Concorde

Concorde

Role	Supersonic airliner
Manufacturer	BAC (now BAE Systems) Aérospatiale (now EADS)
First flight	2 March 1969
Introduction	21 January 1976
Retired	26 November 2003
Status	Retired from service
Primary users	British Airways Air France Braniff International Airways
Number built	20 (including 6 non-airline aircraft)^[1]^[2]
Unit cost	£23 million in 1977

The Aérospatiale-BAC Concorde aircraft was a turbojet-powered supersonic passenger airliner, a supersonic transport (SST). It was a product of an Anglo-French government treaty, combining the manufacturing efforts of Aérospatiale and the British Aircraft Corporation. First flown in 1969, Concorde entered service in 1976 and continued for 27 years.

Concorde flew regular transatlantic flights from London Heathrow (British Airways) and Paris-Charles de Gaulle Airport (Air France) to New York JFK and Washington Dulles, profitably flying these routes at record speeds, in less than half the time of other airliners. Indeed, Concorde held many speed records.

With only 20 aircraft built, the costly development phase represented a substantial economic loss. Additionally, Air France and British Airways were subsidised by their governments to buy the aircraft. As a result of the type's only crash (on 25 July 2000), world economic effects arising from the 9/11 attacks, and other factors, operations ceased on 24 October 2003. The last "retirement" flight occurred on 26 November 2003.

Concorde remains an icon of aviation history, and has acquired an unusual nomenclature for an aircraft. In common usage in the United Kingdom, the type is known as "Concorde" rather than "the Concorde" or "a Concorde".

Development

Concorde's final flight, G-BOAF from Heathrow to Bristol, on 26 November 2003. The extremely high fineness ratio of the fuselage is evident

Pre-production Concorde number 101 on display at the Imperial War Museum Duxford, UK

Concorde G-BOAB in storage at London Heathrow Airport following the end of all Concorde flying. This aircraft flew for 22,296 hours between its first flight in 1976 and its final flight in 2000.

In the late 1950s, the United Kingdom, France, United States and Soviet Union were considering developing supersonic transport. Britain's Bristol Aeroplane Company and France's Sud Aviation were both working on designs, called the Type 223 and Super-Caravelle, respectively. Both were largely funded by their respective governments. The British design was for a thin-winged delta shape (which owed much to work by Dietrich Küchemann) for a transatlantic-ranged aircraft for about 100 people, while the French were intending to build a medium-range aircraft.

The designs were both ready to start prototype construction in the early 1960s, but the cost was so great that the British government made it a requirement that BAC look for international co-operation. Approaches were made to a number of countries, but only France showed real interest. The development project was negotiated as an international treaty between the two countries rather than a commercial agreement between companies and included a clause, originally asked for by Britain, imposing heavy penalties for cancellation. A draft treaty was signed on 28 November 1962. By this time, both companies had been merged into new ones; thus, the Concorde project was between the British Aircraft Corp. and Aerospatiale.

The aircraft was initially referred to in Britain as "Concorde," with the French spelling, but was officially changed to "Concord" by Harold Macmillan in response to a perceived slight by Charles de Gaulle. In 1967, at the French roll-out in Toulouse the British Government Minister for Technology, Tony Benn announced that he would change the spelling back to "Concorde." This created a nationalist uproar that died down when Benn stated that the suffixed "e" represented "Excellence, England, Europe and Entente (Cordiale)." In his memoirs, he recounts a tale of a letter from an irate Scotsman claiming: "you talk about 'E' for England, but part of it is made in Scotland." Given Scotland's contribution of providing the nose cone for the aircraft, Benn replied "it was also 'E' for 'Écosse' (the French name for Scotland) — and I might have added 'e' for extravagance and 'e' for escalation as well!"

Construction of two prototypes began in February 1965: 001, built by Aerospatiale at Toulouse, and 002, by BAC at Filton, Bristol. Concorde 001 made its first test flight from Toulouse on 2 March 1969, piloted by Andre Turcat, and first went supersonic on 1 October. The first UK-built Concorde flew from Filton to RAF Fairford on 9 April 1969, piloted by Brian Trubshaw. As the flight programme progressed, 001 embarked on a sales and demonstration tour on 4 September 1971. Concorde 002 followed suit on 2 June 1972 with a tour of the Middle and Far East. Concorde 002 made the first visit to the United States in 1973, landing at the new Dallas-Fort Worth Regional Airport to mark that airport's opening.

These trips led to orders for over 70 aircraft, but a combination of factors led to a sudden number of order cancellations: the 1973 oil crisis, acute financial difficulties of many airlines, a spectacular Paris Le Bourget air show crash of the competing Soviet Tupolev Tu-144, and environmental concerns such as the sonic boom, takeoff-noise and pollution. Only Air France and British Airways (the successor to BOAC) took up their orders, with the two governments taking a cut of any profits made. In the case of BA, 80% of the profit was kept by the government until 1984, while the cost of buying the aircraft was covered by a state loan.

The United States cancelled its supersonic transport (SST) programme in 1971. Two designs had been submitted; the Lockheed L-2000, looking like a scaled-up Concorde, lost out to the Boeing 2707, which was intended to be faster, to carry 300 passengers and feature a swing-wing design. Other countries, such as India and Malaysia, ruled out Concorde supersonic overflights due to noise concerns.

Both European airlines flew demonstration and test flights from 1974 onwards. The testing of Concorde set records that have not been surpassed; the prototype, pre-production and first production aircraft undertook 5,335 flight hours. A total of 2,000 test hours were at supersonic speeds. Unit costs were £23 million (US$46 million) in 1977. Development cost was six times the projected amount.

