Background During the
Second World War, the British government made the decision to dedicate its aircraft industry to the production of
combat aircraft and to source the majority of its
transport aircraft from manufacturers in the
United States. Having foreseen that the effective abandonment of any development in terms of civil aviation would put Britain's aviation industry at a substantial disadvantage once the conflict had come to an end, during 1943 a British government committee began meeting under the leadership of
Lord Brabazon of Tara with the aim of investigating and forecasting the post-war civil aviation requirements of Britain and the
Commonwealth of Nations. The committee, which had become known simply as the
Brabazon Committee, delivered its report, which was likewise known as the
Brabazon Report. The report called for the construction of a total of four of five designs they had studied. Of those designs, the
Type I was a very large transatlantic airliner, the
Type II was a short-haul airliner, the
Type III was a medium-range airliner for the multiple-hop "
Empire" air routes, and the
Type IV was an innovative jet-powered 500 mph (800 km/h) airliner. In particular, the Type I and Type IV were regarded as being of very high importance to the industry, particularly the jet-powered Type IV, which would give Britain a commanding lead in the field of jet transport. An outline of the specifications for the various envisioned aircraft, including the gigantic Type I, was issued by the Committee. Additionally, Bristol's design team had already been considering the requirements of an aircraft capable of conducting routine transatlantic flights, which had led to projections of the necessary size, weight and range of such an airliner. Amongst those, it was determined that, in order to be profitable, a minimum payload of 100 passengers should be carried by the type. In 1942, the
Air Ministry issued a draft operational requirement from the Air Staff, which sought a
heavy bomber design that would be capable of carrying a payload of at least 15 tons of bombs. In response, Bristol dusted off their original work and updated it to incorporate their newer and substantially more powerful
Bristol Centaurus engines. The Bristol design team, led by
L. G. Frise and
Archibald Russell, worked with several key performance parameters. Those included a range of 5,000 mi (8,000 km), 225 ft (69 m) wingspan, eight engines buried in the wings driving four
pusher propeller installations, and enough fuel for transatlantic range. The
Convair B-36 was in many ways the American equivalent of that projected "100-ton bomber". In 1942, the Brabazon Report was published and Bristol chose to respond, submitting a slightly modified version of their bomber to fulfil the Type I requirement. Bristol's earlier work had demonstrated the sort of performance that the Brabazon Committee had been looking for, and so the Committee authorised the firm to begin preliminary design of such an aircraft that year, with the proviso that work on wartime aircraft should not be disrupted by the project.
Bristol 167 In November 1944, after further work on the design, a final concept for the Type 167 was published. The final design featured a large 177 ft (54 m) fuselage, paired with a sizable wing. The wing, which had a 230 ft (70.1 m) wingspan, possessed an enormous internal volume, to house sufficient fuel for the transatlantic flights envisioned for the type. The Brabazon Report had assumed that the wealthy people flying in the aircraft would consider a long trip by air to be uncomfortable, and so designed the Type I for luxury, demanding 200 ft3 (6 m3) of space for every passenger, which was expanded to 270 ft3 (8 m3) for luxury class. If outfitted with conventionally spaced seating, the dimensions of the Type 167 could have accommodated up to 300 passengers, instead of the 60 seats opted for. To meet these varied requirements, the Type 167 specified a huge -diameter fuselage, which was about 5 ft (1.5 m) greater than the 1970 Boeing 747 "jumbo jet", with full-length upper and lower decks. That enclosed sleeping berths for 80 passengers, a dining room, 37-seat cinema, promenade and bar or, alternatively, day seats for 150 people. At one point, the Committee recommended the adoption of a narrower fuselage to house a total of 50 passengers. The
British Overseas Airways Corporation (BOAC) agreed with that recommendation, and also expressed its preference for a design accommodating only 25 passengers. In August 1943, an agreement with the airline led to the selection of an interior layout which contained a forward area housing six compartments, each one for six passengers, along with a seventh compartment for just three passengers, a midsection above the wing – the wing was deep at that point – which accommodated 38 seats arranged around tables in groups of four along with a
pantry and
galley, and a rear area with 23 seats in an aft-facing cinema, complete with a cocktail bar and lounge. Similar to the
Saunders-Roe Princess, the Brabazon concept was a fusion of prewar and postwar thinking, using highly advanced design and engineering to build an aircraft that was no longer relevant in the postwar world. The Brabazon was the first aircraft to be outfitted with 100 per cent powered flying controls; it was also the first with electric engine controls, and the first equipped with high-pressure hydraulics. The large span and mounting of the engines close inboard, together with structural weight economies, demanded some new measure to prevent bending of wing surfaces in turbulence. One of the innovative features of the Brabazon was a purpose-developed gust-alleviation system, which used an assortment of
servos that were triggered from a gust-sensing probe installed on the exterior of the aircraft's nose; an improved version of this system, along with fully automated
trimming, was to have been deployed on the Brabazon Mark II.
