AIRCRAFT
The Airbus A340 is a long-range four-engined widebody commercial passenger airplane. It is very similar in design to the two-engined A330, it is in fact a four-engined version of the same basic concept.
The first published studies for the A340 were as the TA11 (TA for Twin Aisle) in 1981, in the November issue of Air International (coinciding with the display of the A300 at that year's Farnborough Air Show). Concept drawings of the A320 (SA 9) and A330 (TA9) were also published, along with the performance figures expected by Airbus.
The new aircraft was launched in June 1987 as a long-range complement to the short-range A320 and the medium-range A300. At the time, Airbus's twinjets were at a disadvantage against aircraft such as the Boeing 747 because of the ETOPS (Extended-range Twin-engine Operation Performance Standards) problem: two-engined aircraft had to stay within close range of emergency airfields in case one of their engines malfunctioned.
Airbus' engineers designed the A340 in parallel with the twin-engine A330, which was also launched in June 1987: both aircraft share a similar fuselage structure derived from the A300, and basically have the same new wing. Only small aerodynamic differences are necessary to allow for the difference in the number of engines, and the structure is also identical except for some differences in skin thickness and the engine attachments.
The wing is of advanced design with a very high aspect ratio (= length divided by width). It is also notable for its use of variable camber, using an on-board computer to tailor the camber through small movements of the trailing edge flaps to suit the weight, speed and altitude at which the aircraft is flying.
Although the A340 operates at slightly higher weights than the A330, wing bending moments are similar because of the extra relief provided by the weight of the outside engines. Additionally, the lighter, shorter-range A330 needs as much strength as the A340 because it makes more fatigue-inducing flights in a given number of hours.
Both models use the same carbon-fiber reinforced plastic (CFRP) fins as the A310, and a CFRP tailplane trim-tank as in the A310-300. Cockpit and systems are based on those of the A320, with a computerized fly-by-wire flight control system, and an advanced EFIS (Electronic Flight Instrument System) flightdeck. Instead of normal control columns, there are two sidestick controllers, one to the left of the pilot, and one to the right of the co-pilot. The cockpit also features CRT-based glass cockpit displays on the A340-200 and A340-300 and LCD-based ones on the -500 and -600 (these latter two versions were launched in 1997 and entered service in 2002. They are described separately).
The original intention was to use the new superfan engines of IAE (International Aero Engines) in the A340 but IAE decided to stop their development and the CFMI CFM56-5C4 was used instead.
The four engine configuration, as well as providing ETOPS-immunity (Virgin Atlantic Airways used the slogan "4 Engines 4 The Long Haul" for its A340 fleet), is more efficient for long range flights for another reason too: twins need more power for a given weight in order to ensure adequate engine-out-on-takeoff performance.
The A340-300 has the same fuselage length (63.65 m) as the A330-300, while the shortened A340-200 (59.39 m) trades seating capacity for greater range: 7,340 nm (13,600 km) with a standard 305 passenger load for the -200, against 6,640 nm (12,300 km) with 335 passengers for the -300, or 6,700 nm (12,400 km) with 295 passengers in a typical three-class cabin layout.
Final assembly of both the A340 model range and the A330 model range is undertaken by EADS Aérospatiale in Toulouse, France, and the two models share a common pilot rating, which is also shared with the rest of the Airbus range.
When the A340 (a -300) first flew on October 25, 1991, engineers noticed a major problem: the wings were not strong enough to carry the outboard engines at cruising speed without warping and fluttering. To alleviate this, a central underwing bulge called the plastron, named after the under-shell of a tortoise, was developed to correct airflow problems around the engine pylons.
The first flight of the A340-200 was on April 1, 1992, and JAA certification for both the 200 and 300 at an MTOW of 257 tonnes was on 22 December, 1992. In 1993 the A340 broke several aviation records by circling the globe with only one stop.On March 17, 1993, Lufthansa became the first airline to put the A340 into service (and also went on to become its largest operator, with 30).
In December 1994, Singapore Airlines added to its initial order for seven A340s with a contract for ten heavier A340-300Es, plus 20 options, powered by the newly certificated CFM56-5C4 engines. At 34,000lb thrust, they were the most powerful CFM56s built. Singapore was the first airline to operate the -300E, with first delivery in April, 1996.
The A340-300E is available in 271,000 kg (597,450 lb) and 275,000 kg (606,260 lb) max takeoff weights, and their typical ranges with 295 passengers are 7,100 nm (13,160 km) and 7300 nm (13,530 km) respectively.
The 275,000 kg (606,260 lb) MTOW A340-8000 is based on the -200 but has extra fuel in three additional rear cargo-hold tanks. With 232 three-class passengers, this version offers a 8,100 nm (15,000 km) range, hence the A340-8000 designation. It too is powered by CFM56-5C4s. One -8000 was built for the Sultan of Brunei.
The A340-313X is a heavyweight version of the A340, and was first delivered to Singapore Airlines in April 1996. However, the airline no longer operates the model.
The A340-313E is the latest version of this type and was first delivered to Swiss International in 2003. It has a MTOW of 276,500 kg (609,570 lb) and a typical range with 295 passengers of between 7,200 and 7,400 nm (13,100 km and 13,500 km). The engines are again the 34,000 lb thrust CFMI CFM56-5C4s.
Airbus Industrie developed a number of innovative options for the spacious lower deck hold. One option is sleeper cabins in the underfloor area, with typical layouts featuring full length beds for up to ten passengers. Another is for a separate washroom area below the Economy class cabin, with up to five lavatories. This arrangement frees up space for an additional ten seats, while also enhancing passenger cabin appeal. The A340 was also the first aircraft to feature an underfloor sleeping area for the cabin crew.
In a poll conducted by UK Market research company MORI, the A340 was preferred for its seating and engine configuration by a five-to-one factor over its closest competitor.
The direct Boeing equivalent is the 777-200ER. When fuel costs rose, orders for the 777 rose, while orders for the A340 began to decline. It can be argued that, with modern engines having extremely low failure rates (as seen in the ETOPS certification of most twinjets) and increased power output, four engines are no longer necessary except for very large aircraft, such as the Airbus A380 or Boeing 747. In 2005, Airbus had only 15 orders for the A340.
To improve the situation, in January 2006 Airbus announced plans to develop an improved version of the aircraft called the A340E, where E stands for enhanced. Airbus claims this will be more fuel-efficient than earlier versions and will allow the model to compete more effectively with the Boeing 777.
As of November 2006, total deliveries of the A340-200/300 stood at 240. Of these, 237 were still in service.
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