Misplaced Pages

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96-413: The Avro Type 688 Tudor was a British piston-engined airliner based on Avro 's four-engine Lincoln bomber, itself a descendant of the famous Lancaster heavy bomber , and was Britain's first pressurised airliner. Customers saw the aircraft as little more than a pressurised DC-4 , and few orders were forthcoming, important customers preferring to buy US aircraft. The tailwheel undercarriage layout

192-471: A 30-aircraft order which Guthrie had cancelled. The Standard VC10 had higher operating costs than the 707, largely due to BOAC's requirement at the design stage for the aircraft to have excellent hot and high performance for Commonwealth (African/Asian) routes, but the larger Super VC10 was a success with American passengers on the North Atlantic and was profitable. The next major order of Boeing aircraft

288-777: A Tudor I. In 1955, G-AIYA and the Tudor I G-AGRG were lengthened to Tudor IV standard. Together with the un-lengthened Tudor I G-AGRI, which had become a 42-seat passenger aircraft, they were used on the Air Charter Ltd Colonial Coach Services between the UK, Tripoli and Lagos. To meet a BSAA requirement, some Tudor Is were lengthened by 5 ft 9 in (1.75 m), powered by 1,770 hp (1,320 kW) Rolls-Royce Merlin 621s and 1,760 hp (1,310 kW) Rolls-Royce Merlin 623s. With 32 seats and no flight engineer position, these were known as Tudor IVs, and when fitted with

384-597: A capacity of 1,820 L (64 cu ft), making a total capacity of 25,480 L (900 cu ft) for the largest versions. For piston engines, an engine's capacity is the engine displacement , in other words the volume swept by all the pistons of an engine in a single movement. It is generally measured in litres (l) or cubic inches (c.i.d., cu in, or in ) for larger engines, and cubic centimetres (abbreviated cc) for smaller engines. All else being equal, engines with greater capacities are more powerful and consumption of fuel increases accordingly (although this

480-574: A charter flight from Ireland, crashed at RAF Llandow , South Wales, with the resulting death of 80 of its passengers and crew. In 1953, Lome Airways leased an ex BSAA Tudor 5 from Surrey Flying Services as CF-FCY for freight operations in Canada. It was retired at Stansted and scrapped in 1959. The Tudor VI was to be built for the Argentinian airline FAMA for South Atlantic service, with 32–38 seats or 22 sleeper berths , but none were built. The Tudor VII

576-698: A circular groove in the piston head. The rings fit closely in the groove and press lightly against the cylinder wall to form a seal, and more heavily when higher combustion pressure moves around to their inner surfaces. It is common to classify such engines by the number and alignment of cylinders and total volume of displacement of gas by the pistons moving in the cylinders usually measured in cubic centimetres (cm or cc) or litres (l) or (L) (US: liter). For example, for internal combustion engines, single and two-cylinder designs are common in smaller vehicles such as motorcycles , while automobiles typically have between four and eight, and locomotives and ships may have

672-469: A cylinder to drive a reciprocating engine in a local-pollution-free urban vehicle. Torpedoes may use a working gas produced by high test peroxide or Otto fuel II , which pressurize without combustion. The 230 kg (510 lb) Mark 46 torpedo , for example, can travel 11 km (6.8 mi) underwater at 74 km/h (46 mph) fuelled by Otto fuel without oxidant . Quantum heat engines are devices that generate power from heat that flows from

768-423: A double-deck non-stop eastbound service from New York City to London Airport (later Heathrow). However, because of the prevailing westerly winds, the westbound flights needed re-fuelling at Shannon and Gander before reaching New York. Another four Stratocruisers were taken over from a frustrated SAS order and seven were bought secondhand in the mid-1950s. The Handley Page Hermes and Canadair DC-4M Argonaut joined

864-418: A dozen cylinders or more. Cylinder capacities may range from 10 cm or less in model engines up to thousands of liters in ships' engines. The compression ratio affects the performance in most types of reciprocating engine. It is the ratio between the volume of the cylinder, when the piston is at the bottom of its stroke, and the volume when the piston is at the top of its stroke. The bore/stroke ratio

960-463: A flight engineer's position and 28 seats, as Tudor IVBs. BSAA's new flagships received mixed reviews from pilots. Some greeted it with enthusiasm, such as Captain Geoffrey Womersley, who described it as "the best civil airliner flying." Others rejected it as an unsound design. BSAA's chief pilot and manager of operations, Gordon Store, was unimpressed: "The Tudor was built like a battleship. It

1056-406: A hot to a cold reservoir. The mechanism of operation of the engine can be described by the laws of quantum mechanics . Quantum refrigerators are devices that consume power with the purpose to pump heat from a cold to a hot reservoir. In a reciprocating quantum heat engine, the working medium is a quantum system such as spin systems or a harmonic oscillator. The Carnot cycle and Otto cycle are

