Flights began resuming across the United States late Friday after the Federal Aviation Administration lifted a nationwide ground stop that kept departures on the ground for more than four hours, a rare halt that left travelers stranded and airlines scrambling to reposition aircraft and crews.
The FAA ordered the ground stop at 3:54 p.m. Eastern time, pausing all departures across the country, and lifted it at about 8:15 p.m. Transportation Secretary Sean Duffy said the agency began seeing instability in its radar and communications systems at about 3:30 p.m., affecting air route traffic control centers and terminal radar approach control facilities.
Duffy said about 3,500 aircraft were in the air when the order was issued and that all of them landed. He said the systems that remained in place kept everyone safe, and that FAA technicians were investigating what set off the problem.
At a news conference Friday evening, Duffy blamed an aging air traffic control network that still relies on analog telecommunications. He said switches and routers became overloaded with data and began providing inconsistent information, which led to the system being shut down. He called on Congress to provide billions of dollars for a complete overhaul, described the situation as an emergency and warned that similar outages could happen again without new funding.
Homeland Security Secretary Markwayne Mullin said nothing so far indicated a cyberattack or a terror threat, calling the incident a telecommunications outage. AirSpace Intelligence, the company behind the FAA's AI-powered SMART air traffic management system, said the ground stop was not caused by its technology, and Duffy said the system could not have affected the outage.
Airlines began restarting operations as soon as the order was lifted. Delta Air Lines said it had resumed all scheduled flights, while United Airlines said it was resuming operations, including some Friday night flights. American Airlines said it would be all hands on deck to get customers moving, and Alaska Airlines said some flights within Alaska and Hawaii were not affected. Mullin said international flights were handled case by case, with some departing Friday evening. Flights from Europe to the United States were also canceled or delayed, and hundreds of flights were diverted while the stop was in place.
Officials warned that it would take time for airports and airlines to return to full capacity, and some carriers said the effects could last into the weekend. Duffy said he expected conditions to improve Saturday and that the system would be operational heading into Thanksgiving travel.
The shutdown was only the second nationwide ground stop since the September 11 attacks. The previous one came in January 2023, when a failure of the FAA's system that issues safety notices to flight crews halted departures for about 90 minutes.
The outage drew quick reaction from Capitol Hill. House Democratic leader Hakeem Jeffries called it an unprecedented breakdown and demanded answers from the administration. Sen. Tammy Duckworth said she would press the FAA for answers, and Sen. Maria Cantwell said her committee would review the communications technology problems behind the outage.
