View source for Bristol Brabazon

{{Short description|British propeller-driven large airliner prototype}}
{{distinguish|Brabazon, Bristol}}
{{Use dmy dates|date=January 2021}}
{{Use British English|date=December 2016}}
{{Infobox aircraft
 |name= Brabazon
 |image= ATP 018936 G.jpg
 |caption= Brabazon in 1950
 |type= [[Airliner]]
 |national_origin= United Kingdom
 |manufacturer= [[Bristol Aeroplane Company]]
 |designer=
 |first_flight= 4 September 1949
 |introduction=
 |retired= 1953
 |status= Scrapped
 |primary_user=<!--please list only one-->
 |more_users=<!--up to three more. please separate with <br />.-->
 |produced=<!--years in production, e.g. 1970-1999, if still in active use but no longer built-->
 |number_built= 1
 |variants=
}}

The '''Bristol Type 167 Brabazon''' was a large British [[piston engine|piston-engined]] [[Propeller (aircraft)|propeller]]-driven [[airliner]] designed by the [[Bristol Aeroplane Company]] to fly [[Transatlantic flight|transatlantic]] routes between the UK and the United States. The type was named ''Brabazon'' after the [[Brabazon Committee]] and its chairman, [[John Moore-Brabazon, 1st Baron Brabazon of Tara|Lord Brabazon of Tara]], which had developed the specification to which the airliner was designed.<ref name = "airspace canc"/>

While Bristol had studied the prospects of developing very large aircraft as [[bomber aircraft|bombers]] prior to and during the [[World War II|Second World War]], it was the release of a report compiled by the Brabazon Committee which led the company to adapt its proposed bomber into a large civil airliner to meet the ''Type I'' specification for the long-distance transatlantic route. Initially designated the '''Type 167''', the proposed aircraft had a {{convert|25|ft|adj=on}}-diameter fuselage, containing full upper and lower decks on which passengers would be seated in luxurious conditions. It was powered by an arrangement of eight [[Bristol Centaurus]] [[radial engine]]s which drove eight paired [[contra-rotating propellers]] set on four forward-facing [[nacelle]]s.

Bristol decided to submit the Type 167 proposal to meet [[List of Air Ministry specifications#1940–1949|Air Ministry Specification 2/44]]. Following a brief evaluation period, a contract to build a pair of prototypes was awarded. At the time of its construction, the Brabazon was one of the largest aeroplanes ever built, being sized roughly between the much later [[Airbus A300]] and [[Boeing 767]] airliners. Despite its vast size, the Brabazon was designed to carry only 100 passengers, each one allowed an area about the size of the interior of a small car. On 4 September 1949 the first prototype made its [[maiden flight]]. 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. On 17 July 1953 [[Duncan Sandys]], the [[Minister of Supply]], announced that the Brabazon had been cancelled due to a lack of military or civil orders. In the end, only the single prototype was flown, and it was broken up in 1953 for scrap, along with the incomplete, [[turboprop]]-powered '''Brabazon I Mk.II'''.

==Design and development==
===Background===
{{Main|Brabazon Committee}}
During the [[World War II|Second World War]], the British government made the decision to dedicate its aircraft industry to the production of [[Military aircraft#Combat aircraft|combat aircraft]] and to source the majority of its [[Military transport aircraft|transport aircraft]] from manufacturers in the [[United States]].{{refn|Some sources consider the British decision to have been the product of a formal diplomatic agreement between the British Government and the Government of the United States under which the former would focus on manufacturing bomber aircraft while the latter would dedicate its efforts to developing more capable transport aircraft. Author Stephan Wilkinson asserts that "No such agreement existed", and said that many of the American airliners had their origins in efforts that had predated the war.<ref name = "airspace canc"/>|group=N}} 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 [[John Moore-Brabazon, 1st Baron Brabazon of Tara|Lord Brabazon of Tara]] with the aim of investigating and forecasting the post-war civil aviation requirements of Britain and the [[Commonwealth of Nations]].<ref name = "airspace canc"/><ref name = "Kaplan 115">Kaplan 2005, p. 115.</ref>

