Copper Wire Upgrade Behind US Flight Shutdown, Duffy Says, as Contractor Faces Scrutiny

The nationwide shutdown that grounded every flight in the continental United States on Friday began with routine maintenance on decades-old wiring, Transportation Secretary Sean Duffy said on Saturday. Work to swap copper lines for fibre went wrong, he said, and the government now wants to know whether the contractor or the equipment was at fault.

How a wiring job shut down US airspace

Speaking at a news conference, Duffy said the upgrade was being carried out by L3Harris, a technology contractor, as part of a move away from copper wire that he described as so old “it was being discontinued.” He called the network “an incredibly old telecommunications system.”

According to Duffy, a router that engineers were working on began flooding other air traffic control systems with traffic. That caused communication problems between controllers and aircraft, and the government decided to close the airspace for safety. The question investigators are now trying to answer, he said, is whether the failure came down to “incompetence” by the company doing the work or to faulty equipment.

Officials were keen to rule out a more sinister explanation. The government does not believe a cyber-attack was involved, Duffy said, though the investigation is not finished. Federal Aviation Administration chief Bryan Bedford went further: “We see zero evidence of anything nefarious, and zero evidence of anything AI related.”

The longest stoppage since 9/11

No flight was allowed to take off from the continental US for more than four hours after the ground stop began at 15:54 EST (19:54 GMT) on Friday. It was the longest suspension of its kind since all flights were grounded for several days after the 11 September 2001 attacks. SmartAI News covered the shutdown as it happened, from the FAA’s initial nationwide ground stop order to the moment the airspace reopened.

The aftershocks are still being felt. More than 3,500 US flights were cancelled and over 2,000 delayed on Saturday, according to tracking site FlightAware. Some passengers were left stuck on aircraft on the tarmac, unable either to depart or return to the gate, while some international departures were allowed to leave in an apparent effort to free up space at airports. The FAA administrator has said air travel should recover by the end of Sunday.

A warning to Congress

Duffy used the news conference to press lawmakers for money. Without upgrades to air traffic control infrastructure, he warned, a similar failure could happen again. President Donald Trump has asked Congress for $30.1bn for the work, and Republicans control both the House and the Senate.

Former Transportation Security Administration chief John Pistole told the BBC that restarting the system within about four and a half hours showed “a resilience in the system,” but added: “what’s to say it’s not going to happen tomorrow?”

What happens next

The immediate focus is on clearing the backlog of stranded passengers and aircraft out of position. The bigger questions will take longer: what went wrong with the router during the upgrade, why a single piece of equipment could disrupt the wider network, and whether Congress will now move faster on the modernisation funding the administration says is needed to stop a repeat.

Sources: BBC News report on Transportation Secretary Sean Duffy’s news conference (November 14, 2026); The Times of Israel liveblog (November 14, 2026).