FAA ground stop halts all US departures for over four hours, Duffy blames overloaded routers
Duffy said routers got overloaded with data, and Mullin said investigators will check whether a new AI system played any part.
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The FAA ground stop on Friday 13 November halted every departing flight in the United States for more than four hours, after the Federal Aviation Administration cited “extraordinary circumstances” and safety, NBC News reported. The agency lifted the order at 8:15 p.m. Eastern time. By then more than 7,000 flights had been cancelled and airports were packed with stranded passengers, NBC said.
What happened during the FAA ground stop
The FAA issued the alert at 3:54 p.m. Eastern time, saying that all departing traffic should remain ground stopped until further notice. CNBC reported that the agency pointed to communication problems at multiple air traffic control centres. There were over 3,500 airplanes in the air when the order came, Duffy said, and hundreds of flights were diverted, according to the Associated Press.
Sean Duffy blames overloaded routers
Transportation Secretary Sean Duffy blamed an outdated system at a White House news conference on Friday evening. He said routers “got overloaded with data”, which led to instability for the radar and communications in the centres, NBC reported. The FAA did not lose all telecom or radar capability, Duffy said, and the ground stop was a cautionary measure.

“It’s going to continue to fail,” Duffy said of the country’s air traffic control infrastructure, CNBC reported. He urged lawmakers to provide more funding for the overhaul that is under way.
Homeland Security Secretary Markwayne Mullin said there was no sign of a cyberattack and the public was never in danger, NBC reported. Asked whether he could rule out a cyberattack or a rogue artificial intelligence incident, Mullin said: “There’s nothing completely certain right now,” the AP reported.
Key numbers
- 3:54 p.m. Eastern time: when the FAA issued the ground stop, per NBC News.
- 8:15 p.m. Eastern time: when the FAA lifted it, per NBC News.
- More than 7,000: flights cancelled, per NBC News.
- Over 3,500: airplanes in the air when the order came, per NBC News.
Flight cancellations and what travellers face
Airlines could not return to normal at once, because so many planes and crews were out of position, the AP reported. CNBC said flight cancellations will stretch into the weekend, and that some college sports teams were among those disrupted. Duffy said he anticipates American airspace will catch up before the Thanksgiving travel rush, NBC reported.
Why the air traffic control system failed
Nationwide ground stops are extremely rare. The last was in January 2023, after a failure of a pilot communication system, CNBC reported, and the AP called Friday’s the second since the aftermath of the 11 September 2001 attacks. In September, hundreds of flights into Newark and Philadelphia were cancelled, delayed or diverted after a Verizon fiber cable was accidentally cut, CNBC added. Duffy described a decades-old system that uses analog equipment, NBC said.
What happens next after the FAA ground stop
Investigators will look at whether there is any link to the FAA’s nationwide rollout of a new artificial intelligence system, the AP said, and Mullin could not rule out another outage. Duffy has pressed Congress for money to modernise the network. The next test is the Thanksgiving travel rush, when the FAA ground stop and its backlog would be hardest to absorb again.
A nationwide ground stop is rare, and this one reached airports, airlines and teams across the United States just before the Thanksgiving travel rush. Officials blame ageing equipment and want Congress to fund an overhaul, while the open question about the new AI system will decide how much blame lands on the FAA.