US air travel hit by massive delays after copper wire upgrade goes wrong

A nationwide ground stop across the United States grounded flights for more than four hours following a technical failure linked to a copper wire upgrade. Transport Secretary Sean Duffy stated that officials are investigating whether the fault stemmed from company incompetence or faulty equipment, while ruling out any cyber-attack. The disruption began on Friday at 15:54 EST when departures across the continental US were halted, marking the longest aviation suspension in the country since the September 11 attacks. Technology provider L3Harris was conducting maintenance to replace old copper wires with fibre optic cables when a router being worked on flooded other air traffic control systems, cutting off communication with aircraft and forcing authorities to shut down airspace for safety. Federal Aviation Administration chief Bryan Bedford confirmed investigators found no evidence of malicious activity or artificial intelligence involvement. L3Harris stated it had completed over 70 percent of its infrastructure modernisation work before the shutdown and is fully cooperating with the FAA inquiry. The fallout continued into Saturday, resulting in more than 3,500 flight cancellations and over 2,000 delays according to FlightAware, with some passengers stranded on tarmacs and knock-on travel impacts expected to last for days.

Context

Air traffic control systems rely on complex digital and telecommunications networks that require careful, scheduled updates to maintain safety and efficiency. When core routing equipment fails during high-level maintenance, backup protocols must be triggered immediately to prevent mid-air risks, which often necessitates temporary airspace closures.