Wichita ? Emboldened by a successful strike authorization vote, negotiators from the second-largest union at Boeing Co.’s Wichita plant return to the table today for a new round of contract talks with the aerospace giant.

But upset that the company has not budged despite two votes by employees to reject previous contract offers, the Society of Professional Engineering Employees in Aerospace also is making plans to go out on strike.

“Although that is not where we want to head, we are going to be very prepared if in fact it does come to that,” said Bob Brewer, the union’s Midwest director.

The union has contacted local law enforcement and Boeing security to make strike arrangements, has spoken with other local unions and is setting up a support fund to assist workers who may end up on the picket line. The union also is working with the United Way to provide counselors for striking workers who could need help with economic and personal issues.

“It is going to be a very stressful time,” Brewer said.

Boeing, meanwhile, pledges it will “absolutely” keep its production line running during a strike, said spokesman Fred Solis. As it does during contract negotiations with all its unions, Chicago-based Boeing has contingency plans in place for a strike.

“We have customers to satisfy,” Solis said.

While the union believes today’s talks will be a good indicator of whether negotiators will be able to come to an agreement, Boeing officials don’t expect to make any changes to their wage package, which is the union’s main problem with the company’s past offers.

The union, which represents about 3,400 technical and professional employees in Wichita, has been working under a contract that expired in February.

Both sides have said Boeing’s efforts to sell the Wichita facility are not a factor in the stalled negotiations. But aerospace analyst Richard Aboulafia , of the Teal Group, believes a strike could play a role in the sale.

“Good labor relations are an attractive selling point for any facility,” he said.