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1152-456: A large number of unusual varieties of piston engines that have various claimed advantages, many of which see little if any current use: BOAC British Overseas Airways Corporation ( BOAC ) was the British state-owned airline created in 1939 by the merger of Imperial Airways and British Airways Ltd . It continued operating overseas services throughout World War II. After the passing of

1248-625: A number of airlifts including but not limited to the Berlin Airlift in 1948, Abadan Air lift as part of the Abadan Crisis in June 1951, and as part of an airlift of Hungarian refugees from Vienna to London as a response to the Hungarian Revolution in 1957. Such a political outlook was also an important narrative in the context of Britain’s colonies and the wider Commonwealth . Described in

1344-403: A reciprocating engine is proportional to the volume of the combined pistons' displacement. A seal must be made between the sliding piston and the walls of the cylinder so that the high pressure gas above the piston does not leak past it and reduce the efficiency of the engine. This seal is usually provided by one or more piston rings . These are rings made of a hard metal, and are sprung into

1440-480: A sequence of strokes that admit and remove gases to and from the cylinder. These operations are repeated cyclically and an engine is said to be 2-stroke , 4-stroke or 6-stroke depending on the number of strokes it takes to complete a cycle. The most common type is 4-stroke, which has following cycles. The reciprocating engine developed in Europe during the 18th century, first as the atmospheric engine then later as

1536-509: A very basic passenger conversion. This was the first sustained North Atlantic landplane service. By September 1944 BOAC had made 1,000 transatlantic crossings. In late 1942, the new hard-surface airport at Lisbon permitted the use of civil registered Liberators to North and West Africa and Egypt. Arguably, BOAC's most famous wartime route was the ' Ball-bearing Run ' from Leuchars to Stockholm ( Bromma ) in neutral Sweden . Initially flown with Lockheed 14s and Lockheed Hudson transports,

1632-576: A view to encourage further expansion and exploitation of regional resources. BOAC held both formal and informal interests in a number of associated enterprises operating in several parts of the British Commonwealth . In 1957, these associated organisations were brought under a subsidiary company called BOAC Associated Companies Limited. These included Aden Airways , Bahamas Airways, Fiji Airways , Ghana Airways , Gulf Aviation and Nigeria Airways . By 1960, BOAC Associated Companies Limited

1728-433: Is inside a cylinder , into which a gas is introduced, either already under pressure (e.g. steam engine ), or heated inside the cylinder either by ignition of a fuel air mixture ( internal combustion engine ) or by contact with a hot heat exchanger in the cylinder ( Stirling engine ). The hot gases expand, pushing the piston to the bottom of the cylinder. This position is also known as the bottom dead center (BDC), or where

1824-586: Is not to be confused with fuel efficiency , since high efficiency often requires a lean fuel-air ratio, and thus lower power density. A modern high-performance car engine makes in excess of 75 kW/L (1.65 hp/in ). Reciprocating engines that are powered by compressed air, steam or other hot gases are still used in some applications such as to drive many modern torpedoes or as pollution-free motive power. Most steam-driven applications use steam turbines , which are more efficient than piston engines. The French-designed FlowAIR vehicles use compressed air stored in

1920-412: Is not true of every reciprocating engine), although power and fuel consumption are affected by many factors outside of engine displacement. Reciprocating engines can be characterized by their specific power , which is typically given in kilowatts per litre of engine displacement (in the U.S. also horsepower per cubic inch). The result offers an approximation of the peak power output of an engine. This

2016-394: Is the fictitious pressure which would produce the same amount of net work that was produced during the power stroke cycle. This is shown by: where A p {\displaystyle A_{p}} is the total piston area of the engine, S {\displaystyle S} is the stroke length of the pistons, and V d {\displaystyle V_{d}}

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2112-459: Is the ratio of the diameter of the piston, or " bore ", to the length of travel within the cylinder, or "stroke". If this is around 1 the engine is said to be "square". If it is greater than 1, i.e. the bore is larger than the stroke, it is "oversquare". If it is less than 1, i.e. the stroke is larger than the bore, it is "undersquare". Cylinders may be aligned in line , in a V configuration , horizontally opposite each other, or radially around

2208-425: Is the total displacement volume of the engine. Therefore: Whichever engine with the larger value of MEP produces more net work per cycle and performs more efficiently. In steam engines and internal combustion engines, valves are required to allow the entry and exit of gases at the correct times in the piston's cycle. These are worked by cams, eccentrics or cranks driven by the shaft of the engine. Early designs used

2304-423: Is then fed through one or more, increasingly larger bore cylinders successively, to extract power from the steam at increasingly lower pressures. These engines are called compound engines . Aside from looking at the power that the engine can produce, the mean effective pressure (MEP), can also be used in comparing the power output and performance of reciprocating engines of the same size. The mean effective pressure