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 "[[British Empire|Empire]]" air routes, and the ''Type IV'' was an innovative jet-powered 500&nbsp;mph (800&nbsp;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.<ref name = "airspace canc"/>

As early as 1937, the [[Bristol Aeroplane Company]] had conducted studies into very large [[bomber]] designs, one of which received the internal company designation of ''Type 159'', and another, undesignated design that broadly resembled the eventual configuration of the Brabazon.<ref name = "Kaplan 115 116">Kaplan 2005, pp. 115–116.</ref> 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.<ref name = "Kaplan 116">Kaplan 2005, pp. 116.</ref>

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 [[Leslie Frise|L. G. Frise]] and [[Archibald Russell]],<ref>Jackson 1973, p. 311.</ref> worked with several key performance parameters. Those included a range of 5,000&nbsp;mi (8,000&nbsp;km), 225&nbsp;ft (69&nbsp;m) wingspan, eight engines buried in the wings driving four [[pusher configuration|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".<ref name = "Kaplan 115"/> 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. Instead, it was decided to continue development of the existing [[Avro Lancaster]], which led to the production of the improved [[Avro Lincoln]].<ref name = "Kaplan 115 116"/><ref>Buttler 2004, p. 128.</ref>

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.<ref name = "Kaplan 115"/> Bristol was soon issued with a contract to produce a pair of prototype aircraft.<ref name=century>{{cite web |title=Bristol Type 167 Brabazon |url=http://www.century-of-flight.net/Aviation%20history/coming%20of%20age/Bristol%20%20Brabazon.htm |publisher=Century of Flight |access-date=2017-09-09 |archive-date=2017-11-15 |archive-url=https://web.archive.org/web/20171115204914/http://www.century-of-flight.net/Aviation%20history/coming%20of%20age/Bristol%20%20Brabazon.htm |url-status=dead}}</ref>

===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&nbsp;ft (54&nbsp;m) fuselage, paired with a sizable wing. The wing, which had a 230&nbsp;ft (70.1&nbsp;m) wingspan,{{refn|The wingspan of the Brabazon was 35&nbsp;ft/11&nbsp;m greater than the [[Boeing 747]], a [[widebody]] [[jetliner]] that was developed two decades later.|group=N}} possessed an enormous internal volume, to house sufficient fuel for the transatlantic flights envisioned for the type.<ref name = "airspace canc"/> It was powered by eight Bristol Centaurus 18-cylinder [[radial engine]]s, which were the most powerful British-built piston engines available at the time, each being capable of generating {{convert|2,650|hp}}.<ref name = "airspace canc"/> These were set in pairs in the wing, and instead of using a common crankshaft, the paired engines each had their driveshafts angled towards an enormous central [[gearbox]]. They drove a series of eight paired [[contra-rotating propellers]], which were set on four forward-facing nacelles.<ref name = "airspace canc"/><ref name = "Kaplan 117">Kaplan 2005, p. 117.</ref>

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&nbsp;ft<sup>3</sup> (6&nbsp;m<sup>3</sup>) of space for every passenger, which was expanded to 270&nbsp;ft<sup>3</sup> (8&nbsp;m<sup>3</sup>) 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.<ref name = "airspace canc"/> Other high-comfort measures were proposed, such as an onboard [[movie theater|cinema]], a [[cocktail bar]], and lounge area. 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]].<ref name = "airspace canc"/> Meanwhile, some figures within the aircraft industry were forecasting heavy demand from  passengers then relying on [[ocean liner]]s.<ref name = "Kaplan 116 117">Kaplan 2005, pp. 116–117.</ref>

To meet these varied requirements, the Type 167 specified a huge {{convert|25|ft|adj=on}}-diameter fuselage, which was about 5&nbsp;ft (1.5&nbsp;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,<ref>Barnes p. 325.</ref> 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 {{convert|6|ft}} deep at that point – which accommodated 38 seats arranged around tables in groups of four along with a [[pantry]] and [[galley (kitchen)|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.<ref>Winchester 2005, p. 18.</ref>

