Bristol Britannia

Bristol Britannia
Royal Air Force Bristol Britannia 'Spica' in 1964
Description
Role	Civil/military air transport
Crew
First flight
Entered service
Manufacturer
Dimensions
Length	124 ft 3 in	37.9 m
Wingspan	142 ft 3 in	43.6 m
Height	37 ft 6 in	11.4 m
Wing area	ft²	m²
Weights
Empty	82,500 lb	37,400 kg
Loaded	lb	kg
Maximum takeoff	185,000 lb	84,000 kg
Capacity
Powerplant
Engines	4 x Bristol Proteus 765 turboprops
Power	17,760 hp	13,244 kW
Performance
Cruise speed	357 mph	575 km/h
Maximum speed	397 mph	639 km/h
Range	4,270 miles	6,870 km
Service ceiling	24,000 ft	7,300 m
Rate of climb	2,220 ft/min	680 m/min
Avionics
Avionics

The Bristol Type 175 Britannia was a medium/long-range airliner built by the Bristol Aeroplane Company in 1952 to fly a number of air routes across the British Empire. Soon after entering production the engines proved unusually susceptible to icing, and two prototypes were lost while solutions to the problems were found. By the time it was cleared through testing the US-built jet airliners were about to enter service, and only eighty-five Britannias were built. Nevertheless the Britannia is often considered the high point in turboprop airliner design.

In 1942, during World War II, the US and UK agreed to split responsibility for aircraft construction; the US would concentrate on transport aircraft while the UK would concentrate on their heavy bombers. This would leave the UK with little experience in transport construction at the end of the war, so in 1943 a committee met under the leadership of Lord Brabazon of Tara in order to investigate the future needs of the British civilian airliner market. The Brabazon Committee delivered a report calling for the construction of four main "Types" of aircraft.

Bristol won both the Type I and Type III contracts, soon delivering their Type I design, the Bristol Brabazon in 1949. The initial requirement for the Type III, C2/47, was issued by the Minister of Supply for an aircraft capable of carrying 48 passengers and powered with Bristol Centaurus radial engines. Turboprop and compound engines were also considered, but they were so "new" that Bristol could not guarantee the performance specifications with these engine types. After wrangling between the Ministry of Supply and BOAC over costs, the go-ahead was given in July 1948 for three prototypes, although the second and third were to be convertible to Bristol Proteus turboprops.

In October, with work already underway, BOAC changed their mind and decided that only a Proteus-engined aircraft was worth working on, and the project was redrawn to allow for both turboprop and piston aircraft. BOAC purchased options for 25 aircraft in July 1949, the first six with the Centaurus engine and the rest with the Proteus, and now enlarged for 74 passengers.

By the time the first prototype flew on August 16, 1952 BOAC and Bristol had dropped the Centaurus version as the turboprop Proteus had shown such promise. The Britannia was now a 90-seater and BOAC ordered 15 of these Series 100s. In 1953 and 54 three de Havilland Comets disappeared with no explaination, and the Air Ministry demanded that the Britannia undergo a lengthy series of tests. Further delays were caused by a series of engine problems, mostly related to icing. This delayed the in-service date until February 1957, when BOAC put their first Britannia 102s into service on the London to South Africa route, with Australia following a month later.

Bristol then upgraded the design as a larger transatlantic airliner for BOAC, resulting in the Series 200 and 300. The new version had a fuselage stretch of 10ft 3 in (3.12m) and upgraded Proteus engines, and was offered as the all-cargo Series 200, the cargo/passenger (combi) Series 250, and the all-passenger Series 300.

The first 301 flew on July 31, 1956. BOAC ordered seven Model 302s but never took delivery of them - instead they were taken on by several other airlines including Aeronaves de México and Ghana Airways. The main long range version was the 312, of which BOAC took 18 and, after deliveries began in September 1957, put them into service between London and New York. In total 45 Series 300's were built, the first airliner to enter regular non-stop transatlantic service in both directions.

A further 23 Model 252 and 253 aircraft were purchased by the RAF, as the Britannia C.Mk 2 and C.Mk1 respectively. Those in RAF service were commonly allocated the names of stars, "Arcturus", "Sirius", "Vega" etc. The last of these were retired in 1975, and were used by civil operators in Africa, Europe and the Middle East into the 1980s.

A licence was also issued to Canadair to build the type as a maritime reconnaissance aircraft and transport, the Canadair Argus. Unlike the Britannia the Argus was built for endurance, not speed, and so used four Wright R-3350-32W Turbo-Compound engines which use very little fuel (although it is perhaps surprising that it did not use the Napier Nomad, an even more efficient turbo-compound designed expressly for this role). The interior was left with almost no room to move, completely packed with various sensors and weapons.

Models

100 Series - 90 passenger airliner, powered by four Bristol Proteus 705

101 - Two prototypes, initially powered by Proteus 625, later 705

102 - 25 ordered by BOAC. The last ten were cancelled in favour of the 300 series

200 Series - all-cargo stretched version of the 100 series, with an extra 10 ft (3 m) in length.

Five options from BOAC, but cancelled in favour of the 310.

250 Series - similar to the 200 series, but mixed passenger and freight

252 - Three ordered by RAF.

253 - 22 ordered by RAF, with designation C Mark 1.

300 Series - as 200 series, by passenger only. Capable of carrying up to 139 passengers.

301 - one prototype

302 - Ten ordered by BOAC, but cancelled in favour of 305, and later, 310. 2 were completed, but not delivered.

305 Series - similar to the 300, but with increased fuel capacity

306 - 1 built, leased to El Al

307 - 2 ordered by Air Charter. One was a conversion of the sole 306

307F - 1960's conversion of 307 to freighter (both converted)

308 - 2 ordered by Transcontinental

308F - 1960's conversion of 308 to freighter (both converted)

309 - 1 ordered by Ghana Airways

310 Series - As 305 series, but with strengthened fuselage skin and undercarriage. Originally known as 300LR.

311 - one prototype,

312 - 19 ordered by BOAC

312F - 1960's conversion of 312 to freighter (five converted)

313 - Four ordered by El Al

314 - Six ordered by Canadian Pacific

317 - Two ordered by Hunting-Clan Air Transport

318 - Four ordered by Cubana

320 Series - similar to the 310, with increased maximum range

324 - Two ordered by Canadian Pacific

Units using the Bristol Britannia

Royal Air Force

• No. 99 Squadron
• No. 511 Squadron

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