2,500 Flights Canceled as FAA Grounds Traffic for Four Hours

The Federal Aviation Administration ended a nationwide suspension of flights at approximately 8:15 p.m. Eastern Time on Friday. This interruption marked the longest grounding of air traffic in 25 years. More than 2,500 domestic flights were canceled on Saturday, according to data from FlightAware. Hundreds of additional flights experienced delays.

Officials stated that the disruption was caused by a new technology being integrated into the national air traffic control system. The software update overloaded aging equipment, leading to intermittent communications and gaps in radar coverage. Transportation Secretary Sean Duffy explained that the agency closed the skies for more than four hours as a precautionary measure.

Duffy noted that the system is not yet fully stable. He warned that restoring normal operations will be a slow process. He also suggested that further interruptions could occur as the system continues to adjust. "We didn't think we would have this kind of system failure. We did," Duffy said.

The grounding has created a ripple effect across the country. Airlines are required to offer free rebooking on alternate flights to passengers who wish to continue their travel. If a flight was canceled and a passenger decides not to travel, the airline must provide a full refund. International flights are being managed on a case-by-case basis, according to Homeland Security Secretary Markwayne Mullin.

In San Francisco, flights bound for the Pacific region received clearance to depart from Friday night onward. This included routes to Hawaii and Asia. In Europe, the continent's aviation agency suspended departures to the United States at the FAA's request. Those suspensions were in effect from 5 p.m. Eastern Time on Friday until midnight.

Mullin stated that there is no evidence linking the outage to a cyberattack. He also confirmed that the incident was unrelated to a service disruption at Microsoft that took Outlook and other services offline on Thursday. "There were never lives in danger. There were no flights in danger. The FAA was able to handle it. We did it," Mullin said.

The incident highlights the ongoing efforts to modernize the U.S. air traffic control system. Congress approved $12.5 billion in funding last year to begin this modernization. The White House and Duffy are now pushing for an additional $30 billion to complete the work.

Travelers are advised to contact their airlines directly for the most current information on their specific flights. While the immediate grounding has ended, the full normalization of the system remains a work in progress.

Authorities expect the system to be operating normally in time for the holiday travel rush. They aim to have capacity ready for the increased number of passengers traveling for Thanksgiving.