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.<ref name = "Kaplan 119">Kaplan 2005, p. 119.</ref> 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 [[Servomechanism|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 [[trim tab|trimming]], was to have been deployed on the Brabazon Mark II.<ref name = "Kaplan 119"/><ref>[http://www.flightglobal.com/pdfarchive/view/1951/1951%20-%201506.html "Airborne in the “Brab”."] ''Flight'', 3 August 1951, p. 149.</ref>{{refn|According to aviation author Philip Kaplan, difficulties experienced in the development of the improved gust-alleviation system for the Brabazon Mark II played a major role in the ultimate cancellation of the project.<ref name = "Kaplan 119"/>|group=N}} [[hydraulics|Hydraulic]] power units were also designed to operate the aircraft's giant control surfaces.<ref name=century/>

A tremendous effort was put into saving weight across the aircraft. The Type 167 used a number of non-standard gauges of skinning in order to tailor every panel to the strength required, thereby saving several tons of metal. Bristol employed revolutionary new machining and construction methods for drilling, milling, folding, and rolling many of the airframe's components.<ref name = "Kaplan 118"/> [[Rivet]]s were sealed in [[aircraft dope]] to greatly reduce the number required for airframe assembly. Significant emphasis had been placed upon simplifying the construction process and incorporating several manufacturing efficiencies.<ref name = "Kaplan 118 119">Kaplan 2005, pp. 118–119.</ref> Some of the design and construction work for the aircraft was shared out to other British companies, such as [[Folland Aircraft]].<ref>{{cite journal |title=Brabazon Bulletin |journal=Flight |date=29 September 1949 |pages=15–16 |url=https://www.flightglobal.com/pdfarchive/view/1949/1949%20-%201644.html}}</ref>

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.<ref name = "Kaplan 117"/> Bristol's existing factory at [[Bristol Filton Airport]] proved to be too small to handle what was one of the largest aircraft in the world, let alone producing the type in quantity, while the adjacent 2,000&nbsp;ft (610&nbsp;m) runway was too short for it to take off from. 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.<ref name = "Kaplan 117 118">Kaplan 2005, pp. 117–118.</ref> 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.<ref name = "Kaplan 118">Kaplan 2005, p. 118.</ref>
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.<ref name = "Kaplan 118"/> The designer of the new assembly hall, [[Terence Patrick O'Sullivan|T. P. O'Sullivan]], was subsequently awarded the [[Institution of Civil Engineers|Telford Premium]] for the work. The runway was lengthened to 8,000&nbsp;ft (2,440&nbsp;m) and widened; this extension had necessitated the controversial compulsory relocation of the inhabitants of the village of [[Charlton, Bristol|Charlton]] to neighbouring [[Patchway]].<ref name = "Kaplan 118"/>

===Mark II===
During the early 1940s, the only means for providing propulsion to large aircraft was to produce increasingly complex and enlarged radial engines.<ref name = "airspace canc"/> The emergence of [[jet propulsion]], specifically the [[turboprop]] engine, happened to coincide with the Brabazon's development. Accordingly, there was considerable interest in applying such an engine to the airliner as it potentially offered a simpler and more powerful alternative to the original Centaurus powerplant.<ref name = "airspace canc">Wilkinson, Stephan. [http://www.airspacemag.com/history-of-flight/cancelled-design-by-committee-118026858/ "Cancelled: Design by Committee."] ''Air & Space Magazine'', May 2012.</ref> Other advantages of turboprops included lower [[vibration]] levels, which would increase passenger comfort, and better performance at higher altitudes.<ref name = "Kaplan 121"/>

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.<ref name = "airspace canc"/><ref>King, H.F. [http://www.flightglobal.com/pdfarchive/view/1949/1949%20-%201653.html "Brabazon Mark II."] ''Flight'', 29 September 1949, p. 416.</ref> This would have increased the Brabazon's cruising speed, from 260 to 330&nbsp;mph (420–530&nbsp;km/h), and its ceiling, while reducing the aircraft's empty weight by about 10,000&nbsp;lb (4,540&nbsp;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 (material)|fatigue]] issues at one stage.<ref name = "Kaplan 121"/> Although the Proteus was slimmer than the Centaurus, the wing thickness was not to be reduced in the Mark II, but the [[leading edge]] would be extended around the engines.

