The U.S. Federal Aviation Administration says it should have done a better job of ensuring Southwest Airlines had certified completion of maintenance on 88 used Boeing 737 jets, as noted in a report by the U.S. Transportation Department's Inspector General seen by Reuters ahead of its release.
The report, to be released on Thursday, said Southwest operated more than 150,000 flights carrying 17.2 million passengers on 88 used Boeing 737 jets without confirmation that required maintenance had been completed.
The report said the FAA has not "effectively overseen Southwest Airlines' systems for managing risks." The FAA said in a response included with the report it concurred with all 11 recommendations by the inspector general.
The FAA has also come under scrutiny from lawmakers for its oversight of the newer Boeing 737 MAX jet, which was grounded last March after two crashes that killed a total of 346 people.
On the separate issue of Southwest's maintenance practices, the agency said it agreed its office overseeing the airline "did not perform in accordance with existing guidance" by allowing the 88 planes to enter service and that it "lacked a comprehensive conformity inspection for used aircraft."
Southwest told Reuters Tuesday that eight of the 88 used jets remain out of service until needed repairs are completed. Southwest added it disagreed with some of the report's findings, calling them "unsubstantiated references" to lax safety practices.
The inspector general's report said: "Given the significant unresolved safety concerns that FAA has identified at Southwest Airlines, it is clear that the agency is not yet effectively navigating the balance between industry collaboration and managing safety risks at the carrier."
It chided the FAA, saying the agency "accepted the air carrier's justification that the issues identified were low safety risks." It also said FAA's laxity meant the agency "cannot provide assurance that the carrier operates at the highest degree of safety in the public's interest, as required by law."
The FAA noted it changed the leadership of its office that oversees Southwest and it "continues to address deficiencies in the work functions and culture." The agency has agreed to ensure Southwest "complies with regulatory requirements that the 88 previously owned aircraft conform to U.S. aviation standards."
Southwest said it has completed a thorough review of 80 aircraft "and the analysis of findings indicates very low risk, well within acceptable parameters per our FAA-approved Safety Management System."
The report also said FAA violated its own guidance in addressing non-compliance by Southwest on weight and balance data. FAA agreed to ensure Southwest complies with requirements "to provide accurate weight and balance information" or to grant an exemption for non-compliance.
Last month, the Wall Street Journal published an article on a draft of the inspector general report.
On Jan. 10, the FAA said it was seeking to impose a $3.92 million fine on Southwest for alleged weight infractions on 21,505 flights on 44 aircraft between May 1, 2018 and Aug. 9, 2018.