The Bush administration is checking the accuracy of a watch list of suspected terrorists banned from traveling on airliners in the US and will probably cut the list in half, the head of the Transportation Security Administration said on January 17.

Kip Hawley told the US Congress that the more accurate list, combined with a new passenger screening system, should take care of most incidents of people wrongly being prevented from boarding a flight or frequently being picked out for additional scrutiny.

A "no-fly" list of suspected terrorists and criminals considered too dangerous to travel on commercial airliners in this country has existed for decades. But since the terrorist attacks of Sept. 11, 2001, the list expanded. Tightened security procedures have led to closer scrutiny of air travelers and resulted in many complaints.

The TSA has been working with intelligence agencies and the FBI to improve the watch list. Before the 9/11 attacks, almost every intelligence agency had its own list of undesirables and resisted sharing it with other agencies.

Even cutting the list in half is "nice but not all that meaningful," said Barry Steinhardt, an attorney with the American Civil Liberties Union. He noted that various estimates of the list's size, which is classified, have ranged from 50,000 to 350,000 names.

"Cutting a list of 350,000 names is not all that impressive," Steinhardt added.

At a hearing of the Senate Commerce Committee, Hawley ran into inquiries from lawmakers with family members or friends who had encountered problems at airport checkpoints.

Among them was Sen. Ted Stevens, R-Alaska, who complained that his wife, Catherine, was being identified as "Cat" Stevens and frequently stopped due to confusion with the former name of the folk singer now known as Yusuf Islam, whose name is on the list. In 2004 he was denied entry into the US, but officials declined to explain why.

Hawley explained that Secure Flight, the new passenger screening program, which he hopes will be running in 2008, would make such problems "a thing of the past."

Hawley said his agency sends correctives to the airlines.

"Unfortunately, it depends airline by airline how their individual systems work as to how effectively that's done," he said.

Hawley was questioned by Sen. Jay Rockefeller, D-W.Va., about the lack of screening for passengers on private aircraft, which Rockefeller called "very disturbing."

Hawley said there are many security measures in place on the ground around general aviation terminals, but that the department is considering the longer-term issue of whether such private flight passengers should be subjected to individual screening.

Senators also asked Hawley about a provision recommended by the 9/11 Commission, and passed by the House last week, that would require 100 percent physical inspection of all air cargo loaded onto passenger planes. The Senate has yet to act on the measure.

"We prefer not to have a 100 percent requirement on anything," Hawley said. "Because you tend to be focused then on, how do we accomplish what is written in the law, as opposed to a smarter security that says, okay, we're in a risk-based business, how are we going to stop the bomb from being in here?"

Also, the Homeland Security Department launched a new program for passengers who feel wronged to try correcting the list on January 17.

The program will give travelers "a clearly-defined process" to report problems, said Homeland Security Secretary Michael Chertoff in a written statement.

Beginning Feb. 20, the program, dubbed Traveler Redress Inquiry Program, will serve as a central processing point for all inquiries about Homeland Security agencies' databases.