Over 8,000 flights were canceled as the Federal Aviation Administration issued a nationwide ground stop on Friday due to a communications system failure. The outage, which lasted nearly five hours, was the longest in the United States since the September 11 attacks.

Officials attributed the issue to outdated air traffic control equipment and overloaded routers. Airlines have started to resume operations, but delays and cancellations are expected to continue as they work to restore their schedules.

American and United Airlines have waived fees for passengers affected by the disruption, while Delta is offering flexible rebooking options. The incident has raised concerns about the aging infrastructure of the air traffic control system and the need for modernization funding.

The FAA has confirmed that the system was restored after testing, but the backlog of flights and passengers remains. Transportation Secretary Sean Duffy expects the system to return to normal by the Thanksgiving travel period.

However, the incident has highlighted the risks of relying on outdated technology, with officials calling for additional funding to upgrade the air traffic control network. The disruption has also affected international flights, with some European and Canadian departures temporarily suspended at the FAA's request.