A Sample Feature From Aviation News

Classic Airliners

Bristol Britannia

Click on DVD cover to visit our shop

Above: The prototype Bristol Britannia (G-ALBO) required little design change to make it an effective and efficient airliner, liked by test pilots and airline crew alike. The quietness of its engines was a distinctive aspect of this aircraft, dubbed ‘Whispering Giant’ by spectators and passengers. Displayed at every Farnborough Air Show from 1953 to 1957, G-ALBO was broken up in 1968. (Photos, Av News Files)

In the first of a new series looking at famous airliners since the Second World War, this month we review the staggered origins and missed opportunities with one of the most famous British airliners of the period.

IT was largely a result of unprecedented expansion in the US aircraft manufacturing industry that when war ended in September 1945 American aircraft would dominate the limited market for commercial airliners. This had been anticipated by the British years earlier. Within several months of the US declaring war on Japan and Germany following the attack on Pearl Harbor in December 1941, a committee was formed under the chairmanship of Lord Brabazon of Tara to map future aircraft requirements for post-war Britain and her then expansive empire. The first Brabazon Committee sat on December 29, 1942, and on February 9, 1943, the cabinet received its initial recommendations for four  types to fill post-war UK needs, a credible display of foresight and intuition.

Type I defined a transatlantic airliner serving high volume routes such as the London-New York run, Type II would replace the DC-3 and the Dragon Rapide, Type III would satisfy the need for a medium-range aircraft serving the empire and Type IV would produce a 100-seat jet-powered airliner for linking London and Sydney by way of staging stops. After a contest against the Miles X-15, the Type I specification resulted in the failed Brabazon project based on the redundant Air Ministry requirement for a ‘100-ton bomber’ issued in 1942. The Type II requirement would split in two, satisfied by the de Havilland Dove and the Airspeed Ambassador (Type IIA) and the Vickers Viceroy and Armstrong Whitworth AW55 (Type IIB). The Type IV was added at the personal urging of Geoffrey de Havilland, emerging as the Comet.

Below: Built by Shorts, the first of six Britannia 314s (CF-CZA) for Canadian Pacific Airlines leaves Sydenham on February 6, 1958, en route to Bristol prior to delivery to the customer on April 9, 1958. Much of the aircraft’s success was owed to the detailed design experience garnered on the mammoth Brabazon, aspects that made it so popular with operators.

The original Type III requirement was for a 32-seat transport aircraft with a range of 2,500 miles, met by the Lockheed Constellation ordered by BOAC after the war thereby making it redundant. Instead, during December 1946, British Overseas Airways Corporation (BOAC) specified the requirement for a Medium Range Empire (MRE) aircraft and Bristol proposed a modified Constellation built under licence in the UK and powered by Centaurus 660 series engines. The government would not allow dollar deals for licence production and specification 2/47 was issued for a new aircraft, competed for by Armstrong Whitworth, Avro, Blackburn, Bristol and Handley Page. None of these proposals could match the projected performance of Bristol’s 32-36 seat Type 175, with a weight of 94,000lb and a wing area of 1,620sq ft powered by four 2,950hp Centaurus 662 radial engines. Believing the aircraft to be over-powered with the specified engines, by October 1947 the size of the airframe was increased to embrace a 42-48-seat design with an all-up weight of 103,000lb and a wing area of 1,775sq ft.

Reluctant to buy off the drawing board in what were parlous times for both BOAC and the government, the Ministry of Supply (MoS) stepped in and ordered three Bristol Type 175 prototypes on July 5, 1948. The first two with either Centaurus radial engines or 2,800ehp Proteus gas turbine engines, the latter designed with reverse flow because it originated with the aborted Brabazon Type I and Saunders-Roe Princess, both of which had wing leading edge inlets, the latter with pusher propellers. However, the Proteus had serious problems and it would take a complete redesign to make it work as a reliable and effective engine. With increasing interest from BOAC in the larger turboprop engine, the manufacturer started to look at transatlantic route applications. Once again the airframe grew in size and when Bristol went to see BOAC in late 1948 they revealed a Type 175 with an all-up weight of 118,000lb, a wing area of 2,055sq ft and a seating capacity for up to 64 passengers or 38 sleeping berths, or 83 passengers in a stretched version for the Atlantic.

In November 1948 the airline backed the MoS and BOAC ordered 25 Type 175 airliners. By 1950 progress was being made with the Proteus since tests had begun with Avro Lincoln SX972 in June 1949. The third prototype (VX454) was canceled as a result. Bristol had learned much from the design experience with the Brabazon. The Type 175’s wing comprised a box-spar tapered to the tip in plan and thickness, in effect an optimised skin-stringer form with double-slotted flaps replacing the earlier Fowler-type, across a 12ft diameter fuselage at constant radius for 50ft of the fuselage length. In all, an advanced design with powerful engines aimed directly at a potentially global market. In January 1951 the design was frozen at a 64-seat airliner in mixed class or a maximum of 90 in tourist layout, powered by four Proteus 625 series engines.

Above: RAF Britannia C.1 XM518 ‘Spica’ displayed in 1964. The type was in service with RAF Transport Command from June 1959 to 1975. (Photo, Av News Files)

The first prototype Bristol Type 175 (G-ALBO), designated Britannia 101, took to the skies at Filton on August 16, 1952, only five months after the giant Brabazon, devoid of orders from any airline, had been cancelled. A new age in air transport was about to dawn, with aircraft powered by turbojet and turboprop engines. That first flight was eventful for chief test pilot A J ‘Bill’ Pegg, shortly after take-off the Britannia went through some dramatic porpoising moments brought on by over sensitive controls and in preparation for landing the starboard main bogie stuck in the 90? position necessitating some deft handling, all to which was added an ominous smell of burning seeping into the cockpit from an overheated electric motor! Only seconds before touchdown the errant bogie freed itself and a perfect landing ensued. Following modifications to the elevator controls, a second flight took place on August 21.

Below: The centre bay of the Bristol Aeroplane Company’s Filton assembly hall showing a fuselage centre-section being craned into position in the foreground. There are just five survivors: Series 101, G-ALRX forward fuselage at Kemble; Series 308F, G-ANCF under restoration in Liverpool on the former airside apron; Series 312 G-AOVF at the RAF Museum Cosford; Series 312, G-AOVT at the IWM Duxford; and C.1, XM496 Regulus at Kemble in RAF colours.

Click on DVD cover to visit our shop

For the rest of this article please see the February 2009 issue.