787 wing-section prototype aligns easily; now it's ready to be broken

Boeing has completed a large prototype 787 wing section, and now engineers will try to destroy it.

On the first day of the Farnborough Air Show outside London, Boeing released details and photos of the 50-foot-long section — the longest piece of the new jet's structure yet built and the first largely plastic wing for a jet airliner.

Boeing's message at the year's premier aviation showcase: The 787 will soon be a reality, not just a computer-generated image.

In a pre-show briefing to Seattle journalists, 787 program chief Mike Bair fairly gushed about the way the wing's structural components had come together perfectly inside its Seattle research center — without any need for mechanics to improvise little bits of gap filler or shims.

"This big center wing box, with determinate assembly — meaning you pre-drill all the holes before you put the structure together — all the holes lined up," Bair said. "There's not a single shim in the whole thing. It's just gorgeous stuff."

But this wing will never fly. Boeing is set to begin structural testing next month. The piece will be tested to destruction, bent until it breaks.

Bair said the purpose of the full-scale test piece is not to help design the wing — that's largely done — but to confirm the previous computer analysis and ensure the structure performs as predicted.

Boeing will also use the test wing to prove the repair methods developed for the plastic materials used in its building.

Later in the 787 certification process, sometime next year, Boeing will conduct structural tests on a full-scale, complete airframe and will bend the wings on that structure to a breaking point, too. Bair said the tests on this wing piece will minimize the chance of surprises during that test.

The piece just completed is a large portion of the wing, beginning where it joins the fuselage and stopping at about two-thirds of the span. It is about 17 feet wide and 4 feet deep at the thickest point.

Unlike a conventional aluminum wing, this one has upper and lower skins of carbon-fiber reinforced plastic that are molded as single pieces and cured to hardness in a high-pressure oven.

The same material forms the strengthening rods inside the skins that stiffen them, and the long spars that run the length of the wing at the front and rear.

The ribs forming an internal ladderlike lattice between the skins are each machined from a single aluminum block.

The wing section was designed and built in Seattle by a team of Boeing, Mitsubishi Heavy Industries and Fuji Heavy Industries. Mitsubishi has built a similar test piece at its Nagoya, Japan, site.

The prototype wing, which is held in a sophisticated fixture for testing — "a marvel of complication," Bair said — weighs 55,000 pounds, including a lot of test-only hardware and instrumentation.

It took about 18 months to complete the piece and the tooling that holds it. The tooling was more problematic than building the wing itself, Bair said.

"Because the design is all-new, we feel it is important to get early test results," he said.

Emirates order for 747-8

Emirates Airlines will announce an order for the cargo version of the 747-8 Tuesday at the Farnborough Air Show, a highly placed source at the airline confirmed.

Reuters earlier reported the Emirates order will be for 10 of the 747-8 jets.

The airline source said also that an Emirates order for A340-600s, which was suspended in March pending improvements to the airplane, will likely not materialize at all.

Meanwhile, Aviation Capital Group, which acquired Bellevue-based Bouilloun Aviation Services in 2004, is expected to announce today an order for 14 737s at the show.

Through July 11, Boeing had logged 390 net orders for the 737 this year.

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