US Nationwide Ground Stop Lasts Over Four Hours, Cancelling More Than 4,700 Flights; Washington Blames a Telecom Outage

The US Federal Aviation Administration (FAA) halted departing flights at airports nationwide at 15:54 Eastern Time on Friday 13 November 2026 (00:24 on Saturday 14 November Tehran time). Transportation Secretary Sean Duffy called the cause a "communication issue" at air traffic control centres and said switches and routers went down after being overloaded with data; he said communications and radar were not lost entirely.

Airspace reopened at 20:15 Eastern Time (04:45 on Saturday in Tehran), after more than four hours. Al Jazeera, citing FlightRadar, reported more than 4,700 flights cancelled and about 10,000 delayed on Friday, with another 700 already cancelled for Saturday. Cirium counted at least 827 diverted flights by 19:05 Eastern Time. It was the third nationwide ground stop of all departures since the 11 September 2001 attacks.

Homeland Security Secretary Markwayne Mullin said no cyberattack was involved and that "the public was never at danger". Microsoft said it saw no indication of a link between the ground stop and its own separate worldwide outage. Duffy called for $50 billion in upgrades to the air traffic control system.