Design

Concorde was an ogival (also "ogee") delta-winged aircraft with four Olympus engines based on those originally developed for the Avro Vulcan strategic bomber. The engines were jointly built by Rolls-Royce and SNECMA. Concorde was the first civil airliner to have an analogue fly-by-wire flight control system. It also employed a trademark droop snoot lowering nose section for visibility on approach.

These and other features permitted Concorde to have an average cruise speed of Mach 2.02 (about 2,140 km/h or 1,330 mph) with a maximum cruise altitude of 18,300 metres (60,000 feet), more than twice the speed of conventional aircraft. The average landing speed was 298 km/h (185 mph, 160 knots).

The Concorde programme's primary legacy is in the experience gained in design and manufacture which later became the basis of the Airbus consortium. Snecma Moteurs' involvement with the Concorde programme prepared the company's entrance into civil engine design and manufacturing, opening the way for Snecma to establish CFM International with General Electric and produce the successful CFM International CFM56 series engines.

Although Concorde was a technological marvel when introduced into service in the 1970s, 30 years later its cockpit, cluttered with analogue dials and switches, looked dated. With no competition, there was no commercial pressure to upgrade Concorde with enhanced avionics or passenger comfort, as occurred in other airliners of the same vintage, for example the Boeing 747.

The key partners, BAC (later to become BAE Systems) and Aerospatiale (which was later merged into EADS), were the joint owners of Concorde's type certificate. Responsibility for the Type Certificate transferred to Airbus with formation of Airbus SAS.

Movement of centre of pressure

When any aircraft passes the critical mach of that particular airframe, the centre of pressure shifts rearwards. This causes a pitch down force on the aircraft, as the centre of mass remains where it was. The engineers designed the wings in a specific manner to reduce this shift. However, there was still a shift of about 2 metres. This could have been countered by the use of trim controls, but at such high speeds this would have caused a dramatic increase in the drag on the aircraft. Instead, the distribution of fuel along the aircraft was shifted during acceleration and deceleration to move the centre of mass, effectively acting as an auxiliary trim control.

Engines

To be economically viable, Concorde needed to be able to fly reasonably long distances, and this required high efficiency. For optimum supersonic flight, turbofan engines were considered, but rejected, as due to their large master cross-section they would cause excessive drag. Turbojets were found to be the best choice of engines. The quieter high bypass turbofan engines such as used on Boeing 747s could not be used. The engine chosen was the twin spool Rolls-Royce/Snecma Olympus 593, a version of the Olympus originally developed for the Vulcan bomber, developed into an afterburning supersonic engine for the BAC TSR-2 strike bomber and then adapted for Concorde.

The inlet design for Concorde's engines was critical. All conventional jet engines can take in air at only around Mach 0.5; therefore the air needs to be slowed from the Mach 2.0 airspeed that enters the engine inlet. In particular, Concorde needed to control the shock waves that this reduction in speed generates to avoid damage to the engines. This was done by a pair of intake ramps and an auxiliary flap, whose position was moved during flight to slow the air down. The ramps were at the top of the engine compartment and moved down and the auxiliary flap moved both up and down allowing air to flow in or out. During takeoff, when the engine's air demand was high, the ramps were flat at the top and the auxiliary flap was in, allowing more air to enter the engine. As the aircraft approached Mach 0.7, the flap closed; at Mach 1.3, the ramps came into effect, removing air from the engines which was then used in the pressurisation of the cabin. At Mach 2.0, the ramps had covered half their total possible distance. They also helped reduce the work done by the compressors as they not only compressed the air but also increased the air temperature.

Engine failure causes large problems on conventional subsonic aircraft; not only does the aircraft lose thrust on that side but the engine is a large source of drag, causing the aircraft to yaw and bank in the direction of the failed engine. If this had happened to Concorde at supersonic speeds, it could theoretically have caused a catastrophic failure of the airframe. However, during an engine failure air intake needs are virtually zero, so in Concorde the immediate effects of the engine failure were countered by the opening of the auxiliary flap and the full extension of the ramps, which deflected the air downwards past the engine, gaining lift and streamlining the engine, minimising the drag effects of the failed engine. In tests, Concorde was able to shut down both engines on the same side of the aircraft at Mach 2 without any control problems.

The aircraft used reheat (afterburners) at take-off and to pass through the transonic regime (i.e. "go supersonic") between Mach 0.95 and Mach 1.7, and were switched-off at all other times. The engines were capable of reaching Mach 2 without reheat, but it was discovered that it burnt more fuel that way, since the aircraft spent much longer flying in the high-drag transonic regime even though reheat is inefficient.

Due to jet engines being highly inefficient at low speeds, Concorde burned two tonnes of fuel taxiing to the runway. To conserve fuel only the two outer engines were run after landing. The thrust from two engines was sufficient for taxiing to the ramp due to low aircraft weight upon landing at its destination.

However, when operating Concorde at its design point at Mach 2, it was the world's most efficient jet engine.

Heating issues

Beside engines, the hottest part of the structure of any supersonic aircraft is the nose. The engineers wanted to use (duralumin) aluminium throughout the aircraft, due to its familiarity, cost and ease of construction. The highest temperature that aluminium could sustain over the life of the aircraft was 127 °C, which limited the top speed to Mach 2.02.

Concorde went through two cycles of heating and cooling during a flight, first cooling down as it gained altitude, then heating up after going supersonic. The reverse happened when descending and slowing down. This had to be factored into the metallurgical modelling. An expensive test rig was built that repeatedly heated up a full-size section of the wing, and then cooled it, and periodically samples of metal were taken for testing. This cost millions of pounds per year to run.

