Delta faces US investigation over handling of system outage

Delta Air Lines Inc. is under investigation by US authorities over its handling of a technology glitch that has led to thousands of canceled flights.

The Department of Transportation has opened a probe “to ensure the airline is following the law and taking care of its passengers during continued widespread disruptions,” US Transportation Secretary Pete Buttigieg said Tuesday in a post on X.

The decision adds to the strain on the carrier after it said a day earlier that it expects cancellations to stretch later into the week. Delta has fared the worst among US carriers, with most other airlines getting back on track over the weekend after an outage Friday caused by CrowdStrike Holdings Inc. disrupted systems across numerous industries worldwide.

Delta didn’t immediately respond to a request for comment. The company said in a statement Monday that it was working “around the clock” to restore operations, with more than half of its worldwide IT relying on Microsoft Corp.’s Windows operating system affected by the software error.

The carrier canceled 430 daily flights as of Tuesday morning, or 12% of its normal schedule, according to tracking service FlightAware.com. That pushed its total since Friday’s breakdown to about 5,400 grounded trips.

By comparison, rival carriers American Airlines Group Inc., United Airlines Holdings Inc. and Southwest Airlines Co. had canceled fewer than 100 combined flights Tuesday.

Delta customers expressed frustration on social-media platforms, complaining about having their original and rescheduled flights canceled, lost baggage and not receiving food and hotel vouchers.

The airline abruptly barred anyone under 18 from traveling alone while it’s working through the flight disruptions, announcing the change on July 19, and later extending the ban from Sunday. “Those already booked will not be able to travel,” the carrier posted on its website. “Please do not book new travel for unaccompanied minors.”

Delta’s longer recovery stemmed from the outage’s impact on an internal system used to process changes to many flights and their crews. That created a cascading effect, leaving Delta unable to get its crews and planes fully aligned.