2400-514: The 711 Trader . They were not built, but a parallel design using the same landing gear was produced as the jet-powered Avro Ashton . Two Tudor Is, G-AIYA and G-AJKC, were sent to Armstrong Whitworth for completion as VIP transports for cabinet ministers. They could accommodate 10 passengers and had nine berths. They were re-registered as VP301 and VP312 , and both were acquired by Aviation Traders in September 1953, VP301 being reconverted into

2496-513: The Civil Aviation Act 1946 , European and South American services passed to two further state-owned airlines, British European Airways (BEA) and British South American Airways (BSAA). BOAC absorbed BSAA in 1949, but BEA continued to operate British domestic and European routes for the next quarter century. The Civil Aviation Act 1971 merged BOAC and BEA, effective 31 March 1974, forming today's British Airways . On 24 November 1939, BOAC

2592-452: The D slide valve but this has been largely superseded by piston valve or poppet valve designs. In steam engines the point in the piston cycle at which the steam inlet valve closes is called the cutoff and this can often be controlled to adjust the torque supplied by the engine and improve efficiency. In some steam engines, the action of the valves can be replaced by an oscillating cylinder . Internal combustion engines operate through

2688-557: The Tudor V . The third of the pre-production Tudor 2s, initially G-AGRZ, was used for pressurisation tests as VZ366 at RAE Farnborough. The second Tudor II to be completed, G-AGRY, went to Nairobi for tropical trials as VX202 , but these were unsatisfactory and Tudor II orders were reduced to 18. Eventually, only four Tudor IIs were completed including the prototype. From 1946 on, the potential purchase of US aircraft by operators such as BOAC led to criticism of government policy, because of

2784-470: The steam engine . These were followed by the Stirling engine and internal combustion engine in the 19th century. Today the most common form of reciprocating engine is the internal combustion engine running on the combustion of petrol , diesel , liquefied petroleum gas (LPG) or compressed natural gas (CNG) and used to power motor vehicles and engine power plants . One notable reciprocating engine from

2880-573: The AW Ensigns, were due to be withdrawn. The corporation's aircraft, bases and personnel were scattered around the world, and it took a decade to reorganise it into an efficient unit at Heathrow . In 1943, the Brabazon Committee had laid down a set of civil aircraft transport types for the British aircraft industry to produce, but these were to be several years in coming, and particularly in the case of

2976-609: The BOAC fleet between 1949 and 1950, replacing the last of the non-pressurised types on passenger services. When service entry of the Bristol Britannia was delayed in late 1956, BOAC was permitted to purchase ten new Douglas DC-7 Cs. These long-range aircraft enabled BOAC to operate non-stop westbound flights from London and Manchester to New York and other US East Coast destinations, in competition with DC-7Cs of Pan Am and Lockheed Super Constellations of Trans World Airlines (TWA). This

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3072-499: The German-controlled Skagerrak direct route. Between 1939 and 1945 6,000 passengers were transported by BOAC between Stockholm and Great Britain. At the end of the war, BOAC's fleet consisted of Lockheed Lodestars, lend-lease Douglas DC-3s , Liberators, converted Sunderlands, and the first Avro Lancastrians , Avro Yorks , and Handley Page Haltons . The Short Empire, Short S.26 and Boeing 314A flying boats, plus

3168-545: The January 1959 edition of the BOAC in-house magazine, the BOAC Review , an article described that “BOAC is often able to earn the goodwill of various communities by doing some slight service, perhaps unconnected with air travel[…] 14 dolls in traditional costume for Johannesburg; 30 lbs. of haggis for Nassau and smaller quantities for Singapore and Kuala Lumpur”. Whilst these suggest charitable motives, often these are seen alongside

3264-545: The Lincoln's wing, Chadwick, who had worked on the Lancaster, designed the Tudor to incorporate a new pressurized fuselage of circular cross-section, with a useful load of 3,765 lb (1,705 kg) and a range of 3,975 mi (6,400 km). Two prototypes were ordered in September 1944 and the first, G-AGPF, was assembled by Avro's experimental flight department at Manchester's Ringway Airport and first flew on 14 June 1945. It

3360-597: The North Atlantic pre-war by Imperial Airways Empire flying-boats with improved fuel capacity, some using in flight refuelling, culminating in a series of mail/courier flights made by BOAC's Clare and Clyde to LaGuardia in camouflage during the Battle of Britain . These were BOAC's first New York services. In 1941, BOAC was tasked with operating a 'Return Ferry Service' from Prestwick to Montreal to reposition ferry pilots who had flown American-built bombers from Canada, and they were provided with RAF Consolidated Liberators with

3456-517: The Shetland Islands, BOAC presented itself as a national service aware of its wider responsibilities” BOAC were keen to promote their sense of wider obligation to the general public and wider world. In 1948, BOAC’s PR department published Operation India. A World's Record Air-Lift , referencing BOAC’s support in the events of the Partition of India. Throughout the years, BOAC would participate in