In fact, owing to the heat generated by compression of the air as Concorde travelled supersonically, the fuselage would extend by as much as 300 mm (almost 1 ft), the most obvious manifestation of this being a gap that opened up on the flight deck between the flight engineer's console and the bulkhead. On all Concordes that had a supersonic retirement flight, the flight engineers placed their hats in this gap before it cooled, where the hats remain to this day. In the Seattle Museum of Flight's Concorde a protruding cap was cut off by a thief in an apparent attempt to steal it, leaving a part behind. An amnesty led to the severed cap being returned.

In order to keep the cabin cool, Concorde used the fuel as a heatsink for the heat from the air conditioning. The same method also cooled the hydraulics. During supersonic flight the windows in the cockpit became too hot to touch.

Concorde also had restrictions on livery; the majority of the surface had to be painted with a special highly reflecting white paint to avoid overheating the aluminium structure due to the supersonic heating effects of Mach 2. In 1996, however, Air France briefly painted F-BTSD in a predominantly-blue livery (with the exception of the wings) as part of a promotional deal with Pepsi Cola. In this paint scheme, Air France were advised to remain at Mach 2 for no more than 20 minutes at a time, but there was no restriction at speeds under Mach 1.7. F-BTSD was chosen for the promotion because the aircraft was not then scheduled to operate any long flights that required extended Mach 2 operations.

Structural issues

Due to the high speeds at which Concorde travelled, large forces were applied to the aircraft structure during banks and turns. This caused twisting and the distortion of the aircraft's structure. This was resolved by the neutralisation of the outboard elevons at high speeds. Only the innermost elevons, which are attached to the strongest area of the wings, are active at high speed.

Additionally, the narrow fuselage meant that the aircraft flexed more, particularly during takeoff. Pilots were able to look back down the cabin and see this occurring, but it was less visible from most of the passengers' viewpoints. The cabins of both Air France and British Airways featured lavatories and bulkheads midway down the cabin to reduce the appearance of the "long tube effect" to passengers in the aft of the aircraft.

Brakes and undercarriage

Due to a high average takeoff speed of 250 miles per hour (400 km/h), Concorde needed upgraded brakes. Like most airliners, Concorde used an anti-skid braking system which prevents the tyres from sliding when the brakes are applied for greater control during roll-out. The brakes, developed by Dunlop, were the first carbon-based brakes used on an airliner. They could bring Concorde, weighing up to 185 tons (188 tonnes) and traveling at 190 miles per hour (310 km/h), to a stop from an aborted takeoff within one mile (1600 m). This braking manoeuvrings brought the brakes to temperatures of 300 °C to 500 °C, requiring several hours for cooling.

Another issue during the research for Concorde was the undercarriage. It turned out that the undercarriage had to be unusually strong. This was due to the unusual loadings due to the high angle of attack that Concorde needed during take-off, due to its delta-wing. This increased the weight and required a major redesign.

One interesting note about the main undercarriage is that if both were to just swing up to be stowed away they would hit each other and jam. The combined length of both undercarriages is greater than the distance between both undercarriage roots. This problem required that the undercarriage be first retracted vertically and then swung inwards to be tucked in the wing and fuselage belly.

Range

Concorde needed to travel between London and New York or Washington nonstop, and to achieve this the designers gave Concorde the greatest supersonic range of any aircraft. This was achieved by a combination of careful development of the engines to make them highly efficient at supersonic speeds, by very careful design of the wing shape to give a good lift to drag ratio, by having a modest payload and high fuel capacity, and by moving the fuel to trim the aircraft without introducing any additional drag.

Nevertheless, soon after Concorde began flying, a Concorde "B" model was designed with slightly larger fuel capacity and slightly larger wings with leading edge slats to improve aerodynamic performance at all speeds and featuring more powerful engines with sound deadening and without the fuel-hungry and noisy reheat. This would have given 500 km greater range even with greater payload, and would have opened up new commercial routes. This was cancelled due to poor sales of Concorde.

Increased radiation exposure

The high altitude at which Concorde cruised meant passengers received almost twice the flux of extraterrestrial ionising radiation as those travelling on a conventional long-haul flight. Due to the proportionally reduced flight time, however, the overall equivalent dose was less than a conventional flight over the same distance. Unusual solar activity led to an increase in incident radiation, so the flight deck had a radiometer and an instrument to measure the rate of decrease of radiation. If the level was too high, Concorde descended to below 47,000 feet (14,000 m). The rate of decrease indicator indicated whether the aircraft needed to descend further, decreasing the amount of time the aircraft was at an unsafe altitude.

Cabin pressurisation

Airliner cabins are usually pressurised to 6-8,000 ft (1,800-2,400 m) elevation while the aircraft flies much higher. Concorde's pressurisation was set to an altitude at the lower end of this range, 6,000 feet (1,800 m). Some passengers can have difficulty even with that pressurisation. A sudden reduction in cabin pressure is hazardous to all passengers and crew. Concorde's maximum cruising altitude was 60,000 feet (18,000 m) (though the typical altitude reached between London and New York was about 56,000 feet (17,000 m)); subsonic airliners typically cruise below 40,000 feet (12,000 m). Above 50,000 feet (15,000 m), the lack of air pressure would give a 'time of useful consciousness' in even a conditioned athlete to no more than 10–15 seconds. A cabin breach could even reduce air pressure to below the ambient pressure outside the aircraft due to the Venturi effect, as the air is sucked out through an opening. At Concorde's altitude, the air density is very low; a breach of cabin integrity would result in a loss of pressure severe enough so that the plastic emergency oxygen masks installed on other passenger jets would not be effective, and passengers would quickly suffer from hypoxia despite quickly donning them. Concorde, therefore, was equipped with smaller windows to reduce the rate of loss in the event of a breach, a reserve air supply system to augment cabin air pressure, and a rapid descent procedure to bring the aircraft to a safe altitude. The FAA enforces minimum emergency descent rates for aircraft and made note of Concorde's higher operating altitude, concluding that the best response to a loss of pressure would be a rapid descent. Pilots had access to CPAP (Continuous Positive Airway Pressure) which used masks that forced oxygen at higher pressure into the crew's lungs.

