U.S. Sens. Arlen Specter and Bob Casey slammed US Airways yesterday for what they called "breached" commitments to the Pittsburgh area and urged the airline to reconsider its vast cutbacks and its treatment of local workers.

"The point is, we've gone to hell and back for [US Airways], and they've thumbed their nose at the city," Mr. Specter, a five-term Republican, told reporters.

In a statement, airline officials said they were reacting to market realities and couldn't stand by promises made before US Airways merged with Tempe, Ariz.-based America West Airlines in 2005.

As recently as Aug. 24, US Airways Chief Executive Doug Parker sent an e-mail message to a union leader saying that the airline had no plans to further reduce its presence in Pittsburgh.

But six weeks later Mr. Parker announced a decision to cut another 40 flights in January, eliminate 450 local jobs and shift 500 local pilots and flight attendants elsewhere in its system, leading to the closure of its Pittsburgh crew base.

That will leave the region's largest carrier with just 68 daily flights and 1,800 local employees, down from highs of 542 flights and 11,995 people in September 2001.

US Airways also announced yesterday that it is offering buyouts to 314 senior flight attendants in the area.

In a letter to Mr. Parker, Mr. Specter and Mr. Casey criticized the company for not offering the same deal to machinists, pilots and ground workers who don't want to relocate after their Pittsburgh jobs are eliminated.

"A lot of these people want to stay in Pittsburgh. They shouldn't be penalized," Mr. Casey said. "We're not asking for much. We're asking for basic fairness."

In a separate letter, Mr. Specter said his support for the airline has been "steadfast" since the $1 billion Pittsburgh International Airport opened in 1992 with US Airways as its main tenant. From 1995 to 2007, Mr. Specter said, he wrote 11 letters supporting applications for new international routes. He also backed US Airways' 2002 application for federal loan guarantees following the 9/11 attacks.

In December 2002, an airline official called Mr. Specter to contact the U.S. secretaries of labor, commerce, and the treasury for urgent help with its talks with Alabama's state pension fund.

"Well, getting somebody on a Friday afternoon is pretty tough stuff, especially in Christmas season," Mr. Specter said. "I went to bat and got those people."

But on March 30, 2003, as US Airways emerged from its first bankruptcy, the airline rejected its lease agreements with the Allegheny County Airport Authority. Mr. Specter said he "was advised that this action violated a written promise to honor the lease agreements made by US Airways only weeks earlier."

Then in May 2004, US Airways stripped Pittsburgh of its hub status "and with it the service expectations envisioned by the public when the airport was constructed to US Airways' specifications for $1 billion," the senator wrote.

In late August, Mark Gentile, president of Association of Flight Attendants Local 40, contacted the airline CEO after hearing rumors that Mr. Parker had said something to a Charlotte, N.C., training class about a "big reduction in Pittsburgh." Mr. Parker, he said, "immediately" messaged the union official back with the assurance that Pittsburgh was safe.

"I certainly don't want to shrink [the airport] any more than we have," Mr. Parker wrote. "We currently have no plans to do so."

Mr. Gentile informed his members that rumors of a dramatic downsizing were unfounded.

About three weeks later, Mr. Parker visited Pittsburgh for a Sept. 12 Steelers-themed plane dedication, and hinted that more flight cuts might be on the way, saying Pittsburgh was now "marginally unprofitable."

Mr. Gentile said he talked to Mr. Parker that same day and was told "we are losing money on a couple of flights" and that "we are going to have to take a look at that." There was nothing about a shutdown of "the whole base," Mr. Gentile said.

On Oct. 3, Mr. Gentile said he got a call at 9:30 a.m. informing him of the airline's decision to make new cuts. "I went running upstairs and confronted" Mr. Parker, who was in Pittsburgh to tell employees what was happening. Mr. Gentile asked the CEO about the assurances given in the Aug. 24 e-mail.

"I think he said something about 'I know what I wrote you.'"

"I said, 'I better read it to you again.'"

"Doug said, 'I had to. We are losing $40 million a year. We can't operate like that.'"

Not satisfied with that explanation, the Association of Flight Attendants hired a financial analyst to examine the company's books. "I didn't see anything compelling in the company's justification for why this had to be done," Mr. Gentile said. "Not to this extent."

In a statement, US Airways said, "The airline industry today is vastly different than it was 15 years ago when the commitments Sen. Specter references were made, and long before the merger of US Airways and America West. Since that merger, we've worked very hard to find ways to make Pittsburgh viable against the new realities of the industry, including the impacts of low-cost carriers and sky-high fuel prices.

"Our decision to draw down flying again -- made two years after the merger -- reflects a great deal of soul-searching and our best judgment of ways to make Pittsburgh viable, and measured against a backdrop of the right decisions for all employees across the US Airways system."

That mirrors what Mr. Parker argued to Mr. Specter in a prior letter sent on Oct. 15, after the senator complained to an Airport Area Chamber of Commerce luncheon about US Airways' customer service and its lack of "consideration" for this area.

The CEO said he was not with the airline when some of these decisions were made and even offered an apology to the senator "if one of my predecessors led you to believe that US Airways would commit to maintaining service levels in Pittsburgh similar to where it was in the 1990s."

Mr. Parker joined US Airways two years ago when he engineered the merger of the old US Airways, based in Arlington, Va., with America West Airlines.

Mr. Specter dismissed his arguments, saying the airline still has a duty to uphold commitments made by its former leadership.

"I would like to see them get out a sharp pencil and go back to the drawing board," he said. "If Southwest [Airlines] can add lines, and other carriers can add lines, so can US Airways."

He and Mr. Casey said they planned to convene a meeting of the full Pennsylvania congressional delegation to discuss how to handle the airline's future legislative needs, although Mr. Specter added that lawmakers weren't "making any threats."

Still, he said of the airline, "I think they'll feel this pressure."