viernes, 19 de noviembre de 2010

Concorde

Uno de los textos interesantes de clase de inglés ( igual me parece interesante porque el nivel es bajo y lo entiendo y todo...) Vale, si no fuera mis deberes igual yo tampoco lo leería. Lo publico porque me sirve de recuerdo





Concorde

Supersonic Passenger Aircraft (1976-2003)
Designing Modern Britain - Design Museum
Until 26 November 2006

One of the best-loved engineering design projects of the 20th century, CONCORDE (1976-2003) is a rare example of successful international collaboration. Its Anglo-French designers produced the world’s first supersonic commercial passenger aircraft which at its fastest flew from New York to London in less than three hours.


When the British government established the Supersonic Transport Aircraft Committee in 1956 to explore the possibility of developing the world’s first passenger aircraft able to fly faster than the speed of sound, it could take as long as eighteen hours for a commercial jet to fly from London to New York.
It was to take nearly twenty years for the committee’s work to culminate in the first commercial flight of a supersonic aircraft, but the subsequent performance of that jet, Concorde, exceeded even the most optimistic expectations. Routinely flying faster than twice the speed of sound, Concorde sported a take-off speed of 250 mph (400 kmph) and a cruising speed of 1,350 mph (2,160 kmph) at an altitude of up to 60,000 feet, twice the height of Mount Everest. At its fastest on 7 February 1996, Concorde flew from New York to London in just 2 hours, 52 minutes and 59 seconds, less than a sixth of the time that the same journey would have taken by air in 1956.


Hailed for its beauty as well as its speed, Concorde seemed to belong less to the modern world than to the future. During 27 years of commercial service from 1976 to 2003, it became one of the best-loved engineering design projects of the 20th century. An exemplar of technological excellence, Concorde struck such a strong emotional chord with the public that children cheered whenever they spotted it in the sky.


Concorde was Britain and France’s response to the space race in which the US and the Soviet Union had battled for supremacy throughout the late 1950s and 1960s. Aircraft production had flourished during World War II, and in the late 1940s and 1950s many of the technologies developed for military use were adapted to make passenger aircraft faster and more powerful. The next logical step was to develop a supersonic passenger aircraft capable of flying faster than the speed of sound. The British government formed the Supersonic Transport Aircraft Committee in 1956 and the Bristol Aeroplane Company started work on the development of the Type 233 supersonic jet. The French were pursuing the same goal with Sud Aviation’s Super-Caravelle and, in 1962, the two countries decided to collaborate in the interests of efficiency and economy.


The agreement was formalised as a treaty between the British and French governments, rather than a commercial contract. By this time both the Bristol Aeroplane Company and Sud Aviation had merged with other companies to become the British Aircraft Corporation and Aerospatiale respectively. The name Concorde was first used by President De Gaulle of France in 1963, and the British initially spelt it without an ‘e’. In 1967 Tony Benn, the minister for technology, announced that Britain would adopt the French spelling and squashed nationalistic protests by proclaiming that the ‘e’ stood for “excellence, England, Europe and entente (cordiale)”. When an irate Scot wrote an angry letter demanding to know what ‘e’ represented to his country, Benn replied that it was ‘Ecosse’, the French word for Scotland.


The technical challenges facing the British engineers at Filton, Gloucestershire and their French peers in Toulouse were immense, as were the political and economic problems that dogged the project from the start. When the collaboration began in 1962 Concorde was expected to cost between £150 and £170 million. The first prototype was scheduled to fly in late 1966 and the Certificate of Airworthiness to be issued at the end of 1969. France was to complete 60% of the work on the airframe and 40% of the engine, and Britain 40% of the airframe and 60% of the engine.
In reality the project was so complex that it took much longer and cost far more. The radical implications of Concorde’s extraordinary speed for its weight, shape, noise and components meant that every element of its design was dramatically different from that of a conventional jet, as were the safety requirements. An early design decision was that its wings should be a slender, swept-back triangular shape, rather than rectangular like a Boeing 747’s, to allow Concorde to move easily through the air at exceptionally high speed. These triangular or ‘delta’ wings not only optimised speed by reducing drag, but provided sufficient lift for take-off and landing at subsonic speed, and enough stability during flight to eradicate the need to install horizontal stabilisers on the tail.
The shape of the wings had important implications for the design of one of Concorde’s most famous features – its long needle-shaped nose. A delta-winged aircraft has to take off and land at steeper angles than one with rectangular wings, and Concorde’s pilots would have been unable to see the runway if its nose had been conventional in shape. To resolve this and to maximise aerodynamic efficiency, Concorde’s nose was designed to tilt by 13 degrees. During flight the nose was raised, and when Concorde landed it was lowered to give the pilots an unobstructed view of the runway.


