Microsoft said early Friday that an outage of its cloud services in the central United States had been resolved after it led to the grounding and cancellation of several flights.
Low-cost carriers Frontier Airlines, a unit of Frontier Holdings, Allegiant and Sun Country, have reported disruptions that have affected operations. Frontier said late Thursday that it was resuming normal operations and that the grounding had been lifted.
U.S. Transportation Secretary Pete Buttigieg said the department is monitoring the flight cancellation and delay issues at Frontier, adding that the agency will hold the company and all other airlines “responsible to meet the needs of passengers.”
Frontier earlier said a “major technical outage at Microsoft” temporarily impacted its operations, while Sun Country said a third-party vendor affected its booking and registration facilities, without naming the company.
“Allegiant’s website is currently unavailable due to a Microsoft Azure issue,” Nevada-based Allegiant said in a statement to CNN. Allegiant did not immediately respond to Reuters’ request for comment.
Frontier canceled 147 flights on Thursday and delayed 212 others, according to data tracker FlightAware. Allegiant’s planes were delayed for 45%, while Sun Country delayed 23% of its flights, the data showed. The companies did not provide details on how many flights were affected.
Microsoft said the outage began around 6 p.m. ET on Thursday, as a subset of its customers experienced issues with multiple Azure services in the central U.S. region.
Azure is a cloud computing platform that provides services for building, deploying, and managing applications and services.
Separately, Microsoft said it is investigating an issue affecting various Microsoft 365 apps and services.