The US air traffic control system remained stable Saturday following a nationwide outage, but thousands more flights were expected to be canceled as airlines worked to restore normal operations, Federal Aviation Administration (FAA) Administrator Bryan Bedford said.
“This morning, the system remains stable, and our airline partners are working through the operational recovery,” Bedford told reporters at a joint news conference with Transportation Secretary Sean Duffy.
Bedford said airlines were expected to cancel between 4,000 and 5,000 of the approximately 41,000 flights scheduled Saturday as they worked to reposition aircraft and crews stranded by Friday’s nationwide ground stop.
He said airlines expected to restore their full schedules by the close of business Sunday.
“I do think the worst is behind us, but we still do have a significant amount of recovery work to do with our airline stakeholder group,” he said.
According to Bedford, about 50,000 flights were scheduled Friday, with approximately 30,000 completed or already airborne when the FAA imposed a nationwide ground stop around 3.45 pm Eastern Time.
The agency managed to recover approximately 8,000 of the remaining 20,000 flights during the four-hour disruption, while 12,000 could not be recovered, including 9,000 commercial flights and 3,000 general aviation flights.
Bedford said officials detected instability affecting 17 of the FAA’s 22 en route air traffic control facilities, with problems spreading to radar and communications systems.
He emphasized that no facility completely lost operations, but authorities imposed the ground stop as a precaution after failing to identify the cause of the instability for approximately 45 minutes.
Duffy said the disruption appeared to have originated during routine maintenance by FAA contractor L3Harris at a remote facility, where aging copper telecommunications lines were being replaced with fiber-optic connections.
L3Harris, which has worked with the FAA for more than 20 years, owns the agency’s legacy telecommunications network, he said.
A router involved in the maintenance began flooding other routers with more than 1,000 connection attempts every four to five seconds, disrupting aircraft communications and radar feeds.
Officials are investigating whether the incident resulted from contractor error, improper installation or configuration, or defective equipment.
“We haven’t determined what the fault was,” Duffy said.
He added that the system returned to normal after officials isolated the affected maintenance operation.
No evidence of cyberattack
Both officials said there was no evidence that the disruption resulted from a cyberattack or artificial intelligence-related systems.
“We see zero evidence of anything nefarious, and zero evidence of anything AI-related,” Bedford said.
Duffy also rejected suggestions that the FAA’s newly deployed Smart system, which helps manage weather and aircraft trajectories, contributed to the outage.
The transportation secretary used the incident to renew his call for congressional funding to modernize the nation’s aging air traffic control infrastructure.
He said approximately 69% of the FAA’s copper communications network had already been converted to fiber-optic technology, but additional investment was needed to replace outdated equipment.
Bedford said the agency had received $12.5 billion for modernization, while Duffy indicated that he would submit a broader funding request to Congress on Monday.
Bedford warned that the existing telecommunications infrastructure would remain vulnerable until it was replaced.
“Let’s not kid ourselves; it will continue to break until we replace it,” he said.
The FAA administrator also apologized to passengers affected by the disruption, saying airlines were working to accommodate travelers or provide refunds.
Duffy said officials would continue investigating the cause and determine whether L3Harris or an equipment supplier should be held responsible.