Update: The ground stop has been lifted, and domestic flights resumed late Friday.
For only the third time in U.S. history, the Federal Aviation Administration(FAA) has issued a nationwide ground stop of all flights.
U.S. Secretary of Transportation Sean Duffy confirmed the ground stop at 4:16 p.m. ET. More than 2,000 flights have already been affected and flights into the U.S. have also been halted.
Homeland Security Secretary Markwayne Mullin told the press that today's national stoppage was caused by a "telecommunications outage," not a national security threat.
Is the ground stop connected to AI?
One day prior, ArsTechnica reported on the FAA's recent roll out of its new $875 million AI tool, the Strategic Management of Airspace, Routes and Trajectories (SMART) system. SMART is a cloud-based platform system designed to help air traffic controllers evaluate and manage national airspace, the FAA explained in a system fact sheet.
"Using AI, SMART analyzes airline schedules, weather, airport capacity, airspace conditions, and operational constraints to predict traffic flows and identify potential conflicts before they occur," the administration wrote.
Users online pointed out the coincidental timing almost immediately. Air Space Intelligence (ASI), the American aerospace and defense company behind SMART, denied on social media any connection to the ground stop.
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At this time, officials have not confirmed any connection between the deployment of the FAA's SMART tool and the ground stop. SMART has been active in Washington, DC airspace since at least Sept. 21, ArsTechnica reported, and the FAA announced a rollout to 22 centers across the country on Nov. 10. According to the administration, SMART had successfully helped reroute 180 flights.
When asked about the possibility that SMART could have impacted the nation's air traffic control systems, Mullin said, "You can't rule out anything at this point. We are going through that process and we're going to find out what happened. When we do, we'll take the appropriate actions to make sure it doesn't happen again."
ASI posted a statement to X refuting claims its system resulted in the FAA stoppage. "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 wrote.
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UPDATE: Nov. 13, 2026, 3:41 p.m. This story was updated with a quote from Air Space Intelligence (ASI).
