• 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.

While Vickers-Armstrong's submission had been rejected as too conservative, 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 didn't think there could be too much insurance.

Although the idea of developing, much less fielding as turned out to be the case, three entirely different large aircraft in response to a single request is unthinkable now, aircraft were less sophisticated in those days, development was not generally so troublesome, and certainly 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 in fact beat the first Shorts Sperrin into the air by several months. It had only been 27 months since issue of the contract. 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 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 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 initial Valiant jet bomber prototype was lost due to an in-flight engine fire in January 1952, all the crew escaping safely except for the co-pilot, who struck the tail after ejecting and was killed.

After modifications to the fuel system to eliminate a fire hazard, the second prototype first flew on 11 April 1952, though it was fitted with RA.7 Avon engines with 3,400 kilograms (7,500 pounds) thrust each, rather than the Sapphires originally planned. The loss of the initial prototype did not seriously compromise schedule, since the accident occurred so late in the flight test program.

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.

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, at the expensive of making engine access for maintenance and repair more troublesome, and increasing 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, with a large 45-degree angle of sweepback in the inner third of the wings and a shallow angle of about 24 degrees sweep outboard. 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 following 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 sweptback, and the horizontal tailplane was mounted well up the vertical tailplane to keep it out of the engine 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 volts 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 bombbay. 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, particularly 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 4,500 kilogram (10,000 pound) nuclear weapon or up to 21 450 kilogram (1,000 pound) bombs in its bombbay. Large external tanks, one carried under each wing and with a capacity of 7,500 liters (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 4,301 kilograms (9,500 pounds) 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 takeoff, resulting in asymmetric thrust.

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

39 Valiant B.1 pure bomber variants, including five preproduction Type 674 and 34 Type 706 full-production aircraft. The Type 674 was powered by Avon RA.14 engines with the same 4,310 kilograms (9,500 pounds) thrust each as the earlier Avon 201, while the Type 706 was powered by Avon RA.28 204 or 205 engines with 4,760 kilograms (10,500 pounds) thrust each, longer tailpipes, and water-methanol injection for takeoff 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 removeable "crate" in the bombbay, carrying up to eight narrow-view / high resolution cameras and four survey cameras.

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. Under 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 pounded targets in the Falkland Islands during the Falklands Crisis 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, and although the Valiants dropped a total of 856 tonnes (942 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, it had also been focused on the nuclear strike mission, and 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 Valiant was concerned, however, this was a wasted effort, since it never dropped a bomb in anger again.

A Valiant B.1 of 49 Squadron was the first RAF aircraft to drop a British operational atomic bomb, performing a test drop of a downrated Blue Danube weapon on Maralinga, South Australia, on 11 October 1956. A few months later, a 49 Squadron Valiant B(K).1 dropped the first British hydrogen bomb, the Green Granite Small, over the Pacific as part of OPERATION GRAPPLE. The blast was impressive, but 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 were finally terminated in November 1958, when the British government decided they would perform no more nuclear test blasts, eventually renouncing 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 standoff missile that was carried by the Victor and Vulcan, but in fact the Valiant was only used to test a two-thirds scale powered prototype of the weapon. Blue Steel didn't go into service until 1963, well after the Valiant was no longer 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 defenses 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 for an aircraft that was going out of service in a few years anyway, and had been built as a interim solution to begin with. The Valiant force was grounded in October 1964, to be officially withdrawn from service in January 1965.

The Valiant was a thoroughly competent and effective aircraft, and 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, and Britain could have had every bit as effective a V-bomber force at lower cost, though this isn't an idea that would necessarily please V-bomber enthusiasts.

The Valiant was also the last act of Vickers in the field of aviation. After the Valiant, Vickers went back to its traditional ships, tanks, and guns, and in fact design a tank named the Valiant. As a last act, the Valiant bomber was a good one. Only one complete Valiant survives today, and is on static display at the RAF Museum at Hendon, in North London.