A cable upgrade grounded 11,000 US flights after a router overload

A routine telecommunications upgrade caused a nationwide ground stopGround stopAn order that requires planes to stay on the ground at airports. Open in glossary that disrupted air travel across the United States. Transportation Secretary Sean Duffy explained that the outage happened during scheduled maintenance conducted by L3Harris, a longtime contractor for the Federal Aviation Administration.

How a routine switch led to system failure

Workers were replacing legacy copper wire with fiber optic cable at a remote site on Friday afternoon. Following the physical upgrade, a router overwhelmed a vital FAA communication network.

Rebecca Guy, the acting chief technology officer at the FAA, reported that the agency detected abnormal network instability. Technicians identified two network locations sending unusually heavy traffic, recording roughly one thousand connection attempts every four to five seconds. Once staff disabled those points, the network stabilized. Officials are still investigating whether the disruption stemmed from technician error during installation or a defective router.

Thousands of flights halted nationwide

The system outage triggered only the third nationwide ground stop in the United States this century. Data from aviation analytics firm Cirium showed more than 8,200 flights were canceled on Friday evening. Travel disruptions carried over into the following day, leading to at least 3,000 additional cancellations on Saturday.

The incident occurred shortly after the FAA introduced an artificial intelligence tool for air traffic controllers, which had faced objections from the controllers union over a lack of consultation. However, FAA Administrator Bryan Bedford stated that investigators found no evidence of cyberattacks or artificial intelligence involvement. Officials confirmed the failure was strictly a hardware and installation issue. Duffy stated the agency will reevaluate scheduling policies that currently permit remote network switchovers to occur during daytime hours, while renewing calls for Congress to increase funding for aviation equipment upgrades.