“Just because we’ve imposed does not mean we’re cutting off further discussions,” Northwest spokesman Bill Mellon said. ”Northwest remains available to negotiate with the AFA.”

AFA interim president Mollie Reiley said the union also is willing to negotiate but that it is unclear whether talks will take place and what would be discussed.

Northwest, which seeks $1.4 billion in total labor savings, has said it needs $195 million in givebacks from its flight attendants. The carrier has deals with its other unions.

A bankruptcy court in June said Northwest could terminate its contract with the flight attendants if the two parties could not reach a consensual deal. The AFA had said it would disrupt airline service if management voided its contract.

“We served our 15-day strike notice last night advising Northwest that we believe we do have the right to strike,” Reiley said.

By issuing a 15-day notice, the AFA honored an agreement made with the airline by the Professional Flight Attendants Association, the union that previously represented the Northwest flight attendants. The AFA said the 15-day period concludes on August 15 at 9 p.m. CT.

The AFA said it plans to use a strategy called CHAOS (Create Havoc Around Our System) to pressure Northwest management to yield a better contract. CHAOS could involve any number of measures, from informational picketing and leaflet distribution to service interruptions and intermittent strikes.

One expert said a strike would be devastating for the airline, costing the carrier loyal customers who won’t risk being inconvenienced.

“This could poison people’s attitude toward Northwest,” said Joe Schwieterman, transportation expert at DePaul University.

“The combination of bankruptcy and a strike threat could steer frequent fliers away,” he said. “Buying Northwest means buying risk with the current labor situation.”

But Schwieterman and another expert believe the AFA and airline management will come to an agreement within 15 days.

“I really, really do expect this thing is going to get settled,” said Terry Trippler, an industry expert at travel club myvacationpassport.com. “Cooler heads will prevail.”

Still open to debate is the legality of a strike by airline workers against a bankrupt carrier.

“A strike or work action by AFA flight attendants would be illegal under the Railway Labor Act,” Mellon said. “If AFA threatened any work action, NWA would take appropriate legal action in federal court.” The airline has not yet requested the court to block a strike.

The federal Railway Labor Act permits a walkout only after mediation fails to resolve a dispute. The act, written in the 1920s, safeguards interstate travel by restricting workers’ rights to disrupt it and covers the airline industry.

It is unclear whether the restrictions apply if a collective bargaining agreement is changed or nullified against the will of the workers. Experts also disagree over whether an employee group can strike against a company in bankruptcy.

Reiley acknowledged that the legality of a strike under these conditions is untested in court and, therefore, uncertain.

She said that if Judge Allan Gropper in New York’s federal bankruptcy court were to declare a strike illegal, CHAOS could employ other methods that follow the law.

“I think this is going to play out in the legal arena,” she said.

The government intervened in pilots’ strikes in the late 1990s at AMR Corp’s American Airlines and Northwest Airlines. In both cases, the president, acting under the authority of the RLA, demanded further mediation.