On Friday morning, major U.S. airlines, including American Airlines, Delta Airlines, and United Airlines, issued ground stops due to communication issues. This action came less than an hour after Microsoft resolved a cloud services outage that had affected several low-cost carriers, Reuters news report said.
The exact connection between the ground stops and the earlier Microsoft cloud outage remains unclear.
What Microsoft Azure said
Microsoft Azure website said starting at approximately 21:56 UTC on 18 Jul 2024, a subset of customers may experience issues with multiple Azure services in the Central US.
“We are aware of this issue and have engaged multiple teams. We’ve determined the underlying cause. A backend cluster management workflow deployed a configuration change causing backend access to be blocked between a subset of Azure Storage clusters and compute resources in the Central US region,” Microsoft Azure said in a status statement on its website.
“This resulted in the compute resources automatically restarting when connectivity was lost to virtual disks. Mitigation has been confirmed for all Azure Storage clusters, the majority of services are now recovered. A small subset of services is still experiencing residual impact. Impacted customers will be continuing to communicate through the Azure service health portal,” Microsoft Azure said.
Who faced challenges
Besides American and Delta, Allegiant Air also grounded flights. The Federal Aviation Administration (FAA) has not yet responded to requests for comment.
Earlier, low-cost carriers such as Frontier Airlines, Allegiant, and SunCountry reported outages impacting their operations. Frontier announced late Thursday that it was resuming normal operations and had lifted the ground stop. The airline attributed the disruption to a “major Microsoft technical outage.” SunCountry mentioned that a third-party vendor affected its booking and check-in systems, without specifying the vendor.
U.S. Secretary of Transportation Pete Buttigieg stated that the department is monitoring the issues at Frontier and will hold the company and other airlines accountable for meeting passenger needs.
Allegiant reported that its website was down due to the Microsoft Azure issue.
Data from FlightAware showed that Frontier canceled 147 flights and delayed 212 others on Thursday. Allegiant saw 45 percent of its flights delayed, while Sun Country experienced delays for 23 percent of its flights. Specific numbers of affected flights were not provided by the airlines.
Baburajan Kizhakedath
