Meanwhile, the Japanese partners, which will be charged with actually manufacturing the wings, are getting ready for production at their plants near Nagoya, one of Japan's main industrial centers. Mitsubishi is working on the main wing box, Kawasaki is doing part of the trailing edge, and Fuji is making the so-called center wing box, which is a heavily reinforced structure inside the fuselage that secures the wings and holds the landing gear. (Spirit AeroSystems Inc., in Tulsa, Okla., is making the leading edge, and Hawker de Havilland Ltd., in Bankstown, Australia, is making the rest of the trailing edge.)
The Japanese expertise with composites comes from a variety of projects, among them the F-2 attack fighter, for which Mitsubishi designed and built composite wings. Japan has also chalked up experience in building space vehicles, helicopters, trains, and other transportation systems. But even for the three Japanese companies, making the 787's wings is a big step in terms of scale and complexity. All three are expanding their plants, with Mitsubishi alone spending $768 million, half in R&D and half to build a new facility capable of fabricating the 787's parts.
The fabrication of a composite part begins at a large automated stacking machine that lays sheets of composite material on top of a mold known as a layup mandrel, which gives the part its shape. Next, the piled sheets go into an immense autoclave, which is essentially a pressurized oven that cures the sheets together. After the part undergoes some trimming, polishing, and painting, it is ready for use.
Boeing is also enmeshed in the tests required to make sure it will get the wing it needs. Later this year, a group of engineers plan to perform a series of lightning experiments in a laboratory to assess the 787's ability to withstand direct strikes.
A lightning strike can damage the composite material and also produce a voltage surge that, in theory at least, can interfere with electronic equipment, such as flight-control computers. But the most serious problem would be a spark inside the fuel tanks, which are usually located inside the wings. In 1963, the left wing of a commercial airliner exploded over Maryland, resulting in the deaths of all 81 onboard. An investigation ruled that lightning was the cause of the explosion.
"The idea with lightning protection is you really want to get the current spread out over large areas," says Edward Rupke, a senior engineer at Lightning Technologies Inc., in Pittsfield, Mass. With a metal fuselage and wings, he says, the electricity will do just that, dispersing without much problem. But composites do not conduct as well as metal, and some don't conduct at all.
Rupke says the usual solution is to add aluminum or copper sheets or meshes to the surface of the plane. These metallic laminates provide a conductive path for the electrical current, which for a potent strike can reach 200 000 amperes.
Boeing says that even though no one has ever built such a large composite wing, lightning protection solutions already available will work for the 787. The company declines to give any details other than to say it will embed a metal mesh throughout the entire surface of the wings.
In their tests, the Boeing engineers will use special high-voltage equipment to produce lightning and hit a large piece of the composite wing. They will then measure the electric current levels around the wing's surface and analyze the extent of damage to the material, using nondestructive inspection techniques that involve ultrasound, X-rays, and thermography.
"We'll actually get some very serious current put through it," Jenks says. "We want to validate that there's no way for that current to get into the wing itself."
If things continue on track for Boeing, the first 787 jets will be certified and enter service in 2008. The company says parts will come in from all over the world to its facilities in Everett, where the final assembly of a 787 will take only three days.
The development of any large new plane is risky. Estimates for the development costs of the 787 range from $8 billion to $10 billion. Boeing is expected to spend $5.8 billion, with its partners kicking in the rest. The project seems on target so far, but Boeing's previous projects have often suffered from delays and cost overruns. And a few observers worry that Boeing has outsourced so much of the 787 that someday it may find itself competing against a Japanese company--Mitsubishi, for instance--in the market for commercial airliners.
And, of course, Airbus isn't standing idly by. Not long after Boeing announced the 787, the European jet maker said it was going to develop the two-engine A350, which will have large composite wings. Airbus has ample experience with composites and other advanced materials, such as Glare, a laminate of aluminum, fiberglass, and epoxy. But because the A380 is keeping Airbus quite busy, the A350 won't take flight before mid-2010. At press time, Boeing had 293 firm orders and commitments for its 787, versus 143 for the A350.
When the first 787 takes off for its inaugural flight, the wing design teams in Everett and Nagoya will savor the moment with a mixture of contentment and relief.
"If you look at what they're doing, there's an awful lot of risk there," says Teal consultant Aboulafia. "If it works out, though, this would be one of the most successful industrial programs we've seen in years."
Boeing 787 Composite Wing
Goal: Design a wing made primarily of composites instead of aluminum for the new 787 jetliner.
Why It's a Winner: The new wing is lighter and more resistant to fatigue and corrosion than aluminum wings. It will help save fuel and lower maintenance costs.
Organizations: Boeing, Mitsubishi Heavy Industries, Kawasaki Heavy Industries, and Fuji Heavy Industries.
Centers of Activity: Everett, Wash., and Nagoya, Japan.
Number of People on the Project: Confidential.
Budget: Confidential (estimates for the whole plane range from US $8 billion to $10 billion).
