Composite wings come near to major assembly

Airbus is claiming to be on track with the 2013 commercial roll-out of its A350 — its first airliner to be constructed with wings and a fuselage made primarily of composites.

The manufacturer has unveiled the site at its Broughton, North Wales, wing assembly centre where the long-range, mid-sized airliner’s massive wings — with a planned span of 65m — will be constructed. Airbus expects major assembly of the wings to start in late 2010.

Brian Fleet, head of the wing programme, said the wings will be made entirely out of composite apart from the internal cross beams — the ribs — which will be metallic. The composite upper and lower wing covers, he claimed, will be the largest composite structures ever manufactured for any purpose.

Airbus is confident in its wing design after putting it through years of computational fluid dynamic (CFD) modelling and wind tunnel tests at its Filton site near Bristol.

David Phipps, manager of Airbus’s next-generation composite wing programme, said several failed designs taught them that most of the wing’s internal structure must be made of the same material as external parts of the wing because of thermal constraints.

The different way these materials expand in certain temperatures, he explained, causes too much strain on the wings.

Phipps said experiments showed this problem could be overcome with the wing ribs but not its spars, which are longitudinal beams inside the wing.

Neil Scott, vice-president of engineering at Filton, said it was a top priority of Airbus to incorporate as much composite in the wing as possible because the material is lighter than metal and has the potential to make the aircraft more fuel efficient.

‘Seventy-five per cent of air frame performance comes from the wing,’ he said. ‘The A350 wing is the best wing Airbus has ever designed in terms of aerodynamic performance.’

Scott said there is still more work that needs to be done to perform aerodynamic performance such as improving laminar flow.

When assembly is under way late next year, the A350 wing’s composite covers will be constructed at Airbus’s facilities in Bremen, Germany, and Illescas, Spain, and delivered to the Broughton site in the belly of Airbus’s massive 86-tonne ‘Beluga’ transport aeroplane.

The wings will be assembled at the Broughton site in a new €400m (£358m) facility across the runway from the Airbus A380 wing assembly plant.

Fleet said the A350 wings will be assembled through a process tried once before — unsuccessfully, he claimed — in the industry.

The highly automated process, he explained, will assemble the wings in a horizontal fashion and drive the structures from jig to jig. Each jig, he added, is specially designed to perform a single assembly task such as drilling.

The new production method, Fleet said, will replace vertical methods of wing assembly that required personnel and machines to move around a static structure.

Given that the method is new for most workers at the Broughton site, he added, Airbus has modest goals for throughput at the start of wing assembly. The initial goal is to produce one wing a month, but the facility is expected to turn out seven to 13 wings a month after a few years’ time.

Tom Williams, head of programmes and customer support at Airbus, said the A350 will initially be designed to fly along side the currently operating A330 airliner when it is introduced in 2013.