3552-505: The Treasury blocked the idea, and an agreement was reached instead to allow BEA to serve Ankara in Turkey , and in return to leave all routes east and south of Cyprus to BOAC. Paradoxically, through its effective control of Cyprus Airways , BEA was able to continue to serve destinations ceded to BOAC, including Beirut and Cairo by using Cyprus Airways as its proxy. However, it was only following

3648-833: The Tudor 8, the Ministry of Supply ordered six Tudor 9s, based on the Tudor II but powered by four Rolls-Royce Nenes and utilizing a tricycle undercarriage . The original design was then modified and the type was produced as the Avro 706 Ashton with the first Ashton flying on 1 September 1950. All except the prototype built by Avro at their Chadderton factory and assembled and test flown from Woodford Aerodrome. Data from Jane's Fighting Aircraft of World War II General characteristics Performance Related development Aircraft of comparable role, configuration, and era Piston-engine There may be one or more pistons. Each piston

3744-615: The Tudor IVB and Tudor Freighter I configurations. As a result of all the Tudor I delays, BOAC – with the support of the Ministry of Civil Aviation – sought permission to purchase aircraft with known performance and reliability, such as the Lockheed Constellation and the Boeing Stratocruiser , for its Atlantic routes instead of the Tudor. Despite BOAC's reluctance to purchase Tudors, the Ministry of Supply continued to subsidize

3840-560: The U.S.S.R. " references a flight from Miami Beach aboard a BOAC aircraft. In the song Montego Bay by Bobby Bloom , the first line is "Vernon will meet me when the BOAC lands". It is referenced in the James Tiptree Jr. story "The Last Flight of Dr. Ain." Multiple references throughout the Netflix TV Series The Crown . In The Sopranos , Season 6 Episode 19 “The Second Coming," Paulie Walnuts reminisces that he

3936-514: The US-built passenger aircraft – such as the Lockheed Constellation – as well as later on US-ordered variants of the Vickers Viscount . The first example, G-AHNJ "Star Panther", first flew on 9 April 1947. The Tudor IV received its Certificate of Airworthiness on 18 July 1947, and on 29 September, BSAA took delivery of G-AHNK "Star Lion", the first of its six Tudor 4s to be delivered. It departed

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4032-483: The World War II era was the 28-cylinder, 3,500  hp (2,600 kW) Pratt & Whitney R-4360 Wasp Major radial engine. It powered the last generation of large piston-engined planes before jet engines and turboprops took over from 1944 onward. It had a total engine capacity of 71.5 L (4,360 cu in), and a high power-to-weight ratio . The largest reciprocating engine in production at present, but not

4128-559: The aircraft could not be used in hot and high conditions which resulted in Qantas ordering the Constellation and South African Airways, the Douglas DC-4 instead, with the total order reduced to 50. During further testing, the prototype was destroyed on 23 August 1947 in a fatal crash on take off from Woodford which killed Roy Chadwick; air accident investigators later discovered that the crash

4224-475: The aircraft. The passenger capacity of the Avro 688 was considered unsatisfactory, so a larger version was planned from the outset. Designated the Avro 689 (also Avro XXI), the Tudor II was designed as a 60-seat passenger aircraft for BOAC, with the fuselage lengthened to 105 ft 7 in (32.18 m) compared to the Tudor I's 79 ft 6 in (24.23 m) and the fuselage increased by 1 ft (0.30 m) to 11 ft (3.4 m) diameter, making it

4320-576: The allied world, often under enemy fire, and initially with desperate shortages of long-range aircraft. During the war, the airline was sometimes loosely referred to as 'British Airways', and aircraft and equipment were marked with combinations of that title and/or the Speedbird symbol and/or the Union Flag . BOAC inherited Imperial Airways' flying boat services to British colonies in Africa and Asia, but with

4416-628: The backbone of the wartime fleet. (Only a handful of these had long range tanks but many were eventually upgraded with larger tankage and operated at overload weights.) The Empire flying-boats were at their limit on the 1,900-mile Lisbon-Bathurst sector. Refuelling at Las Palmas in the Canary Islands was permitted by Spain for some Empire flying-boat flights in 1940 and 1941. In 1941 longer range Consolidated Catalinas , Boeing 314 As (and later converted Short Sunderlands ) were introduced to guarantee non-stop Lisbon to Bathurst sectors (thus eliminating

4512-400: The ball-bearings is debatable, but these night flights were an important diplomatic gesture of support for neutral Sweden which had two DC-3s shot down on its own service to Britain. Other types used to Sweden included Lockheed Lodestars , Consolidated Liberators, and the sole Curtiss CW-20 (C-46 prototype) which BOAC had purchased; these types had more payload, and some had the range to avoid

