Tanker sortie was on 9 December 1964 in XD812 on a sortie over the North Sea refuelling Lightning aircraft. The Captain was Wing Commander Ken Smith DFC, commander of 214 Squadron, Marham, flying with Valiant Captain Flight Lieutenant Ian Strachan and his crew.

The last known Valiant Bomber sortie was on 9 December 1964 in XD818. The Captain was Wing Commander John Langston (OC 49 Sqn), in the 6th seat doing a crew check on Flt Lt Brian Pettit and his regular crew. This flight is believed to have landed after that of the Valiant Tanker. XD818, the last remaining Valiant, is now preserved in RAF Cosford museum. This was also the aircraft which had dropped nuclear weapons during Operation Grapple.

The Valiant was a thoroughly competent and effective aircraft. It was particularly noteworthy for the short time in which it was designed and introduced, with remarkably few changes between the initial prototype and production machines. In fact, some aviation observers suggest that if the Valiant B.2 had been adopted, it could have been more effective than the Victor and Vulcan, particularly at low level.

The Valiant was Vickers' last purpose built military aircraft. It was followed by the Vanguard, a passenger turboprop designed in 1959 and flying into the 1990s, and the Vickers VC-10, a jet passenger aircraft from 1962, though the latter is used as a military transport and tanker for the RAF.

Operators

United Kingdom

Royal Air Force operated Valiants out of RAF Gaydon, RAF Finningley, RAF Honington, RAF Marham, RAF Wittering and RAF Wyton by:

  • No. 7 Squadron
  • No. 18 Squadron
  • No. 49 Squadron
  • No. 90 Squadron
  • No. 138 Squadron
  • No. 148 Squadron
  • No. 199 Squadron
  • No. 207 Squadron
  • No. 214 Squadron
  • No. 543 Squadron
  • No. 232 Operational Conversion Unit RAF

Survivors

Vickers Valiant B1 XD818 - RAF Museum Cosford in 2006
  • Vickers Valiant B1 XD818 - RAF Museum Cosford, on display with the other two V bombers, the Victor and Vulcan in the Cold War Jets Collection.
  • Cockpit Section on display at Bruntingthorpe. The cockpit is accessible and allows people the opportunity to see how small a space the pilots had when flying.

Accidents and incidents

  • 12 January 1952 First Prototype WB210 Crashed near Hurn.
  • 13 September 1957 Valiant B(PR)K1 WZ398 of No. 543 Squadron caught fire in a hangar at RAF Wyton, not repaired.
  • 11 September 1959 Valiant BK1 XD869 of No. 214 Squadron flew into the ground after a night take off from RAF Marham.
  • 12 August 1960 Valiant BK1 XD864 of No. 7 Squadron stalled and crashed into the ground at Spanhoe airfield. Fractured centre plane spar was found at the scene, it was not investigated.
  • 3 November 1961 Valiant B(PR)K1 WZ399 of No. 543 Squadron abandoned take-off at Offut AFB, Nebraska, United States, caught fire after overshooting runway onto a railway line.
  • 14 March 1961 Valiant B. 1 WP200 at RRFU Pershore, failed to complete take off, written off
  • 6 May 1964 Valiant B1 WZ363 of No. 148 Squadron dived into the ground at night at Market Rasen, Lincolnshire.
  • 23 May 1964 Valiant B(PR)K11 WZ396 of No. 543 Squadron landed on foam with landing gear problems at RAF Manston, not repaired.

Specifications (Valiant B.1)

General characteristics

Valiant B.1
  • Crew: five - two pilots, two navigators (one navigator plotter + one navigator bomber), air electronics officer
  • Length: 108 ft 3 in (32.99 m)
  • Wingspan: 114 ft 4 in (34.85 m)
  • Height: 32 ft 2 in (9.80 m)
  • Wing area: 2,362 ft (219 m)
  • Empty weight: 75,880 lb (34,420 kg)
  • Military load: 21,000 lb (9,500 kg)
  • Max takeoff weight: 138,000 lb (62,600 kg)
  • Overload take-off: 175,000 lb (79,400 kg) with underwing tanks)
  • Powerplant: 4 Rolls-Royce Avon RA28 Mk 204 turbojet, 10,000 lb (44 kN) each

Performance

  • Maximum speed: Mach 0.84 (414 mph, 666 km/h) at 30,000 ft+
  • Range: 4,500 mi (7,200 km) with 10,000 lb bomb halfway, with underwing tanks
  • Service ceiling: 54,000 ft (21,000 m)
  • Rate of climb: 4,000 ft/min (20 m/s)
  • Wing loading: 58 lb/ft (286 kg/m)
  • Thrust/weight: 0.29

Armament

  • Bombs:
    • 1 10,000 lb (4500 kg) bomb or
    • 21 1,000 lb (450 kg) bombs
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