The post-World War 2 Bristol "Brabazon" was born from committee work in 1943 and held direct origins in a wartime bomber design by the Bristol Aeroplane Company. The "Brabazon Committee" was headed by politician and English aviation pioneer Lord Brabazon (1st Baron Brabazon of Tara) and met to begin fleshing out the civil aviation environment to come in the post-war era. British airline industry was all but halted to concentrate on wartime fighters and bombers during the conflict and this left the civilian-hauling industry in limbo for some time. Several large aircraft types were devised by the committee and Bristol delivered a revised form of its heavy bomber as the "Model 167".
The company was granted funding for two flyable prototypes based on its proposal. The requirement called for a trans-Atlantic airliner to ferry a fair number of passengers from airports in Britain to major cities along the American East Coast. Performance was to come from 8 x Bristol Centaurus 18-cylinder radial engines driving paired contra-rotating propeller units, eight pairs fitted to wing leading edge nacelles. Internally, the fuselage would support up to 100 passengers in complete style - from large seating areas to a cinema, dining hall and full sleeping berths. Special skinning techniques were employed to keep the aircraft's weight in check and power-assisted control surfaces were made standard - the latter making the Brabazon the first aircraft anywhere to feature a wholly power-assisted control scheme. The initial prototype was designated Mk I.
To complete the massive bird, a special hangar was constructed while the fuselage was being built nearby. The test runway was lengthened to provide the necessary run for the big aircraft. Mk I tested her engines during December 1948 and recorded her first flight on September 4th, 1949. It was debuted for the public at Farnborough 1950 and conducted a dramatic flyby during its performance. Its next notable stop came at the Paris Air Show of 1951.
Its design was wholly 1950s with its raw silver metal skin left unfinished. The fuselage was tubular with the flight deck directly over the nose and a large vertical tail fin featured at rear. The wing mainplanes were set at midships and featured the engine propeller stems along the leading edges, just outboard of the fuselage sides. Exhaust ports were built into the engine trailing edges just ahead of the control surfaces. The horizontal tailplanes were low-mounted as set noticeable aft along the fuselage sides. The undercarriage was of a tricycle arrangement. Portholes dotted the fuselage sides for passenger viewing with some windows also situated along the fuselage roof.
The second prototype was Mk II and this form appeared back in 1946. Instead of the Centaurus engines featured in Mk I, MK II carried 8 x Bristol Proteus turboprop engines in a coupled arrangement. Each engine installation drove a large-diameter four-bladed propeller with a gearbox shared between each coupled unit. The coupling not only increased performance considerably but the airframe was also lightened as a result.
Despite the amount of time and money put into the project, airline companies showed little interest in the now-expensive and still in-development venture. Structural problems also arose which threatened the aircraft's lease on life going forward. On July 17th, 1953, the project was cancelled by the British government after no takers could be found - not even military operators. Both prototypes were then scrapped.
As completed, the Brabazon would have featured a complete flying crew of six for its 100 passengers. Dimensions included a length of 177 feet, a wingspan of 230 feet and a height of 50 feet - these values made it one of the largest aircraft built during the period. Empty weight was 145,100 pounds with a Maximum Take-Off Weight (MTOW) of 290,000 pounds reported. Each Centaurus engine outputted at 2,650 horsepower. Performance included a maximum speed of 300 miles per hour, a cruise speed of 250 miles per hour, a range out to 5,500 miles, a service ceiling of 25,000 feet and a rate-of-climb of 750 feet per minute.