4608-954: The cause of the two accidents, and the remaining aircraft were flown as unpressurised freighters under the designations Tudor Freighter IV and IVB. A Tudor IV was tested at De Havilland's Hatfield Airfield on 1 April 1949 to check "no lift angle" and flown to Heathrow on 8 April. After storage for some years at Manchester Airport , four ex-BSAAC Tudor IVs were bought by Air Charter Limited in late 1953. They were fitted with 6 ft 10 in (2.08 m) by 5 ft 5 in (1.65 m) cargo doors aft by Aviation Traders and designated Super Traders IV or IVB, receiving their Certificate of Airworthiness in March 1955. These were operated by Air Charter Ltd on long distance freight flights as far as Christmas Island . Some remained in service until 1959, until G-AGRH "Zephyr" crashed in Turkey on 23 April 1959. The Tudor V

4704-470: The crankshaft. Opposed-piston engines put two pistons working at opposite ends of the same cylinder and this has been extended into triangular arrangements such as the Napier Deltic . Some designs have set the cylinders in motion around the shaft, such as the rotary engine . In some steam engines, the cylinders may be of varying size with the smallest bore cylinder working the highest pressure steam. This

4800-506: The cylinder by this stroke . The exception is the Stirling engine , which repeatedly heats and cools the same sealed quantity of gas. The stroke is simply the distance between the TDC and the BDC, or the greatest distance that the piston can travel in one direction. In some designs the piston may be powered in both directions in the cylinder, in which case it is said to be double-acting . In most types,

4896-445: The damage that could potentially be caused to Britain's civil aircraft industry by a failure to buy the Tudor. L.G.S. Payne, The Daily Telegraph ' s aeronautical correspondent, said that British government policy had led to the development of aircraft which were uncompetitive in price, performance and economy. He blamed the Ministry of Supply's planners for this failure, since the industry had effectively been nationalised and argued that

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4992-478: The efforts made by Britain in the implementation of the Colonial Development and Welfare Acts which were often designed to improve the export industries of colonies at the expense of other more pressing needs like food and healthcare. As Smith argues, BOAC were prominent promoters of the colonial development agenda, with advertisements often highlighted the positive impact of such policies in Africa often with

5088-564: The flight of the swept-wing Boeing 367–80 (707 prototype) in 1954. In 1953 Vickers had started building the swept wing VC-7/V-1000 with Rolls-Royce Conway turbofan engines, but BOAC short-sightedly decided the Britannia and Comet 4 would be adequate for its purposes, and when the military version of the V-1000 was cancelled in 1955 the 75% complete prototype was scrapped. In October 1956 BOAC ordered 15 Boeing 707s with Conway engines (briefly

5184-428: The government should pursue the development of jet aircraft instead of "interim types" such as the Tudor. BOAC cancelled its order for Tudors in 1947, instead taking delivery of 22 Canadair North Stars which they renamed C-4 Argonauts, and used them extensively between 1949 and 1960. Six aircraft ordered as Tudor IIs were intended to be modified with tricycle landing gear, for use by BSAA as freighters, and designated

5280-424: The largest UK airliner at the time. At the end of 1944, while it was still in the design stage, BOAC, Qantas and South African Airways decided to standardise on the Tudor II for Commonwealth air routes, and BOAC increased its initial order for 30 examples to 79. The prototype Tudor II G-AGSU first flew on 10 March 1946 at Woodford Aerodrome . The changes in design had however resulted in a loss of performance and

5376-588: The largest ever built, is the Wärtsilä-Sulzer RTA96-C turbocharged two-stroke diesel engine of 2006 built by Wärtsilä . It is used to power the largest modern container ships such as the Emma Mærsk . It is five stories high (13.5 m or 44 ft), 27 m (89 ft) long, and weighs over 2,300 metric tons (2,535 short tons ; 2,264 long tons ) in its largest 14 cylinders version producing more than 84.42 MW (113,209 bhp). Each cylinder has

5472-416: The linear movement of the piston is converted to a rotating movement via a connecting rod and a crankshaft or by a swashplate or other suitable mechanism. A flywheel is often used to ensure smooth rotation or to store energy to carry the engine through an un-powered part of the cycle. The more cylinders a reciprocating engine has, generally, the more vibration-free (smoothly) it can operate. The power of

5568-650: The long West Africa route had to be employed (over-water via Lisbon, Bathurst , Freetown , Lagos ), then by landplane to Khartoum on the Horseshoe Route. The Empire routes had contained landplane sectors, but the Armstrong Whitworth Ensign and de Havilland Albatross ordered to replace the Handley Page HP.42 'Heracles' biplanes had proved disappointing, leaving the Short Empire flying boats as

5664-596: The main BOAC fleet at peak demand, and in a reciprocal arrangement BOAC would provide capacity to BOAC-Cunard on some operations when it had a shortfall. The effect of this arrangement was to remove competition on western routes. The operation was dissolved in 1966. The following is an incomplete list of destinations historically served by BOAC: During the time of the airline's existence, BOAC operated these aircraft: Dates above are for service with BOAC or its forerunners; those still in service in 1974 subsequently passed to British Airways. The Beatles song " Back in

