CHARLOTTE, N.C. -- Pilots at US Airways ( LCC) are headed toward an election that could oust the Air Line Pilots Association as their union representative, in a particularly timely example of what can happen when there is no agreement on the seniority list in an airline merger. On Tuesday, the National Mediation Board said it authorized an election among the approximately 5,300 US Airways pilots. The board responded to an application filed by the US Airline Pilots Association that was supported by about 3,200 signature cards. Telephone and Internet voting will take place from March 20 through April 17, the NMB said Wednesday. "We are gratified to know that the US Airways pilots will finally be afforded an opportunity to select a new collective bargaining agent," said USAPA President Stephen Bradford, in a prepared statement. ALPA spokesman Peter Janhunen said the 76-year-old union remains the best solution for all US Airways pilots. He called the division in the pilot group "tragic" and said joint negotiations on a new contract offers the best outcome for all parties. "US Airways pilots are losing out" because their attention has been diverted, he said. The NMB ruling comes as pilots at Delta ( DAL) and Northwest ( NWA) seek to reach an agreement that would facilitate a merger between their two companies. Those talks have been slowed by seniority issues, sources say, as pilots attempt to reach an agreement in a few weeks on a matter that often takes years to resolve. At issue is an effort by Northwest negotiators to enhance their pilots' relative seniority at the expense of Delta pilots, a source said. However, pilots and management have reached a general agreement on a combined labor contract, absent seniority specifics. The boards of the two airlines were scheduled to meet today to review merger possibilities, in light of the general agreement, which they had been awaiting. USAPA's creation was spawned by a questionable seniority ruling following the 2005 merger of US Airways with America West. An arbitrator's ruling would force hundreds of pilots with 15 years or more in the cockpit to become junior to pilots employed by the company for only a few years. Pilots from the former US Airways contend the arbitrator's ruling violated ALPA merger policy, partially because it provides a windfall to one pilot group at the expense of another. A lawsuit is pending. Janhunen said the premise of the lawsuit is false because the merger policy is not meant to guide the arbitrator, who acts independently from ALPA. "ALPA had nothing to do with the selection or guidance criteria for the arbitrator, and yet some pilots are trying to unseat ALPA as if it had responsibility for the award," he said. Twenty-two months after the merger, pilots at America West and the former US Airways continue to have separate contracts and to be represented by separate ALPA chapters. Last month, committees from the two groups met for a 10-day retreat to try to iron out their differences, but made no significant progress.