Hydraulic power units were also designed to operate the aircraft's giant control surfaces. Some of the design and construction work for the aircraft was shared out to other British companies, such as
Folland Aircraft. Manufacturing the Brabazon was found to be a challenge. During the first two years of the development, the question of how and where to manufacture the aircraft was amongst the biggest issues that had preoccupied the design team and delayed progress on the project. Work on the project was slowed as Bristol's wartime commitments had to be met. Amongst the early physical steps was the construction of a full-scale wooden mockup in the old No. 2 Flight Shed so that components and fittings could be applied and tested. In October 1945, construction of the first prototype's fuselage commenced in an existing
hangar while a gigantic hall for performing final assembly of up to eight Brabazons was constructed; at the time of construction, the hall was the largest hangar in the world. Other advantages of turboprops included lower
vibration levels, which would increase passenger comfort, and better performance at higher altitudes. This would have increased the Brabazon's cruising speed, from 260 to 330 mph (420–530 km/h), and its ceiling, while reducing the aircraft's empty weight by about 10,000 lb (4,540 kg). This Brabazon Mark II would have been able to cross the
Atlantic from London to New York in a reduced time of 12 hours. However, by 1950, development of the Proteus engine had run into substantial difficulties, being both overweight and underpowered, and being subject to
fatigue issues at one stage.
Testing In December 1945, Bristol Chief Test Pilot
Bill Pegg was selected to be the chief pilot for the Brabazon. During December 1948, the Mk.I prototype, registration
G-AGPW, was rolled out for engine runs. On 3 September 1949, the prototype, piloted by Pegg and co-piloted by Walter Gibb, along with a crew of eight observers and flight engineers, performed a series of trial taxi runs; these revealed no problems save for the nosewheel steering not working correctly; it was temporarily disabled. The Brabazon's appearance at Farnborough led to the adoption of a formal and deliberate company policy to carry out much of the aircraft's test programme in the vicinity of various British cities to spread public awareness. Accordingly, the Brabazon was demonstrated at the 1950 Farnborough Airshow, at which it performed a takeoff, clean configuration flypast and a landing. In June 1950, the Brabazon made a visit to London's
Heathrow Airport, during which it made a number of successful takeoffs and landings; it was also demonstrated at the 1951
Paris Air Show. Gibb, who flew the aircraft as pilot-in-command on multiple flights, summarised his flying experiences with the type: "It was very comfortable. It flew very well. It was big. You didn't whip it around like a
Tiger Moth or
Spitfire, but as long as you treated it like a
double-decker bus or a large aeroplane, you had no trouble at all". While the Brabazon's flight tests were being performed, BOAC became increasingly uninterested with the prospects for operating the type. Bristol had been subject to financial hardship, while development of the Proteus engine intended to power the envisioned and improved Brabazon Mark II was proving troublesome. Flight tests of the aircraft itself had revealed some fatigue issues in the inner
wingbox area, while the projected operating costs for the Brabazon had been revised upwards as the programme had proceeded. Gibb stated of the situation: "the spec wasn't correct for post-war flying. The people who wrote the specs... conceived of an aeroplane with all this comfort, bunks, and a great dining room to eat in. And, of course, come the day, that wasn't what the airlines wanted. They wanted to ram as many passengers as possible into the tube and give 'em lunch on their laps." At one point, although some interest was shown by
British European Airways (BEA) for conducting operational flights using the prototype Brabazon itself, various problems that would typically be expected to be present on a prototype meant the aircraft would never receive an
airworthiness certificate.
Cancellation By 1952, about £3.4 million had been spent on development and there were no signs of purchase by any airline. In March, the British government announced that work on the second prototype had been postponed. The cancellation of the project was announced by the
Minister of Supply (
Duncan Sandys) on 17 July 1953 in the Commons, saying the programme had given all the useful technical knowledge it could but without any firm interest from either civil or military users, there was no justification for continuing to spend money on the Brabazon. By this point, roughly £6 million had been spent on the programme and a further £2 million would have been required in order to complete the Mark II. In October 1953, after 164 flights totalling 382 hours' flying time, the first prototype was broken up and sold for £10,000 in scrap value, along with the uncompleted Mk.II prototype. In addition, many of the techniques which had been developed during the Brabazon project were applicable to any aircraft, not just airliners. Bristol had also been awarded the contract for the Type III aircraft, for which they delivered the Britannia. By making use of the advances made during the development of the Brabazon, Bristol were able to design the Britannia to possess the best
payload fraction of any aircraft up to that time, and it held that record for a number of years. Although the Britannia was delayed after problems with the separate Type IV, the jet-powered
de Havilland Comet, it went on to be a workhorse for many airlines into the 1970s. ==Specifications (Mark I)==