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.<ref>King, H.F. [http://www.flightglobal.com/pdfarchive/view/1949/1949%20-%201655.html "The Story of the Brabazon: A Comprehensive Appraisal of Britain's Greatest Airliner: Vicissitudes/ Development: Prototype and Operational Versions Studied."] ''Flight'', 29 September 1949.</ref>

===Testing===
[[File:Maiden flight of the Bristol Brabazon - geograph.org.uk - 1161274.jpg|thumb|Bristol Brabazon ''G-AGPW'' takes off on its maiden flight on 4 September 1949 at Filton Aerodrome]]

In December 1945, Bristol Chief Test Pilot [[Bill Pegg]] was selected to be the chief pilot for the Brabazon.<ref name = "Kaplan 119"/> In preparation for the impending flight testing, as a means of gaining experience in operating such a vast aircraft, Pegg accepted an invitation issued by [[Convair]] to travel to [[Fort Worth]], [[Texas]], to fly their [[Convair B-36 Peacemaker|B-36 Peacemaker]], a large strategic bomber operated by the [[United States Air Force]].<ref name = "Kaplan 121">Kaplan 2005, p. 121.</ref>

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.<ref name = "Kaplan 121"/> On 4 September 1949, the prototype performed its [[maiden flight]] over the Bristol area, flying for 25 minutes, captained by Pegg. Around 10,000 people had gathered at the airfield's perimeter to witness takeoff.<ref name = "Kaplan 121"/> During this flight, it ascended to about 3,000&nbsp;ft (910&nbsp;m) at 160&nbsp;mph (257&nbsp;km/h) and landed at 115&nbsp;mph (185&nbsp;km/h), throttling back at 50&nbsp;ft (15&nbsp;m). The British press mainly reported favourably, one newspaper praising the aircraft as being "the queen of the skies, the largest land-plane ever built".<ref name = "airspace canc"/>

Four days later, the prototype was presented at [[Society of British Aerospace Companies|Society of British Aircraft Constructors]]' [[Farnborough Airshow|Airshow at Farnborough]]; according to author Philip Kaplan, the timing of the first flight had been chosen to enable this high-profile early appearance.<ref name = "Kaplan 121 122">Kaplan 2005, pp. 121–122.</ref> 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 [[de Havilland Tiger Moth|Tiger Moth]] or [[Supermarine Spitfire|Spitfire]], but as long as you treated it like a [[double-decker bus]] or a large aeroplane, you had no trouble at all".<ref name = "Kaplan 122">Kaplan 2005, p. 122.</ref>

While the Brabazon's flight tests were being performed, BOAC became increasingly uninterested with the prospects for operating the type.<ref name = "Kaplan 122"/> On a test flight, BOAC chairman Sir [[Miles Thomas]] briefly took the controls and found the aircraft to be underpowered and very slow to respond to the controls. BOAC quickly decided it was not for them.<ref>{{cite book|title=Out on a Wing|author=Sir Miles Thomas|publisher=Michael Joseph|location=London|date=1964|page=295}}</ref> 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,{{refn|As a result of engineering analysis performed during the program, it was found that the Brabazon's airframe had a fatigue life of 5,000 flying hours; according to aviation author Phillip Kaplan, this figure had been "far too low" for airworthiness certification to be realistically expected.<ref name = "Kaplan 123"/>|group=N}} while the projected operating costs for the Brabazon had been revised upwards as the programme had proceeded.<ref name = "Kaplan 122"/> BOAC, being unconvinced of the aircraft's merits, ultimately chose not to place any order for the type.<ref name = "Kaplan 123">Kaplan 2005, p. 123.</ref> 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."<ref name = "Kaplan 122 123">Kaplan 2005, pp. 122–123.</ref>

