Since it became clear that it was gaining unprecedented orders for the 787, Boeing has acknowledged that it might need a second final assembly line. But it has put off saying much more. Now CEO James McNerney says the company is "actively looking" at such a prospect.

Officially, just where it will be located and when it will be opened is unclear. "Eventually, I believe we will do a second line," McNerney said last week during the Paris air show. "The question is when."

But industry officials say Boeing is ready to move very quickly. They expect the company to announce shortly that North Charleston, S.C., is its preferred location and to establish the line next year. If true, that decision will roil Boeing's home in the Puget Sound area of Seattle, particularly Everett, Wash., where the 787 is now assembled.

The North Charleston scenario sees initial production dedicated to the stretch 787-9 that is expected to receive its firm design configuration in October. That would indicate the start of major assembly work in the fourth quarter of 2010.

In 2008, Boeing bought a 50% share in Global Aeronautica, which integrates 787 fuselage sections in North Charleston produced by Alenia, Fuji, Kawasaki and Vought Aircraft. Locating a second line there would provide Boeing with available infrastructure and land and proximity to the Global Aeronautica and Vought factories.

The site is a key logistics hub for the 787's DreamLifter subassembly global transportation system and slots relatively easily into the sequence of flights necessary for the aircraft's final assembly. The site is nonunionized, and the 787 already has received extensive state tax and educational benefits for locating there.

If Boeing makes the shift to the American South, a region hungry to expand its aerospace footprint, it would be a bitter blow to its unionized workforce in the Puget Sound area, the traditional home of Boeing airplanes.

"I'd like to see the second line in Everett," says International Assn. of Machinists in Aerospace District 751 President Tom Wroblewski, who spoke before it was learned how quickly Boeing is moving on the alternative site. "They have loaded up that 787 line with [IAM] members to bring this airplane onto [the first flight] line."

That sentiment is shared by the Society of Professional Engineering Employees in Aerospace (Speea). "The company needs to stop this outsourcing to achieve lower costs," a Speea spokesman says. "If they need a second line, put it where the experienced workforce is. That's the only way to get [the line] up and running as quickly as possible."

Boeing's original plan was to use about 350 IAM members in final assembly. But the rework of assemblies left uncompleted by suppliers prompted 787's managers to transfer in floor workers from other programs. The company has not revealed its 787 headcount, but it acknowledges having to build up the 787 line as it pushes to achieve first flight and establish a regular production rhythm.