SSI got its start in the Air Transportation Security Act of 1974 ( Pub . L. No. 93-366 ) , which , among other things , authorized the Federal Aviation Administration ( FAA ) to prohibit disclosure of information obtained whose disclosure would constitute an unwarranted invasion of personal privacy ; reveal trade secrets or privileged or confidential commercial or financial information obtained from any person ; or would reduce the safety of passengers &mdash; all notwithstanding the Freedom of Information Act . On June 28 , 1976 , FAA published a proposal to create Title 14 Code of Federal Regulations ( CFR ) Part 191 entitled " Withholding Security Information from Disclosure under the Air Transportation Security Act of 1974 . " Part 191 created the category of sensitive but unclassified information now known as Sensitive Security Information ( SSI ) , and described the information to be protected from disclosure , including " the security program of any airport ; the security program of any air carrier ; any device for the detection of any explosive or incendiary device or weapon ; and , any contingency security plan . " Less than a year after the December 21 , 1988 , bombing of Pan Am Flight 103 over Lockerbie , Scotland , the President 's Commission on Aviation Security and Terrorism recommended improvements in FAA security bulletins , leading to the creation of Security Directives and Information Circulars . In 1990 , section 9121 of the Aviation Safety and Capacity Expansion Act of 1990 ( Pub . L. 101-508 ) broadened 14 CFR Part 191 to prohibit disclosure of " any information obtained in the conduct of security or research and development activities . " The Aviation Security Improvement Act of 1990 ( Pub . L. No. 101-604 ) required minimizing the number of people with access to information about threats , often contained in security directives ( SDs ) and information circulars ( ICs ) . On March 21 , 1997 , FAA revised 14 CFR Part 191 , and changed its title to " Protection of Sensitive Security Information . " It also strengthened the existing rule to protect SSI from unauthorized disclosure , expanded its application to air carriers , airport operators , indirect air carriers , foreign air carriers , and individuals , and specified in more detail the information protected to include SDs , ICs , and inspection , incident , and enforcement-related SSI
Pan Am Flight 103
Pan Am Flight 103
Sensitive Security Information