The Federal Aviation Administration has nearly completed a review of United Airlines it opened in March to ensure the carrier’s compliance with safety regulations, the agency’s head said on Wednesday.

The FAA initiated a formal evaluation of the Chicago-based airline after a series of safety incidents earlier this year. FAA Administrator Mike Whitaker told reporters after a speech that the review “is almost finished.

United in April said it had delayed the start of two new international routes, citing a pause on some certifications by the FAA following the opening of the safety review.

Whitaker said in May the carrier could accept delivery of new planes after requiring the presence of FAA personnel when United conducted final inspections of new aircraft replacing older models.

On March 15, an external panel was found to be missing from a United aircraft when it landed in Oregon. Before that, a United-operated Boeing 737 MAX rolled onto the grass in Houston and another United 777 lost a tire after takeoff and was diverted to Los Angeles, where it landed safely.

United CEO Scott Kirby was asked at an industry forum Tuesday about the FAA review and he referred to the three widely publicized incidents. “None of them were related,” Kirby said. “While there have been no major findings in that process … it confirmed that that foundation was really strong.”

In July, the FAA said it was launching a similar safety review of Southwest Airlines after a series of near-miss incidents involving pilot-related issues that raised serious concerns. Whitaker said the Southwest review “is a bit more narrow.”

Southwest told pilots this week it would hold a safety day for pilots providing for frank discussions without fear of retribution, “an in-depth, facilitated, peer-to-peer discussion about specific events.” Pilots will attend between November 2024 and early 2025 based on schedules and availability.

Whitaker said he has had conversations with Southwest CEO Bob Jordan about the issue. “They are working it, we are working with them — so pilot training seems like an appropriate outcome,” Whitaker said.