As many as 500 furloughed mechanics could return to work in Moon as a result of the US Airways-America West merger, according to a top union official.

"That is the first good news I have had in 10 years," said Bill Freiberger, assistant general chairman of the International Association of Mechanics and Aerospace Workers.

Mr. Freiberger was citing a provision in the union's contract requiring heavy maintenance on Airbus jets to be brought in-house and a prior company decision to base that work in Pittsburgh.

But a US Airways spokesman in Tempe, Ariz., said it is still too early to know if any new in-house work will result from the merger, and if so, where that work would be done.

"If we need to add additional maintenance lines, it could happen in a number of places," said Carlo Bertolini, the US Airways spokesman. "It wouldn't necessarily have to be in Pittsburgh."

Prior to the merger, America West had 88 Airbus jets in its fleet to US Airways' 117. America West contracted its heavy maintenance to outside companies -- which is cheaper than union labor.

Mr. Freiberger argues that policy has to change if the new US Airways honors the IAM contract, signed in January, that requires heavy maintenance work to be done by union workers in Charlotte, N.C., or Moon, where US Airways maintains several hangars.

The old US Airways agreed to send all Airbus work to Pittsburgh, saving 600 of the 800 local maintenance jobs.

"The new company said they would honor the contract," Mr. Freiberger said, but, "they didn't like it. They were really upset."

Getting the work on 88 airplanes would probably mean recalling 400 to 500 mechanics from furlough, Mr. Freiberger said. Another union official, Frank Schifano, said a couple hundred would be needed at first and maybe 400 to 500 over time.

"It would be great for our local mechanics," Mr. Freiberger said.

It would also be a welcome bit of good news for a local US Airways work force already smarting from more than 9,000 job losses since 2001 and round after round of pay cuts and benefit reductions.

But Mr. Bertolini, the spokesman, pointed out that the combined airline still has to meld separate contracts covering 3,000 mechanics at the old US Airways (represented by the IAM) and 800 at the old America West (represented by the International Brotherhood of Teamsters). The National Mediation Board will determine which union represents all US Airways workers.

The provisions of that single contract, Mr. Bertolini said, are still "to be determined, including the amount of work and how it is done. We need to see what the new all-encompassing contract looks like before we can answer this type of question definitively."

Mr. Schifano believes the IAM contract will supersede the Teamsters contract because US Airways is the surviving company.

Of course, the Teamsters could argue that America West may have changed its name but that it actually bought US Airways -- its executive team is in charge and the airline is based in Tempe at America West's old headquarters.

A Teamsters spokesperson could not be reached for comment.