Wing panel assembly, British Aerospace Airbus.
Airbus wing after removal from main assembly jigs at British Aerospace Airbus, Broughton.
A set of Airbus A340 wings are loaded into the Airbus Industrie A300-600T Beluga freighter at British Aerospace, Broughton.
A 1:28 A3XX model is tested in the UK's DERA (Defence Evaluation and Research) pressurized 5-m tunnel at Farnborough.
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British Aerospace (BAe) has delivered its 2000th wing set to the Airbus Consortium. BAe is a major partner in Airbus and has been responsible for designing and building wings for all Airbus variants. Since the mid '90s , production and delivery rates for the wings have almost tripled. The first set of wings was completed in November 1971 and it took until May 1992 to reach the 1000th set. However, at present manufacturing rates, the 3000th set will be completed in only three years. The 2000th set, produced at BAe's wing assembly plant at Broughton, North Wales, was for a GulfAir A330.
It is almost 30 years since BAe took responsibility for the first Airbus A300 wing set and the technology that was engendered has played a key part in the success of the Airbus family. Technical Director Jeff Jupp comments on the company's initial role in design and building of Airbus wings: "We built on basic research in the 1950s and 1960s for aircraft such as the Trident, VC10, and Concorde."
From the outset of Airbus production, a family of aircraft was envisaged and the next step after the A300 was the A310, a smaller aircraft that demanded an all-new wing to improve efficiency. "The major advance we incorporated was in the area of high speed aerodynamics, made possible by the increase of computer power available in the 1970s," says Jupp.
Other Airbus developments included the fly-by-wire A320 before BAe pioneered the use of a common wing design for the twin-engined A330 and four-engined A340. It was a novel innovation. "To achieve this we further developed the structural concepts of the A300, the aerodynamics of the A310 and system improvements, such as fly-by-wire from the A320. We then had to engineer and produce the largest wing to be produced in Europe. But having variants of one wing for two aircraft reduced costs considerably," says Jupp.
BAe had first used CAD (Computer Aided Design) for the A320's wings; for the A330/A340, all manufacturing data was generated using the technique. From the initial work on the A300, the company had responsibility for integrating the whole wing design. Says Jupp: "To support this, we have progressively taken on responsibility for the design of the fuel system and the landing gear. We are now responsible for the complete aircraft landing system for the A330/A340."
Now, BAe is applying advances in design technology for the new large Airbus aircraft scheduled for production, the A340-500 and Ð600. Jupp explains: "We are automating our knowledge base. Not so long ago, it took 20 people six months to design a set of wing ribs. Now, the same job can be done by two people in just six weeks."
The next step in BAe's Airbus involvement is the wing for the planned A3XX. The span will be close to 80 m. Again, that will spawn an Airbus subfamily. Chris Voysey, who heads the A3XX design team at BAe, says: "The first version of the A3XX will seat 550 passengers on two decks. Both decks will be twin-aisle. The aisles will be wider than on current aircraft. Seats will also be wider and galleys larger."
Currently, 19 airlines are contributing input to the development process. Following the 550 seater, extended range and both higher and lower capacity versions will be developed. The seating range in these aircraft will be from about 480 to 650. A freighter version is scheduled.
According to Vorsey, the technical challenges to design and build wings for the A3XX are considerable. "We are looking at new design concepts and manufacturing processes," he says. "Some parts, including the spars and ribs, will be so large that conventional machining will not be possible (currently, material is not available in sufficiently large sizes) so we will have to fabricate these items. We are also looking at using new materials and manufacturing techniques, together with existing materials. By a combination of these, we will be able to reduce cost and weight and deliver improved aircraft performance to the customer." Voysey says BAe is working more closely with its Airbus partners and with potential suppliers: "We are also using common design tools and processes, all of which allow us to use our resources more efficiently."
Many of these elements will be used for future projects. Meanwhile, Phil Swash, Head of Operations for the A340-600 explains how current wing sets are manufactured. Aluminum billets arrive at Broughton in lengths up to 31 m and weighing up to 3.5 tonnes. "Each is given a number that can be linked to the end customer and so every person working on the wings can identify which customer they are for Ñany of 150 airlines," he says.
Airbus wing structure.
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Milling the billets into wing panels or skins takes about 50 hours. This is achieved on the largest com-puter controlled milling machines in Europe. Up to 75% of the original billets are machined away and much of the resultant swarf is recycled, often into alloys used by car manufacturers. Access holes are cut into the skins, which will receive titanium covers.
The next step in the wing making process sees the use of shot peening to create the required aerodynamic shape. That work is carried out by a company based 8 km from Broughton, but to improve logistic efficiency it will soon be moving to a purpose-built facility at the plant. Says Swash: "The wing panels are then treated and painted to prevent corrosion before being moved to the sub-assembly area where stringers are fastened to the panels. A new facility is now being installed which will automate the treatment process and double the throughput of panels. New facilities will also be installed for machining spars and stringers."
Each complete Airbus wing can include up to 60,000 rivets and bolts. Two automotive riveting machines are used but again there are improvements coming on stream with the application of LVERs (Low Voltage Electro-Magnetic Riveters). "These will do the job in a third of the time," says Swash. The traditional automatic fastening method involves moving the panels several times and, in the case of smaller wings for single aisle aircraft, the process takes 15 days. "With LVER, we aim to achieve the same result in one location in under five days."
After riveting, the structures are moved to the main assembly jigs where critical structures for the wing box are loaded: the front and rear spars and the center spar together with the ribs. These form the inner structure of the wing. New jigs for the forthcoming A340-600 (a 380 seat aircraft with a range of 13,900 km are now being installed and these will join the 20 jigs currently in operational use.
BAe operates a just-in-time philosophy at Broughton. Although the components for the inner wing box are assembled on site, the gear rib, leading edge, and outer wingboxes are assembled at the company's Filton, Bristol, site some 285 km away. Outside suppliers are responsible for about 70% by cost on larger Airbus wings.
The wings spend about three weeks in the assembly jigs. To facilitate movement at the end of this phase, they are moved on "rafts" using a hover system, allowing removal from the jigs by only a few operators. The wings are then taken to the equipping section, explains Swash: "For the wings of twin-aisle aircraft, a team works on leading and trailing edges and fitting fuel, hydraulic, and anti-icing systems. They carry out the pre-work for the flying surfaces, which are added later by our German partner, DaimlerChrysler Aerospace Airbus." The "finals team" carries out checks before the wings are moved to the paint shop. Next they are sent to a dispatch hangar in readiness for loading into Airbus Industrie's A300-600ST Super Transporter (Beluga) freighters to be flown to Bremen for final equipping and then transferred to Airbus's Toulouse facility for final assembly. Wings for the single aisle aircraft are fully equipped by British Aerospace and dispatched via Beluga direct to the final assembly lines Ñ in Hamburg for the A319 and A321, in Toulouse for the A320.
Stuart Birch