Droop nose

Concorde's famous drooping nose was a compromise between the need for a streamlined design to reduce drag and increase aerodynamic efficiency in flight and the need for the pilot to see properly during taxi, takeoff, and landing operations. A delta-wing aircraft takes off and lands with a high angle of attack (a high nose angle) compared to other wing planforms, due to the way the delta wing generates lift. The pointed nose would obstruct the pilots' view of taxiways and runways, so Concorde's nose was designed to allow for different positioning for different operations. The droop nose was accompanied by a moving visor that was retracted into the nose prior to the nose being lowered. When the nose was raised back to horizontal, the visor was raised ahead of the front cockpit windscreen for aerodynamic streamlining in flight.

A controller in the cockpit allowed the visor to be retracted and the nose to be lowered to 5° below the standard horizontal position for taxiing and takeoff. Following takeoff and after clearing the airport, the nose and visor were raised. Shortly before landing, the visor was again retracted and the nose lowered to 12.5° below horizontal for maximum visibility. Upon landing, the nose was quickly raised to the five-degree position to avoid the possibility of damage. On rare occasions, the aircraft could take off with the nose fully down.

A final possible position had the visor retracted into the nose but the nose in the standard horizontal position. This setup was used for cleaning the windscreen and for short subsonic flights.

The two prototype Concordes had two fixed "glass holes" on their retractable visors. The USA Federal Aviation Administration objected to that restrictive visibility and demanded a different design before it would permit Concorde to serve US airports, which led to the redesigned visor used on the production aircraft and the four "pre-production" aircraft (101, 102, 201, and 202).

Avionics

The avionics of Concorde were unique as it was the first commercial aircraft to employ hybrid microcircuits, these were a combination of discrete electronic components and laser-etched silicon microcircuits. These were produced at the Sperry manufacturing plant in Bracknell, Berkshire (this later became BAe dynamics group which remained in Bracknell until the plant closed in 1989).

Flight characteristics

While commercial jets take eight hours to fly from New York to Paris, the average supersonic flight time on the transatlantic routes was just under 3.5 hours. In transatlantic flight, Concorde travelled more than twice as fast as other aircraft — other aircraft frequently appeared to be flying backwards.

In regular service, Concorde employed an efficient cruise-climb flight profile. As aircraft lose weight from consuming fuel, they can fly at progressively higher altitudes. This is (generally) more efficient, so conventional airliners employ a stepped climb profile, where air traffic control will approve a change to a higher flight level as the flight progresses.

During a landing approach Concorde was on the "back side" of the drag force curve, where raising the nose would increase the sink rate. The delta-shaped wings allowed Concorde to attain a higher angle of attack than conventional aircraft, as it allowed the formation of large low pressure vortices over the entire upper wing surface, maintaining lift. This low pressure caused Concorde to disappear into a self-induced bank of fog on humid days. These vortices formed only at low air speeds, meaning that during the initial climb and throughout the approach Concorde experienced light turbulence and buffeting. Interestingly, the vortex lift created by Concorde's wing just prior to touchdown supplied its own mild turbulence.

With no other civil traffic operating at its cruising altitude of about 56,000 ft (17,000 m), dedicated oceanic airways or "tracks" were used by Concorde to cross the Atlantic. These SST, ("Super-Sonic Transport"), tracks were designated:

Due to the nature of high altitude winds, these SST tracks were fixed in terms of their co-ordinates, unlike the North Atlantic Tracks at lower altitudes whose co-ordinates alter daily according to forecast weather patterns. Concorde would also be cleared in a 15,000-foot (4,600 m) block, allowing for a slow climb from 45,000 to 60,000 ft (18,000 m) during the oceanic crossing as the fuel load gradually decreased.

Concorde actually flew fast enough that the weight of everyone onboard was temporarily reduced by about 1% when flying east. This was due to centrifugal effects since the airspeed added to the rotation speed of the Earth. Flying west, the weight increased by about 0.3%, because it cancelled out the normal rotation and, with it, the normal centrifugal force and replaced it with a smaller rotation in the opposite direction. Concorde flew high enough that the weight of everyone onboard was reduced by an additional 0.6% due to the increased distance from the centre of the Earth.

BA flights flown by Concorde added "Concorde" in addition to the standard "Speedbird" callsign to notify Air Traffic Control of the aircraft's unique abilities and restrictions. The flight numbers of BA's Concorde flights to/from the USA were 001–004; these BA Concordes therefore used callsigns "Speedbird Concorde 1" through to "Speedbird Concorde 4". The service to/from Barbados, special charter flights and test flights prior to a return to service following maintenance used the prefix "Speedbird Concorde" followed by the relevant four digit flight number. With the retirement of Concorde, the BA flight numbers 001 - 004 are now unused. Air France Concordes used the standard "Airfrans" callsign.