5760-513: The most economical commercial engine option). They entered service in 1960. (The British airworthiness authorities insisted on tail-fin modifications which Boeing made available to all 707 users.) Sir Giles Guthrie , who took charge of BOAC in 1964, preferred Boeing aircraft for economic reasons, and indeed BOAC began turning a profit in the late 1960s. After a row in Parliament the government instructed BOAC to purchase 17 Vickers VC10 aircraft from

5856-599: The national flag-carrying airline in the broadest sense. Early publicity emphasised its role in alleviating famines and flooding, in the supply of medicines and in the transportation of athletes and explorers. More than this, BOAC strove to embed itself in the cultural fabric of the nation. By taking pressurised oxygen canisters to climbers on Everest, transporting a 7,000 year-old skill from the British School in Jerusalem or flying astronomers as close as possible to an eclipse over

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5952-572: The need to refuel at Las Palmas). BOAC's flying-boat base for Britain was shifted from Southampton to Poole , Dorset , but many flights used Foynes in Ireland, reached by shuttle flight from Whitchurch. Use of Foynes reduced the chance of enemy interception or friendly fire incidents over the English Channel . BOAC had large bases at Durban , Asmara , Alexandria and a pilots' school at Soroti , Uganda . Experimental flights had been made across

6048-462: The next day from Heathrow on a flight to South America, and on 31 October began flights from London to Havana via Lisbon, the Azores, Bermuda and Nassau. On the night of 29–30 January 1948, Tudor IV G-AHNP "Star Tiger", with 31 people on board, disappeared without trace between Santa Maria in the Azores and Bermuda. Tudors were temporarily grounded and while the cause of the accident was never determined,

6144-410: The ones most studied. The quantum versions obey the laws of thermodynamics . In addition, these models can justify the assumptions of endoreversible thermodynamics . A theoretical study has shown that it is possible and practical to build a reciprocating engine that is composed of a single oscillating atom. This is an area for future research and could have applications in nanotechnology . There are

6240-526: The original fin and rudder were replaced by larger vertical surfaces. BOAC added to the delays by requesting more than 340 modifications, and finally rejected the Tudor I on 11 April 1947, considering it unacceptable for North Atlantic operations. It had been intended that 12 Tudors would be built in Australia for military transport, but this plan was abandoned. Twelve Tudor I aircraft were built, of which three were scrapped, while others were variously converted to

6336-423: The piston forms the largest volume in the cylinder. The piston is returned to the cylinder top (top dead center) (TDC) by a flywheel , the power from other pistons connected to the same shaft or (in a double acting cylinder ) by the same process acting on the other side of the piston. This is where the piston forms the smallest volume in the cylinder. In most types the expanded or " exhausted " gases are removed from

6432-488: The press, British manufacturers and the unions accused BOAC management of only wanting American aircraft. Whilst the major world airlines abandoned flying-boats at the end of WWII, BOAC continued with theirs until 1950, and even introduced the new Short Solent on the leisurely Nile route to South Africa. In 1948, the unpressurised Yorks were still operating passenger services as far afield as Nairobi (Kenya), Accra (Gold Coast, later Ghana), Delhi and Calcutta (India), and

6528-576: The production order to 20 in April 1945. The Tudor I suffered from a number of stability problems, which included longitudinal and directional instability. The problem was handed over to the Royal Aircraft Establishment at RAE Farnborough , where an extensive programme of testing was carried out, the test pilot being Eric Brown . Following the RAE's recommendations, a larger tailplane was fitted, and

6624-622: The recommendations of the 1969 Edwards Report that a new British Airways Board, combining BEA and BOAC, was constituted on 1 April 1972. This event coincided with the establishment of the Civil Aviation Authority , the UK's new, unified regulator for the air transport industry. BOAC would have become one of the first operators of the Concorde , had it not merged to become British Airways. BA's Concordes carried registrations of G-BOAA to G-BOAG . The first Concorde delivered to British Airways

6720-477: The revised Comet 4 were designed to be fail-safe: in the event of, for example, a skin-failure due to cracking the damage would be localised and not catastrophic. In October 1958 BOAC operated the first transatlantic jet service with the larger and longer-range Comet 4. In the 1950s turbine powered airliners were developing rapidly, and the Comet and the seriously delayed Bristol Britannia were soon rendered obsolescent by

6816-456: The tailwheel Avro Tudor , not what BOAC wanted. Since 1941, the advanced pressurised Lockheed Constellation had been under development, and in 1946 BOAC was permitted to use dollars to purchase an initial fleet of five for the prestigious North Atlantic route (there were no equivalent British types available). Throughout the whole of BOAC's existence, the argument over buying American or (often delayed) British products continued, and Parliament,

6912-539: The trailing edges of the centre section and inner wings. A 3,300 imp gal (15,000 L; 4,000 US gal) fuel capacity was given by eight bag tanks, one on either side of the fuselage in the centre section and three in both inner wings. The all-metal tail unit had a dorsal fin integrated with the fuselage, and a 43 ft (13 m) twin-spar tailplane with inset divided elevators . The control surfaces were mass-balanced, and each had controllable trim and servo tabs . The circular cross-section fuselage

