The FAA’s nationwide ground stop followed a telecommunications outage caused by overloaded routers during maintenance work, US Transportation Secretary Sean Duffy has said, as he called for a complete overhaul of the agency’s ageing network.
The disruption on Friday led to thousands of cancelled flights and left travellers stranded at airports at the start of the weekend. Duffy said the Federal Aviation Administration was investigating the incident with contractor L3Harris Technologies, while the FBI was providing support.
Maintenance had been carried out at a remote facility in El Dorado, Arkansas, to replace ageing copper communications lines with fibre-optic connections. As a router was switched over, it began flooding other routers with data and overloaded the system.
Duffy said investigators were examining why the installation began broadcasting data, as well as a second issue at a facility in Amarillo, Texas, where work had been completed several weeks earlier.
“We’re looking at that right now, and when we know what the root cause of this issue was — was it the install from L3Harris, was it the router — I’m going to tell you and the American people what we find,” he said.
He said the work had been carried out “appropriately” and was part of routine maintenance on an old telecommunications architecture. Similar upgrades had been completed thousands of times without a comparable failure, he added.
“We have to get off old network, old telecom,” Duffy said, arguing that the FAA system should be “built brand new”. He said more than 70% of copper lines had been replaced with fibre without incident, including connections supporting almost 470 radios, new electronic flight strips and airport towers.
FAA seeks funding for new telecommunications system
Duffy said the FAA needed $50 billion from Congress to overhaul its telecommunications network. Although the agency had received funding through the One Big Beautiful Bill, he said Congress had specified how that money should be spent.
“But what I don’t have money for is a new telecom system. I don’t have money for new software. Those are critical pieces to the infrastructure, and it’s been historically underinvested in,” he said.
President Trump also urged Congress to approve further funding, saying much of the current air traffic control system was 50 years old and that the work should be completed “all at once, not in drips and drabs”.
Duffy said flights were operating with some delays, but expected the airspace to be running at full capacity by the end of Sunday and into Monday. Aircraft and crews had been left out of position by the ground stop, he said, meaning airlines needed time to restore their normal operations.
