Outdated routers blamed for nationwide FAA shutdown that grounded US flights

A nationwide shutdown of US air traffic was triggered by overloaded, aging network equipment, according to Transportation Secretary Sean Duffy.
Speaking after the November 13 disruption, Duffy said older routers and switches in the Federal Aviation Administration's communications network began producing inconsistent data, prompting officials to halt flights as a safety precaution.
The FAA's infrastructure still relies on legacy telecommunications systems, including copper connections dating back decades. Duffy said recently installed equipment remained operational while older components failed under the strain.
The nationwide ground stop lasted roughly five hours, affecting thousands of flights and disrupting travel for more than a million passengers.
Federal officials said they had found no evidence of a cyberattack, although investigators were still examining the precise cause of the failure.
The FAA has since lifted the ground stop, but airlines warned that cancellations and delays could continue as aircraft and crews return to their normal schedules.
The incident has renewed scrutiny of aging US aviation infrastructure and the challenges of modernizing critical systems without disrupting existing operations.