7008-581: The two airlines to negotiate air rights through the British colony of Cyprus . The chairman of BOAC, Miles Thomas , was in favour of the idea as a potential solution to a disagreement between the two airlines as to which should serve the increasingly important oil regions of the Middle East , and he had backing for his proposal from the Chancellor of the Exchequer at the time, Rab Butler . However, opposition from

7104-470: The type continued to operate freight schedules until late 1957. After its first six Lockheed 049 Constellations, BOAC had to use some ingenuity to increase its Constellation fleet. In 1947, Aerlínte Éireann in Ireland bought five new Lockheed 749 Constellations, and prepared to launch a transatlantic service with assistance and crew-training from Captains O. P. Jones and J. C. Kelly-Rogers of BOAC. The project

7200-557: The type returned to service on 3 December 1948, when a weekly service was begun from London to Buenos Aires via Gander, Bermuda, and other stops, returning via the Azores. Disaster struck again on 17 January 1949, when Tudor IV G-AGRE "Star Ariel" also disappeared, this time between Bermuda and Kingston, Jamaica , with the loss of 20 people, and the Tudor IVs were once more grounded. The subsequent fleet shortage led to BSAA being taken over by BOAC. Pressurisation problems were suspected to be

7296-417: The unsuitable Armstrong Whitworth Whitley "civilianised" bombers were also used between 9 August and 24 October 1942 ("Civilianised" meant that all the armaments and unnecessary guns and turrets had been removed, a legal requirement for operating a commercial civilian service to a neutral country). The much faster civilian registered de Havilland Mosquitoes were introduced by BOAC in 1943. The significance of

7392-513: The wartime loss of the route over Italy and France to Cairo these were replaced by the expatriate ' Horseshoe Route ', with Cairo as a hub, and Sydney and Durban as end destinations. Linking Britain to the Horseshoe Route taxed the resources of BOAC. Although Spain denied access, Portugal welcomed BOAC's civilian aircraft at Lisbon . However, the Mediterranean route from Lisbon or Gibraltar to Egypt via Malta risked enemy attack, so

7488-479: The wreckage recovered from the Mediterranean sea-bed and observation of a sample fuselage in a pressurisation test-tank at Farnborough revealed that the repeated pressurisation / depressurisation cycles of airline operation could cause fatigue cracks in the thin aluminium alloy skin of the Comet leading to the skins ripping away explosively at altitude and disintegration of the aircraft. Later jet airliners including

7584-471: Was a Lincoln bomber with a new circular section pressurized fuselage and a large single fin and rudder in place of the predecessor's double ones. During the design stage, the idea of a simple conversion was abandoned and the Avro 688 was designed, which retained the four Rolls-Royce Merlin engines. It was designed by Roy Chadwick who, due to wartime restrictions, could not design a completely new aircraft, but had to use existing parts, tools and jigs. Using

7680-471: Was a modified version of the stretched Tudor II equipped with 44 seats. BSAA acquired five which never entered passenger service with the airline. They were instead stripped of their fittings and used as fuel tankers on the Berlin Airlift . They completed a total of 2,562 supply sorties in 6,973 hours, carrying 22,125 tons (20,071 tonnes) of fuel into Berlin. On 12 March 1950, G-AKBY , which had been returned to passenger service with Airflight Ltd, on

7776-554: Was abandoned in February 1948, and BOAC were able to buy the almost new 749s without dollar expenditure four months later. This enabled BOAC to serve Australia with Constellations from 1949. A total of 25 Constellations passed through the BOAC fleet, including 12 749As obtained from Capital Airlines in the mid-1950s, with BOAC's older 049s in part exchange. BOAC was also permitted to spend dollars on six new Boeing 377 Stratocruisers for its key transatlantic routes from October 1949, offering

7872-528: Was also dated and a disadvantage. Avro began work on the Type 688 Tudor in 1943, following Specification 29/43 for a commercial adaptation of the Lancaster IV bomber, which was later renamed Lincoln . The specification was based on recommendations of the Brabazon Committee , which issued specifications for nine types of commercial aircraft for postwar use. Avro first proposed to build the Avro 687 (Avro XX), which

7968-420: Was an all-metal semi- monocoque structure, of 10 ft (3.0 m) diameter, fitted with kapok noise insulation above floor level. The hydraulically operated main-wheel units were similar to those of the Lancaster, had single Dunlop wheels and retracted rearward into the inboard engine nacelles. The twin tailwheels retracted rearward into the fuselage and were enclosed by twin longitudinal doors. The Tudor I

8064-662: Was created by the British Overseas Airways Act 1939 to become the British state airline, formed from the merger of Imperial Airways and British Airways Ltd . The companies had been operating together since war was declared on 3 September 1939, when their operations were evacuated from the London area to Bristol . On 1 April 1940, BOAC started operations as a single company. Following the Fall of France (22 June 1940), BOAC aircraft kept wartime Britain connected with its colonies and

