WASHINGTON -- U.S. Rep. Chip Cravaack is challenging the Transportation Security Administration and the White House over potential cuts to a program that arms airline pilots as the last line of defense against hijackers.

As part of its Department of Homeland Security budget, the U.S. House this summer passed a Cravaack amendment that would increase funding for armed-pilot training by $10 million.

The Republican-backed House bill takes aim at the TSA and White House proposal to slash funding by half, a move spurred by one key fact: No pilot has used a gun on an airplane in the decade since Congress approved the program.

During his time as a commercial pilot for Northwest Airlines, Cravaack, R-Minn., says he packed a pistol as a member of the Federal Flight Deck Officer program. As he pushes for a boost in funding, Cravaack has spent the spring and summer telling his colleagues in Congress that trained, armed pilots are a necessary security backstop.

"Ultimately, they are the ones that are going to stop the terrorists," Cravaack told a crowd during a speech at the Heritage Foundation this spring.

The showdown between the Minnesota congressman and the TSA illustrates the tense debate over which federal programs created in the aftermath of the Sept. 11 attacks should stick around.

"It's been a controversial program since it started," said Jeff Price, an aviation security expert and aviation professor at Metropolitan State University of Denver.

As part of the legislation that created the TSA, Congress approved the armed-pilot program less than a year after terrorists hijacked and crashed several commercial airliners. The number of program participants is classified, but Cravaack maintains that armed pilots outnumber federal air marshals and are far less expensive.

Cravaack's amendment would boost the training budget to $35.5 million by pulling funds from TSA payroll and maintenance accounts. He says underfunding in the armed-pilot program has left a backlog of willing volunteers waiting for background checks.

The White House and Homeland Security want to slice the budget in half, to $12.5 million from $25 million. They point to revamped safety plans they say are a more efficient and economical means of providing security.

Price said critics question the usefulness of the weeklong training because federal marshals and other law enforcement officers undergo longer, more intensive firearms instruction. International standards established by a United Nations agency recommend that pilots carry nonlethal weapons, such as electronic stun guns.

Since the armed-pilot program began in 2002, no pilot trained in the program has purposely used the government-issued Heckler & Koch semiautomatic pistol. One pilot accidentally fired a round in 2008, blasting a small hole in the plane as the crew prepared to land.

Budget battle

A freshman lawmaker representing northeastern Minnesota, Cravaack has made aviation security one of his calling cards on Capitol Hill. Two of his friends died in the Sept. 11 attacks.

Cravaack told TSA officials in May that the country's next large-scale terrorist attack will emerge from people who sneak weapons on planes because of lax security around aircraft parked at the gate.

"The next incident is going to come ... from the shadow of the aircraft," he said. "It's not going to come through the passenger terminal."

Cravaack declined to make himself available for an interview for this story. He has said that the White House and TSA would cripple the program by cutting its budget, but Homeland Security Secretary Janet Napolitano and TSA officials deny that claim.

Department of Homeland Security spokesman Peter Boogaard said the agency values the armed-pilot program as another layer of security. However, he said, administrators must deal with fiscal restraints. To trim the budget, Boogaard said, the agency might restructure the program's training contract, consolidate facilities and focus its efforts on recertification of already-trained pilots, rather than training new volunteers.

The Air Line Pilots Association and National Rifle Association are among the organizations that support Cravaack's push.

Airlines for America, a trade association that represents Delta Air Lines and many of the country's other major carriers, said it supports the program "as one part of the layered approach to security."

The White House's Office of Management and Budget says beefed-up security measures -- including locked cockpit doors and enhanced security screening -- have decreased chances of "unauthorized cockpit access," but notes that Congress has the right to overrule its recommendation.

The Senate Appropriations Committee approved $24 million for the program, a slight decrease from last year. The full Senate has not taken action on the bill.

Price, the aviation security expert, said the program's value is hard to gauge.

"What we can't measure is deterrence," he said.

Corey Mitchell is a correspondent in the Star Tribune Washington Bureau. Twitter: @StribMitchell