Hours later, it was lifted, and federal officials used the incident to highlight the need for more funding to update aging systems.

Transportation Secretary Sean Duffy initially blamed a communication issue impacting all Air Route Traffic Control Centers.

In a White House press briefing later on Friday night, Homeland Security Secretary Markwayne Mullin attributed the disruptions to technology upgrades, for “overwhelming” the antiquated equipment.

“It’s going to continue to fail,” he warned.

Despite recent hacking incidents of freezers in Europe and U.S. military bases, he said it “doesn’t appear” that a cyberattack was involved though he admitted that “there’s nothing certain right now.” Earlier, he ruled out a terrorist attack and said “This isn’t another 9/11.”

Just days before the ground stop, the FAA announced it would deploy an AI tool to help air-traffic controllers

During the briefing, Duffy also suggested that the problem was related to old equipment being overloaded.

“Our fix gives us a pretty good indication that it was a legacy network problem that went down,” he said.

Duffy also called on Congress to provide emergency funding to fix the FAA’s aging systems, saying the Trump administration needs another $30 billion, then putting the price tag at $50 billion.

Still, the massive disruption comes as airlines in Europe suffered a wave of phony bomb threats this week. While they all appeared to hoaxes, at least one flight was diverted to a military base in France.

Spanish Foreign Minister Jose Manuel Albares said Friday that Europe appeared to be facing “hybrid aggression and a form of psychological warfare.”

Meanwhile, consumers are still grappling with the aftermath of a Microsoft outage that shut down email, collaboration and AI functions. The company said Friday it had no indication that the ground stop is related to its global outage.

The National Weather Service also said there has been no disruption to its radar systems Friday, denying talk online that it had caused the FAA communications issue.

The FAA last issued a nationwide ground stop in 2023, when files related to an alert system for pilots was unintentionally deleted. It delayed thousands of flights, but they resumed soon after the disruption.

Earlier this year, flights at New York airports were halted when a contractor accidentally cut a fiber communications line in New Jersey.