Composite hopes for the future

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GKN Aerospace is building on its carbonfibre expertise, and its position in Airbus and Boeing programmes, to become a leader in composite wings and aerostructures

With high-profile civil and military aircraft projects adopting ever-greater reliance on composite structures to cut weight and improve performance, GKN is not alone among the world's major aerospace engineering companies in putting substantial resources into developing composites expertise.

But GKN Aerospace chief executive Marcus Bryson can at least declare that his company's vision is to become the market leader in composite wings and aerostructures from the strong position of having projects in the works which, if successful, can reasonably be expected to realise that dream.

Bryson is expecting a strong performance this year, with sales at GKN Aerospace forecast to reach $2 billion, including $1.1 billion from aerostructures, $550 million from propulsion systems and $350 million from special products.

That represents growth of nearly a quarter on top of the $1.6 billion achieved in 2007, which itself was up by nearly a fifth over 2006.

Expertise in carbonfibre

But Bryson is looking to double that business by 2017, assuming what he calls "fairly conservative build rates" in the "good, robust set of programmes" the company now supplies, including the Airbus A350 and A380, Boeing 787 and Lockheed Martin F-35 Joint Strike Fighter and C-130J.

Business won in the past year includes manufacturing composite fuselages for the HondaJet business aircraft and Sikorsky CH-53K heavylift helicopter,

A350 wing spars and wing trailing edges, a contract to design, develop and manufacture blended winglets for the Boeing 767-300ER and 737-300/500 (with 767 deliveries beginning during the fourth quarter of 2008), and a contract to develop and supply advanced titanium metal matrix composite thrust links for the 787.

The 787 thrust links will be the first commercial application of TMMC, which offers weight savings of up to 40% over traditional material. But it is expertise in carbonfibre that Bryson expects to drive the business forward.

 The big incremental growth opportunity is in the next generation of single-aisle airliners and in engines, where composites will become significant downward drivers of weight and cost.

GKN has already done some work developing carbonfibre fan blades, and is establishing a joint venture with Rolls-Royce to press ahead in this area.

What makes the next generation of single-aisle airliners so significant for GKN, however, is the fact that its exposure to the current single-aisle generation - the Airbus A320 family and the 737 - is small, about $50,000 a set.

As Bryson puts it, when sourcing decisions were taken for those programmes, "we didn't exist". But for their replacements, Bryson says GKN would be disappointed with anything less than $500,000 per set - and he is looking to be a key player in both Airbus and Boeing programmes.

GKN believes that its ticket to ride on these programmes is going to be expertise in fabricating large structures, such as wings, from carbonfibre.

The important thing to recognise about carbonfibre, says Bryson, is that it is not just about lightweight and corrosion-resistance. Critically, it is about mass production, as the material lends itself to automation, reliable and accurate reproduction, and speed.

 As Bryson likes to point out, a fan case GKN makes for the GENx engine is a six-month project from order to delivery, including materials ordering. A case in carbonfibre could be delivered in five days, from the time the material is taken out of the freezer.

As for the potential of carbonfibre in aerospace, Bryson says: "We've not really touched it."

Enabling Programme

To that end, GKN is focused strategically around wing manufacture and two key projects. One is its plan to acquire part of Airbus's production site at Filton, as part of the airframer's Power8 restructuring plan.

Filton will be an important A350 production site, and Bryson sees that aircraft as a "stepping stone" to the next-generation single-aisle airliner.

The other is the £100 million Next Generation Composite Wing project, an Airbus-led collaboration between 17 UK research organisations and companies, including GKN.

 Launched earlier this year, the NGCW project aims to develop the technology needed to ensure the UK is prominent in the design and manufacture of wings for next-generation single-aisle aircraft.

Senior technical director and chief technologist Phil Grainger believes the NGCW project will prove to be "one of the most successful enabling programmes". The NGCW is not about developing new technologies, says Grainger rather, it is about bringing existing technologies effectively to play in a new type of product - and to GKN that means making best use of carbonfibre's suitability for mass production any next-generation single-aisle aircraft is likely to be in large demand, so production rates will be high.

Among GKN's contributions is its work on microwave curing of carbonfibre parts. Critically, microwave curing allows a large structure to be cured in parts, which allows melding of segments or components.

double diaphragm forming
 © GKN

It is also a huge advantage to be able to do this without an autoclave, which represents a bottleneck in production, as parts have to be taken off line and brought to the autoclave before being redistributed to assembly points.

If that curing technology can be mastered, what GKN ultimately hopes to achieve as its major contribution to the NGCW project is a "one-piece" wing. Here, Grainger envisages a wing that is lighter and does away with the traditional design, which is essentially a "gutter" of spars, covers and fasteners.

For the wings, GKN hopes to employ automated fabrication techniques to make an integrally moulded product that would result in a lighter wing, and also a cheaper wing - by doing away with the fasteners that account for 10% of the cost of today's metal wings as well as a substantial proportion of their mass.

gkn automatic tape layer
 © GKN

Airbus's dream, he says, is for the NGCW project to develop a wing with all the control systems plumbed in before it is delivered for final assembly - a process that is hugely complicated by the time-consuming and expensive business of clamping and clipping all the cables and controls.

In practice, he says, a no-fastener wing may never be achieved but it is a reasonable dream to have a one-piece front edge that incorporates the internal workings.