Delta Air Lines says it expects to cancel more flights this week as it tries to recover from a severe technical failure.
As of Monday afternoon local time, the airline had grounded nearly 900 flights, bringing the total number of flights grounded since the incident last Friday to almost 4,700. Delta Air Lines said it is working "around the clock" to restore operations, with more than half of its global IT business, which relies on the Microsoft Windows operating system, impacted by a software error.
Delta Air Lines CEO Ed Bastian said in a video message to employees on Monday that it might take several days for the company to get back on track.
In the massive outage, Delta performed the worst among US airlines, with most other carriers resuming operations over the weekend. The problems began with a software update by CrowdStrike last Friday that caused the airline to be unable to process many changes in flights and crew members. This created a domino effect, making it impossible for Delta Air Lines to fully align crew members and planes.
"When their crew management system came back online, they had a much more complex problem to solve than the other airlines," said Bob Edwards, former chief information officer of United Airlines. "It took them longer to recover from the initial blow."
Delta Air Lines said ensuring that one of the most critical systems in place for all of its flights to have crew members is "very complex and requires a lot of time and manual support to synchronize."
Delta Air Lines CEO Bastian acknowledged in the video message to employees that this is not the company's finest hour.
"It's been a terrible weekend for all of us," he said. "This problem came out of nowhere."