More than 4,000 flights were cancelled and 3,000 more delayed as the United States worked to recover from the longest nationwide ground stop in 25 years.
US airspace reopened at 1.15am Irish time on Saturday following a five-hour shutdown that threw the aviation industry into turmoil.
The Federal Aviation Administration issued the nationwide ground stop due to extraordinary circumstances and reasons of safety. Senior government sources told CBS News that the issue stemmed from a telecommunication outage, while The Guardian reported that US transportation secretary Sean Duffy stated the stoppage stemmed from routine maintenance.
Duffy said that the issues began when a contractor performed routine maintenance at a remote FAA facility to switch telecommunications lines from legacy copper wire to a fiber optic cable.
“What we’re working to determine is whether we had incompetence,” Duffy said, “or did they install a faulty router.”
Transatlantic Disruption
The majority of flights between Ireland and the US operated as normal following the airspace closure. Aer Lingus ran a full transatlantic service while working to accommodate passengers whose travel plans had been disrupted.
Two incoming flights from Chicago and New York were cancelled, alongside outbound flights to the same destinations.
Flights from New York, Dallas, Atlanta, and Minneapolis experienced delays, leaving about 400 passengers airside needing connections, according to daa’s Grame McQueen, as reported by RTÉ.
Dublin Airport worked closely with airlines to assist impacted passengers transferring through the terminal. Shannon Airport reported that services operated normally throughout the incident.
Here’s the latest: Operations are slowly returning to normal this morning. Planes are pushing back, taxiing, and taking off, and it is safe to fly. We are in close coordination with the airlines to support the ongoing recovery. You will continue to see some delays and…
Contractor Investigation
Preliminary investigations by the FAA led the agency to believe the issue was limited to Cisco 600 series routers manufactured between 2001 and 2006, according to CBS News. Government sources said that the faulty equipment was identified and isolated after the routers became overwhelmed and fed out-of-sync data packets into the broader air traffic control system.
The system is operated by L3Harris. The contractor issued a statement confirming its support for the investigation.
“We are supporting the FAA in its investigation to understand the conditions that led to the ground stop of our nation’s air travel,” the contractor said.
White House officials stated there was no indication of a cyber attack or threat.
“There is no indication, we had no reason to believe, that as of right now, that this was a threat to the United States,” said Mullin, adding that it was a telecommunication outage throughout the FAA.
Airlines Recovery
Airlines worked to recover schedules after the four-hour ground stop. FlightAware data showed that more than 4,000 flights within, into, or out of the US were cancelled by 11am ET on Saturday, adding to more than 8,000 cancellations recorded on Friday.
Friday marked the second-worst travel day for airlines in 2026, trailing only a massive snowstorm on January 25, 2026, that led to 11,607 cancellations.
Flightradar24 tracked about 3,100 airborne aircraft bound for US airports when the ground stop began.
Bryan Bedford, the FAA’s head, apologized to passengers during a Saturday briefing.
“We will still have delays and cancellations today, but that will set,” Bedford said.
American Airlines said that the lingering effects of the major disruption to the national airspace system would continue to impact customers and team members with additional delays and cancellations.
Questions about US airspace reopening and flight cancellations
When did the US airspace reopen?
US airspace reopened at 1.15am Irish time on Saturday, November 14, 2026, after a five-hour ground stop ordered by the Federal Aviation Administration.
How many flights were affected by the shutdown?
Major airlines in the US cancelled more than 4,000 flights and delayed 3,000 more on Saturday, following more than 8,000 cancellations recorded on Friday.
There are currently 3,100 airborne aircraft bound for US airports amid nationwide ground stop. No additional aircraft are taking off at this time. pic.twitter.com/GGqfb8QXhP
What caused the telecommunication outage?
US officials reported that the issue stemmed from routine maintenance at a remote FAA facility while switching telecommunications lines from copper wire to fiber optic cable, which involved Cisco 600 series routers.
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