Most airlines except one are recovering from the CrowdStrike tech outage. The feds have noticed

Delta Air Lines struggled for a fourth straight day to recover from a worldwide technology outage caused by a faulty software update, stranding tens of thousands of passengers and drawing unwanted attention from the federal government.

Other carriers were returning Monday to nearly normal levels of service disruptions, intensifying the glare on Delta’s relatively weaker response to the outage that hit airlines, hospitals and businesses around the world.

Transportation Secretary Pete Buttigieg spoke to Delta CEO Ed Bastian on Sunday about the airline’s high number of cancellations since Friday. Buttigieg said his agency had received “hundreds of complaints” about Delta, and he expects the airline to provide hotels and meals for travelers who are delayed and to issue quick refunds to customers who don’t want to be rebooked on a later flight.

“No one should be stranded at an airport overnight or stuck on hold for hours waiting to talk to a customer service agent,” Buttigieg said. He vowed to help Delta passengers by enforcing air-travel consumer-protection rules.

Delta has canceled more than 5,500 flights since the outage started early Friday morning, including at least 700 flights canceled on Monday, according to aviation-data provider Cirium. Delta and its regional affiliates accounted for about two-thirds of all cancellations worldwide on Monday, including nearly all the ones in the United States.

United Airlines has been the next-worst performer since the outage started, canceling nearly 1,500 flights. United canceled only 17 Monday flights by late morning, however.

Other airlines that were caught up in the first round of groundings also returned mostly to normal operations by Monday. That included American, Spirit, Frontier and Allegiant.

Bastian, the Delta CEO, said in a message to customers Sunday that the airline was continuing to restore operations that were disrupted. One of the tools Delta uses to track crews was affected and could not process the high number of changes triggered by the outage.

“The technology issue occurred on the busiest travel weekend of the summer, with our booked loads exceeding 90%, limiting our re-accommodation capabilities,” Bastian wrote. Loads refers to the percentage of seats on each flight that had been sold.

Atlanta-based Delta has offered waivers to make it easier for customers to reschedule trips.

Delta’s meltdown is reminiscent of the December 2022 debacle that caused Southwest Airlines to cancel nearly 17,000 flights over a 15-day stretch. After a federal investigation of Southwest’s compliance with consumer-protection rules, the airline agreed to pay a $35 million fine as part of a $140 million settlement with the Transportation Department.

The airline industry might be the most visible victim of the worldwide tech problems caused by a faulty update of cybersecurity software from Texas-based CrowdStrike to Microsoft computers. Microsoft says the glitch affected 8.5 million machines. CrowdStrike says it has deployed a fix, but experts say it could take days or even weeks to repair every affected computer.