GovernmentExecutive.com

The Government Accountability Office in a report Wednesday (GAO-07-375) noted progress made in protecting the United States from terrorism since the Sept. 11, 2001, attacks, but said additional measures are necessary to fill gaps that remain in security.

"While the nation cannot expect to eliminate all risks of terrorist attacks upon commercial aviation, agencies have made progress since Sept. 11 to reduce aviation-related vulnerabilities and enhance the layers of defense directly exploited by the terrorist hijackers," the report states. "In general, these efforts have resulted in better airline passenger screening procedures designed to identify and prevent known or suspected terrorists, weapons, and explosives from being allowed onto aircraft."

The reported plot to detonate liquid explosives on passenger airplanes flying between the United Kingdom and the United States proves that the aviation system remains an attractive target for terrorists, the report states.

The Homeland Security Department "and others need to follow through on outstanding congressional requirements and recommendations by GAO and others to enhance security and coordination of passengers and checked bagging, and improve screening procedures for domestic flights, among other needed improvements," it says.

Homeland Security must continue to prepare a "risk-based framework" for allocating resources to protect U.S. critical assets such as power plants and passenger rail stations, according to the GAO report.

The government must also address the issues of information sharing, risk management and transformation of the Homeland Security Department, the report said.