Operational history

When the U.S. ban on JFK Concorde operations was lifted in February 1977, New York banned Concorde locally. The ban came to an end on 17 October 1977 when the Supreme Court of the United States declined to overturn a lower court's ruling rejecting the Port Authority's efforts to continue the ban (The noise report noted that Air Force One, at the time a Boeing VC-137, was louder than Concorde at subsonic speeds and during takeoff and landing.). Scheduled service from Paris and London to New York's John F. Kennedy Airport began on 22 November 1977. Flights operated by BA were generally numbered "BA001" (London to New York), "BA002" (New York to London), "BA003" (London to New York) and "BA004" (New York to London). Air France flight numbers were generally "AF001" (New York to Paris) and "AF002" (Paris to New York).

In 1977, British Airways and Singapore Airlines shared a Concorde for flights between London and Singapore International Airport via Bahrain. The aircraft, BA's Concorde G-BOAD, was painted in Singapore Airlines livery on the port side and British Airways livery on the starboard side. The service was discontinued after three return flights because of noise complaints from the Malaysian government; it could only be reinstated on a new route bypassing Malaysian airspace in 1979. A dispute with India prevented Concorde from reaching supersonic speeds in Indian airspace, so the route was eventually declared not viable and discontinued in 1980. During the Mexican oil boom, Air France flew Concorde twice-weekly to Mexico City's Benito Juárez International Airport via Washington, DC or New York City, from September 1978 to November 1982. The worldwide economic crisis during that period resulted in this route's cancellation; the last flights were almost empty. The routing between Washington or New York and Mexico City included a deceleration, from Mach 2.02 to Mach 0.95, to cross Florida subsonically and avoid unlawfully sonic-booming it; then a reacceleration to cross the Gulf of Mexico at Mach 2.02. British Airways later implemented this new routing on 1 April 1989, with G-BOAF, on an Around-The-World luxury tour charter. From time to time, Concorde came back to the region on similar chartered flights to Mexico City and Acapulco.

From 1978 to 1980, Braniff International Airways leased 10 Concordes, five each from Air France and British Airways. These were used on subsonic flights between Dallas-Fort Worth and Washington Dulles International Airport, flown by Braniff flight crews. Air France and British Airways crews then took over for the continuing supersonic flights to London and Paris. The aircraft were registered in both the United States and their home countries: a sticker covered up the European registration for the few hours it was being operated by Braniff, retaining the AF/BA full colour schemes. The flights were not profitable and were usually less than 50% booked, which forced Braniff to end its tenure as the only U.S. Concorde operator in May 1980.

By around 1981 in the UK, the future for Concorde looked bleak. British government had lost money operating Concorde every year, and moves were afoot to cancel the service entirely. A cost projection came back with greatly reduced metallurgical testing costs, as the test rig for the wings had built up enough data to last for 30 years and could be shut down, but still, having lost money for so many years, the government was not keen to continue. In late 1983, the managing director of BA, Sir John King, managed to get the government to sell the aircraft outright to (the then state owned, later privatised) BA for £16.5 million plus the first year's profits.

After doing a market survey and discovering that their target customers thought that Concorde was more expensive than it actually was, BA progressively raised prices to match these perceptions. It is reported that BA then ran Concorde at a profit, unlike their French counterparts. The plane was reckoned to make an operating profit for British Airways. BA's profits have been reported to be up to £50 million in the most profitable year, with a total revenue of £1.75 billion, before costs of £1 billion.

Between 1984 and 1991, British Airways flew a thrice-weekly Concorde service between London and Miami, stopping at Washington's Dulles International Airport. The routing from Dulles to Miami was flown subsonically as far as Carolina Beach VOR; then there was a very rapid climb to 60,000 ft (estimated at 6,000 ft (1,800 m) per minute) and Mach 2.02 that was possible due to the aircraft's very light weight: an average of only about 25-30 passengers and fuel only for the short Dulles-Miami sector. After about 6-8 minutes at Mach 2.02, deceleration and descent was begun into Miami. On several occasions, bad weather at Dulles and a light passenger payload out of Miami enabled nonstop Miami-London sectors to be flown. The fastest such flight took just 3 hours 47 minutes to fly over 4,000 nautical miles (7,400 km) from Miami to London, with 70 passengers. On such trips, the flight plan was filed to Shannon, Ireland, with en route re-clearance on to London secured later in the flight after the minimum required fuel for London was clearly present. This flight was farther than a sector often claimed as the farthest ever flown nonstop by Concorde: a special charter for Middle Eastern VIPs from Washington to Nice, France.

Concorde G-BOAF. The final flight of Concorde landing at Filton Airfield, near Bristol, on 26 November 2003.

Up to 2003, Air France and British Airways continued to operate the New York services daily. Concorde also flew to Barbados's Grantley Adams International Airport during the winter holiday season. Until the AF Paris crash ended virtually all charter services by both AF and BA, several UK and French tour operators operated numerous charter flights to various European destinations on a regular basis.

Paris crash

On 25 July 2000, Air France Flight 4590, registration F-BTSC, crashed in Gonesse, France, killing all 100 passengers and nine crew on board the flight, and four people on the ground. It was the only fatal incident involving the type.

