FLUG REVUE November 2003: Airbus A380 construction advances

A380 PRODUCTION UNDER WAY

By Sebastian Steinke/Matthias Gründer

“The A380 is setting new standards of technological innovation,” announced a visibly proud Gérard Blanc, Executive Vice President Programmes at Airbus, on the occasion of a ceremony in Nantes to mark the completion of the first centre wing box on 19 August. This key structural component, known as “Section 21” on the project, is the keystone that will later connect the two wings to the aircraft fuselage and will be “transversed” by the three main wing spars.

Airbus A380

“Section 21 comprises the essence of our experience and our objectives, which are the product of forty years of research. It is a milestone, a showpiece for our industry,” Blanc enthused. “Although you can see immediately that the wing box is very big, its most important feature, namely the fact that it is made out of composite materials, is not visible from the outside. Nor is all the close collaboration with our suppliers, our employees and the unions immediately apparent. The workforce in Nantes have gone to great lengths to stick to the schedule. We feel passionately about this plane that we are building. Meanwhile we are already working on the seventh wing box. Today's delivery will go down in history as a significant event.”

The A380 uses a carbon fibre reinforced plastic (CFRP) structure for its massive wing box, which measures 7.8m x 7m x 4m – a first both for Airbus and for commercial aircraft of more than 100 seats. Five of the seven segments, whose walls are up to 45mm thick, including the forward, centre and aft spars and both of the double-layer upper and lower panels, were manufactured out of CFRP, consisting of 60 percent carbon fibre and 40 percent synthetic materials. In fact, 40 percent of the entire structure of an A380 and its components is to consist of composite materials.

The unusually high wall thickness of the CFRP components on the A380 wing box, which was necessary to achieve the required strength, is quite new to aircraft construction at Airbus, as previously manufactured CFRP wing panels for the ATR 72 were only 10mm thick. Again, the “Keal Beam”, i.e. longitudinal reinforcement in the lower fuselage of the A340-500 and -600, constructed from the same material, is “only” 20 mm thick.

A new generation of gore-folding machines in Nantes are now enabling the automatic production of A380 sections from carbon fibre layers to the desired thickness – and that is with double the productivity. The final component is formed out of individual carbon fibre sheets, which are laid precisely along the later direction of load, are handled like large rolls of fabric and, heated together with synthetic materials, are then moulded into shape.

This technology means that, compared with a conventional aluminium component, 1.5 tonnes of weight can be saved. Moreover, the high-strength component, to which maintenance access will be difficult in the finished aircraft, is more resistant to corrosion. Whereas in the passenger version, the A380 will initially possess a “dry” wing box, in later versions of the A380 family that have a higher take-off weight it will be possible to carry additional kerosene here without having to assign space otherwise available for lucrative cargo to additional fuel tanks.

Airbus is pursuing the same concept of lightweight construction with new materials on the upper fuselage shell of the A380. This will be made from glass fibre reinforced aluminium (GLARE), a laminate in which layers of aluminium and glass-fibre reinforced adhesive are alternated. The result is a weight saving of 800kg compared with an equivalent aluminium design. This has enabled the Airbus engineers to move the centre of gravity aft by around six percent, which in turn means that the vertical tail surface can be reduced by 40m², making it a lot lighter, while preserving the stability of the aircraft in-flight.

Despite the party mood in Nantes, Gérard Blanc warned against the dangers of becoming complacent from too much optimism. “A programme of this order of magnitude is an important step for the entire industry. As of the middle of August we had 129 firm orders for the A380, a testimony to the high demand, the confidence that the market has in us and a proof of our success. We have made a lot of progress in a very short time, and in so doing we have completed the first stage on a long journey. But this success does not mean we should rest on our laurels. The A380 investment is costing us $10 billion. We must therefore remain on our guard.”

As well as the wing boxes, the ailerons, the air intakes for the engines and the radar nose of the A380 are also being manufactured from carbon fibre in Nantes, where there is no less than 20 years' experience of working with this high-strength, resistant and yet very light material, which nevertheless requires special processing.

Meanwhile Getafe of Illescas, Spain has been building the first tailcone for the A380 since June. This 5m x 3.5m component, in which a mock-up of the auxiliary turbine has already been mounted for test purposes in order to demonstrate its ease of maintenance access to airline representatives, is also constructed out of carbon fibre.

In the last week of August the first wing box was then transported from Nantes to Saint Nazaire for integration into a larger component before delivery to the final assembly line in Toulouse in the spring of 2004. Also bound for Saint Nazaire, “Polaris 2” assembly hall, was the first forward fuselage section, built by Alenia in Italy, which arrived by ship and truck in time for assembly of the section to begin on 28 August. This entails laying out the lower fuselage section with laser precision and connecting it up to four other segments: the main deck structure from Sogerma, the lower trim panels from Sabca of Belgium, the centre wing box and the two halves of the main undercarriage bay from Méaulte in France. Each half of the main undercarriage bay is 11.5m long, 2.5m high and 4.5m deep.

The lower fuselage was expected to be mounted by mid-October and the upper fuselage segments to then be added by mid-November. In the third and final phase, the panelling for the fuselage-wing joint will be attached by the end of the year.

