Duffy says aging routers led to nationwide FAA ground stop

The Federal Aviation Administration ordered a nationwide halt to departing flights on November 13, 2026, after a communications issue affected all 22 air route traffic control centers that guide planes between airports.

The FAA set the ground stop’s start time at 3:54 p.m. ET, and Transportation Secretary Sean Duffy said radar and other air traffic communications started to fail at 3:36 p.m. The agency lifted the stop at 8:15 p.m. ET, while Nextgov reported it ended at about 9 p.m. EST. Flights already in the air continued to their destinations, and controllers handled inbound international flights case by case. During the stop, air traffic controllers experienced intermittent communication and radar, sometimes unable to immediately communicate with pilots or see aircraft positions.

Cirium reported that cancellations topped 8,200 flights, exceeding 31 percent of U.S. flights scheduled for Friday. Nextgov estimated that delays exceeded 10,000 flights and that disrupted air travel touched more than 2 million passengers.

FlightAware recorded more than 7,800 flight delays and roughly 350 cancellations as of about 4:45 p.m. ET, and by 6:30 p.m. ET delays reached about 10,500 with 2,700 cancellations. FlightRadar24 counted more than 1,000 aircraft heading to U.S. airports while airborne. Flighty listed more than 30,000 departures and arrivals scheduled for the remainder of November 13, 2026, and TSA screened almost 2.5 million people on Thursday, November 12, 2026, versus more than 2 million on a typical day.

The FAA asked 42 pan-European countries to suspend flights to the United States from 5 p.m. ET until midnight ET, according to a Eurocontrol notice. Canada offered help, including accommodation of U.S.-bound aircraft, but the United States had not accepted the offer. NAV CANADA put traffic management measures in place at Toronto Pearson, Montréal-Trudeau, Calgary and Vancouver, lifting them shortly after 6 p.m. ET. By 6:40 p.m. ET, Canadian airports reported roughly 156 canceled departures, 271 delayed departures, 187 canceled arrivals and 320 delayed arrivals, and Caribbean Airlines canceled several flights and delayed others while flights crossing U.S. airspace were also affected.

Markwayne Mullin, the Homeland Security secretary, said there was no evidence of a cyber attack and no footprints of anyone improperly accessing FAA systems, though officials were still looking and would not rule it out. “there’s no chatter, we haven’t seen any footprints,” Mullin said.

The FBI does not believe a cyber attack or criminal activity caused the outage and is examining whether a software update was responsible, according to a person familiar with the matter. The FAA has not announced an official root cause, and officials said the incident was unrelated to a Microsoft outage earlier in the week and that the FAA’s recently deployed artificial intelligence systems had nothing to do with the outage.

Sean Duffy said data flooded aging routers and switches, which produced inconsistent information and caused the FAA to shut down the system. Mullin said the FAA issued the ground stop out of caution after patches and new technology overwhelmed the older system, and Duffy described the U.S. air traffic control system as using 1980s little copper lines that would keep failing without major upgrades.

He called on Congress to approve an additional $50 billion in emergency funding to modernize the air traffic control system, noting that lawmakers had already approved $12.5 billion in 2025 through the One Big Beautiful Bill Act but called the sum insufficient. Duffy traveled from Dallas to Washington, D.C., after speaking at Texas Christian University when the FAA began experiencing radar and communication instabilities.

The FAA has not named an official root cause for the outage. Multiple sources said an update to the private network linking air traffic control caused it to reboot and crash, and L3Harris operates the network.

The November 13 ground stop was the third issued by the FAA this century and the second-longest since the September 11, 2001, ground stop. The previous nationwide ground stop came in January 2023, when a contractor accidentally erased files while working on the pilot safety notice system; officials found no evidence of a cyber attack. The FAA said the previous week that it had started removing floppy disks from use, and the agency began using an AI congestion tool near Washington in September 2026, though no report has linked that tool to the November 13 outage. The ground stop occurred about two weeks before Thanksgiving, one of the busiest U.S. travel periods.

Duffy said commercial flights would take precedence over private and charter flights during the recovery. He predicted schedules would be fully restored by the Thanksgiving travel season, when Airlines for America projected about 2.7 million daily passengers on U.S. airlines, though delays would persist for several days, and Dartmouth professor Vikrant Vaze said getting air travel back to normal could take days after an event of this scale. Digitally upgraded air traffic facilities escaped the overload problems that caused the ground stop. The FAA said the ground stop rested on extraordinary circumstances and safety reasons.

American Airlines said it expected disruptions for the rest of November 13, 2026. Southwest Airlines said it was resuming a few flights on Friday, November 13, 2026. United Airlines said it had canceled some flights and still expected others to operate.

Duffy urged college football teams to coordinate with the FAA on flight scheduling so games could happen the next day. The Brooklyn Nets were stuck on a team plane on Friday ahead of a Saturday game against the Memphis Grizzlies, while the University of Texas Longhorns football team was stranded at an airport ahead of a Saturday game against Louisiana State University. A Saturday men’s college basketball game was postponed, featuring teams from University of North Carolina Greensboro and Cornell University, and the Kansas City Current’s trip to New York City for a Sunday National Women’s Soccer League semifinal against Gotham FC was affected by the ground stop.

Hakeem Jeffries described the ground stop as part of a pattern of unacceptable air travel incidents under failed leadership by the Trump administration. Markwayne Mullin said the situation was serious but posed no safety threat to Americans. Mullin said the ground stop was not another 9/11 and gave the public no reason to be afraid.