8160-498: Was declared to have holdings in eighteen companies. In 1962, BOAC and Cunard formed BOAC-Cunard Ltd to operate scheduled services to North America, the Caribbean and South America. BOAC provided 70% of the new company's capital and eight Boeing 707s. The independent Cunard Eagle Airways , of which Cunard held a 60% shareholding, provided two more 707s. BOAC-Cunard leased any spare capacity to BOAC which could use it to supplement

8256-478: Was dosed with LSD when a BOAC stewardess put it in his drink, during a 1968 visit to the Copacabana nightclub. In Ian Fleming's Goldfinger, a BOAC aircraft is hijacked by the villain, Auric Goldfinger, and James Bond held captive upon it until he is able to retrieve the situation. One of the Concorde aircraft operated by British Airways was tail-named G-BOAC. Because of this coincidental reference to BOAC, it

8352-448: Was due to incorrect assembly of the aileron control circuit. The engines on the second prototype were changed to Bristol Hercules radials and the aircraft became the prototype Tudor 7 , which did not go into production. Unimpressed by the type's performance during further tropical trials, BOAC did not operate the Tudor II and only three production Tudor IIs were built. Six aircraft were built for British South American Airways (BSAA) as

8448-512: Was for 11 Boeing 747-100s . On 22 April 1970 BOAC received its first 747, but the aircraft did not enter commercial service until 14 April 1971 due to BOAC's inability to settle crewing and pay rates with the British Air Line Pilots' Association . BOAC's successor British Airways later became the largest Boeing customer outside North America. The first attempt at a merger of BOAC with BEA arose in 1953 out of inconclusive attempts between

8544-533: Was intended for use on the North Atlantic route. At the time, the United States had the Douglas DC-4 and Lockheed Constellation , which could both carry more passengers than the Tudor which only carried 12, and also weighed less than the Tudor weight of 70,000 lb (32,000 kg). The Tudor tailwheel layout was also obsolete. Despite this, the Ministry of Supply ordered 14 Tudor I aircraft for BOAC , and increased

8640-477: Was noisy, I had no confidence in its engines and its systems were hopeless. The Americans were fifty years ahead of us in systems engineering. All the hydraulics, the air conditioning equipment and the recircling [sic] fans were crammed together underneath the floor without any thought. There were fuel-burning heaters that would never work; we had the floorboards up in flight again and again. The Tudor IV's fuel-burning heaters were made by Janitrol and were also used on

8736-456: Was of NACA 23018 section at the root, and was a five-piece, all-metal, twin-spar structure. The untapered centre section carried the inboard engines and main undercarriage, while the inner and outer sections were tapered on their leading and trailing edges, with the inner sections carrying the outboard engines. The ailerons were fitted with trim and balance tabs, and there were hydraulically operated split flaps in three sections on each side of

8832-498: Was rebuilt to Tudor IV standards. It was later fitted with four Rolls-Royce Nene 4 turbojets in under-wing paired nacelles. Given the serial VX195 , The Tudor 8 carried out its first flight at Woodford on 6 September 1948, and a few days later, it was demonstrated at the SBAC Show at Farnborough. Later, the Tudor 8 was used for high-altitude tests at Boscombe Down and RAE Farnborough before being broken up in 1951. Following tests of

8928-485: Was registered G-BOAC. Flight was out of the financial reach of the vast majority of travellers in Britain. However as a nationalised industry , British taxpayers were funding BOAC’s operations overseas. As a result, in the immediate post-war period BOAC saw a need to promote their aviation services beyond traditional travel. Scott Anthony and Oliver Green described in their 2012 book: “New Elizabethan ambitions made BOAC into

9024-448: Was the first British pressurised civilian aircraft, although the prototype initially flew unpressurised. The prototype Tudor I had 1,750 hp (1,305 kW) Rolls-Royce Merlin 102 engines, but the standard engines were 1,770 hp (1,320 kW) Merlin 621s. The Tudor was a low-wing cantilever monoplane with four engines, a single fin and rudder and a retractable tailwheel undercarriage (in its original configurations). The wing

9120-465: Was the first production Tudor II fitted with Bristol Hercules air-cooled radial engines in an attempt to give better performance. The sole example built, G-AGRX, made its first flight on 17 April 1946, and was later fitted in June 1948 with shorter landing gear with the engines repositioned (inclined) to give better ground clearance. G-AGRX was used for cabin temperature experiments, and was finally sold for spares in March 1954. The second prototype Tudor I

9216-553: Was the first purchase of aircraft direct from the Douglas Aircraft Company in BOAC's history. In May 1952 BOAC was the first airline to introduce a passenger jet into airline service. This was the de Havilland Comet which flew via Nairobi to Johannesburg and via the Far East to Tokyo. All Comet 1 aircraft were grounded in April 1954 after four Comets crashed, the second last being a BOAC aircraft at altitude. Examination of

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