Copper Wiring Upgrade Triggers Nationwide US Ground Stop

“The worst is behind us,” Bryan Bedford said.

Federal officials worked to restore normal schedules across the United States after an unprecedented telecommunications failure forced the longest nationwide ground stop in 25 years on November 13, 2026. The disruption left nearly 10,000 flights cancelled and over 7,000 delayed on one of the worst travel days in US history, according to RTÉ.

Maintenance work to replace aging copper wiring with new fibre optic connections triggered the crisis. Secretary of Transportation Sean Duffy said that an L3Harris contractor was upgrading the system when a router became overloaded with data, flooding air communication channels with inconsistent information and radar gaps.

Transportation officials blamed outdated infrastructure for the sudden failure. What we have is an incredibly old telecommunications system, Duffy said, calling for a $50 billion funding package to modernize the aviation system.

Homeland Security Secretary Markwayne Mullin confirmed that federal investigators found zero evidence connecting the outage to a cyberattack or artificial intelligence incursion. CBS News reported that preliminary investigations isolated the issue to Cisco 600 series routers manufactured between 2001 and 2006.

Airlines face massive backlog

Major carriers absorbed heavy operational damage as aircraft and flight crews remained stranded out of position. Delta Air Lines, United Airlines, and American Airlines each cancelled roughly 20% of their schedules, while JetBlue cancelled 40%. Flight tracking data showed that about 3,100 airborne aircraft were aloft when the emergency ground stop took effect.

Because the Federal Aviation Administration ordered the grounding for safety reasons, airlines hold no legal requirement to compensate stranded passengers. Travelers crowded terminals from Boston to Seattle as major hub airports blocked incoming flight diversions to clear congested tarmacs.

Financial markets reacted immediately to the bottleneck. Shares of American Airlines, United Airlines, and Delta Air Lines dropped between 1% and 2% in after-hours trading, while JetBlue shares fell 3%. Contractor L3Harris saw its stock drop by approximately 3% following the incident.

L3Harris did not respond to multiple requests for comment regarding the network failure. The disruption marked only the second nationwide ground stop ordered in the United States since the September 11 attacks, following a brief 90-minute pause in January 2023.

“The fact that they were able to get it restarted in four-and-a-half hours is good news – it shows a resilience in the system – but what’s to say it’s not going to happen tomorrow?” said John Pistole, former TSA Administrator, as reported by the BBC.