Delta’s operational difficulties, triggered by the July 19 CrowdStrike outage, have continued into a fifth day.

As of 12:30 p.m. Eastern time, the airline had canceled 460 mainline flights on Tuesday, accounting for 13% of its schedule, according to FlightAware. Additionally, 21% of Delta’s schedule was delayed.

Endeavor, Delta’s subsidiary operating Delta Connection regional flights, saw cancellations moderate to 2% of its Tuesday schedule.

Delta explained that more than half of its worldwide IT systems are Windows-based, and the CrowdStrike failure required manual repairs and reboots. Synchronizing various applications added to the delay.

“Delta’s crews are fully staffed and ready to serve our customers, but one of Delta’s most critical systems – which ensures all flights have a full crew in the right place at the right time – is deeply complex and is requiring the most time and manual support to synchronize,” the airline said.

Delta will issue SkyMiles points or travel vouchers to impacted customers and reimburse hotel, meal, and transportation expenses. Affected customers can request refunds at delta.com/refund.

BSOD Windows 10
The faulty CrowdStrike update caused Windows machines to become inoperable, displaying this image called the ‘blue screen of death’ or BSOD.

Delta customer Akhtar Nawab, a Diamond Medallion member, criticized the airline’s response. He endured a 14-hour journey from Orange County to New York LaGuardia via Minneapolis due to delays. His flight from LaGuardia to Norfolk, Va., was also repeatedly delayed. Frustrated, his family rebooked on Southwest for a subsequent leg of their journey.

“It’s insane that they’re not prepared at all for this,” Nawab said. He also noted that agents at Delta’s specialized Diamond Medallion call center lacked helpful information.

Delta acknowledged the strain on its digital tools but noted customers were informed about delays and cancellations via text and the Fly Delta app, with rebooking options available online.

Delta’s travel waiver, waiving fare differences for rebookings starting by July 28, expires at the end of July 23.

Despite Tuesday’s cancellations, Delta seems to be making progress. The carrier canceled 1,159 mainline flights on Monday, with Tuesday’s cancellations occurring at a slower pace.