A federal judge has cleared the runway for a class action from disgruntled passengers against Delta Air Lines as turbulence from last year’s CrowdStrike debacle continues to buffet the carrier.

Delta was one of the US airlines most severely hit by the outage, which was caused by a faulty software update issued by CrowdStrike that crashed millions of Windows devices worldwide.

Problems began on July 19, 2024, and although the broken update was swiftly dealt with, for many customers the damage had been done. “Delta cancelled more than 4,500 flights between Friday, July 19, and Sunday, July 21, 2024,” say the plaintiffs.

Even after many other airlines managed to get back up and running, with most resuming normal operations by the end of the weekend, Delta “continued to cancel and delay a staggering number of flights – far more than any other airline,” according to court documents [PDF].

Delta blamed its reliance on Microsoft software and the CrowdStrike incident for its woes. However, according to the plaintiffs in the action, both companies offered the airline assistance, which Delta turned down.

Customers of the Atlanta-based carrier affected by the delays and cancellations claim they struggled to secure refunds and compensation from the airline. The plaintiffs allege that “although Delta offered reimbursement of eligible expenses through their website and app, Delta failed to clarify that the customer would only be receiving a partial reimbursement.”

“Furthermore, Delta did not disclose to its customers that acceptance of the partial reimbursement would release any legal claims the customer may have against Delta until after the customer ‘click[ed] on the button to accept the partial reimbursement.'”

The action concerns both US domestic and international travel. The former is covered by US Department of Transportation rules, which require airline agents to “inform customers of their right to a refund … before making an offer for alternative transportation, travel credits, vouchers, or other compensation in lieu of refunds.”

The latter claims come under the Montreal Convention, which is designed to be a single, universal treaty to govern airline liability.

Delta, which estimated its operational losses at around half a billion dollars due to the outage, sought to dismiss the complaint.

While the US District Judge, Mark H. Cohen, granted the airline’s motion to dismiss some of the claims, he permitted others to proceed. These were Count I (breach of contract based on failure to refund) and Count XII (violation of the Montreal Convention).

Joseph Sauder, a lawyer for some of the plaintiffs, told Reuters: “This ruling is a major step forward for Delta passengers seeking accountability.”

The judge ordered that the parties file an Amended Joint Preliminary Report and Discovery Plan by May 20. ®