Flight attendants for Air Wisconsin — which operates as a US Airways Express carrier — will hold a strike-authorization vote, the Association of Flight Attendants said. Citing stalled contract negotiations, the union said strike-vote ballots will be sent to more than 300 flight attendants next week, with ballots to be counted on May 22.

Air Wisconsin, the largest privately held regional airline in the nation, flies about 100 US Airways Express departures daily from Philadelphia International Airport.

If the National Mediation Board determines contract talks are deadlocked, it could release both sides for a 30-day "cooling off" period before any strike is called.

— Paul Nussbaum