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]].<ref>{{cite web |title=Bristol Type 167 Brabazon |url=http://www.century-of-flight.net/Aviation%20history/coming%20of%20age/Bristol%20%20Brabazon.htm |publisher=Century of Flight |access-date=27 August 2018 |archive-date=24 August 2018 |archive-url=https://web.archive.org/web/20180824110017/http://www.century-of-flight.net/Aviation%20history/coming%20of%20age/Bristol%20%20Brabazon.htm |url-status=dead }}</ref>

===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.<ref name = "Kaplan 123"/><ref name="End of the Brabazons.">King, H.F. [http://www.flightglobal.com/pdfarchive/view/1953/1953%20-%200948.html "End of the Brabazons."] ''Flight'', 29 September 1949.</ref> 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.<ref name = "airspace canc"/> All that remains are a few parts at the [[M Shed]] museum in Bristol and the [[National Museum of Flight]] in Scotland.

[[File:bristol brabazon model arp.jpg|thumb|Brabazon model]]

Although considered a failure and a [[white elephant]], the record of the Brabazon is not entirely unfavourable. At least half of the large sums spent on the project had been expended upon the construction of infrastructure, including £6 million for new large hangars and an extended runway at Filton.<ref name="End of the Brabazons."/> 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 [[Bristol Britannia|Britannia]]. The same assembly hall was later used in construction of the [[Concorde]].<ref>{{citeweb|url=https://www.heritagegateway.org.uk/Gateway/Results_Single.aspx?uid=1551696&resourceID=19191|title=Historic England Research Records - The Brabazon Hangar}}</ref> 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.<!--until when?--> 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)==
[[File:bristol brabazon wheel arp.jpg|thumb|right|Bristol Brabazon main [[Landing gear|undercarriage]] wheels.]]
{{Aircraft specs
|ref=''Flight International.''<ref name = "Flight 419 430"/>
|prime units?=imp
<!--
        General characteristics
-->
|crew=6–12
|capacity= 100 passengers<ref>"Brabazon brochure". ''Bristol Aeroplane Company'', 1949.</ref>
|length ft=177
|length in=
|length note=
|span ft=230
|span in=
|span note=
|height ft=50
|height in=
|height note=
|wing area sqft=5317
|wing area note=
|aspect ratio=<!-- sailplanes -->
|airfoil=root: T.P.4; tip: T.P.5<ref name="Selig">{{cite web |last1=Lednicer |first1=David |title=The Incomplete Guide to Airfoil Usage |url=https://m-selig.ae.illinois.edu/ads/aircraft.html |website=m-selig.ae.illinois.edu |access-date=16 April 2019}}</ref>
|empty weight lb=145100
|empty weight note=
|gross weight lb=
|gross weight note=
|max takeoff weight lb=290000
|max takeoff weight note=
|fuel capacity={{cvt|13650|impgal|USgal l|0}}
|more general=
<!--
        Powerplant
-->
|eng1 number=8
|eng1 name=[[Bristol Centaurus]]
|eng1 type=18-cylinder air-cooled radial sleeve-valve piston engines
|eng1 hp=2650
|eng1 note=paired, driving contra-props through combining gearboxes.

|prop blade number=3
|prop name=[[Rotol]]
|prop dia ft=16
|prop dia note=fully-feathering contra-rotating propellers<ref name = "Flight 419 430">''Flight'' 29 September 1949, pp. 419, 430.</ref>
<!--
        Performance
-->

