Concorde informations and photos

The Aérospatiale/BAC Concorde (/ˈkɒŋkɔːrd/) is a Franco-British turbojet-powered supersonic airliner that was operated from 1976 until 2003. It had a maximum speed over twice the speed of sound, at Mach 2.04 (1,354 mph or 2,180 km/h at cruise altitude), with seating for 92 to 128 passengers. First flown in 1969, Concorde entered service in 1976 and operated for 27 years. It is one of only two supersonic jetliner models to operate commercially; the other is the Soviet-built Tupolev Tu-144, which operated in the late 1970s.

Concorde was jointly developed and manufactured by Sud Aviation (later Aérospatiale) and the British Aircraft Corporation under an Anglo-French treaty. Twenty aircraft were built, including six prototypes and development aircraft. Air France and British Airways were the only airlines to purchase and fly Concorde. The aircraft was used mainly by wealthy passengers who could afford to pay a high price for the aircraft's speed and luxury service. In 1997, the round-trip ticket price from New York to London was $7,995 (equivalent to $12,900 in 2020), more than 30 times the cost of the least expensive scheduled flight for this route.[page needed]

The original programme cost estimate was £70 million before 1962, (£1.39 billion in 2020). The programme experienced huge cost overruns and delays, with the programme eventually costing between £1.5 and £2.1 billion in 1976, (£9.44 billion-13.2 billion in 2020). This extreme cost was the main reason the production run was much smaller than expected. Another factor that affected the viability of all supersonic transport programmes was that supersonic flight could be used only on ocean-crossing routes, to prevent sonic boom disturbance over populated areas. With only seven airframes each being operated by the British and French, the per-unit cost was impossible to recoup, so the French and British governments absorbed the development costs. British Airways and Air France were able to operate Concorde at a profit after purchasing their aircraft from their respective governments at a steep discount in comparison to the programme's development and procurement costs.

Among other destinations, Concorde flew regular transatlantic flights from London's Heathrow Airport and Paris's Charles de Gaulle Airport to John F. Kennedy International Airport in New York, Washington Dulles International Airport in Virginia, and Grantley Adams International Airport in Barbados; it flew these routes in less than half the time of other airliners. While subsonic commercial jets took eight hours to fly from Paris to New York (seven hours from New York to Paris), the average supersonic flight time on the transatlantic routes was just under 3.5 hours.

Concorde aircraft were retired in 2003, three years after the crash of Air France Flight 4590, in which all passengers and crew members on board were killed; this was the only fatal incident involving Concorde. The general downturn in the commercial aviation industry after the September 11 attacks in 2001 and the end of maintenance support for Concorde by Airbus, the successor to Aérospatiale, contributed to the aircraft's retirement.

The origins of the Concorde project date to the early 1950s, when Arnold Hall, director of the Royal Aircraft Establishment (RAE), asked Morien Morgan to form a committee to study the supersonic transport (SST) concept. The group met for the first time in February 1954 and delivered their first report in April 1955.

At the time it was known that the drag at supersonic speeds was strongly related to the span of the wing.[N 1] This led to the use of short-span, thin trapezoidal wings such as those seen on the control surfaces of many missiles, or in aircraft such as the Lockheed F-104 Starfighter or the Avro 730 that the team studied. The team outlined a baseline configuration that resembled an enlarged Avro 730.

This same short span produced very little lift at low speed, which resulted in extremely long take-off runs and frighteningly high landing speeds. In an SST design, this would have required enormous engine power to lift off from existing runways, and to provide the fuel needed, "some horribly large aeroplanes" resulted. Based on this, the group considered the concept of an SST infeasible, and instead suggested continued low-level studies into supersonic aerodynamics.

Soon after, Johanna Weber and Dietrich Küchemann at the RAE published a series of reports on a new wing planform, known in the UK as the "slender delta" concept. The team, including Eric Maskell whose report "Flow Separation in Three Dimensions" contributed to an understanding of the physical nature of separated flow, worked with the fact that delta wings can produce strong vortices on their upper surfaces at high angles of attack. The vortex will lower the air pressure and cause lift to be greatly increased. This effect had been noticed earlier, notably by Chuck Yeager in the Convair XF-92, but its qualities had not been fully appreciated. Weber suggested that this was no mere curiosity, and the effect could be used deliberately to improve low speed performance.

Küchemann's and Weber's papers changed the entire nature of supersonic design almost overnight. Although the delta had already been used on aircraft prior to this point, these designs used planforms that were not much different from a swept wing of the same span.[N 2] Weber noted that the lift from the vortex was increased by the length of the wing it had to operate over, which suggested that the effect would be maximised by extending the wing along the fuselage as far as possible. Such a layout would still have good supersonic performance inherent to the short span, while also offering reasonable take-off and landing speeds using vortex generation. The only downside to such a design is that the aircraft would have to take off and land very "nose high" to generate the required vortex lift, which led to questions about the low speed handling qualities of such a design. It would also need to have long landing gear to produce the required angle of attack while still on the runway.