According to the official investigation conducted by the French accident investigation bureau (BEA), the crash was caused by a titanium strip, part of a thrust reverser, that fell from a Continental Airlines DC-10 that had taken off about four minutes earlier. This metal fragment punctured a tyre on the left main wheel bogie. The tyre exploded, and a piece of rubber hit the fuel tank and broke an electrical cable. The impact caused a hydrodynamic shockwave that fractured the fuel tank some distance from the point of impact. This caused a major fuel leak from the tank, which then ignited due to severed electrical wires which were sparking. The crew shut down engine number 2 in response to a fire warning but were unable to retract the landing gear, hampering the aircraft's climb. With engine number 1 surging and producing little power, the aircraft was unable to gain height or speed, entering a rapid pitch-up then a violent descent, rolling left. The impact occurred with the stricken aircraft tail-low, crashing into the Hotelissimo Hotel in Gonesse.

Others have disputed the BEA report, citing evidence that the Air France Concorde was overweight, had unbalanced distribution in the fuel tanks, and lacked a critical spacer in the landing gear which caused it to veer. They came to the conclusion that the aircraft veered off course on the runway, which reduced take-off speed below the crucial minimum.

Prior to the accident, Concorde had been arguably the safest operational passenger airliner in the world in terms of passenger deaths-per-kilometres travelled with zero. After the accident, the death rate was 12.5 fatal events per million flights, more than three times that of the second worst aircraft. However, no aircraft's safety can be accurately measured from a single incident, and safety improvements were made in the wake of the crash. The crash of the Air France Concorde nonetheless proved to be the beginning of the end for the type.

The accident led to modifications, including more secure electrical controls, Kevlar lining to the fuel tanks and specially-developed burst-resistant tyres. In July 2008, a French prosecutor filed involuntary manslaughter charges against Continental Airlines and five persons, and a judge ordered them to stand trial. The defendants include two Continental employees, two employees of Aerospatiale and an employee of the French civil aviation authority. A Continental spokesman called the charges "outrageous". The trial, which is still pending, has been postponed several times.

Return to service

The first test flight after the modifications departed from London Heathrow on 17 July 2001, piloted by BA Chief Concorde Pilot Mike Bannister. During the 3:20 hr flight over the mid-Atlantic towards Iceland, Bannister attained Mach 2.02 and 60,000 ft (18,000 m) before returning to RAF Brize Norton. The test flight, intended to resemble the London-New York route, was declared a success and was watched on live TV, and by crowds on the ground at both locations.

Another BA assessment flight carrying passengers took place on 11 September 2001, and was in the air during the September 11, 2001 attacks in the United States. This was not a revenue flight, as all the passengers were BA employees.

Normal commercial operations resumed on 7 November 2001 by BA and AF (aircraft G-BOAE and F-BTSD), with service to New York JFK, where passengers were welcomed by then-mayor Rudy Giuliani.

Retirement

On 10 April 2003, Air France and British Airways simultaneously announced that they would retire Concorde later that year. They cited low passenger numbers following the 25 July 2000 crash, the slump in air travel following the September 11 attacks and rising maintenance costs.

That same day, Sir Richard Branson offered to buy British Airways' Concorde fleet at their "original price of £1" for service with his Virgin Atlantic Airways. Branson claimed this to be the same token price that British Airways had paid the British Government, but BA denied this and refused the offer. The real cost of buying the aircraft was £26 million each but the money for buying the aircraft was lent by the government (which in turn took 80% of the profits). Subsequently BA bought two aircraft for a book value of £1 as part of the £16.5 million buy out in 1983.

Branson wrote in The Economist (23 October 2003) that his final offer was "over £5 million" and that he had intended to operate the fleet "for many years to come." Any hope of Concorde remaining in service was further thwarted by Airbus' unwillingness to provide maintenance support for the ageing airframes.

It has been suggested that Concorde was not withdrawn for the reasons usually given, but that during the grounding of Concorde it became apparent to the airlines that they could actually make more revenue carrying their first class passengers subsonically.

Rob Lewis suggested that the precipitous Air France retirement of its own Concorde fleet was the direct result of a secret conspiracy between Air France Chairman/CEO Jean-Cyril Spinetta and then-AIRBUS CEO Noel Forgeard, and stemmed as much from a fear of being found criminally liable under French law for future AF Concorde accidents as it did from simple economics. Further, on the British Airways side, a lack of engineering (maintenance) commitment to Concorde by then-Director of Engineering Alan MacDonald was cited as undermining BA's resolve to continue operating Concorde from within.

Air France

Air France made its final commercial Concorde landing in the United States in New York City from Paris on 30 May 2003. Fire trucks sprayed the traditional arcs of water above F-BTSD on the tarmac of John F. Kennedy airport. The final passenger flight for the airline's SSTs was a charter around the Bay of Biscay. During the following week, on 2 June and 3 June 2003, F-BTSD flew a final round-trip from Paris to New York and back for airline staff and long-time employees in the airline's Concorde operations. Air France's final Concorde flight took place on 27 June 2003 when F-BVFC retired to Toulouse.

An auction of Concorde parts and memorabilia for Air France was held at Christie's in Paris on 15 November 2003. Thirteen hundred people attended, with several lots exceeding their predicted values by an order of magnitude.

After the end-of-service, French Concorde F-BVFC was retired to Toulouse, and kept functional (including engine runs) for a short while, in case taxi runs were required in support of the French judicial enquiry into the 2000 crash. The aircraft is now fully retired and no longer functional. It is open to the public.

French Concorde F-BTSD has been retired to the "Musée de l'Air et de l'Espace" at Le Bourget (near Paris) and, unlike the other museum Concordes, a few of the systems are being kept functional, so that for instance the famous "droop nose" can still be lowered and raised.

This led to rumours that they could be prepared for future flights for special occasions. Without the necessary maintenance organisation, or spares, this is no longer possible.