The problem of the noise emitted by the powerful engines developed for Concorde by Rolls-Royce in Britain and SNECMA in France proved less tractable. It was a struggle from the start to secure approval for Concorde to be permitted to fly to and from New York, and the noise issue meant that the number of airports where it was authorised to operate remained restricted.
Similarly, Concorde’s development was marked by the struggle to squeeze in as many seats and as much cargo as possible, to optimise its potential for income generation, while minimising its size and weight. Made mostly from aluminium, the resulting aircraft was 203 feet 9 inches (62.1 metres) long, 37 feet 1 inch (11.3 metres) high with a wingspan of 83 feet 8 inches (25.5 metres). Concorde stretched between 6 and 10 inches during flight as the airframe heated – with the cabin becoming perceptibly warmer – even though it was coated in a white paint specially developed to dissipate the heat.


In an era when luxury was still equated with the grandeur of size, one of the most surprising elements to Concorde passengers was to discover that the cabin was so small, as were the seats. The cabin was only 1.8 metres high with space for just 100 seats – 40 in the front section and 60 in the rear – with no space for overhead storage, which meant that cabin baggage was tightly restricted. Each seat on Concorde was considerably narrower than its equivalent in the first and business class cabins of British Airways and Air France. As Concorde only flew during the day, its compact seats did not cause too much discomfort as passengers did not sleep on them overnight.
Each of the four Rolls-Royce/SNECMA Olympus 593 engines produced 38,000 pounds of thrust. The most powerful pure jet engines in commercial flight, they used reheat technology to add fuel to the final stage of the journey, thereby providing extra power for take-off and for the transition to supersonic flight. Part of the fun for Concorde passengers was hearing the pilot’s description of its progress during the flight as it gathered speed and gained height, eventually cruising at Mach 2, 1,350 mph or 2,160 kmph, twice the speed of sound, as high as 60,000 feet or twice the height of Mount Everest.


Each Concorde had a range of 4,143 miles (6,667 km) and the capacity to carry 26,286 gallons (119,500 litres) of fuel. Typically it consumed some 5,638 gallons (25,629 litres) of fuel during each hour of flight.
On 2 March 1969, Concorde 001 set off on its first test flight from Toulouse and the first supersonic flight was completed on 1 October that year. It then took another six years to secure the Certificate of Airworthiness. The testing of Concorde was unprecedented and is still unsurpassed today. The prototype, pre-production and first production aircraft undertook 5,335 flight hours, some 2,000 of which were supersonic. As a result Concorde was submitted to four times as many tests as standard commercial aircraft.


The delays and political problems – from successive changes of British governments, to the sustained disapproval of Britain’s principal ally, the US – contributed to an escalation of the development budget, which is believed to have reached to £1 billion by 1976, when Concorde finally began commercial flights. At the start of the Anglo-French collaboration, airlines from over a dozen countries had expressed interest in ordering Concorde, but by the end of its development only two remained, British Airways and Air France.


Bookings opened for the first commercial supersonic flights on 14 October 1975. The British Airways Concorde flew from London to Bahrain on 21 January 1976 and the Air France Concorde from Paris from Rio de Janeiro. As flights to New York were banned because of noise concerns, British Airways and Air France began Concorde’s US flights to Washington, but by late 1977 New York had succumbed by allowing Concorde to fly there.
A total of 20 Concordes were constructed: six for development and 14 for commercial service. More than 2.5 million passengers flew supersonically on the British Airways Concorde alone between 1976 and 2003. A typical flight from London to New York was three hours and 20 minutes, compared with seven hours for a Boeing 747 jumbo jet. As Concorde flew twice as high as conventional long haul jets, turbulence was rare and passengers could see the curvature of the earth through the windows. Nicknamed ‘Big Bird’, Concorde was cherished as a national design treasure in both Britain and France, and was soon used for celebratory flypasts on special occasions.


Concorde held the distinction of being the world’s safest working passenger aircraft until 25 July 2000 when Air France Flight 4590 crashed in France killing 113 people including all of the passengers and flight crew. Air France suspended Concorde flights, as did British Airways. After an overhaul British Airways resumed flights on 11 September 2001. On the same day, the World Trade Center in New York was destroyed by terrorists. International travel declined steeply and the relaunched Concorde struggled financially.
Another problem was that, as no supersonic competitors had emerged, there had been no pressure to upgrade Concorde or to invest in new suppliers and sub-contractors. As a result, maintenance costs had risen steadily and keeping Concorde in flight was increasingly expensive. On 10 April 2003, British Airways and Air France announced that they were withdrawing Concorde from service by the end of the year. On 24 October 2003 Concorde completed its final supersonic flight as the world’s fastest passenger aircraft.






© Design Museum, 2006





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