The US Federal Aviation Administration (FAA) ordered a nationwide ground shutdown on Friday after a massive communications failure disrupted air traffic control centers across the United States, affecting critical radio frequencies, radar capabilities and flight coordination systems.
It marked only the second nationwide grounding of flight departures since attacks of September 11, 2001, following a similar shutdown in January 2023.
The emergency shutdown began around 3:54 p.m. Eastern time, exit stops at airports throughout the country. Planes that were already airborne were allowed to land.
Eurocontrol has suspended departures to the US from Europe at the request of the FAA.
The disruption caused more than 4,700 flight cancellations, over 10,000 delays and hundreds of diversions, which severely affected domestic and international aviation.
Transportation Secretary Sean Duffy attributed the failure to overloading of switches and routers within the FAA's aging communications infrastructure, resulting in widespread system instability. Homeland Security officials reported no evidence of a cyber attack, while investigators looked into the technical failure and its possible ramifications.
After more than 4 hours, the nationwide ground shutdown was lifted around 8:15 p.m. Eastern time, which allows the ports to gradually resume with the restoration of the communication systems.
The unprecedented incident renewed concerns about the vulnerability of America's air traffic control infrastructure and the urgent need for modernization.