Vickers Valiant
From Wikipedia, the free encyclopedia
- For other uses see: Valiant
| Valiant | |
|---|---|
 |
|
| RAF Valiant in anti-flash white | |
| Type | Strategic bomber |
| Manufacturer | Vickers |
| Maiden flight | 1951-05-18 |
| Introduced | 1955 |
| Retired | January 1965 |
| Primary user | Royal Air Force |
| Number built | 107 |
The Vickers Valiant was a British four-jet bomber, once part of the RAF's V bomber force.
Contents |
[edit] V-Bomber origins: B.35/46 / 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 WW2 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 perform a nuclear strike on a target.
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 England'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.
The Short's design became the S.A.4 Sperrin. A prototype Sperrin was completed and flew in 1951, but it was basically a World War II bomber with jet engines on slightly swept wings and straight tail. The engine fit was unusual, with nacelles accommodating twin Rolls-Royce Avon turbojets arranged in a top-and-bottom fashion. Improvements in aeronautical design and engineering had passed the Sperrin by before it ever flew. Although a second prototype was built and flown, further development of the type was abandoned. The Sperrin was never anything more than a footnote to Britain's strategic bomber development effort. Other work would achieve much more significant and impressive results.
Interestingly, 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 small jet powerplants 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.
[edit] Valiant origins: Vickers Type 660
Handley-Page and Avro came up with very advanced designs for the bomber competition. These would become the Victor and the Vulcan respectively, and the Air Staff decided to award contracts to both companies, again as a form of insurance.
Vickers-Armstrong's submission had been rejected as too conservative, but Vickers' chief designer George Edwards energetically lobbied the Air Ministry and made changes to meet their concerns. Edwards managed to sell the Vickers design on the basis that it would be available much sooner than the competition, going so far as to promise delivery of a prototype in 1951 and production aircraft in 1953. The Vickers bomber would be useful as a "stopgap" until the more advanced bombers were available. Apparently, the Air Ministry did not think there could be too much insurance.
Although the idea of developing, much less fielding, three entirely different large aircraft in response to a single request is unthinkable now, aircraft were less sophisticated in those days. Usually, development was not so troublesome, and it certainly was much less expensive. Indeed, one aviation writer observed, with a certain amount of exaggeration, that it cost less to develop a combat aircraft at the dawn of the jet age than it would to produce the manuals for a modern equivalent.
In April 1948, the Air Staff issued a specification with the designation B.9/48 written around the Vickers design, which was given the company designation of Type 660. In February 1949, two prototypes of the aircraft were ordered. The first was to be fitted with four Rolls-Royce RA.3 Avon engines, while the second was to be fitted with four Armstrong Siddeley Sapphire engines and redesignated Type 667.
The first prototype took to the air on 18 May 1951, as George Edwards had promised, and beat the first Short Sperrin into the air by several months. It had been only 27 months since the contract had been issued. The pilot was Jeff "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 replaced Summers on his retirement.
The Vickers Type 660 was given the official name of "Valiant" the next month, recycling the name from the Vickers Type 131 general-purpose biplane of 1931. Traditionally, RAF bombers had been named after towns and cities, for example "Lancaster", "Halifax", and "Canberra", but the new aircraft technology seemed to suggest a break from tradition, and the name "Valiant" was selected by a survey of Vickers employees.
The Valiant jet bomber prototype was lost due to an in-flight engine fire in January 1952, all the crew escaping safely except for the copilot, who struck the tail after ejecting and was killed.
After modifications to the fuel system to eliminate a fire hazard, the second prototype, Vickers Type 667, first flew on 11 April 1952. It was fitted with RA.7 Avon engines with 33 kN (7,500 lbf) thrust each, rather than the Sapphires originally planned. The loss of the initial prototype did not seriously compromise schedule, since the accident occurred late in the flight test programme.
An initial order for 25 production Valiant B.1 (Bomber Mark 1) aircraft had already been placed in April 1951. The first production aircraft flew in December 1953, again more or less on the schedule Edwards had promised, and was delivered to the RAF in January 1955. Britain's "V-bomber" force, as it had been nicknamed in October 1952, was now in operation. The Victor and Vulcan would follow.
[edit] Valiant details and variants
The first Valiant prototype was a relatively conservative and conventional design, with a shoulder-mounted wing and twin Avon RA.3 turbojets, each with 29 kN (6,500 lbf) thrust, in each wing root. The design gave an overall impression of a plain and clean aircraft appealing in its simplicity, like many early jet aircraft. George Edwards described it appropriately as an "unfunny" aircraft.
