A nationwide ground stop that disrupted US air travel was preliminarily blamed on routine maintenance involving outdated communications equipment at a remote Federal Aviation Administration location, Transportation Secretary Sean Duffy said.
A contractor was switching the FAA’s telecommunications lines from copper wire to fibre when communications became unstable, Duffy told a press conference on Saturday. The resulting disruption affected radar feeds and made it difficult for air traffic controllers to communicate.
Duffy identified L3 Harris, described as the department’s “legacy provider”, as the contractor carrying out the work. He said officials were still determining whether the problem resulted from user error, an installation mistake or a faulty router.
“What we’re working to determine was whether we had incompetence – meaning, was it user error or installation error from L3 Harris — or did they install a faulty router?” he said. “We haven’t determined what the fault was. Was it the router? Or were they not doing great work for us at L3 Harris?”
The wire being replaced was so old that it was being discontinued, Duffy said. The switch to fibre allegedly flooded other routers and interrupted the flow of radar information.
Officials do not believe the incident was caused by a cyberattack, according to Duffy. Communications resumed after the issue was detected at the remote FAA site.
FAA chief Bryan Bedford said the ground stop was ordered after officials were unable to identify the source of the communications problem for about 45 minutes. He said the telecommunications system had not completely failed, but had shown signs of instability across several facilities.
The disruption began at 3.36pm Eastern Time, when more than 3,500 aircraft were in the air. Bedford said about 50,000 flights had been scheduled across the US, of which 30,000 had been completed by Saturday.
Of the 40,000 flights scheduled for Saturday, between 4,000 and 5,000 were expected to be cancelled. Delays and cancellations were forecast to continue through the weekend, although Bedford said services should return to normal by the end of Sunday.
Flight-tracking data showed almost 15,000 delays by 1pm Eastern Time on Saturday, including more than 4,000 flights within, into or out of the US. More than 4,400 flights had been cancelled on Saturday.
Calls for modernisation of air traffic control
Duffy used the disruption to renew his call for increased funding for the FAA, saying air traffic control still relied on equipment dating from the 1970s and 1980s. He has urged Congress to provide 50 billion dollars to modernise the system.
He said L3 Harris owned the telecommunications system used by the FAA and that he would prefer to work with major telecommunications companies such as AT&T and Verizon. However, he said the agency was “stuck” with its existing provider until further funding was secured.
“Many of our contractors, many of our partners, they take our money and they provide really poor service to us, full stop. And we have demanded more,” Duffy said.
He added: “We need L3 Harris, or whoever provided that router to us, to do a better job.”
The ground stop was the first since January 11, 2023, when a key FAA computer system malfunctioned, and only the second since the terrorist attacks of September 11, 2001.
