# Duffy Says Router Overload Triggered Nationwide U.S. Flight Ground Stop By Simon Yoon Canonical URL: https://www.tokenpost.com/news/technology/57482 Published: 2026-11-14T17:56:30.000Z Updated: 2026-11-14T17:56:30.000Z Section: Technology > Officials are investigating whether user error, an L3Harris installation error or a faulty router caused the failure. Transportation Secretary Sean Duffy said a router overloaded after a fiber-optic upgrade at a remote location, prompting Friday’s nationwide flight halt and an investigation into the equipment failure. Duffy said L3Harris was replacing copper wire with fiber-optic cable during routine maintenance. He said officials were trying to determine whether the problem stemmed from user error, an installation error by L3Harris or a faulty router. Two locations were pinging the network at a rate of 1,000 connections every four to five seconds, FAA acting Chief Technology Officer Rebecca Guy said. She said the FAA disabled both locations, stabilizing the network, and began a root-cause analysis. More than 8,200 flights were canceled Friday evening, and at least 3,000 more were canceled Saturday as disruptions continued. The new details add to [earlier coverage of the L3Harris system update and ground stop](). The ground stop came a day after the FAA announced an artificial intelligence tool for air traffic controllers. FAA Administrator Bryan Bedford said the agency had seen no evidence of a malicious or AI-related cause. Duffy said officials would reevaluate when the work is scheduled. Switchovers at larger airports are scheduled late at night, while remote-site switchovers take place during the day, he said. ## Links in this article - [earlier coverage of the L3Harris system update and ground stop](https://www.tokenpost.com/news/technology/57473)