US flight suspension caused by copper wire upgrade, transport secretary says

Transport Secretary Sean Duffy said a nationwide ground stop that forced thousands of flights to be cancelled on 13 November was caused by a problem after a copper‑wire upgrade. The incident is the longest such disruption since the 11 September 2001 attacks.

Duffy told a news conference that investigators are examining whether the issue resulted from incompetence by the contractor or faulty equipment, and he said the government does not believe a cyber‑attack was involved, although a probe continues. He added that the United States has an incredibly old telecommunications system and that "It was such an old wire that it was being discontinued," he said.

He explained that a router being worked on began flooding other air‑traffic control systems, creating communication failures with aircraft and leading officials to shut down the airspace for safety reasons.

FAA chief Bryan Bedford said at the same briefing: "We see zero evidence of anything nefarious, and zero evidence of anything AI related."

On Saturday, L3Harris, the contractor carrying out the upgrade, said it had completed more than 70% of the communications‑modernisation work before the shutdown. The company added, "We are supporting the FAA in its investigation to understand the conditions that led to the 13 November ground stop of our nation's air travel," and stated, "L3Harris takes the nationwide ground stop and its impact on travellers, airlines and air traffic operations seriously."