JOHNSTOWN, Pa. -- At the behest of Pennsylvania's Rep. John Murtha, the House Defense Appropriations Subcommittee chairman, the Pentagon has spent about $30 million equipping a little-used airport named for the congressman so that it can handle behemoth military aircraft and store combat equipment for rapid deployment to foreign battlefields.

Most of the expensive improvements, funded through appropriations approved by the subcommittee chaired by Mr. Murtha, D-Johnstown, have not been used for their intended purpose. The projects delighted National Guard and reserve units based in Mr. Murtha's Pennsylvania district, who have suffered from budget cuts, but critics charge that the expenditures are a waste of taxpayer dollars.

Mr. Murtha and other supporters say the upgrades make the airport a critical backup if a military crisis or terrorist attack ever derails operations at the Pittsburgh International Airport, two hours away.

"Congressman Murtha has added billions of dollars for the National Guard and Reserves over the years," said Murtha spokesman Matt Mazonkey. "Ensuring that they have the necessary facilities, equipment and training for both overseas deployments and state emergency response is not only his priority, it's his job."

Several active military officials contacted about the projects declined comment. The Pennsylvania Air National Guard Adjutant General Jessica Wright said that although the unit has never before required a separate emergency location to stand in for Pittsburgh International, " it's a matter of that one time you can't."

Some locals call the Johnstown airport "Fort Murtha" because of the steady stream of wartime projects announced at the facility. Although the airport's runway is capable of servicing the largest airplanes in North America, it is used only by small commuter airplanes that make six trips a day back and forth to Dulles International Airport in Virginia.

Many of the commercial flights, subsidized by federal transportation dollars, carry only a handful of passengers. On a recent visit, all of the flights departing the airport were less than half-full, and one had only four passengers -- screened by seven federal airport workers.

All told, Mr. Murtha has steered about $150 million in federal funds to the airport. This spring, it was among the first four in the country to receive stimulus funds -- $800,000 for a runway widening project.

In 2005, Mr. Murtha shared his vision of turning the tarmac into a military hub. Projects included $17.8 million for a runway, $12 million for a stronger loading area and $1 million for a wider turning lane. The Army also paid $750,000 to lease adjoining airport land where it announced plans to build humidity-controlled sheds for storing sensitive equipment.

"Nobody wants to say 'no' to Congressman Murtha or make him mad because he controls defense appropriations," said Melanie Sloan, executive director of the Citizens for Responsibility and Ethics in Government, a government watchdog group. "Murtha wanted an airport, and he knew he could get one. It's like he's a billionaire, except it's not his money."

Johnstown-Cambria County Airport Authority Chairman Raymond Porsch said the authority wasn't actively involved in crafting the vision of an alternative military base at Johnstown. "We're basically out of the loop in terms of knowing what the military wants or is planning," he said. But Mr. Porsch said he supports new infrastructure in Johnstown to create jobs.

It's not the only military expenditure at the Johnstown airport whose utility is in doubt. Mr. Murtha pushed for the Pentagon to install a state-of-the-art digital radar surveillance system to spot weather systems more than 100 miles away. But the radar tower, built by Raytheon at a cost to taxpayers of $8.6 million, has never been used or monitored by any personnel since its completion in 2004.

The National Guard bureau says this kind of radar, funded via Mr. Murtha's requests, is not part of its plans or priorities for its Johnstown unit of air traffic controllers, and it has no plans to staff it.

But the Pennsylvania-based unit argues that Mr. Murtha's radar is a "perfect complement" to its air traffic control unit's mission. The guard has been paying an electric bill to keep the unmanned radar spinning, roughly $1,500 a month, but says it hopes in the future to staff it.