by Delta Air Lines struggled for a fourth straight day to recover from a global technology outage caused by a faulty software update that stranded tens of thousands of passengers and drew unwanted attention from the federal government.
Other carriers were returning to near-normal levels of service disruptions Monday, intensifying attention on Delta’s relatively weaker response to the outage that has hit airlines, hospitals and businesses around the world.
Transportation Secretary Pete Buttigieg spoke with Delta CEO Ed Bastian on Sunday about the high number of flight cancellations since Friday. Buttigieg said his agency has received “hundreds of complaints” about Delta, and he expects the airline to provide hotel rooms and meals to delayed travelers and quickly refund customers who don’t want to be rescheduled for a later flight.
“No one should be stuck in an airport all night or on hold for hours to speak to a customer service agent,” Buttigieg said. He pledged to help Delta passengers by enforcing consumer protection rules for air travel.
Delta has canceled more than 5,500 flights since the outage began Friday morning, including at least 700 flights canceled Monday, according to aviation data provider Cirium. Delta and its regional subsidiaries accounted for about two-thirds of all cancellations worldwide Monday, including nearly all of those in the United States.
United Airlines has been the worst-hit airline since the outage began, canceling nearly 1,500 flights. As of late Monday morning, United had canceled just 17 flights.
Other airlines affected by the first wave of groundings also resumed normal operations Monday. They include American Airlines, Spirit Airlines, Frontier Airlines and Allegiant Air.
Bastian, Delta’s CEO, said in a message to customers Sunday that the airline was continuing to restore operations that had been disrupted. One of the tools Delta uses to track crews was affected and was unable to process the high number of changes triggered by the outage.
“The technical issue occurred during the busiest weekend of the summer, with a booking rate above 90%, which limited our replenishment capabilities,” Bastian wrote. Booking rate is the percentage of seats sold on each flight.
Airlines have large, multi-layered technology systems, and crew tracking programs are often among the oldest. When the outage began Friday, it also affected systems used to check in passengers, schedule crews and make pre-flight calculations about the weight and balance of planes, the airlines said. United and American reported intermittent problems communicating with crews in flight, contributing to their decisions to briefly ground all flights.
Some airlines, including Southwest Airlines and Alaska Airlines, do not use CrowdStrike, the cybersecurity software vendor whose faulty update to Microsoft Windows triggered the outages. Those airlines have had relatively few cancellations. Aviation experts say Delta likely has more systems running Microsoft Windows than other airlines.
“The impact of the CrowdStrike IT outage will linger for a few more days and will remain on the minds of travelers whose vacations were canceled for even longer,” John Grant, senior analyst at travel data provider OAG, said in a blog post. “Events like this highlight the challenges of an industry reliant on external IT systems that can, and likely will, fail again in the future.”
Atlanta-based Delta has offered waivers to make it easier for customers to reschedule their trips.
The Delta debacle is reminiscent of the December 2022 debacle that caused Southwest Airlines to cancel nearly 17,000 flights over a 15-day period. After a federal investigation into 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 Department of Transportation.
The airline industry may be the most visible victim of the global technology problems caused by the faulty software update from CrowdStrike, a Texas-based cybersecurity company. Microsoft said the problem affected 8.5 million computers. CrowdStrike said it has deployed a patch, but experts estimate it could take days or even weeks to fix every affected computer.
