The attempt to create the world?s largest airline by merging US Airways and American Airlines may have hit another snag as the US Airways machinists? union refuses to sign off on the deal. US Airways has been attempting to settle a contract dispute with the IAM, representing about 3,000 workers, for over two years. US Airways lent help to American Airlines in their negotiations with the IAM in the time leading to the approval of the merger. US Airways suspects that the union may be conducting a slow-down of work, refusing overtime, and possibly delaying flights in an attempt to force the company into an agreement. The union has asked that federal parties get involved, even contacting several members of congress.
See "US Airways faces labor strife ahead of airline merger", Hugo Martin, Los Angeles Times, December 4, 2013