Delta Air Lines Cancelled Flights in the Fourth Day of a Global Software Outage and the U.S. Transportation Department Investigated the Incident

Delta Air Lines has canceled hundreds of flights for the third day in a row, as the airline is struggling to recover from Friday’s global software outage — even as other U.S. airlines are bouncing back and returning to normal operations.

In the public letter, Bastian wrote that several Delta applications run on Microsoft Windows, resulting in many tools being impacted in the outage. The crew tracking tool was inoperable because of the system shutdown and couldn’t process the amount of changes that were triggered.

The airline offered travel waivers to customers on flights impacted by the outage, allowing them to change itineraries and rebook their flights without any added fees.

In a post on X, Transportation Secretary Pete Buttigieg called out the airline on Sunday for its continuous disruptions and “unacceptable customer service.”

Buttigieg added that under new federal regulations, customers are not obligated to accept the travel credit offered to rebook flights but, instead, are entitled to a prompt cash refund.

Pete Buttigieg told Delta they must take care of their passengers and honor their customer service commitments.

Following the incident, the U.S. Transportation Department ordered Southwest to pay $140 million in a civil penalty, which was by far the largest the DOT has ever levied for consumers, the department said in a statement announcing the penalty.

The Department of Transportation opened an investigation into the recent flight disruptions at Delta due to the high volume of consumer complaints.

“This is not just the right thing to do, it’s the law, and our department will leverage the full extent of our investigative and enforcement power to ensure the rights of Delta’s passengers are upheld,” he added.

The airline said it was focused on restoring its operations after IT systems all over the world were rendered inoperable due to a faulty Windows update.

A flawed software update from a cybersecurity group left millions of Microsoft users offline. CrowdStrike said the problem was not a cyberattack but a “software glitch.” The company said it removed the problematic channel file that affected the customers’ systems after identifying the issue.