Initially designated the Type 167, the proposed aircraft had a 25-foot (7.6 m)-diameter fuselage, containing full upper and lower decks on which passengers would be seated in luxurious conditions.

In addition to participating in a flight test programme in support of the intended production aircraft, the prototype made high-profile public appearances at the 1950 Farnborough Airshow, Heathrow Airport, and the 1951 Paris Air Show.

However, due to the high cost per seat mile compared to the alternatives, the Brabazon did not attract any firm orders, so the aircraft was a commercial failure.

[3] 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.

[2] In addition to Bristol, many leading British manufacturers had provided several preliminary studies in response to the Air Ministry's operational requirement.

However, in expectation of long development times, and the difficulties associated with balancing the aircraft's range, load and defensive armament, the Ministry never took up any of the British manufacturer's designs.

[3][6] 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.

The wing, which had a 230 ft (70.1 m) wingspan,[N 2] possessed an enormous internal volume, to house sufficient fuel for the transatlantic flights envisioned for the type.

According to author Stephan Wilkinson, the decision to focus on comfort over other qualities such as speed and payload had been a historic preoccupation of Britain operators to specifically tailor their services towards wealthy travellers, and noted that as having been a key pre-war ethos of the British airline Imperial Airways.

[9] To meet these varied requirements, the Type 167 specified a huge 25-foot (7.6 m)-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.

In August 1943,[10] 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 6 feet (1.8 m) 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.

[12] 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.

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.

While considerations were made for developing the firm's Banwell facility, it was eventually decided to expand the main Filton site to suit the Brabazon.

The runway was lengthened to 8,000 ft (2,440 m) and widened; this extension had necessitated the controversial compulsory relocation of the inhabitants of the village of Charlton to neighbouring Patchway.

[18] In 1946, it was decided to build the second prototype using eight paired Bristol Coupled Proteus turboprop engines driving four-bladed propellers through a common gearbox.

Other planned changes for the Brabazon Mark II included a revised wheel arrangement which would have enabled the type to use the majority of runways on both the North Atlantic and Empire routes.

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.

[1] Four days later, the prototype was presented at Society of British Aircraft Constructors' Airshow at Farnborough; according to author Philip Kaplan, the timing of the first flight had been chosen to enable this high-profile early appearance.

[21] 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.

[23] 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,[N 4] while the projected operating costs for the Brabazon had been revised upwards as the programme had proceeded.

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.

[27] These improvements meant that Bristol was in an excellent position to continue production of other designs; the assembly hall was soon being used for building another transatlantic aircraft, 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.