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Neat trick, but for airplane manufacturers the magic of composites starts with their weight compared to their strength. Depending on how they’re created, composites can be “as strong as steel but one-sixth the weight,” says Lin. That alone would make composites a superior material, but there are several other reasons—existing and yet to emerge from the lab—why they represent the future of airliner design.
Consider the way every airliner before the 787 was assembled. The process involved riveting together thousands and thousands of aluminum panels. Not so with composites. Huge sections can be produced in solid pieces and then bolted and bonded together.
The production of entire sections in solid pieces slashes the number of parts required to create a structure—and with it the cost of manufacturing. “Although composite materials are more expensive per pound than aluminum, the composite components are being produced with fewer parts and hence the ultimate effective cost is lower,” says Tuttle.
The primary structure of the 787 is being built in huge pieces at various sites around the world and then transported to the Boeing plant in Everett for final assembly. At first, final assembly will take six days per plane, but Boeing hopes to pare that to three.
 © 2007 The Boeing Company
Military aircraft have used composites in their primary structures for 20 to 30 years. However, it took relatively recent advances in automated manufacturing techniques to enable Boeing to build a nearly all-plastic plane.
“People have worked on improving composite materials along the way … but the real reason they were able to use composites to such a great extent in the 787 is improvements in manufacturing technologies—how to produce large structures in an economical way,” says Tuttle.
Boeing’s Miller sees the use of composites spreading across manufacturing. More cars will have composite components, he says, and the material is already used in structural support for buildings and bridges. Windmills for green power will use composites for their blades. And the biomedical industry is turning to composites too.
Composites also promise to continue redefining the performance of airliners for years to come. “The next stage in the evolution of aerospace composite materials will be the introduction of nano-reinforcements,” says Tuttle.
One potential nano-application involves embedding tiny tubes of carbon atoms in resin molecules. “The thing about these [tubes] is they have phenomenal properties,” says Tuttle. Invisible to the naked eye, the tubes are incredibly strong. They also make it possible—at least on paper—to produce composite structures that “morph” into a new shape.
Imagine, for example, an airplane wing without any hinged control surfaces. Instead, the edges would bend in response to embedded actuators. “I very much doubt that will be in the very next-generation Boeing aircraft,” says Tuttle, “but it certainly will be, I think, in an airplane of the future.”• Brad Broberg is a Seattle free-lance writer.
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