Copper Wire Upgrade Caused US Flight Ground Stop, Transport Secretary Says

A nationwide US ground stop that caused thousands of flight cancellations and travel chaos was triggered by a technical issue during a copper wire upgrade, according to transport secretary Sean Duffy. Duffy stated that the government is investigating whether the problem stemmed from incompetence by the company performing the upgrades or from faulty equipment. The four-hour suspension on Friday was the longest incident of its kind since the 11 September 2001 attacks, affecting more than 15,000 flights and an estimated 1.5 million passengers.

Technical Cause

Maintenance was being carried out to switch from an extremely old copper wire system to fibre-optic cables by a technology provider named L3Harris. Duffy explained that a router being worked on started flooding other air traffic control systems, creating communication issues with planes and forcing a safety shutdown. Officials do not believe a cyber-attack or artificial intelligence caused the issue, with Federal Aviation Administration head Bryan Bedford confirming zero evidence of malicious activity.

Aftermath

Although the ground stop lifted on Friday evening, knock-on effects persisted on Saturday as airlines cleared backlogs, and schedules faced disruptions globally. L3Harris stated it had completed more than 70% of its modernisation work before the shutdown and is supporting the FAA investigation. Duffy warned that similar issues could recur unless Congress approves funding for infrastructure overhauls, noting that President Donald Trump has requested $30.1bn for these upgrades.

Context

Air traffic control systems rely on complex networks of communication hardware to track and direct aircraft safely across national airspace. When core routing or wiring components fail during updates, safety protocols require grounding flights until communication links are fully restored.