US lifts nationwide flight shutdown caused by air traffic control outage; thousands of flights hit

The US Federal Aviation Administration (FAA) lifted a nationwide ground stop after a communications failure at air traffic control centres triggered widespread disruption at airports, marking the longest nationwide shutdown of flight departures since the September 11, 2001, attacks.

More than 4,700 flights were cancelled and 10,000 delayed on Friday, while another 700 flights had already been cancelled for Saturday, according to FlightRadar24. Aviation analysts warned that it could take several days for airlines to restore their schedules after the grounding lasted more than four hours.

The FAA had ordered all departing flights across the country to remain grounded following the communications failure. Aircraft that were already airborne were allowed to land, while those on the ground were unable to take off. The disruption also affected international travel, forcing the cancellation of flights from Canada and Europe.

The Department of Homeland Security said there was no indication that the outage was caused by a cyberattack.
"There is no indication as of yet that this was a nefarious attack against us. It's just a telecommunication outage as of right now," Homeland Security Secretary Markwayne Mullin told reporters outside the White House, adding that President Donald Trump had been briefed.

Mullin said the department was examining all possible causes, including a new AI-powered air traffic control system.

The disruption is the latest and most dramatic sign of strain on the US air traffic control system, which has been grappling with equipment and communications failures, controller shortages and ageing infrastructure.

Much of the FAA's air traffic control technology is decades old. Last week, the agency said it would phase out floppy disks used to provide weather and other critical information at more than 400 facilities nationwide by the end of 2028.

The disruption left passengers stranded at airports across the country, with departure boards displaying widespread delays and cancellations. Arriving aircraft were also left waiting on taxiways as gates filled up.

US air traffic woes
The world's busiest airspace has experienced setbacks in recent years that have disrupted flights and risked safety. In January 2025, a midair collision at Ronald Reagan Washington National Airport killed 67 people. The White House and Department of Transportation urged Congress on Friday to approve a further $30.1 billion to upgrade the United States' ageing airports and air traffic control system.

The FAA announced the nationwide ground stop at 3.54 pm ET (2054 GMT). At the time the ground stop was issued, 4,042 flights were airborne, destined for US airports, according to Flightradar24. Shortly before the announcement, the FAA halted traffic in Chicago due to air traffic control communications issues.

"If the ground stop continues through the evening, it likely will take the weekend to resolve the disruptions to airlines' networks," said Robert Mann, an aviation analyst and principal of R.W. Mann & Co.

The only other nationwide ground stop since the September 11 attacks came in January 2023, when the FAA halted domestic departures for less than two hours.

The outage comes amid heightened concern about aviation security worldwide after a wave of hoax bomb threats this month disrupted dozens of passenger flights across Europe, forcing unscheduled landings and prompting fighter jets to escort or intercept aircraft.
There was no immediate indication the US communications failure was related to those incidents.

The US National Weather Service also said on Friday it was experiencing nationwide internet and communications issues. There was no immediate indication the two incidents were connected.