Thursday, March 13, 2008

Airbus A340

Airbus A340
The Airbus A340 is a long-range four-engined widebody commercial passenger airliner manufactured by Airbus, a subsidiary of EADS. It seats between 261 and 380 passengers, and has a range between 6,700 and 9,000 nmi. It is similar in design to the twin-engined A330. Initial A340 versions share the fuselage and wing of the A330 while later models are longer and have larger wings.
The A340 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 problem as defined by the then-current regulations: two-engined aircraft had to stay within 60 minutes' flying distance of a suitable diversion airport, which prevented them from competing on long overwater routes. Furthermore, the existing ETOPS immune widebodies in the 250-300 seat range, the trijet DC-10 and L-1011, were aging, as they had been in service since the early 1970's. The A340 was designed in parallel with the twin-engined A330: both aircraft share the same wing and similar fuselage structure, and borrow heavily from the advanced avionics and composite structure technology developed for the A320.
Both the A330 and A340 are assembled on the same final assembly line at Toulouse-Blagnac, France. The four-engined A340 is able to fly long over-water routes. Because of its ETOPS-immunity, Virgin Atlantic Airways used the motto "4 Engines 4 Long Haul," on its A340 fleet.
Kuwait Airways Airbus A340-300 taking-offThe A340 was originally intended to use the new superfan engines of IAE (International Aero Engines) in the A340 but IAE decided to stop their development. The engine nacelles of the superfan engine consisted of provisions to allow a large fan near the rear of the engine. As a result of the superfan cancellation by IAE, the CFMI CFM56-5C4 was used as the sole engine choice instead of being an alternate choice as originally envisioned. The longer-range versions, the A340-500 and -600, are powered by Rolls-Royce Trent 500 engines.
When the A340 first flew in 1991, engineers noticed that the wings were not strong enough to carry the outboard engines at cruising speed without warping and fluttering. To alleviate this, an underwing bulge called a plastron was developed to correct airflow problems around the engine pylons and to add stiffness. The modified A340 began commercial service in 1993 with Lufthansa and Air France.
The A340 incorporates high-technology features such as fully digital fly-by-wire flight control system. It also uses a sidestick controller instead of normal control columns. There is one joystick to the left of the pilot and one to the right of the co-pilot. The A340's flight deck is highly similar to the A320's, and employs a common pilot rating with the A330. This enables A330/A340 flightcrews to fly A320's and vice-versa with minimal extra training. This saves costs for airlines that operate both aircraft families. The cockpit also features CRT-based glass cockpit displays on the A340-200 and A340-300 and LCD-based on -500 and -600. Some composite primary structures are also used.
A340-600 at the Farnborough Air Show, 2006.With the introduction of higher gross weight Boeing 777s such as the 777-200ER and specifically 777-300ER, sales of the A340 began to decline. Over the last few years the 777 has outsold the A340 by a wide margin. Although the larger GE90 engines on the 777-300ER burn considerably more fuel than the Trent 500s, using only two of them compared to four Trents has meant a typical operating cost advantage of around 8-10%.
In January 2006, Airbus announced plans to develop an enhanced version of the A340, dubbed the A340E, where E stands for enhanced. Airbus claims that the enhanced A340E will be more fuel-efficient than earlier A340s and close the 8-10% disparity (range of the 18,000 km [ A340E-500HGW - with Trent 1500 engines ]*) and allow the model to compete more effectively with the Boeing 777-200LR. This would allow the Qantas for schedule direct Sydney to London-Heathrow flights***. However, due to ongoing production problems with the A380 and other internal challenges, it appears (as of October 2007) that the A340 E program is at a standstill. Airbus has predicted that it will probably produce 127 A340 units through 2016, after which production will cease.
[edit] VariantsThere are four variants of the A340 and launched on two separate occasions. The A340-200 and A340-300 were launched in 1987 with introduction into service in March 1993. The A340-500 and A340-600 were launched in 1997 with introduction into service in 2002.
[edit] A340-200One of two initial versions of the A340, the A340-200, with 261 passengers in a three-class cabin layout has a range of 7,450 nautical miles (13,800 km). This is the shortest version of the type and the only version with wingspan measuring greater than the length of the plane. It is powered by four CFMI CFM56-5C4 engines. The plane's range was one of the longest of the time and it was intended to open long and thin routes, especially over water.
One version of this type was ordered by the Sultan of Brunei requesting for a non-stop range of 8,000 nautical miles (14820 km). This A340-8000 had an increased fuel capacity, a MTOW of 275 tonnes similar to the A340-300, and minor reinforcements to the undercarriage. Upon completion its final range was specified at 8,100 nautical miles (15,000 km). It is powered by the 34,000 lbf (151 kN) thrust CFMI CFM56-5C4s similar to the -300E.
Other A340-200s were later given performance improvement packages (PIPs) which helped them achieve similar gains in capability as to the A340-8000. Those aircraft are labeled A340-213X. The range for this version is 8,000 NM (14,820 km).

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