CHICAGO (CBS) — Chicago teachers aren’t the only ones threatening to strike; United Airlines pilots could soon be walking picket lines.

As WBBM Newsradio’s Bob Conway reports, the Air Line Pilots Association says United captains voted 99 percent in favor of authorizing a strike if it comes to that after two years of negotiations.

LISTEN: WBBM Newsradio’s Bob Conway reports

The pilots want a single contract covering United and the former Continental Airlines, which combined to form the present-day United in 2010.

Pilots are seeking raises that would replace separate deals that United and Continental pilots approved last decade, when the airlines were in much worse financial shape.

But a strike is anything but imminent.

The National Mediation Board would have to first declare an impasse triggering a 30-day countdown. Also, the president or Congress could step in to stop a walkout in a key industry such as an airline.

Jay Pierce, chairman of the union’s Continental group, said the strong strike vote reflected frustration with stalled contract talks. “A strike is never the preferred path to reaching agreement, but our pilots have demonstrated that they realize it may be necessary,” he said.

But United spokeswoman Megan McCarthy said the airline expected a strike vote, which is “not uncommon at this point in negotiations.”

Chicago-based United is the world’s biggest airline by passenger miles.

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