The Federal Aviation Administration (FAA) ordered a nationwide ground stop Friday, bringing departing flights across the United States to a halt after a communication outage affected all Air Route Traffic Control Centers.
The FAA’s Air Traffic Control System Command Center issued the order under Advisory 111, citing “extraordinary circumstances” and safety concerns.
Transportation Secretary Sean Duffy confirmed the disruption, saying the FAA had ordered all U.S. airports to stop departures following a communication issue affecting every Air Route Traffic Control Center. FAA technicians were investigating the problem.
Homeland Security Secretary Markwayne Mullin said officials did not believe the outage was the result of a terrorist attack or deliberate action, although investigators had not determined its cause.
“This isn’t another 9/11,” Mullin told reporters, describing the incident as a telecommunications outage. He warned that restoring normal operations would take time and said the disruption was not expected to be resolved within an hour.
The FAA directive, effective at 3:54 p.m. Eastern on Friday, instructed all aircraft operators to keep departing flights on the ground until further notice. International arrivals were to be handled on a case-by-case basis.
Flight crews also reported radio and frequency issues in different parts of the country. ATC audio showed pilots and airline dispatchers discussing the possibility of a nationwide halt before the official order was issued.
The disruption affected flight operations at airports across the country. By approximately 4:45 p.m. Eastern, more than 7,800 flights had been delayed and around 350 canceled in the U.S., according to flight-tracking website FlightAware.
The nationwide ground stop came just days after the FAA announced plans to begin rolling out a new artificial intelligence (AI) system called Strategic Management of Airspace, Routes and Trajectories (SMART) across the country’s airspace.
The $875 million system, developed by Air Space Intelligence (ASI), is designed to help air traffic controllers manage traffic and reduce delays. The FAA had previously tested the technology in a limited program before announcing its wider deployment.
ASI said the current ground stop was not based on or caused by the SMART system, any other ASI product, or the company’s integration work with the FAA and air traffic control.
Microsoft also said it had no indication that the FAA ground stop was related to its ongoing global service disruption.
The FAA advisory lists an effective period through 11:30 p.m. Eastern, although departing traffic is ordered to remain grounded until further notice. The cause of the communication failure and the full extent of its impact remain under investigation.
BREAKING: FAA issues a nationwide ground stop across the United States for an unknown reason. https://t.co/kzFDoj7YeN
— WBC24 (@WBC24News) November 13, 2026