The Federal Aviation Administration (FAA) has lifted the nationwide ground stop issued for all flights in the United States on Nov. 13 for “extraordinary circumstances and for reasons of safety.”
Officials said the reason for the ground stop was that the air traffic control system became overloaded with data and shut down, but they are not yet ruling out other possible problems.
“We have seen zero evidence that this was a cyberattack or [super intelligence],” Homeland Security Secretary Markwayne Mullin told reporters at a news conference. “We’re still looking at it. We’re not ruling out anything.”
Mullin also said new technology was introduced to the older air traffic control system, which overwhelmed it.
Agents with the National Security Agency are assisting in the investigation, Mullin said.
“It’s an old system that went down. It went down everywhere,” said Transportation Secretary Sean Duffy. “It got overloaded.”
The emergency alert, issued at 3:54 p.m. ET, applied to all aircraft operations at all airports. Thousands of travelers were delayed, and at least 5,000 flights were canceled.
Airlines were expected to be able to catch up this weekend with many of the missed flights, Duffy said.
The system could take until Thanksgiving weekend to become fully operational again, Duffy estimated.
Medical flights and emergency ambulances were not grounded during the emergency.
The order was issued following a communication problem “impacting all Air Route Traffic Control Centers,” Transportation Secretary Sean Duffy said.
About 3,500 aircraft bound for U.S. airports were in the air when the nationwide ground stop was ordered, Mullin said.
Thousands of passengers were caught at airports throughout the country waiting for flights.
Gillian Hamilton, a Canadian attempting to fly from Nashville to her home in Saskatchewan, had already boarded her WestJet plane when the FAA issued the ground stop.
“We had already boarded and then had to wait an hour on the plane,” Hamilton said. “The flight attendants didn’t know what to say. They just kept apologizing and served refreshments and snacks.”
Hamilton said she and her friends did not want to wait at the airport amid the uncertainty surrounding their flights, so they decided to rent a car and drive 30 hours to Canada.

Mullin denied any connection to Microsoft’s outage the day before that took Outlook and other programs offline for most of the day.
Other agencies assisting the FAA were the State Department and the Cybersecurity and Infrastructure Security Agency.
By 6 p.m. Eastern Time, Pacific-bound flights were cleared to depart from San Francisco International Airport, including to destinations in Hawaii and Asia, the airport reported. Passengers were asked to check with their airlines for the latest information about flights.
The Air Line Pilots Association said pilots were “ready to get passengers moving again the moment it’s safe to do so.”
“Safety comes first,” the association posted on X.
Flight cancellations reached over 5,000 and continued to rise before 9 p.m. ET.
Trump told Fox News the disruption didn’t seem like a cyberattack or a problem with artificial intelligence. No groups had taken credit for the incident.
Some international flights were allowed to depart on a case-by-case basis after the ground stop was issued, Flightradar24 reported.

“My office and I are closely monitoring the nationwide ground stop,” said New Jersey Democrat Rep. Herb Conaway. “The Trump Administration must answer for this disruption. The American people deserve a full explanation, and Congress must be immediately briefed on what went wrong and who is responsible.”
Illinois Sen. Tammy Duckworth (D-Ill.), a former Blackhawk pilot and Aviation Subcommittee ranking member, said she also planned to thoroughly investigate the incident, while Rep. Delia Ramirez (D-Ill.) said she was “alarmed” by the news and was tracking it.
Nationwide ground stops are extremely rare in the United States. The last time the FAA issued one was Jan. 11, 2023. All domestic departures were halted for about 90 minutes after a contractor erased database files, crashing the Notice to Air Missions pilot safety system.


