Airbus A340

Development

Background

When Airbus designed the Airbus A300 during the 1970s it envisioned a broad family of airliners to compete against Boeing and McDonnell Douglas, two established US aerospace manufacturers. From the moment of formation, Airbus had begun studies into derivatives of the Airbus A300B in support of this long-term goal. Prior to the service introduction of the first Airbus airliners, Airbus had identified nine possible variations of the A300 known as A300B1 to B9. A tenth variation, conceived in 1973, later the first to be constructed, was designated the A300B10. It was a smaller aircraft that would be developed into the long-range Airbus A310. Airbus then focused its efforts on the single-aisle market, which resulted in the Airbus A320 family, which was the first digital fly-by-wire commercial aircraft. The decision to work on the A320, instead of a four-engine aircraft proposed by the Germans, created divisions within Airbus. As the SA or "single aisle" studies (which later became the successful Airbus A320) underwent development to challenge the successful Boeing 737 and Douglas DC-9 in the single-aisle, narrow-body airliner market, Airbus turned its focus back to the wide-body aircraft market.

The A300B11, a derivative of the A310, was designed upon the availability of "ten ton" thrust engines. Using four engines, it would seat between 180 and 200 passengers, and have a range of 6,000 nautical miles (11,000 km; 6,900 mi). It was deemed a replacement for the less-efficient Boeing 707s and Douglas DC-8s still in service. The A300B11 was joined by another design, the A300B9, which was a larger derivative of the A300. The B9 was developed by Airbus from the early 1970s at a slow pace until the early 1980s. It was essentially a stretched A300 with the same wing, coupled with the most powerful turbofan engine available at the time. It was targeted at the growing demand for high-capacity, medium-range, transcontinental trunk routes. The B9 offered the same range and payload as the McDonnell Douglas DC-10, but it used between 25% and 38% less fuel. The B9 was therefore considered a replacement for the DC-10 and the Lockheed L-1011 Tristar.

To differentiate the programme from the SA studies, the B9 and B11 were redesignated the TA9 and TA11 (SA standing for "single aisle" and TA standing for "twin aisle"). In an effort to save development costs, it was decided that the two would share the same wing and airframe; the projected savings were estimated at US$500 million (about £490 million or €495 million). The adoption of a common wing structure also had one technical advantage: the TA11's outboard engines could counteract the weight of the longer-range model by providing bending relief. Another factor was the split preference of those within Airbus and, more importantly, prospective airliner customers. Airbus vice president for strategic planning, Adam Brown, recalled,

North American operators were clearly in favour of a twin[jet], while Asians wanted a quad[jet]. In Europe, opinion was split between the two. The majority of potential customers were in favour of a quad despite the fact, in certain conditions, it is more costly to operate than a twin. They liked that it could be ferried with one engine out, and could fly 'anywhere'— ETOPS (extend-range twin-engine operations) hadn't begun then.

Design effort

The first specifications of the TA9 and TA11 were released in 1982. While the TA9 had a range of 3,300 nautical miles (6,100 km; 3,800 mi), the TA11 range was up to 6,830 nautical miles (12,650 km; 7,860 mi). At the same time, Airbus also sketched the TA12, a twin-engine derivative of the TA11, which was optimised for flights of a 2,000 nautical miles (3,700 km; 2,300 mi) lesser range. By the time of the Paris Air Show in June 1985, more refinements had been made to the TA9 and TA11, including the adoption of the A320 flight deck, fly-by-wire (FBW) flight control system and side-stick control. Adopting a common cockpit across the new Airbus series allowed operators to make significant cost savings; flight crews would be able to transition from one to another after one week of training. The TA11 and TA12 would use the front and rear fuselage sections of the A310. Components were modular and also interchangeable with other Airbus aircraft where possible to reduce production, maintenance, and operating costs.

Airbus briefly considered a variable camber wing; the concept was that the wing could change its profile to produce the optimum shape for a given phase of flight. Studies were carried out by British Aerospace (BAe) at Hatfield and Bristol. Airbus estimated this would yield a 2% improvement in aerodynamic efficiency. However, the plan was later abandoned on grounds of cost and difficulty of development.

Airbus had held discussions with McDonnell Douglas to jointly produce the aircraft, which would have been designated as the AM 300. This aeroplane would have combined the wing of the A330 with the fuselage of the McDonnell Douglas MD-11. However, talks were terminated as McDonnell Douglas insisted on the continuation of its trijet heritage.