The IT issue has wrought global havoc at airports, grounding flights in Europe and the United States in particular, while also derailing television broadcasts in the UK, impacting telecommunications in Australia, and affecting some banks and health care providers.

At Dulles International Airport outside of Washington, Evyn Garson told AFP she and her family had been trying to travel to Florida for a wedding, but now "feel kind of stuck."

"We definitely considered just driving down there. But now it looks like they are checking bags so we might stay."

American Airlines said in a post on social media platform X that it had been able to "safely re-establish our operation" as of 5:00 am EST (0900 GMT) following a "technical issue with a vendor."

United Airlines said, also on X, that "some flights are resuming" as it worked to restore full operations, while Delta Airlines reported it too had resumed "some flight departures."

And Frontier Airlines said it was "gradually normalizing" and "in the process of resuming flight operations," with its ground stop now lifted.

The issue was apparently caused by an update to an antivirus program, with Microsoft saying in a technical post on its website that the problems affected users of its Azure cloud platform running the cybersecurity software CrowdStrike Falcon.

The US Federal Aviation Administration (FAA), which had earlier Friday announced the grounding of US carriers over communication issues, said later it was "closely monitoring a technical issue impacting IT systems at U.S. airlines."

It said several US airlines had requested its "assistance with ground stops for their fleets until the issue is resolved."

Some 1,300 US flights were canceled and approximately 2,900 delayed as of Friday morning, according to tracking service FlightAware.

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American Airlines

X

United Airlines Holdings

MICROSOFT