The legal cloud over Boeing's North Charleston airplane plant is lifting.

A landmark deal between the Boeing Co. and its biggest union clears the way for the National Labor Relations Board complaint targeting the local 787 Dreamliner-making operation to be withdrawn.

Though settlement is not explicitly part of the tentative agreement announced Wednesday, the president of the Seattle-area union said the four-year contract extension, which guarantees the 737 MAX production line will stay in Washington, resolves all of the union's grievances against Boeing.

"If this is ratified next week, we will have discussions with the labor board and we will inform them that ... we are satisfied," Tom Wroblewski, the union's district president, said at a news conference Wednesday.

The NLRB, Boeing and the International Association of Machinists and Aerospace Workers all emphasized that only the federal agency, not the union or Boeing, could withdraw the complaint it filed in April. But, in a statement, NLRB Acting General Counsel Lafe Solomon called the Boeing-Machinists deal "a very significant and hopeful development."

"The tentative agreement is subject to ratification by the employees, and, if ratified, we will be in discussions with the parties about the next steps in the process," he said.

Ratification by the union's tens of thousands of members in Washington, Oregon and Kansas is expected Wednesday.

Good reaction

South Carolina politicians offered their immediate approval but kept the heat on the NLRB to drop its controversial case.

U.S. Rep. Tim Scott, a Republican whose district includes Boeing's North Charleston campus, said the agreement "hopefully dissolves the lawsuit, but when we're talking about the NLRB, we can't assume anything."

Gov. Nikki Haley's spokesman issued a statement congratulating Boeing on "their win."

"[T]oday's actions confirm two things we've said all along: the NLRB is nothing more than a rogue agency run by the President's union backers; and that when the feds attack a company in South Carolina they can expect us to fight back, and expect us to win," the Republican governor said, according to the statement.

Early solution

Relations between the company and the union have been contentious, with three strikes in the past four labor negotiations, making this week's proposed deal especially surprising.

Boeing spokesman Tim Healy said "what is really remarkable about this agreement is it changes the paradigm in the relationship between the company and the union in a way that really focuses less on who wins and who loses."

The timing of the proposed agreement is also notable. The machinists' contract with Boeing doesn't expire until September and typically negotiations wouldn't begin until next August, union spokesman Bryan Corliss said. This time, Boeing opened the door to an extension in late October.

"For it to happen as early as it did is unusual," Corliss said. "We're not absolutely positive this is the first time ever, but this is the first time in anyone's memory that this has happened."

In addition to the 737 MAX commitment, the contract provides for pension and wage increases. And, Corliss noted, the "$5,000 ratification bonus will come in handy right around Christmastime."

Company success

The announcement of the deal came just a few hours after Boeing Commercial Airplanes CEO Jim Albaugh spoke to investors in New York and answered questions about both the 737 MAX program and the expiring labor contract. He said the company would choose where to build the 737 MAX "when we have all the facts and data." As for the labor contract, he said he was optimistic but also referred to persistently "thorny" issues.

The announcement closes a notable month for Boeing, one that saw the company break its own single order-value record twice, first with an order for 50 777s from Emirates, then just a few days later, with an order for 230 737s to Lion Air of Indonesia.

The reported agreement also comes as Boeing begins an across-the-board production ramp-up in an effort to reduce a staggering order backlog. Whether the state of the NLRB, which is scheduled to lose one of its three members, and thus its voting functionality, at year end, played any role is unclear.

Rolling out the 787

South Carolina Boeing spokeswoman Candy Eslinger said this week's agreement "doesn't affect our operations here in South Carolina."

"Our focus right now in South Carolina is ramping up to rate on aft- and mid-body and rolling out our first 787 here for delivery," Eslinger said. That first plane, according to Eslinger, is now "just over 50 percent complete" and is on track for customer delivery early next year.

South Carolina seemed to be only marginally in the running for the 737 MAX production line, but there had been much speculation about Boeing's consideration of sites outside of Washington.

The company chose to build its second 787 assembly line in South Carolina in fall 2009, touching off shock waves in Washington, where Boeing's jets had always been built. The 737 MAX site-selection process, announced in August and expected to last into early next year, seemed to be following a similar track.

Washington was so concerned it could lose another Boeing assembly line that it commissioned a prominent consultancy to assess its competitiveness in the aerospace industry. Published on Nov. 15, the Accenture report concluded Washington, and especially Renton, were well positioned to win the work.

In other Boeing South Carolina news, the company's Interiors Responsibility Center, a huge building in the Palmetto Commerce Park in North Charleston which will produce pieces like stow bins and class dividers, officially opens today. Boeing will also officially celebrate the operability of the solar panels on its final assembly building's roof Friday morning.

Yvonne Wenger contributed to this report. Reach Brendan Kearney at 937-5906 and follow him at twitter.com/kearney_brendan.