The wing's good size allowed it to have a chord (ratio of wing thickness to length at the root) of 12% and still accommodate the Avon engines within the wing. This engine fit contributed to the aircraft's aerodynamic cleanliness. However, it made engine access for maintenance and repair more troublesome, and increased the risk of "fratricide", with the failure of one engine possibly contributing to the failure of its partner.
The wing had a "compound sweep" configuration, devised by Vickers aerodynamicist Elfyn Richards. It had a large 45° angle of sweepback in the inner third of the wings, with outboard a shallow angle of about 24°. The compound sweep was a good compromise between aerodynamic efficiency and aircraft balance.
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. The tail was swept back, and the horizontal tailplane was mounted well up the vertical tailplane to keep it out of the engines' exhaust and so improve controllability.
The wing loading was relatively low and the Valiant was fitted with double-slotted flaps, shortening take-off run and improving range. 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, with the power system based on 112 V DC. The brakes and steering gear were hydraulic, but its pumps were electrically driven.
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 jump out of the bomber on their own.
In fact, 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 on providing the other three crew members of the Valiant with ejection seats, but this was not done due to the expense. In hindsight the good safety record of the Valiant, and indeed of all the V-bombers, made it clear this would not have been a good use of money.
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 7,500 litres (1,650 Imperial gallons), could be used to extend range. The aircraft had no defensive armament.
Initial Valiant production aircraft featured four Rolls-Royce Avon 201 turbojet engines, with 42 kN (9,500 lbf) thrust each. Trials were performed with two underwing De Havilland Sprite and Sprocket rocket booster engines. However, the booster rockets 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.
[edit] Production
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 42 kN (9,500 lbf) thrust each as the earlier Avon 201.
- 34 Type 706 full-production aircraft, powered by Avon RA.28 204 or 205 engines with 47 kN (10,500 lbf) 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.
The production of the tanker designated aircraft came before the actual use of the equipment, produced by Flight Refuelling Ltd, which was not used operationally until 1959, well after Valiant production was over, although flight refuelling had been tested during the war with a Heydon biplane bomber. Some sources say the tanker versions were simply refits of B.1 and B(PR).1 aircraft, but they were assigned different Vickers type numbers from the start. It is possible that these aircraft were B.1 or B(PR).1 aircraft that were produced with minor changes ready for the addition of the tanker gear when it became available.
With inflight refuelling probes fitted to Valiants and tanker conversions available, the Valiant could go beyond "medium range", and the RAF had a true strategic bombing capability.
A number of Valiants were also 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.
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, one was for an advanced variant, the Valiant B.2, intended as a low level pathfinder - penetrating to a target area at low level and marking it with flares for a follow-up strike by other bombers, as such it required a strengthened airframe to cope with the tougher ride at low level. For centre of gravity reasons, the B.2 featured a lengthened fuselage forward of the wings for a total length of 34.8 m (114 ft), in contrast to a length of 33 m (108 ft 3 in) for the Valiant B.1. The strengthened wing entailed changes to the main landing gear. Featuring four wheels instead of two, it retracted backwards into fairings in 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 at sea level compared to 414 mph.
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, the Air Ministry had realized that target marking was an outdated concept, and 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 in the humiliating role of "ballistic target" for ground gunnery.
Vickers also considered an air transport version of the Valiant, with a low-mounted wing, wingspan increased to 42.7 m (140 ft) from 34.8 m (114 ft 4 in), fuselage lengthened to 44.5 m (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.
[edit] Valiant in service
As the Valiant was an entirely new class of aircraft for the RAF, the 232 Operational Conversion Unit was established at RAF Gaydon to help get the bomber into service. The first operational RAF unit to be equipped with the Valiant was 138 Squadron, also at RAF Gaydon at first, 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 real 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 pounded Egyptian targets with high-explosive bombs. It was the last time the V-bombers flew an actual strike mission until Avro Vulcans bombed targets in the Falkland Islands during the Falklands War in 1982.
Although 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 856 tonnes (842 long tons) of bombs, only three of the seven airfields were seriously damaged.
