Delta under DOT investigation as meltdown hits Day 5, and 5,000 cancellations

Find updated coverage here: Delta says its operations are getting back on track — but plenty of questions remain

The Biden administration is opening up an investigation into Delta Air Lines as the carrier's operational meltdown stretched to a fifth day of mass cancellations in the wake of an IT outage affecting industries worldwide on Friday.

The U.S. Department of Transportation's Office of Aviation Consumer Protections is looking into the airline's "continued widespread flight disruptions," and "reports of concerning customer service failures," the agency said Tuesday morning.

That revelation comes as the Atlanta-based carrier has canceled 1,100 flights daily — or more — on four straight days from Friday through Monday.

On Tuesday, Delta had already canceled 442 additional flights as of 10:30 a.m. EDT, according to data from flight-tracking site FlightAware. That's about 12% of its operation. Flight cancellation totals on each of those days have mounted as the day has gone on, perhaps a foreboding sign for Tuesday's travelers.

More broadly, the disruptions have led to chaotic scenes at airports across the country, particularly at Delta's home base, Hartsfield-Jackson Atlanta International Airport (ATL).

Frustrated passengers, long lines for customer service and images of travelers resting on airport concourse floors have been commonplace in recent days.

"We have made clear to Delta that they must take care of their passengers and their customer service commitments," said Transportation Secretary Pete Buttigieg in announcing the investigation Tuesday, which "will continue to evolve," the department said, as it processes a high volume of consumer complaints.

Several U.S. airlines and many more globally were affected by Friday's IT glitch at Austin-based CrowdStrike, which caused major problems for Microsoft clients.

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However, Delta's problems have snowballed even as other U.S. carriers recovered.

Delta has canceled more than 5,000 flights since Friday, per FlightAware data. Its cancellation rate has regularly topped 30% in recent days, far exceeding the 0.3% of flights it had previously canceled in 2024.

Crew scheduling system problems

In an update Monday, CEO Ed Bastian noted nearly half of the carrier's global IT systems are Windows based, and required Delta staff to manually repair and reboot each machine, "with additional time needed for applications to synchronize and start communicating with each other."

Delta cites particular troubles with its critical crew-scheduling system, which helps the airline get crews to the right place at the right time.

U.S. travelers know all too well how significantly crew scheduling software outages can affect air travel. Southwest Airlines' holiday 2022 meltdown was greatly exacerbated by problems with its crew scheduling systems, which caused mounting problems — and contributed to nearly 17,000 cancellations – following a December winter storm just before Christmas.

"It's critical because you have to get the aircraft, the cabin crew, the flight crew, all at the right place at the right time in order for you to operate your schedule," explained Michael McCormick, a longtime Federal Aviation Administration veteran.

"When the system goes down ... you have to resort to manually trying to plan it," he explained. "That's requiring emails, texts, phone calls, all around the system in order to try to do that."

A vulnerability exposed?

In the eyes of McCormick, who now serves on the faculty at Embry-Riddle Aeronautical University, this recent outage — and the subsequent meltdown it triggered — should serve as a wakeup call for airlines.

"I think this highlights the need to have better firewalls, so, that's cybersecurity, but in addition to that, redundancy and backup systems," McCormick said. "[Airlines] have grown extraordinarily dependent upon automation, and as we saw — and continue to see — they cannot operate their flight schedules without that automation."

How Delta is responding

Delta says it's providing affected passengers with an option with flight credits for future use, or cash refunds for eligible travelers. You can submit a refund request at delta.com/refund.

The airline also notes it's providing stranded passengers with meals, hotel and ground transportation per its commitments listed on the Airline Customer Service Dashboard.

Read more, here, on what you can do if you're affected by Delta's meltdown.

In the meantime, Delta staff is working "around the clock" to get operations back on track, CEO Ed Bastian said in a video message to employees Monday — a message that did leave uncertainty on when the problems might finally end.

"Keep taking great care of our customers and each other in the coming days," Bastian said.

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