THE CRUNCH
A nationwide ground stop that halted flights across the United States on Friday was caused by a seemingly routine maintenance job gone wrong, Transportation Secretary Sean Duffy said at a Saturday press conference. Contractor L3Harris, a longtime Federal Aviation Administration supplier, was upgrading copper wire to fibre optic cable at a remote location when a router overloaded a critical communication system, triggering the stop. Duffy said officials are working to determine whether the fault was "user error or installator error from L3Harris" or a faulty router. The FAA's acting CTO, Rebecca Guy, said the agency saw two devices pinging its network at a very high rate, disabled both, and stabilised the network; a root cause analysis is under way.
The disruption was severe. More than 8,200 flights were cancelled on Friday evening, according to aviation data firm Cirium, with at least another 3,000 flights canceled on Saturday after the stop was lifted. It was only the third nationwide ground stop of the 21st century.
The timing raised eyebrows: the stop came a day after the FAA announced an AI tool for air traffic controllers, a system the controllers' union said it was not consulted on. But FAA administrator Bryan Bedford said the agency sees "zero evidence of anything nefarious and zero evidence of anything AI-related", calling it an equipment issue. Duffy also faced questions about why the upgrade ran at 3pm on a Friday rather than overnight; he said remote switchovers happen during the day, and that "there will be reevaluation of when we do this work."