The Federal Aviation Administration (FAA) lifted a US ground stop on Friday after a communications failure halted departures nationwide for more than four hours, disrupting thousands of flights.
FAA officials described the suspension as a safety precaution after a temporary telecommunications outage affected air traffic control centres. Technicians began investigating the failure, whose precise cause remained unclear.
Aircraft already airborne continued to their destinations and landed safely. Controllers handled incoming international flights individually, while the agency confirmed it had accounted for every flight.
Flight-tracking service FlightRadar24 reported that over 4,700 flights were canceled and 10,000 faced delays on Friday. An additional 700 flights already faced cancellations for Saturday. The disruption affected not just American airports but also led to cancellations in Canada and Europe. Aviation analysts warned that airlines might need several days to restore their schedules
United Airlines and American Airlines warned passengers about widespread disruption. Some travellers waited aboard aircraft or returned to departure gates.
Arriving planes faced a separate problem: occupied gates left some waiting on taxiways. Passengers crowded departure halls and airline counters at airports from Boston to Seattle and New York to Los Angeles.
Investigators had found no immediate indication of a cyberattack, according to the Department of Homeland Security.
Homeland Security Secretary Markwayne Mullin told reporters outside the White House that authorities were examining all possible causes. “It’s just a telecommunications outage as of right now,” he said.
Mullin said authorities were examining a new artificial intelligence-powered air traffic control system as a possible cause. Authorities had not established what triggered the failure.
Separately, Transportation Secretary Sean Duffy and Office of Management and Budget Director Russell Vought asked Congress for another $30.1 billion to upgrade airports and air traffic control infrastructure.
Their letter sought funding for telecommunications, controller hardware and software, control towers and airport facilities. In July 2025, Congress approved $12.5 billion over five years for air traffic control upgrades and controller recruitment.
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A previous nationwide suspension in January 2023 lasted about 90 minutes after a computer failure affected the FAA’s Notice to Air Missions (NOTAM) system.
Much of the agency’s technology dates back decades. In a November 5 announcement, the FAA outlined plans to replace four systems dating from the 1980s.
Its programme covers outdated floppy-disk-based equipment used for weather and other critical information at more than 400 air traffic control facilities. A consolidated digital platform is scheduled to replace those systems by the end of 2028.