As the modern military expression has it: "Train as you fight, fight as you train." The Valiant force was not only new and inexperienced but it had also been focused on the nuclear strike mission. Its personnel were therefore lacking in training and procedures for carrying out conventional bombing missions. In response, the RAF began to re-emphasize training for conventional bombing missions. As far as the Valiants were concerned, this was a wasted effort, since they never dropped a bomb in anger again.
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 Green Granite Small, over the Pacific as part of Operation Grapple. The blast was impressive, but the test was not a complete success, as the measured yield was less than a third of the maximum expected. The British still needed to do a bit more work on their fusion weapons.
The Grapple series of tests continued into 1958, and the first really satisfactory drop occurred in April 1958, with a Green Granite Large bomb exploding with ten times the yield of the original Green Granite Small. Further tests followed, but testing was finally terminated in November 1958, when the British government decided it would perform no more nuclear test blasts. Eventually Britain renounced such tests completely.
Valiants were originally assigned to the strategic nuclear bombing role, but by the early 1960s they had been replaced in this capacity by the Victor and Vulcan. Some sources claim the Valiant carried the Blue Steel nuclear-tipped stand-off missile that was carried by the Victor and Vulcan, but the Valiant was used only to test a two-thirds-scale powered prototype of the weapon. Blue Steel did not go into service until 1963, well after the Valiant stopped being used in the strategic bombing role.
Three squadrons of Valiants were assigned to support NATO in the low-level tactical bombing role, and two more squadrons served as tankers. They also continued to give good service in the strategic photo-reconnaissance role.
In the tactical bombing role, improved air defences had made high-altitude bombing tactics questionable, and the Valiants were switched to low-altitude tactics. They were given a new camouflage paint job, replacing their anti-flash white scheme.
Low-level operations proved too much for the Valiant. Following a series of accidents, inspections showed that the main wing spars of the Valiants in operation were suffering from excessive fatigue. Despite the aircraft's continuing usefulness, particularly in the tanker role, replacing the wing spars was deemed too expensive since the aircraft was going out of service in a few years anyway, and had been built as an interim solution to begin with. The Valiant force was grounded in October 1964, and was officially withdrawn from service in January 1965.
The Valiant was a thoroughly competent and effective aircraft. It was particularly noteworthy for the speed with 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, the Victor and Vulcan would have been redundant. This would have given Britain just as effective a V-bomber force at a lower cost. This isn't an idea that would necessarily please V-bomber enthusiasts.
The Valiant was Vickers last 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 craft from 1962, though the latter did act as military transport for the RAF.
Only one complete Valiant survives today. This aircraft, Vickers Valiant B1 XD818 has recently been moved from RAF Museum Hendon to RAF Museum Cosford. Here it will join a Victor K2 and Vulcan B2, amongst other jets of the period as part of a new Cold War Jets Collection planned to open sometime in 2006.
[edit] Operators
[edit] Deployment
The Valiant was operated by the following RAF squadrons from RAF Gaydon, RAF Honington, RAF Marham and RAF Wyton:
- No. 7 Squadron
- No. 49 Squadron
- No. 138 Squadron
- No. 148 Squadron
- No. 207 Squadron
- No. 214 Squadron
- No. 543 Squadron
[edit] Specifications (Valiant B.1)
General characteristics
- Crew: five - two pilots, two navigators, electronics engineer
- 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 ft² (219 m²)
- Empty weight: 75,880 lb (34 420 kg)
- Military load: 21,000 lb (9500 kg)
- Max takeoff weight: 138,000 lb (62 600 kg)
- Overload take-off: 175,000 ib (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 at 30,000 ft plus, 414 mph (666 km/h)
- Range: 4,500 miles with 10,000 lb bomb halfway, with underwing tanks (7200 km)
- Service ceiling: 54,000 ft (21,000 m)
- Rate of climb: 4,000 ft/min (20 m/s)
- Wing loading: 58 lb/ft² (286 kg/m²)
- Thrust/weight: 0.29
Armament
- 1 × 10,000 lb (4500 kg) bomb or
- 21 × 1,000 lb (450 kg) bombs
[edit] External links
[edit] References
- This page is based on "The Vickers Valiant" version 1.1, by Greg Goebel. The original version (placed in the public domain) can be accessed at: http://www.vectorsite.net/avval.html
[edit] Related content
Comparable aircraft
Handley Page Victor - Avro Vulcan
Designation sequence
Varsity - Viscount - Vickers Type 667 - Valiant - Vanguard - VC-10
