Audit slams safety US oversight of Southwest Airlines

The Federal Aviation Administration's lax oversight allowed Southwest Airlines to put millions of passengers at risk, according to a new audit that adds to scrutiny of the US regulator.

The audit shows the FAA, already facing questions for its certification of the grounded Boeing 737 MAX, permitted domestic-focused Southwest to operate planes purchased from other carriers in an "unknown airworthiness state."

Southwest operated more than 150,000 flights that did not meet US standards, the FAA's inspector general said in the report released Tuesday.

The airline was "putting 17.2 million passengers at risk," according to the Transportation Department's internal watchdog.

The criticism relates to 88 planes Southwest acquired from international airlines between 2014 and 2018 that FAA officials cleared for service without ensuring the planes met US safety standards.

FAA officials relied on summary data provided by Southwest "rather than conducting a comprehensive review of aircraft records themselves," the audit said.

The regulator "used the carrier's summary documentation to complete their review expeditiously to meet the air carrier's timelines, rather than performing an independent analysis," the report said.