DALLAS (AP) — Federal officials are investigating Southwest Airlines over the way it handled structural repairs on dozens of jets, according to a person familiar with the situation.

The Federal Aviation Administration confirmed Tuesday that it is investigating whether Southwest followed safety orders dealing with the maintenance of older planes.

Inspectors believe Southwest and a repair shop near Seattle conducted repairs on 44 jets without getting FAA approval first.

The person familiar with the matter did not want to be identified because he was not authorized to discuss an ongoing investigation.

Last year, Southwest agreed to pay $7.5 million to settle charges that it operated nearly 60,000 flights with planes that had missed mandatory inspections for structural cracks. In September, the FAA ordered Southwest to replace unapproved parts on about 50 planes.