Travelers wait in a long line to speak with a Delta representative at the help desk in the McNamara terminal at the Detroit Metropolitan Wayne County Airport on July 20, 2024
Travelers wait in a long line to speak with a Delta representative at the help desk in the McNamara terminal at the Detroit Metropolitan Wayne County Airport on July 20, 2024 AFP

Delta Air Lines struggled on Monday with lingering effects from a global IT outage, canceling hundreds more flights than US aviation rivals.

The information technology outage, stemming from a flawed update to an antivirus program, wreaked havoc on Friday across myriad industries including banking, health care and media, as well as aviation.

But by Monday air travel competitors such as American and United had cancelations numbering only in the dozens, according to flight tracking programs.

But there were 784 Delta flights canceled as of early afternoon Monday, more than half the total cancelations, according to the FlightAware website.

Delta also experienced 1,028 flight delays on Monday, also more than the other two big carriers.

"While other airlines have largely been able to recover, Delta is continuing to have difficulties," US Department of Transportation officials told AFP in an email, adding that Transportation Secretary Pete Buttigieg spoke with Delta CEO Ed Bastian on Sunday.

"The Secretary reminded him of Delta's responsibilities to their customers and DOT's enforcement role," DOT said.

Bastian apologized to customers in a message posted to the carrier's website. The IT problem affects the Microsoft Windows system, which Delta employs for applications such as a crew tracking tool, he said.

"Our teams have been working around the clock to recover and restore full functionality," said Bastian, who issued a travel waiver to customers to make changes at no charge.

Delta did not immediately response to questions from AFP.

The cancelations are a setback for Delta, which usually wins high ratings for reliability and has marketed itself as providing a high quality flying experience.

Buttigieg said on the social media platform X that Delta will be held accountable.

"We have received reports of continued disruptions and unacceptable customer service conditions at Delta Air Lines, including hundreds of complaints filed with the Department of Transportation," Buttigieg said.

"I have made clear to Delta that we will hold them to all applicable passenger protections."

Shares of Delta fell 1.9 percent in afternoon trading, while both American and United climbed more than one percent.