British Airways

Concorde (G-BOAC) at the Manchester International Airport Aviation Viewing Park

In a final week of farewell flights around the United Kingdom, Concorde visited Birmingham on 20 October, Belfast on 21 October, Manchester on 22 October, Cardiff on 23 October, and Edinburgh on 24 October. Each day the aircraft made a return flight out and back into Heathrow to the cities concerned, often overflying those cities at low altitude. Over 650 competition winners and 350 special guests were carried.

On 22 October, Heathrow ATC arranged for the inbound flight BA9021C, a special from Manchester, and BA002 from New York to land simultaneously on the left and right runways respectively.

On the evening of 23 October 2003, the Queen consented to the illumination of Windsor Castle as Concorde's last west-bound commercial flight departed London and flew overhead. This is an honour normally reserved for major state events and visiting dignitaries.

British Airways retired its aircraft the next day, 24 October. G-BOAG left New York to a fanfare similar to that given for Air France's "F-BTSD", while two more made round trips, G-BOAF over the Bay of Biscay, carrying VIP guests including many former Concorde pilots, and G-BOAE to Edinburgh. The three aircraft then circled over London, having received special permission to fly at low altitude, before landing in sequence at Heathrow. The two round-trip aircraft landed at 4:01 and 4:03 p.m. BST, followed at 4:05 by the one from New York. All three aircraft then spent 45 minutes taxiing around the airport before finally disembarking the last supersonic fare-paying passengers. The captain of the New York to London flight was Mike Bannister.

All of BA's Concorde fleet have been grounded, have lost their airworthiness certificates and have been drained of hydraulic fluid. Ex-chief Concorde pilot and manager of the fleet, Jock Lowe, estimated in 2004 it would cost £10-15 million to make G-BOAF (at Filton) airworthy again. BA maintains ownership of their fleet, and has stated that they will not fly again, as Airbus ended support of the aircraft in 2003.

On 1 December 2003, Bonhams held an auction of British Airways' Concorde artifacts at Kensington Olympia, in London. Items sold included a Machmeter, nose cone, pilot and passenger seats, cutlery, ashtrays and blankets used on board. Proceeds of about £750,000 resulted, with the first half-million going to Get Kids Going!, a charity which gives disabled children and young people the opportunity to participate in sport.

BA announced in March 2007 that they would not be renewing their contract for the prime advertising spot at entrance to London's Heathrow Airport, where, since 1990, a 40% scale model of Concorde was located. BAA, the owners of the site, wanted to charge £1.6 million per year to let it. The Concorde model was removed and transported for display in Surrey, under the care of the local Brooklands Museum.

Restoration

A dedicated group of French volunteer engineers is keeping one of the youngest Concordes (F-BTSD) in near-airworthy condition at the Le Bourget Air and Space Museum in Paris.

Although only a "static" example, Concorde G-BBDG was restored from essentially a shell at the Brooklands Museum in Surrey.

Environmental impact

Prior to Concorde's flight trials, the developments made by the civil aviation industry were largely accepted by governments and their respective electorates. However, the opposition to Concorde's noise, particularly on the eastern coast of the United States, forged a new political agenda on both sides of the Atlantic, with scientists and technology experts across a multitude of industries beginning to take the environmental and social impact more seriously. Although Concorde led directly to the introduction of a general noise abatement programme for aircraft flying out of John F Kennedy Airport, it was later found that Concorde was actually quieter than some aircraft, partly due to the pilots temporarily throttling back their engines to reduce noise during overflight of residential areas.

Concorde produced nitrogen oxides in its exhaust, which, despite complicated chemical interactions with other ozone-depleting chemicals, are understood to produce a net degradation to the ozone layer at the stratospheric altitudes it cruised. It has been pointed out that other, lower-flying, airliners produce ozone during their flights in the troposphere, but vertical transit of gases between the two is highly restricted. The small fleet size meant that any net ozone-layer degradation caused by Concorde was for all practical purposes negligible.

From this perspective, Concorde's technical leap forward can be viewed as boosting the public's (and the media's) understanding of conflicts between technology and the environment. In France, the use of acoustic fencing alongside TGV tracks might not have been achieved without the 1970s controversy over aircraft noise. In Britain, the CPRE have issued tranquillity maps since 1990 and public agencies are starting to do likewise.

Concorde travelled, per passenger, 17 miles (27 km) for each imperial gallon of fuel — 17 miles per imperial gallon (17 L/100 km; 14 mpg_-US). This efficiency is comparable to a Gulfstream G550 business jet (16 miles per US gallon (15 L/100 km; 19 mpg_-imp) per passenger), but much less efficient than a Boeing 747-400 (91 miles per US gallon (2.6 L/100 km; 109 mpg_-imp) per passenger).

Records

Concorde was the more successful of the only two supersonic airliners to have ever operated commercially, the Tupolev Tu-144 being the other. The Tu-144 was nicknamed "Concordski" by Western Europeans for its outward similarity to Concorde. Soviet espionage efforts had resulted in the theft of Concorde blueprints, ostensibly to assist in the design of the Tu-144. The Tu-144 ultimately flew first, achieved a higher maximum speed, but was hampered by higher fuel requirements that restricted its range compared to Concorde.

The fastest transatlantic flight was from London Heathrow to New York JFK on the 7th of February 1996 on a (British Airways) G-BOAD in 2hrs 52mins and 59secs from take off to touch down.

Concorde also set many other records, including the official FAI "Westbound Around the World" and "Eastbound Around the World" world air speed records. On 12-13 October 1992, in commemoration of the 500th anniversary of Columbus' first New World landing, Concorde Spirit Tours (USA) chartered Air France Concorde F-BTSD and circumnavigated the world in 32 hours 49 minutes and 3 seconds, from Lisbon, Portugal, including six refuelling stops at Santo Domingo, Acapulco, Honolulu, Guam, Bangkok and Bahrain.

