FAA lifts the nationwide ground stop for all U.S. airports

The nationwide ground stop that paralyzed the U.S. aviation system on Friday has ended, according to the Federal Aviation Administration.

The rare stop, which lasted about four hours, ground all U.S. airports following a "communication issue," Transportation Secretary Sean Duffy said earlier Friday.

At a press conference Friday night, Duffy said the issue appears to be old technology.

"We have old switches, old routers … it's an old system that went down. It got overloaded," he said.

Homeland Security Secretary Markwayne Mullin joined Duffy at the press conference and said there was no evidence the issue was due to an attack.

"We have seen zero evidence this is a cyber attack," he said.

As of 8 p.m. EST, more than 10,000 flights had been delayed Friday and 5,000 had been canceled in the U.S., according to FlightAware, a flight tracking site. The turmoil comes on the heels of nearly 7,000 flight delays on Thursday.

The FAA said the issue affected Air Route Traffic Control Centers — the regional air traffic control centers across the country that handle high-altitude traffic.

This was only the second national ground stop since September 11, 2001. The U.S. last issued a ground stop of this scale in 2023, when all U.S. airports were shut down due to an outage in the NOTAM (Notice to Air Missions) system, which alerts pilots and airports of real-time hazards.

That outage prompted fears of a cyberattack, but the FAA later determined the issue was caused when contract workers inadvertently deleted critical files.

The FAA has recently begun rolling out an AI-enhanced software tool known as the SMART system as part of its ambitious overhaul of the nation's air traffic control system. But Air Space Intelligence, the company that makes the tool, quickly dismissed speculation that its product could be connected to the flight disruptions.

"The current ground stop is not based on or a result of the SMART system, any product of ASI or our integration with FAA and ATC," the company said on social media.

Passengers stranded

The nationwide ground stop has caused chaos in airports and headaches for travelers — many of whom are already too familiar with flight delays and cancelations during the holiday season.

At the Friday night press conference, Duffy said flights would resume but would take time to clear.

At Dallas Fort Worth International Airport, Regina Harling said she waited hours — long past when her flight was supposed to depart — before she learned of the nationwide grounding by checking the news on her phone.

"There's still a sign right in front of me that says we're boarding in 16 minutes," she said.

Harling needed to travel last minute to San Diego for a family emergency. Stuck at the airport, she's thinking about how soon she can make it to her family, but she's not optimistic.

"I was just thinking to myself that it always feels like it's getting harder to travel than it used to be," she said.

At Chicago O'Hare International Airport, Giliann Karon was on board a plane when the nationwide ground stop was ordered. Karon said she had already experienced a flight delay the day before due to bad weather in New York City, where she is heading.

"It's just kind of like, 'Oh, of course this is happening,'" she said.

This is a developing story.

Deepa Shivaram contributed to this report.