Boeing passes big test in 7E7's new production methods

The Monday after Thanksgiving, at its Seattle research center across from the Museum of Flight, Boeing put in the oven a giant bird — 22 feet long and nearly 19 feet wide.

It was the first full fuselage section of the 7E7, a practice piece made from plastic-infused carbon-fiber composite material.

Baking the single-piece section to hardness was the climactic moment of months of preparation. It was intended to prove the previously untested manufacturing processes that Boeing's partners around the world will use to build their fuselage pieces of the new jet.

More than 100 engineers watched as the section came out of the oven, a huge pressurized heating vessel called an autoclave.

To Boeing's relief, it turned out not to be a turkey. It came out perfectly.

The factory floor rang with cheers and applause, said team leaders who were there.

This first completed piece, the rear section of the fuselage, has a complex curve. Getting it right means the 7E7's manufacturing processes are on track.

When production begins in 2007, Boeing subcontractor Vought will make this piece in Charleston, S.C.

After the successful outcome, Boeing completed tests on the fuselage section, cut out doors and windows, and painted the surface.

Yesterday, Boeing showed off to the media what Walt Gillette, head engineer on the 7E7, called "a piece of aviation history."

"This is the largest piece of pressure-vessel carbon-fiber ever made," Gillette declared.

Made from a lighter material with few joins, the 7E7's airframe will be 20 percent lighter than an aluminum one. It won't corrode or fatigue as metal does, meaning less maintenance.

Boeing already makes single-piece composite barrels for its Delta IV rocket booster and for its Sea Launch rocket, but those are smaller in diameter and not as complex in curvature.

A key challenge was to form the 7E7 fuselage section as a single piece under the tighter cost constraints of the commercial-airplane business.

In today's commercial jets, the fuselage is constructed from rectangular aluminum panels, bolted and riveted together with millions of metal fasteners and stiffened with long rods called stringers attached inside along the fuselage's length.

To make the 7E7 composite airframe, robotic arms apply layers of resin-infused carbon-fiber tape around a central cylindrical tool to form complete sections, including outer tube and internal stringers.

"Aircraft designers have often dreamed of making the fuselage section with no joins," said Gillette, who then motioned with his arm to the two-story airplane section behind him. "This is one part number."

The cross-section of the large piece is not circular. The bottom half, where cargo and baggage goes, is a semi-circle. The top half, where passengers sit, is a slightly larger semi-circle.

The composites-forming process allows a smooth curve from one section to the other.

Other parts of the fuselage, though larger, have less complex curves. Kawasaki of Japan, Alenia of Italy and Boeing Wichita will produce the other large fuselage sections.

Each will use a set of uniquely shaped tools to form its particular section. Boeing designed and built much of the tooling at its Wichita, Kan., operations.

Creating these huge pieces is the key to Boeing's plan to assemble the 7E7 in just three days. The fuselage will essentially be assembled from only five or six separate major pieces, joined using titanium splicing plates with titanium fasteners.

Elsewhere in Boeing's research center, Mitsubishi and Boeing are working on the 7E7 wing-manufacturing processes.

Gillette said the success of the project, which included team members from the partner companies, "shows how the Boeing-led team will cooperate to create the [7E7]."

Boeing will do six more trial fuselage pieces in Seattle this year and another in 2007.

Dominic Gates: 206-464-2963 or dgates@seattletimes.com