It's suddenly East vs. West among pilots flying for the new US Airways.

A day after East Coast veterans of the old US Airways complained about an arbitrator's decision to knock down their seniority status, West Coast pilots who work for Tempe. Ariz.-based America West Airlines fired back, saying the old US Airways pilots should quit griping and instead be thankful they have a job due to America West's takeover of the twice-bankrupt carrier in 2005.

"They need to lose their misplaced sense of entitlement," 49-year-old America West captain Eric Peterson, who lives near Colorado Springs, Colo., said in an e-mail, in which he emphasized that his view does not necessarily represent the official position of his union.

"Before their bankruptcies, for their entire career the US Airways pilots were enjoying industry-leading pay, a defined pension plan (something we never had), work rules -- everything. I don't begrudge the East pilots for their former fortunes at all, but they should recognize that we in this industry have all been there ... we at the old America West should not be penalized for acquiring US Airways."

Following the 2005 merger of the old US Airways and America West, the pilot groups from both airlines agreed to let a federal arbitrator draw up one "seniority" list that determines who gets the best pay, routes and vacation. US Airways pilots, as a group, are older than America West pilots, and if the arbitrator were to use date of hire as a benchmark, US Airways pilots would have retained the prized spots.

But that didn't happen. Instead, the arbitrator put 517 US Airways wide-body pilots at the top of the list but then filled out the rest of the spots by pairing the most senior US Airways pilots with the most senior America West pilots -- a decision viewed as fair by the America West contingent and unfair by the old US Airways pilots. The latter argue that pilots with relatively fewer years at the controls are now in line to take higher-paid captain's seats currently held by the most senior pilots at the old US Airways, where the average age of pilots is 53. The arbitrator also placed 1,800 furloughed US Airways pilots at the bottom, some with as much as 15 years of service.

Former US Airways pilots chairman Bill Pollock, who still flies for the airline, argued Thursday that the award ignores sacrifices made by the East Coast pilots through two bankruptcies and places the more junior pilots in a situation where they will be unable to achieve enough seniority to upgrade to the captain's seat ( and achieve the commensurate increase in pay).

America West pilot T.J. Hvasta countered that view yesterday by noting first that the East Coast pilots not only agreed to the arbitrator but pledged to live by his decision. "They are now crying because they didn't get their way," he said in an e-mail. "They made their decision to work at USAir; I made mine to work at America West, which, by the way, has historically been the LOWEST paid airline in the U.S. The East pilots have been paid far and above what America West pilots have been paid over the same period of time doing the same job."

As for the sacrifices made by the old US Airways pilots through two bankruptcies: "Their salary and benefits cuts have finally brought them down to what we have been paid all along," Mr. Hvasta said. "And now because we saved their bacon from the fire we should be junior to them?"

The dispute over the seniority list is yet another labor challenge facing US Airways a year and a half after merging with America West. The carrier still does not have a single contract governing several of its work groups, including the pilots. Now the East-West bickering threatens to drag that process out, with the old US Airways pilots making some noise about an appeal to the national Air Line Pilots Association.