Major airlines flights grounded due to communication issue, FAA says

(CNN) – All flights from several major US airlines – including Delta, United and American Airlines – were grounded early Friday morning due to a communication issue, according to the Federal Aviation Administration.

The ground stop impacts all flights from the airlines, regardless of their destination, said the FAA.

It’s unclear how long the ground stop will last.

“All Delta flights are paused as we work through a vendor technology issue. Any customers whose flights are impacted will be notified by Delta via the Fly Delta app and text message. Customers should use the Fly Delta app for updates,” according to a statement from Delta Airlines.

Just after 5 a.m., American Airlines issued a statement with some good news for its passengers.

“Earlier this morning, a technical issue with a vendor impacted multiple carriers, including American. As of 5 a.m., we have been able to safely re-establish our operation. We apologize to our customers for the inconvenience,” according to the statement.  

Their grounding comes after a significant Microsoft outage brought Frontier Airlines to a standstill for hours on Thursday – though the ground stop for those airlines has since been lifted.

Earlier Thursday, Frontier said its systems had been impacted by the outage, and offered refunds to inconvenienced passengers.

Other competitors including Allegiant and SunCountry also said they were having difficulties, including with their booking, check-in and trip-managing functions online.

The FAA also announced Friday morning all Allegiant flights would be grounded.

On the Azure cloud software status report site, Microsoft said that service went down for some customers in the central United States around 6 p.m., “including failures with service management operations and connectivity or availability of services.”

The company said it determined the cause and is working to fix it. A company spokesman did not immediately respond to a request for comment.

A number of international airlines also reported tech disruptions on Friday, including Virgin Australia and Qantas, along with airports across Europe and Asia-Pacific.