The charge, which was received by the board Monday, "will be assigned to a board agent and that agent will conduct an investigation," he said.
"Typically, on a charge of this nature, an investigation wouldn't be done until mid-February."
The complaint, filed by union member Robley Evans of Kent, Wash., asks the board to seek an injunction to delay the vote, arguing the union is not providing members "a reasonable opportunity to vote" because many will still be on vacation following the company's annual holiday leave.
The International Association of Machinists' national leadership announced Saturday it was ordering a vote Jan. 3 by members in Seattle; Portland, Ore.; and Wichita, Kan., on a revised contract extension offer by Boeing.
Boeing says it will build the planned 777X in its Puget Sound plants if the contract is approved, but otherwise will look at many other sites.
Local Machinist leaders have adamantly opposed such a vote, arguing the offer is not much of an improvement over the one union members soundly rejected Nov. 13.
The new offer, which extends the current contract from 2016 to 2024, eliminates Boeing's proposal to lengthen to 16-plus years, from six, the so-called "zoom" period for moving to the top pay for a particular job classification. But it retains Boeing's insistence on stopping accumulations in the Machinists' longstanding pension plan in 2016 and starting a defined-contribution retirement savings plan instead.
Some Machinists have complained that a Jan. 3 vote coincides with their vacation plans — though it's not clear whether that would favor one side or the other.
The local union leadership said on its website Monday that it had the national union's approval to allow absentee voting, unlike its previous elections. The national union leadership has not confirmed that.
In investigating any charge, Sweeney said, an NLRB agent must gather evidence from both sides and contact witnesses when a charge is filed. The agent would then advise the regional director on the charge's merit, and if the issue hasn't already been resolved and can't be settled, the board can issue a complaint that will be dealt with in a hearing before an administrative law judge.
The NLRB can adjudicate disputes between members and their unions just as it does disputes between organized workers and their employers, said Sweeney.