The Transportation Security Administration’s (TSA) use of subsets of the federal government’s consolidated terrorist watch list to vet passenger information before boarding commercial flights does reduce threats to commercial aviation although threats remain, the Department of Homeland Security (DHS) Inspector General says in a report released yesterday.

“Although the No Fly and Selectee lists are largely successful in identifying potential terrorists who could threaten commercial aviation, some individuals not included on the lists may also present threats to aviation security,” says the report, Role of the No Fly and Selectee Lists in Securing Commercial Aviation (OIG-09-64). “Not all known or reasonably suspected terrorists are prohibited from boarding an aircraft, or are subject to additional security screening prior to boarding an aircraft. This is reflected in the number of records and identities in the TSDB (Terrorist Screening Database) that are not included on the No Fly and Selectee lists.”

The redacted report is dated July 20 and was prepared at the request of House and Senate Appropriators in the FY ’08 Homeland Security Appropriations Act. The report reviews TSA’s Secure Flight program, which requires the agency to vet passengers’ full names, date of birth and gender against the No Fly and Selectee subsets of the larger, consolidated federal TDSB.

Other factors are also important in improving aviation security, the IG says. Among these are intelligence gathering, law enforcement investigations, visa issuance, border protection, passenger screening, and behavior detection, and additional watch list screening within Secure Flight, the report says.