Southwest Airlines Co., which is accused of operating planes that had missed key safety inspections, said Tuesday it has placed three employees on leave and hired an outside expert to review its maintenance procedures.
The airline also said it has promised federal regulators that it will fix any shortcomings in its system of tracking maintenance work.
Last week, the Federal Aviation Administration proposed a $10.2 million civil penalty — the largest ever against an airline — after finding that Southwest had missed safety inspections for dozens of planes, then kept flying some of them before they could be examined.
At first, Southwest said it thought the FAA had closed the matter last year — noting that the company had reported the missed inspections itself.
But on Tuesday, Chief Executive Gary Kelly said that upon learning of the investigation last month, he ordered outside experts to look into Southwest's handling of the situation. The airline hired JDA Aviation Technology Solutions, a Washington-based firm headed by a former longtime FAA senior official.
The company sped up the review after it received formal notice of the proposed penalty Thursday, Kelly said.
"I am concerned with some of our findings as to our regulatory compliance processes," Kelly said in a statement. He said he insisted that the airline has the correct organizational structure "to ensure that the right decisions are being made."
Southwest did not identify the employees who were placed on leave by name or position. The airline said it was cooperating with the investigation. Spokeswoman Beth Harbin said the three are being paid.
The FAA said Southwest operated almost 60,000 flights with nearly 50 Boeing 737 aircraft that had missed a required inspection of their fuselage or body for small cracks. Such signs of metal fatigue have been considered an important safety concern since a deadly accident in 1988.
Meanwhile, documents released by congressional investigators paint a picture of FAA inspectors being too cozy with the airlines they regulate.
Two whistle-blowers told the House Transportation and Infrastructure Committee that FAA supervisors and colleagues blunted their attempt to force Southwest to follow an FAA order to re-inspect the planes.
The whistle-blowers, Charalambe Boutris and Douglas E. Peters, said safety and following the rules "have taken a back seat to personal friendships and favors" at the FAA's Irving regional office, wrote Special Counsel Scott Bloch, whose office investigates allegations of retaliation against government whistle-blowers.
FAA officials said last week that an FAA supervisor had failed to confirm that Southwest had grounded the jets but didn't know whether he lied about it.
Rep. James Oberstar, D-Minn., chairman of the committee that released the FAA documents, has said that the FAA needs to "clean house from top to bottom" and is too cozy with the airlines it regulates. He plans a hearing next month featuring the whistle-blowers.
Southwest has said it plans to appeal the $10.2 million penalty.