Process chains from Hamburg

Work on the A380 is also in full swing in Germany. German high technology and experience are contributing to the success of the programme. Production has been under way in Germany since 14 March 2003, when the first aluminium parts for the wing-attachment joint, directly behind the wing, were fashioned. Meanwhile at Airbus Deutschland in Hamburg the main preoccupations have been with completing and equipping the new Major Component Assembly (MCA) hall, officially inaugurated on 21 May for the production of fuselage sections and cabin furnishings, and with improving the infrastructure.

An application was recently submitted for a formal public planning procedure to lengthen the existing runway to enable the still “green” aircraft arriving from Toulouse to land without problems and then, as finished super jumbos, to take off for delivery to customers all round the world. The present 2,684m runway is to be lengthened by 589m to the south-west specially for the A380.

In the Stade factory, Airbus's composite competence centre, the hot phase has also begun: on 23 June production of the first pressure bulkhead started up here. But the impression that production consists only of such isolated actions is actually an illusion. Already in this early phase of construction of the first aircraft, hundreds of suppliers have to be integrated, development, production and delivery have to be co-ordinated and reconciled so that everything functions like a single large organism.

The people of Hamburg are of the opinion that it is just a matter of building a large aircraft, which others could do too. The huge challenge of being involved in the construction of the first megaliner in aviation history brings together technology development, structural development, demonstration trials, skin assembly, structural assembly and fuselage finishing, and requires the hearts and minds of thousands of highly qualified and motivated specialists. In Germany alone, 19,000 men and women are currently involved in making this dream come true.

All of this is contained in the concept of process chains, which was coined in Hamburg. Such a chains exists, for example, in the area of future projects and technology development, as even now the company is already thinking about the future potential of the aircraft, about a family concept and different configuration variants, about aerodynamics, infrastructure and flying operations.

Another process chain extends from technology development to aeronautical physics, system development, structural development, demonstration trials, structural assembly, wing assembly and delivery to final assembly. Development covers numeric procedures and wind tunnel tests for new flap systems through to improved take-off power, lower resistance during the cruise, reduced noise emissions and reduced vortex formation.

Meanwhile in the cabin another process chain runs from design and concept studies to product definition, cabin, cargo bay and system development, validation, laboratory testing and parts manufacture and assembly, ending in delivery to the customer. Completely new system architectures for electronics and cabin management have to be considered here, utilisation of upper deck and underfloor must be maximised, and novel cabin simulators with virtual reality have to be built.

Construction of the fuselage sections in turn entails the use of laser welding technology, and a 30 percent cost reduction and 25% weight reduction are expected during manufacture of the lower skin, while use of the composite material GLARE on the upper skin will bring significant savings compared with conventional metal fuselages. And finally, extensive use of fibre composites, for example in the tail section and the pressure bulkhead with a view to installing fatigue- and corrosion-free structures with high resistance to fire, bring enormous challenges for production technology.

These examples show that it is a task of veritable titanic proportions. But how can one ensure that all these processes are properly co-ordinated and do not lead to chaos? How do tens of thousands of individual parts and hundreds of subassemblies get to the right place at the right time in such a way that undesirable interruptions to the production process are avoided? The technology for this is not fundamentally new; rather, it is based on some thirty years' experience of collaborative aircraft construction in Europe. But at the same time, in the initial construction phase of the A380, it has to be put to the test once again and adapted to the more demanding requirements.

The possibility of unexpected surprises cannot be ruled out, and the plans do allow for possible modifications, but there will be time for this later on. The first subassemblies are being assembled not on prototypes but on test airframes, like those earmarked for fatigue testing in Dresden, for example. Experience gained here will serve to optimise all the processes involved in the pre-production phase.

One of the most significant tools for this is the Advanced Planning & Optimisation (APO) software provided by Walldorf-based SAP AG, which will collect all the process and company data for the various locations and combine it into a unique logistics system. Airbus has already been using SAP software for years in all its production facilities and is now using the new tool components to push forward development of the IT infrastructure and integration of the various business processes. The first project phase affecting the A380 was completed in June 2003.

“Together with SAP, we have established a standard procurement and supply chain planning system which harmonises the processes in all the locations and will ensure that everything proceeds smoothly and efficiently in a closely co-ordinated network,” explains Jean-Pierre Albaret, Airbus Vice President Information Management. “Moreover, the system can be integrated into existing administrative processes without any problems, so that the SAP APO can be implemented quickly.”

Through seamless integration with existing resource planning, the present software solution can retrieve the latest information at any time, for example, production order status and materials availability from the production halls. It makes business processes highly transparent to both assembly workers and also management and provides them with the capability to match personnel, material and plant capacity precisely to expected demand in the production chain.

The A380 super jumbo is now taking shape. The development and construction programme is the culmination of the most extensive peacetime engineering effort in aviation history. The A380 is a unique technology platform from which all future civil aircraft programmes will evolve.

From page 20 of FLUG REVUE 11/2003

Last updated 10 October 2003

FLUG REVUE, Ubierstr. 83, 53173 Bonn, Germany