Aviation Transportation System Security Plan, Supporting Plan to the National Strategy for Aviation Security, March 26, 2007 [open pdf - 114KB]
"The United States Government responded to the attacks of September 11, 2001, with an unambiguous, comprehensive increase in measures to enhance aviation security. Significant improvements were made to existing security methodologies, operations, and technologies through the creation of systems of security in each area of the Aviation Transportation System. The United States Government established a scalable, flexible aviation security system that is responsive to varying threat levels and to the range of current and future threats to the United States and effectively reduced vulnerabilities within the Aviation Transportation System. Greater scrutiny has been paid to individuals in the aviation system from pilots and crew to passengers and workers on the airside. Significant enhancements were made in the ability to detect threat objects and explosives that could be brought on or otherwise used against aircraft, and increases in the security posture of the entire Air Domain were made. […] The Aviation Transportation System Security Plan (Plan) continues, expands, and enhances efforts to further reduce vulnerabilities in all critical system areas. This Plan directs aggressive efforts to: (1) ensure that anyone entering or using the Aviation Transportation System has been identified and vetted or screened; (2) ensure the United States Government is taking all reasonable measures to detect and prevent the use of weapons against elements of the Air Domain, or to use the Aviation Transportation System to transport, become a weapon, or serve as a means of dispersal of weapons including Chemical, Biological, Radiological, Nuclear, or High-Yield Explosives (CBRNE)2, as well as liquid explosives; and (3) harden the critical elements of the Aviation Transportation System infrastructure against other forms of attack, such as Man-Portable Air Defense Systems (MANPADS) and stand-off weapons or cyber attack."
Department of Homeland Security: http://www.dhs.gov/