Flights resumed across the United States on Saturday after being suspended for several hours on Friday, triggering widespread chaos at airports. Authorities warned that it would take some time for air traffic to return to normal following the disruption of thousands of flights.
In a post on X, Transportation Secretary Sean Duffy wrote that "operations are gradually returning to normal," but warned that "delays and cancellations will continue as airlines reschedule flights and reposition aircraft and crews where they are most needed."
The nationwide flight suspension left passengers across the country in a state of uncertainty and confusion, particularly as some were asked to disembark from their planes just moments before takeoff, while airline staff appeared unable to explain the situation.
This was only the second time since the September 11, 2001 attacks that such an alert has been issued in US airspace, one of the busiest in the world.
Four hours after flights were grounded, authorities announced that the suspension had been lifted at 8:15 p.m. Eastern Time (01:15 GMT on Saturday).
Duffy stressed that "it will take some time for operations to fully return to normal," adding: "Your safety and the safety of your families while traveling is our top priority."
On Saturday morning, the effects of the disruption were still evident at major airports, including John F. Kennedy International Airport in New York, whose website showed dozens of delayed and canceled flights.
Nearly 6,000 flights, including international services, were canceled, according to FlightAware.
The disruption continued to have knock-on effects on Saturday, with more than 3,500 flights within the United States canceled, according to the flight-tracking website.
Tim Johnson, Director of Consumer Affairs at the UK Civil Aviation Authority, said the resumption of US flights did not mean the disruption was over, as some of its effects could persist while airlines worked to:
Reposition aircraft and crews where they were needed.
Restore air services to normal operations.
Authorities attributed the decision to ground flights to the aging communications equipment that had been in use for decades, ruling out sabotage as the cause of the incident.
"This is an issue with an outdated system. We have very old switches and very old routers," Duffy said.
"We are using small copper wires dating back to the 1980s. It is an old system that broke down, failing everywhere after being pushed beyond its capacity," he added.
The disruption came a day after Duffy formally asked Congress for $30 billion in funding to modernize the US air traffic control system.
Following the lifting of the flight suspension, the secretary renewed his appeal, saying: "I will say it a million times: Congress must give the president the resources needed" to secure the funding.
Homeland Security Secretary Markwayne Mullin stressed on Friday that there was no evidence of any hostile act.
"There is no indication of a cyberattack or an artificial intelligence attack," he said during a press conference.
He also ruled out any connection between the incident and the outage that affected Microsoft earlier this week, disrupting email systems used by millions of people, public facilities and businesses around the world.
Nationwide flight suspensions are rare in the United States. Flights were grounded for several days following the September 11, 2001 attacks, while an outage in the Notice to Air Missions (NOTAM) system in January 2023 also led to a temporary suspension of flights.
The flight suspension triggered chaos at US airports, with video footage showing crowded gates and planes waiting on taxiways.
At New York's LaGuardia Airport, Tiara Johnson said she was traveling to Orlando with a friend to attend a concert.
"They just keep delaying the flight... It was originally scheduled for 7:55, then it was pushed back to 8:30, then 9:30, and now it's 10:30. We don't know when it's going to take off. We're stuck," she told Agence France-Presse (AFP).
Passengers received little clarification about the decision to ground flights. Some were told that the delays were due to the wind, while others had to piece together the available information themselves.
Among the signs of confusion at airports were:
Information screens continued to show flights as departing at their originally scheduled times.
Electronic boarding passes on some passengers' phones indicated that their flights had already departed, even though they were still on the ground.
Stranded passengers turned to car rental counters in search of alternative transportation, with long queues reported at Las Vegas Airport.
Susan Sardina, who was waiting in line to rent a car, said she had already boarded her flight to Orange County, California, when the crew informed passengers that there was a problem.
Others, meanwhile, saw the flight suspension as an opportunity to extend their vacations.
Kathy Somers was on her way home after visiting friends in Las Vegas when her flight was canceled. "We're lucky our friends are coming back to pick us up. We have one extra night to play cards," she said.
