Delta continued to be plagued with cancellations on Monday, struggling to recover from Friday's CrowdStrike global IT outage.
As of Monday evening, Delta had canceled more than 950 mainline flights, amounting to 19% of its Monday schedule, according to flight-tracker FlightAware. That figure doesn't account for the Delta Connection regional network, which is flown by contracted operators. Delta regional subsidiary Endeavor Air, which is one of those operators, had canceled 103 flights, or 15% of its network.
Monday marks Delta's fourth consecutive day of heavy cancellations after the CrowdStrike outage impacted the Microsoft Windows operating system that Delta and other airlines use. According to airline industry data provider OAG, Delta, including Delta Connection, canceled 4,675 flights between Friday and Sunday, more than any other airline by far. United canceled the second-most flights over that period with 1,706, but had restored its network as of Monday, FlightAware shows.
American canceled 860 flights from Friday through Sunday, with most of problems occurring on Friday.
The CrowdStrike failure also took a heavy toll on Spirit Airlines, which struggled operationally from Friday through Sunday, canceling 550 flights in its much smaller network than the largest three U.S. airlines. Spirit's operation appears to be operating normally on Monday.
In a Sunday update to customers, Delta CEO Ed Bastian explained that the carrier has a "significant number" of applications in the Windows operating system. In particular, he said, one of Delta's crew-tracking tools was affected and therefore could not process the large number of scheduled changes triggered by the operational disruption.
Compounding the problem for customers, Bastian noted, is that the outage occurred on Delta's busiest travel weekend of the summer, when booked aircraft loads exceeding 90% made re-accommodation especially challenging.
"I want to apologize to every one of you who have been impacted by these events. Delta is in the business of connecting the world, and we understand how difficult it can be when your travels are disrupted," Bastian said.
Delta's travel waiver related to the disruption now extends through Tuesday. Fare differences will be waived for rebookings for travel beginning not later than July 28.
The airline is also providing travel vouchers and SkyMiles points to impacted customers.
Travel Weekly has reached out to Delta for an update on when its operation is expected to return to normal.
Correction: Delta regional subsidiary Endeavor Air canceled 15% of its flights on July 22. An incorrect percentage was reported previously.