US resumes flights after nationwide air traffic failure

The United States has reopened its airspace after a nationwide ground stop triggered by a communications failure at air traffic control centres disrupted thousands of flights and left tens of thousands of passengers stranded at airports across the country.

The Federal Aviation Administration (FAA) lifted the restriction on Friday, with Transportation Secretary Sean Duffy announcing that US airspace reopened at 8:15 p.m. Eastern Time (0115 GMT on Saturday).

However, Duffy warned that flight operations would resume gradually, adding that airlines would need time to restore normal schedules.

“It’s going to be slow,” he told reporters at the White House.

According to flight-tracking platform FlightRadar24, more than 6,600 flights were cancelled and 8,600 delayed, while another 1,500 flights had already been cancelled for Sunday.

Aviation analysts warned that the four-hour nationwide grounding could disrupt airline operations for several days.

Duffy said tens of thousands of passengers were stranded at airports nationwide following the disruption.

He disclosed that he and Homeland Security Secretary Markwayne Mullin had met with President Donald Trump at the Oval Office to discuss the incident.

What caused the disruption

Duffy said the problem began at 3:36 p.m. when air traffic control centres experienced instability in their radar and communications systems.

According to him, switches and routers became overloaded with data, resulting in inconsistencies in information transmitted through the network and prompting authorities to shut down the affected system.

“Our switches, our routers actually got overloaded with data and they started to give us inconsistencies in the data from those routers and because of that we shut the system down,” he said.

He maintained that authorities never completely lost radar or communications capabilities and were able to land thousands of aircraft safely.

Duffy said the immediate technical problem had been resolved and that flying was safe, but stressed the need for a comprehensive upgrade of the country’s ageing air traffic control infrastructure.

FG seeks $50bn for aviation overhaul

The Transportation Secretary blamed inadequate congressional funding for delays in modernising the country’s air traffic control system, calling for $50 billion to overhaul the infrastructure.

Earlier on Friday, before the disruption, the White House and the Department of Transportation had urged Congress to approve $30.1 billion for upgrades to the nation’s ageing airports and air traffic control infrastructure.

“What we have is an incredibly old air traffic control system,” Duffy said.

“Give us the money to fix it.”

Meanwhile, Mullin said there was no evidence so far that the incident resulted from a cyberattack or a rogue artificial intelligence system, although investigators had not ruled out either possibility.

“It appears this was mechanically driven, however, we’re still looking,” he said.

He added that the National Security Agency was working with the Department of Homeland Security on the investigation.

Two airline officials said the disruption appeared to have affected a telecommunications network operated by L3Harris Technologies, which handles critical radio frequencies used by air traffic controllers to communicate with pilots.

The company had yet to respond to a request for comment.

Passengers face prolonged disruption

Despite the lifting of the ground stop, passengers continued to face uncertainty as cancellations and delays mounted at airports across the country.

From Boston to Seattle and New York to Los Angeles, travellers crowded departure halls and airline service desks as aircraft remained parked at airport gates.

Among those affected was 50-year-old Edward Kargbo, from West Chester, Pennsylvania, who was scheduled to travel on a 9 p.m. Ethiopian Airlines flight to Lomé, Togo.

Following the disruption, he said he would spend the night at the airport ahead of a rescheduled 6 a.m. Saturday departure.

“I have to squat the night here,” he said. “I’m stranded.”

Also affected was 47-year-old Louise Maher, whose British Airways flight from Newark to London was caught up in the disruption.

“I might cry at some point but not yet,” she said.

US airlines will not be required to compensate affected passengers because the disruption resulted from an FAA system failure rather than circumstances within the carriers’ control.

The only other nationwide ground stop since the September 11, 2001, attacks occurred in January 2023, when the FAA suspended domestic departures for about 90 minutes following an outage involving its Notice to Air Missions system.

The latest disruption also weighed on airline stocks, with shares of American Airlines, United Airlines and Delta Air Lines falling between one and two per cent in after-hours trading, while JetBlue Airways dropped about three per cent.

American Airlines said it was prioritising flights to smaller cities outside its major hubs, as well as international destinations, to reposition aircraft and crews and accelerate the recovery of its operations.