DHS chief won't rule out AI as investigators probe FAA's nationwide ground stop

Every flight in the United States was ordered to stay on the ground on November 13, 2026, after a major communications failure hit multiple Air Route Traffic Control Centers. The FAA issued a nationwide ground stop at roughly 1 p.m. PST. Delays stretched up to 240 minutes — four full hours — for some travelers.

Homeland Security Secretary Markwayne Mullin blamed telecommunications trouble for the breakdown and said there were no immediate links to a cyberattack or terrorism. But he wouldn't close the door on artificial intelligence as a cause. The FAA has recently rolled out AI-powered flight-routing tools meant to boost efficiency and cut delays, which is why the question keeps coming back.

Mullin aimed his message at people watching flight trackers and waiting at arrival gates. “There’s no reason to be concerned about your loved ones if they’re flying.” He paired that reassurance with a caveat: failures in new AI-driven air traffic control systems could be a contributing factor. Nothing has been confirmed, and the investigation is ongoing.

The US airspace has gone quiet before. The last comparable nationwide ground stop came in January 2023, when the NOTAM system that feeds critical notices to pilots failed. That one was traced to an accidental file deletion, not a cyber incident.

The FAA has been testing and deploying AI routing tools since then, drawing safety and oversight concerns along the way. Mullin's comments will sharpen that debate. Airlines and passengers absorb the ripple for hours, with crew schedules, aircraft positioning and connecting itineraries all knocked loose. What to watch next: the official root cause, whether the FAA pauses or reviews its AI routing tools, and whether lawmakers push for new oversight rules on algorithmic systems in air traffic management.