Trump administration officials and Air Traffic Control (ATC) insiders are shedding light on Friday's nationwide ground stop, which resulted in massive delays for thousands of flights and nearly all domestic travelers.
Several sources told CBS News Friday evening that the ground stop was caused by a communication system reboot. According to multiple insiders with knowledge of the incident, an update to a private communications network used by air traffic controllers forced the system to reboot and impede communications at the nation's 22 regional air traffic control centers, CBS News reported.
Hours later, Transportation Secretary Sean Duffy and Homeland Security Secretary Markwayne Mullin said the outage was caused by an outdated air traffic control system coming up against the processing power of newly implemented modern technology.
"Our routers got overloaded by the data," said Duffy. The secretary said the overloaded routers, which he described as "'80s copper lines", caused instability in communications at Terminal Radar Approach Control (TRACON) and Air Route Traffic Control Centers (ARTCCs). Out of an "abundance of caution," the FAA issued the ground stop.
Duffy asserted that only older lines were affected, not newly installed ATC tech. Duffy then called on Congress to provide $50 billion in emergency funding to overhaul the system completely.
The ground stop has now been lifted.
As recently as 6 p.m. ET, insiders reported the FAA was still investigating the circumstances behind the communication blackout.
Following confirmation of a telecommunications outage, social media users theorized the blackout may have been a consequence of the FAA's new AI-powered air traffic control system, known as Strategic Management of Airspace, Routes and Trajectories, or SMART. Others suggested the recent Microsoft outage could have been a factor.
When asked if AI played a role in the ground stop, Homeland Security Secretary Markwayne Mullin told the press that officials couldn't "rule anything out." In comments to the press later that evening, Mullin once again affirmed officials haven't found any indication of a cybersecurity attack but couldn't rule out interference entirely. "There’s nothing completely certain right now. It does not appear that way," Mullin said. "The public was never at danger. There was never any lives at risk. There were no flights at risk."
Air Space Intelligence (ASI), the company behind SMART, denied speculation that the new AI tool was involved in the ground stop. Microsoft also issued a statement, writing: "We have no indication that the FAA’s nationwide ground stop is related to any Microsoft services."
The FAA has undertaken an administration-wide modernization project, including phasing out the use of floppy disks for storing weather conditions, airport status updates, equipment issues, and other critical information.
UPDATE: Nov. 13, 2026, 5:47 p.m. This story was updated with new information from the Department of Transportation and Department of Homeland Security.