|max speed mph=300
|max speed note=at {{cvt|25000|ft|0}}
|cruise speed mph=250
|cruise speed note=at {{cvt|25000|ft|0}}
|stall speed mph=
|stall speed note=
|never exceed speed mph=
|never exceed speed note=
|minimum control speed mph=
|minimum control speed note=
|range miles=5500
|range note=
|ferry range miles=
|ferry range note=
|endurance=<!-- if range unknown -->
|ceiling ft=25000
|ceiling note=
|climb rate ftmin=750
|climb rate note=
|time to altitude=
|lift to drag=
|wing loading lb/sqft=54
|wing loading note=
|fuel consumption lb/mi=
|power/mass={{cvt|0.073|hp/lb}}

|more performance=<!--
* Take-off run: {{cvt||ft|0}}
* Take-off distance to {{cvt|50|ft|0}}: {{cvt||ft|0}}
* Landing run: {{cvt||ft|0}}
* Landing distance from {{cvt|50|ft|0}}: {{cvt||ft|0}}-->

|avionics=
}}

==See also==
* [[Convair XC-99]]
* [[Hughes H-4 Hercules]]
* [[Saunders-Roe Princess]]
{{aircontent
|related=
|similar aircraft=
|see also=
|lists=
* [[List of civil aircraft]]
}}

==References==
===Notes===
{{Reflist|group=N}}

===Citations===
{{reflist|30em}}

===Bibliography===
{{Refbegin}}
* [https://www.flightglobal.com/pdfarchive/view/1951/1951%20-%201505.html "Airborne in the “Brab”: Demonstration Flights from London Airport: Good Progress with Mk. I Development"]. ''[[Flight International|Flight]]'', 3 August 1951, Vol. LX, No. 2219. pp.&nbsp;148–150.
* {{cite book |title= Bristol Aircraft since 1910|last= Barnes|first=C.H. |year=1970 |publisher=Putnam Publishing  |location=London |isbn= 0-370-00015-3}}
* Buttler, Tony. ''Secret Projects 1935–1950 Fighters and Bombers.'' Midland Publishing, 2004. {{ISBN|1-85780-179-2}}.
* Castle, Matt. [http://www.damninteresting.com/?p=939#more-93 "The Plane That Flew Too Soon."] ''damninteresting.com.''
* Gilbert, James. The World's Worst Aircraft. Philadelphia, PA: Coronet Books, 1978. {{ISBN|0-340-21824-X}}.
* Jackson, A.J. British Civil Aircraft since 1919, Volume 1. Putnam & Company Limited. 1973. {{ISBN|0-370-10006-9}}.
* Kaplan, Philip. [https://books.google.com/books?id=LrPgAwAAQBAJ&pg=PA115 "Big Wings: The Largest Aeroplanes Ever Built."] Pen and Sword, 2005. {{ISBN|1-84415-178-6}}.
* Winchester, Jim. "Bristol Brabazon (1949)." ''The World's Worst Aircraft: From Pioneering Failures to Multimillion Dollar Disasters.'' London: Amber Books Ltd., 2005. {{ISBN|1-904687-34-2}}.
{{Refend}}

==External links==
{{Commons category|Bristol Brabazon}}
* [https://web.archive.org/web/20150923180801/http://www.aviationarchive.org.uk/stories/storycontents.php?enum=GE121 The Bristol Brabazon – Engineering masterpiece or Great White Elephant]
* {{YouTube| XSNwQCOXSoo | "130 - Ton Colossus Takes The Air" 1949, ''British Pathé'' }}
* {{YouTube| qxhbMZbh_O0 | "Bristol Brabazon. 1987 Documentary" }}
* [http://www.flightglobal.com/pdfarchive/view/1949/1949%20-%201643.html "Brabazon Bulletin"] a 1949 ''Flight'' article

{{Bristol aircraft}}

{{Authority control}}

[[Category:Bristol Aeroplane Company aircraft|Brabazon]]
[[Category:1940s British airliners]]
[[Category:Eight-engined four-prop tractor aircraft]]
[[Category:Low-wing aircraft]]
[[Category:Aircraft with contra-rotating propellers]]
[[Category:Cancelled aircraft projects]]
[[Category:Aircraft first flown in 1949]]
[[Category:Aircraft with retractable tricycle landing gear]]
[[Category:Eight-engined piston aircraft]]