Washington: Flights have resumed across the United States after a nationwide ground stop disrupted air travel for more than four hours, but passengers continued to face cancellations and delays on Saturday as airlines worked to restore operations.
US Transportation Secretary Sean Duffy said aircraft were taking off and landing again, although returning the aviation network to normal would take time.
The Federal Aviation Administration (FAA) lifted the nationwide restriction at around 8.15 pm Eastern Time on Friday, November 13, after grounding departures because of problems affecting air traffic control communications.
FAA Administrator Bryan Bedford declared that US air travel should be fully recovered from the longest nationwide ground stop in 25 years by the end of Sunday.
Bedford said the flights “will still have delays and cancellations” on Saturday but promised that the “worst is behind us.”
Duffy also cautioned that airlines would need time to reschedule flights, reposition aircraft and organise crew availability. He said the disruption could have consequences for air travel over the coming days, although officials expect operations to stabilise ahead of the Thanksgiving holiday period.
Ageing equipment blamed for disruption
Duffy attributed the disruption to outdated telecommunications infrastructure used by the country's air traffic control system.
He said the network's switches and routers became overloaded with data, resulting in inconsistent information and problems with radar and communication systems at air traffic control facilities.
"Our switches, our routers, actually got overloaded with data … and started to give us inconsistency in the data from those routers. And because of that, we shut the system down," Duffy said during a White House briefing.
Duffy clarified that work to replace copper wire of the system by fibre was ongoing under a contractor called L3Harris- a technology provided company.
"It was such an old wire that it was being discontinued," he says, adding that this work has been going on for many years.
He added that the government is trying to find out whether the problem was caused by "incompetence" on the part of L3Harris, or by a faulty piece of equipment.
The router that was being worked on started flooding other air traffic control systems, he says, which created communication issues with planes that led the government to shut down the airspace for safety reasons.
Duffy also called for additional funding to modernise the ageing infrastructure, describing the situation as an emergency.
No indication of cyberattack
Duffy said there was no indication that a cyberattack had caused the disruption.
Homeland Security Secretary Markwayne Mullin said the incident appeared to have resulted from a technical failure, but acknowledged that the investigation was continuing.
The FAA had ordered the ground stop as a safety precaution after communication and radar instability affected air traffic control operations. Officials said more than 3,000 aircraft that were already airborne when the restriction was imposed landed safely.
Thousands of flights cancelled
The disruption affected a significant portion of US air traffic. Aviation consultant Andrew Charlton estimated that the ground stop affected around a quarter of the country's 45,000 daily flights, according to the Associated Press.
Flight-tracking figures reported by AP showed more than 4,100 cancellations, while thousands of other flights faced delays. The disruption also affected international services, with passengers at airports outside the US facing cancellations and schedule changes.
Airlines continued working on Saturday to accommodate stranded passengers and restore their schedules. The effects extended beyond commercial travel, with sports teams also forced to arrange alternative transport.
First nationwide ground stop since 2023
The latest incident was the first nationwide ground stop since January 2023, when a malfunction in an FAA computer system responsible for sending notices to pilots disrupted air travel.
It was also the second nationwide shutdown of its kind since the September 11, 2001, attacks.
The latest disruption has renewed concerns about the condition of the US air traffic control network, as authorities continue efforts to replace ageing equipment and upgrade the system.
(With inputs from AP)