Küchemann presented the idea at a meeting where Morgan was also present. Test pilot Eric Brown recalls Morgan's reaction to the presentation, saying that he immediately seized on it as the solution to the SST problem. Brown considers this moment as being the true birth of the Concorde project.

On 1 October 1956 the Ministry of Supply asked Morgan to form a new study group, the Supersonic Transport Aircraft Committee (STAC) (sometimes referred to as the Supersonic Transport Advisory Committee), with the explicit goal of developing a practical SST design and finding industry partners to build it. At the first meeting, on 5 November 1956, the decision was made to fund the development of a test bed aircraft to examine the low-speed performance of the slender delta, a contract that eventually produced the Handley Page HP.115. This aircraft would ultimately demonstrate safe control at speeds as low as 69 mph (111 km/h), about .mw-parser-output .sfrac{white-space:nowrap}.mw-parser-output .sfrac.tion,.mw-parser-output .sfrac .tion{display:inline-block;vertical-align:-0.5em;font-size:85%;text-align:center}.mw-parser-output .sfrac .num,.mw-parser-output .sfrac .den{display:block;line-height:1em;margin:0 0.1em}.mw-parser-output .sfrac .den{border-top:1px solid}.mw-parser-output .sr-only{border:0;clip:rect(0,0,0,0);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute;width:1px}1/3 that of the F-104 Starfighter.

STAC stated that an SST would have economic performance similar to existing subsonic types. Although they would burn more fuel in cruise, they would be able to fly more sorties in a given period of time, so fewer aircraft would be needed to service a particular route. This would remain economically advantageous as long as fuel represented a small percentage of operational costs, as it did at the time.

STAC suggested that two designs naturally fell out of their work, a transatlantic model flying at about Mach 2, and a shorter-range version flying at Mach 1.2 perhaps. Morgan suggested that a 150-passenger transatlantic SST would cost about £75 to £90 million to develop, and be in service in 1970. The smaller 100 passenger short-range version would cost perhaps £50 to £80 million, and be ready for service in 1968. To meet this schedule, development would need to begin in 1960, with production contracts let in 1962. Morgan strongly suggested that the U.S. was already involved in a similar project, and that if the UK failed to respond it would be locked out of an airliner market that he believed would be dominated by SST aircraft.

In 1959, a study contract was awarded to Hawker Siddeley and Bristol for preliminary designs based on the slender delta concept, which developed as the HSA.1000 and Bristol 198. Armstrong Whitworth also responded with an internal design, the M-Wing, for the lower-speed shorter-range category. Even at this early time, both the STAC group and the government were looking for partners to develop the designs. In September 1959, Hawker approached Lockheed, and after the creation of British Aircraft Corporation in 1960, the former Bristol team immediately started talks with Boeing, General Dynamics, Douglas Aircraft, and Sud Aviation.

Küchemann and others at the RAE continued their work on the slender delta throughout this period, considering three basic shapes; the classic straight-edge delta, the "gothic delta" that was rounded outward to appear like a gothic arch, and the "ogival wing" that was compound-rounded into the shape of an ogee. Each of these planforms had its own advantages and disadvantages in terms of aerodynamics. As they worked with these shapes, a practical concern grew to become so important that it forced selection of one of these designs.

Generally one wants to have the wing's centre of pressure (CP, or "lift point") close to the aircraft's centre of gravity (CG, or "balance point") to reduce the amount of control force required to pitch the aircraft. As the aircraft layout changes during the design phase, it is common for the CG to move fore or aft. With a normal wing design this can be addressed by moving the wing slightly fore or aft to account for this.[N 3] With a delta wing running most of the length of the fuselage, this was no longer easy; moving the wing would leave it in front of the nose or behind the tail. Studying the various layouts in terms of CG changes, both during design and changes due to fuel use during flight, the ogee planform immediately came to the fore.

While the wing planform was evolving, so was the basic SST concept. Bristol's original Type 198 was a small design with an almost pure slender delta wing, but evolved into the larger Type 223.

To test the new wing, NASA privately assisted the team by modifying a Douglas F5D Skylancer with temporary wing modifications to mimic the wing selection. In 1965 the NASA test aircraft successfully tested the wing, and found that it reduced landing speeds noticeably over the standard delta wing. NASA Ames test center also ran simulations that showed the aircraft would suffer a sudden change in pitch when entering ground effect. Ames test pilots later participated in a joint cooperative test with the French and British test pilots and found that the simulations had been correct, and this information was added to pilot training.

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