The Eastbound record was set by the same Air France Concorde F-BTSD under charter to Concorde Spirit Tours (USA), on 15-16 August 1995. This special promotional flight circumnavigated the world from New York/JFK International Airport in a time of 31 hours 27 minutes 49 seconds, including six refuelling stops at Toulouse, Dubai, Bangkok, Andersen AFB (Guam), Honolulu and Acapulco. Concorde continues to hold both records.

By its 30th flight anniversary on 2 March 1999 Concorde had clocked up 920,000 flight hours, with more than 600,000 supersonic, much more than all of the other supersonic aircraft put together in the Western world.

Public perception

Concorde was normally perceived as a privilege of the rich, but special circular or one-way (with return by coach or ship) charter flights were arranged to bring a trip within the means of moderately well-off enthusiasts.

The presence of a Concorde flying overhead would frequently temporarily halt day-to-day business as people would stop to watch as the plane flew by. A noteworthy example can be found in the TV programme Scrapheap Challenge, where the mechanics drop all their tools and wave as Concorde flies over the yard.

The aircraft was usually referred to by the British as simply "Concorde", whilst in France it was known as "le Concorde" due to "le", the definite article, being used in French grammar to distinguish a proper name from a common noun of the same spelling. In French, the common noun concorde means "agreement, harmony, or peace" and the aircraft's name was almost certainly chosen for its allusion to the collaboration between the British and French governments. Concorde's pilots and British Airways in official publications and videos often refer to Concorde both in the singular and plural as "she" or "her."

Concorde remains a powerful symbol, both for its technology and sculptural shape. It is a symbol of great national pride to many in Britain and France; in France it was thought of as a French aircraft, in Britain as British.

As a symbol of national pride, an example from the BA fleet made occasional flypasts at selected Royal events, major air shows and other special occasions, sometimes in formation with the Red Arrows. On the final day of commercial service, public interest was so great that grandstands were erected at London's Heathrow Airport to afford a view of the final arrivals. Crowds filled the boundary road around the airport and there was extensive media coverage.

Comparison with other supersonic aircraft

The only other supersonic airliner in direct competition with Concorde was the Soviet Tupolev Tu-144. It entered service earlier, and was retired in 1978. Lockheed, North American Aviation and Boeing prepared supersonic airliner studies, but only the Boeing 2707 proceeded even to the mock-up stage, the sole American entry into the supersonic transport sweepstakes.

As a result of a rushed development programme, the first prototype of the Tu-144 was substantially different from the preproduction machines, and even these were cruder and less refined than Concorde, with notably higher cabin noise. The Tu-144S had a significantly smaller range than Concorde, largely due to its low-bypass turbofan engines. It required reheat to maintain Mach 2.0 and cruised at Mach 1.6. The vehicle had poor control at low speeds because of a simpler, dedicated supersonic wing design. In addition, the Tu-144 required parachutes to land while Concorde had sophisticated anti-lock brakes. The Tu-144 also had two crashes, one at the 1973 Paris Air Show, which made further sales impossible, and another during a pre-delivery test flight. Later production versions had retractable canards for better low speed control, and a research version used turbojet engines that gave them nearly the fuel efficiency and similar range to Concorde. It had 126 seats. With a top speed of Mach 2.35 (made possible due to titanium and steel leading edges) and a cruise of Mach 2.16 it was potentially a more competitive aircraft, but it did not sell.

The American designs (Boeing 2707 and Lockheed L-2000) were to have been larger, seating 300. They were also intended to reach higher speeds of up to Mach 3.0, which would have made the construction more difficult: high temperatures ruled out the use of duralumin with design calculations that showed that the extra speed would have only cut Concorde's transatlantic travel by 20 minutes. Running a few years behind Concorde, the winning Boeing 2707 was redesigned to a cropped delta layout; the extra cost of these changes helped to kill the project. The discovery from flights of the XB-70 Valkyrie that sonic booms were quite capable of reaching the ground and the experience from the Oklahoma City sonic boom tests debacle led to the same environmental concerns that contributed to hindering commercial success of Concorde. The American government cancelled the project in 1971, after having spent more than $1 billion.

The only other large supersonic aircraft comparable to Concorde are strategic bombers, principally the Russian Tupolev Tu-22/Tu-22M and Tu-160 and the American B-1B Lancer; only the Russian designs are capable of sustained Mach 2 flight and none of these aircraft are designed for extended supersonic flight like Concorde.

Possible replacements

In November 2003, EADS, parent company of the Airbus aircraft manufacturing company, announced that it was considering working with Japanese companies to develop a larger, faster replacement for Concorde. However, recent news reports suggest only $1m is being invested every year into research, much less than the $1bn needed for the development of a viable supersonic airliner.

In October 2005, JAXA, the Japan Aerospace eXploration Agency, undertook aerodynamic testing of a scale model of an airliner designed to carry 300 passengers at Mach 2 (working name NEXST). If pursued to commercial deployment, it would be expected to be in service around 2020 - 2025.

The British company Reaction Engines Limited, with 50% EU money, are engaged in a research programme called LAPCAT, which is examining a design for a hydrogen-fuelled plane carrying 300 passengers called the A2, capable of flying nonstop from Brussels to Sydney at Mach 5+ in 4.6 hours.

Operators

Specifications

Popular culture

Concorde has numerous appearances in various media. Particularly notable or extended appearances include the following.