A federal judge issued a preliminary injunction on Wednesday to stop the union representing pilots at US Airways Group LCC.N from participating in activities the airline says are hurting its operations.
In July, US Airways accused the U.S. Airline Pilots Association of encouraging its members to "engage in an illegal slowdown in order to put pressure on US Airways" while the two sides negotiated a new contract.
In a 45-page ruling, Judge Robert Conrad of the U.S. District Court in Charlotte, North Carolina, said evidence shows the union encouraged members to "engage in conduct that would increase flight delays and cancellations, as well as the airline's operating costs."
The ruling mentioned activities such as "calling in fatigued" and promoting "pre-flight procedures that affect taxi times."
A spokesman for the union previously has denied the accusation, calling it "categorically false," but was not immediately available to comment.
The carrier and the union, which represents 5,200 pilots, have been in often contentious contract talks since the 2005 merger of the old US Airways with America West Airlines.
Among the obstacles to a joint labour contract is a dispute over the integration of the two carriers' pilot seniority lists.
Shares of US Airways closed one cent higher at $6.12 in trading Wednesday on the New York Stock Exchange. (Reporting by Kyle Peterson; Editing by Tim Dobbyn)