Delta Air Lines was forced to cancel about 775 flights on Tuesday as the airline worked to establish normal operations after a power outage at the airline’s Atlanta base disrupted the flight schedule on Monday.

Delta, however, said the outlook for Wednesday’s operations was “positive”, with about 90 cancellations expected at the beginning of the day leading to normal operations later.

“We continued today to steadily recover from the events of earlier this week that grounded our system, and are working hard to achieve a normal operation by midday,” said Dave Holtz, senior vice president, operations and customer Centre.

“We will have a small number of cancellations in the morning as our operation restarts, so we continue to ask our customers to check their travel plans and flight status.

“We apologise to everyone who has been affected by these events, and we thank them for their patience.”

Delta employees continue to focus on promptly moving departures at the airline’s Atlanta hub, the world’s busiest airport.

Delta sent reservations personnel from the corporate headquarters in Atlanta to help customer service agents process customers at Hartsfield-Jackson Atlanta International Airport.

Delta’s travel waiver has been extended.

Unaccompanied minors that have not yet begun travel will not be accepted until Wednesday.

Those customers will be able to book without fee for a later date.

At the same time, Delta chief executive Ed Bastian updated customers on the outage in a video.

He noted that the airline had cancelled 800 flights Monday, triple the number of mainline Delta cancellations previously during the entire year.

“This isn’t the quality of service, the reliability that you’ve come to expect from Delta Air Lines,” Bastian said.

“We’re very sorry, I’m personally very sorry.”

Bastian thanked customers for their patience and loyalty while acknowledging their frustration.

“We’ll do everything we can to make sure this never happens again,” he said.

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