FAA halts all U.S. departures for over four hours after a telecom outage

The Federal Aviation Administration on Friday stopped every departing flight at U.S. airports for more than four hours after a telecommunications outage cut into communications at air traffic control centers, leaving about 3,000 flights canceled by early evening.

It was only the second nationwide ground stop since the Sept. 11, 2001, attacks, Sourcing Journal reported. The previous one came on Jan. 11, 2023, when a contractor accidentally deleted files from the FAA's Notice to Air Missions system, and it lasted less than two hours.

The order took effect at 3:54 p.m. Eastern time. Aircraft could not leave their gates, and inbound international flights were handled case by case, according to an alert from the agency's Air Traffic Control System Command Center cited by TechCrunch. An FAA spokesperson told the outlet the stop followed communication problems at multiple Air Route Traffic Control Centers, the facilities that manage the country's airspace. Planes already in the air were allowed to keep flying and land. The FAA had already halted traffic in Chicago before the nationwide order.

Transportation Secretary Sean Duffy gave the first official explanation in a post on X at 4:16 p.m., saying the problem affected all of the route centers. He added: "FAA technicians are investigating the issue." Shortly after 5 p.m., the FAA said on X that it had paused flights out of caution during a temporary telecommunications outage and that every flight was accounted for. An advisory at 5:46 p.m. kept the stop in place while letting departures go as facilities recovered, and the agency cleared flights to resume later Friday evening.

The agency has not named the system that failed. Homeland Security Secretary Markwayne Mullin told reporters outside the White House there was "no indication yet that this was a nefarious act," and warned that the recovery would take time. Mullin said the department was examining a possible link through its Cybersecurity and Infrastructure Security Agency and was not ruling out a cyberattack or an AI intrusion. He played down any connection to this week's intermittent Microsoft Outlook outages.

The Wall Street Journal reported that the failure appeared to involve a telecommunications network overseen by L3Harris Technologies, which carries the radio frequencies controllers use to talk with pilots, Sourcing Journal said. It was not immediately clear whether radar feeds were affected. Air Space Intelligence, the company behind the FAA's SMART airspace planning system, said on X that its technology was not the cause. TechCrunch noted that the administration had introduced an AI-powered tool for controllers the same week, and that any link to the outage was unclear.

Airlines and freight carriers took the hit. More than 10,000 U.S. flights had been delayed by about 6:40 p.m., according to FlightAware figures cited by Sourcing Journal. UPS paused all flight operations, and FedEx said it was ready to activate contingency plans and would resume normal flying once the FAA allowed it. Expeditors International warned that export cargo would be delayed or rolled to later flights and that a backlog would persist after departures resumed, with delays likely through the weekend. American Airlines said its schedule would be affected for the rest of the day.

The stop also scrambled weekend sports travel. Duffy urged college football teams to contact the FAA so the agency could help prioritize flights for Saturday games, ESPN reported, putting cancellations at more than 2,500 nationwide. The SEC moved Ole Miss's game at Oklahoma to Sunday at 1 p.m. ET. Auburn took buses to Mississippi State, where kickoff was pushed from noon to 4:15 p.m., and Tulane planned a 350-mile drive to Houston on five buses to play Rice.

The outage adds to a run of equipment failures, communications breakdowns and controller shortages that have strained the air traffic control system. On Friday, the FAA and the White House asked lawmakers for another $30.1 billion to overhaul it. More coverage is on the Tech page.