28 December 2009

Although the Bristol Type 167 Brabazon is often labeled as a "white elephant", the aircraft had many milestones for commercial aviation and set the foundation for bigger successes by the British aviation industry than is widely known. The Brabazon design first originated as a bomber design to meet the Air Staff specification B.8/41 which laid down the features and performance of a very large bomber similar in class to the Convair B-36 Peacemaker. B.8/41 asked for a range of 5,000 miles with a speed of 300mph capable of reaching Russia or Japan. Bristol's design had an all-up weight of 225,000 lbs and a 225-foot wingspan. The project never got pursued, though, as the RAF preferred increased production of the Avro Lancaster.

When Lord Brabazon convened his famous committee to determine the course of British commercial aviation post-war to compete with the Americans, the Bristol bomber design was adopted for the Type I role, that of a large trans-Atlantic airliner with an anticipated service date of 1948. It was christened Brabazon in honor of the committee chairman himself.

When work began at Bristol's Filton works, the runway was 2,000 feet too short and had to be extended for the anticipated flight test program of the Brabazon. Despite local protests and the need for Cabinet approval to start work on the runway, when completed along with a massive assembly hall, it became the longest runway in Europe.

There were four features in particular that were commercial aviation milestones in the design of the Brabazon. It was the first aircraft to be designed from the outset to have 100% fully-powered flying controls, the first commercial aircraft designed to have a high pressure hydraulic system (the higher the pressure, the lighter the hydraulic system), and the first aircraft to have electric engine controls (electric control of engine power and mixture would lay down the foundation for modern FADEC systems). But most significantly yet little known, the Brabazon was the first airliner to be designed with cabin pressurization and air conditioning, and that pressurization was set at 8'000 above sea level, the current standard for modern airliners.

By 1949 the Brabazon was still in flight test and the De Havilland Comet prototype had just flown and BOAC was already using the Boeing 377 Stratocruiser on the trans-Atlantic routes intended for the Brabazon. In 1953 the project was canceled (despite the design of the Brabazon Mk.2 which used Proteus turboprops instead of the Centaurus radials of the prototype), but the expertise gained by Bristol formed the foundation for the more successful Bristol Britannia and when Bristol became part of the British Aircraft Corporation in 1960, the Filton works and its long runway and large assembly hall would be used for the Concorde program.

Source: Airliner Classics, November 2009. "The Bristol Brabazon: White Elephant or Technological Marvel?" by Gerry Sweet, p53-58

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