airport security
The passengers might be cleared, but what about airport workers? Getty

The American Transportation Security Administration was apparently so focused on nabbing would-be terrorists trying to board planes that it failed to identify at least 73 people hired at US airports with suspected links to terrorists or terrorist activity.

The active aviation workers, employed as airport vendors and hired by major airlines, should have been disqualified and flagged under terrorism-related activity codes by the TSA, reveals a new report by the Department of Homeland Security's inspector general. They weren't identified in part because the TSA is not authorised to receive all terrorism-related information under current inter-agency policies, the report said.

Besides missing workers with terrorism links, the TSA lacked "effective controls" to keep prospective employees with criminal histories and illegal status from getting jobs at airports.

Records used to vet the employees was sometimes based on documents and job applications missing information involving things like partial Social Security numbers or initials instead of full names.

TSA demands more terror watchlist data

The TSA also "relied on airport operators to perform criminal history and work authorisation checks, but had limited oversight over these commercial entities," the report notes. "TSA lacked assurance that it properly vetted all credential applicants.

"Without complete and accurate information, TSA risks [giving credentials to] and providing unescorted access to secure airport areas for workers with potential to harm the nation's air transportation system," the report found.

Despite the slip-up, which could have had catastrophic results, the agency's "multi-layered process to vet aviation workers for potential links to terrorism was generally effective. In addition to initially vetting every application for new credentials, TSA recurrently vetted aviation workers with access to secured areas of commercial airports every time the Consolidated Terrorist Watchlist was updated," the report found.

The report recommended, however, that the agency demand additional terror watch list data, require airports to obtain detailed right to work information on all employees, and improve vetting data.

Last week, a report based on an internal investigation revealed that Homeland Security officials were able to get banned items through security checks 95% of the time.