Stung by Boeing's declaration that composite materials would displace significant amounts of aluminium in the structure of the proposed 7E7 Dreamliner, Alcoa insists it is still in the game.

Bill Christopher, president of the aerospace arm of Alcoa, the world's largest aluminium supplier, says the competition is not over yet by any means. "Composites offer reduced weight but they have not been able to match that with lower production costs. Meanwhile, we are now moving ahead with our 20-20 initiative, aiming to cut both cost and weight by 20% over the next two decades."

Christopher expects the 7E7 to be at least 40% metal, and says Alcoa is continuing to offer some of its advanced alloys to the aircraft manufacturer. "Will Boeing revisit their decision? You'll have to go and ask them."

Cornerstone of the 20-20 effort is active collaboration with airframe manufacturers to promote the development of large modular structures featuring far fewer parts and significantly reduced unit weight and cost.

On view at the Alcoa chalet is a one-piece proof-of-concept structure made by forging aluminium slab to the required curvature and then machining. It could form the basis of a crew escape door comprising as few as 11 parts compared with the 113 of a comparable existing unit and costing 29% less.

Alloys

While Alcoa continues to fight for its place in Boeing's next big programme, the US company is well established with Airbus. Its high-damage-tolerance alloys are used extensively for the aircraft's belly skin, and it has contributed a range of specialised fasteners - over one million will be used on each A380 - for areas where metal is joined to composite material.

The company hints at significant economies as a result of the use of its products in the A380. "Airbus calculates we have contributed to cost savings of about 10% in the areas where we are present," says Christopher, "and in other recent applications we have obtained 10-15% on cost and up to 20% on weight."

A380 is Alcoa's most commercially successful programme ever, he adds, with a content percentage higher than in any other aircraft it has been involved with.

Source: Flight Daily News