TEMPE (AP) — The pilot union at US Airways Group Inc. is asking for federal mediation in its negotiations with the airline.

The two sides have been negotiating a new contract since 2005.

America West airlines bought US Airways that year, but pilots from the two airlines still fly different planes under separate union contracts.

The US Airways Pilots Association says the talks are "hopelessly stalled."

Federal mediation is a common step in airline negotiations, which often drag on for years.

The union is in a legal fight with former America West pilots over seniority. Oral arguments on an appeal of that matter are scheduled for next month in the federal Ninth Circuit Court of Appeals.