Boeing engineers unveiled a seamless, rivetless, one-piece barrel of carbon-fiber composite that has the unmistakable profile of a jumbo jet’s back end.

At 22 feet long and 19 feet in diameter, it is a crucial first step in a multibillion-dollar march to prove that the company can build its much anticipated 7E7 Dreamliner, the first passenger jet produced largely from the same kind of reinforced plastic used to make golf club shafts.

“This is probably one of the two or three major milestones . . . for commercial aviation’s second century of flight,” boasted Walt Gillette, the 7E7’s chief engineer.

Boeing’s European archrival, Airbus SAS, may beg to differ. But there’s little doubt the new plane will play a crucial role for Boeing.

The 7E7 is intended to replace the company’s aging 767, which has been trampled in recent years by the A330, a jet built by Airbus. At 217 seats, it will be 20 percent more fuel efficient than the 767 and is designed to fly short and long-distance routes, bypassing congested hubs that routinely snarl air travel.

For Boeing, however, the Dreamliner also will serve a more pressing mission: helping rescue the company from a multiyear tailspin that has seen it slash jobs and fall to a demoralizing second place behind Airbus in the worldwide market for passenger planes.

“They need a way to claw back into a market they once controlled,” said John Leahy, Airbus’ chief commercial officer.

Launching an airplane has famously been called the modern equivalent of building a Gothic cathedral. But Boeing, which hopes to see the 7E7 shuttling passengers through the skies by 2008, is convinced the plane also can launch a new era at the troubled company.

Boeing faces a long, difficult road ahead. And Airbus is doing all it can to stanch its rival’s momentum, including retrofitting the A330 with new wings and engines to compete with the 7E7.

But the inside story of how Boeing set out to build this new, plastic plane, and how it has turned many doubters into believers, provides a vivid snapshot of how a major company innovates to stay competitive in a global economy.

More here.