Sean Duffy reveals bizarre reason behind FAA's rare nationwide ground stop

WASHINGTON, DC: The FAA's aging communications network is under scrutiny after a problem during maintenance at a remote facility was linked to a nationwide flight disruption on Friday.

Transportation Secretary Sean Duffy addressed the failure on Saturday, November 14, explaining how work involving decades-old equipment may have gone wrong.

Investigators are now trying to determine whether a technical fault or an error during the maintenance operation caused the breakdown that disrupted air traffic across the country.

Sean Duffy points finger at contractor

According to Duffy, the trouble started when L3Harris, the company contracted to maintain the FAA's telecommunications network, was replacing old copper lines with fiber-optic connections.

The work was being carried out at a remote FAA facility as part of a routine effort to update aging infrastructure.

The upgrade did not go as planned.

Duffy said a router involved in the work began flooding other routers across the network with connection requests.

Air traffic controllers experienced problems communicating with pilots, while radar systems also began delivering unreliable information about aircraft movements.

With several facilities affected and no immediate way to identify the source of the failure, officials decided to stop departures across the country rather than allow flights to operate with potentially faulty data.

Investigators are now trying to establish whether the contractor made an error during installation or whether the router itself was defective.

Duffy said both possibilities were being examined, without confirming either as the cause.

The secretary also questioned the contractor's performance, noting that L3Harris had worked with the FAA for more than two decades and owned the network used by the agency.

"This was an FAA system that didn't meet the moment. Our contractor didn't meet the moment, or the equipment didn't meet the moment," Duffy said.

Duffy said officials had found no indication that a foreign actor was behind the incident.

Outdated FAA network under scrutiny

America's air traffic system is still relying on communications technology that much of the telecom industry abandoned years ago, and the nationwide shutdown has brought that problem into focus.

The FAA has been trying to replace its aging copper-based network, which carries data between air traffic control centers and other aviation facilities, but the transition is far from complete.

Duffy said the agency was moving away from time-division multiplexing, a system used to transmit data that dates back several decades, and shifting toward internet protocol technology.

The copper lines involved in the failed upgrade were nearing the end of their usable life.

He said the replacement program had covered approximately 70% of the country's lines, leaving the rest still to be converted.

The secretary also pointed to years of underinvestment as a reason the FAA had not modernized at the same pace as other parts of the country's infrastructure.

While much of America's communications network has already moved from analog to digital technology, the aviation agency continues to operate with equipment dating back to the 1980s.

The failure had consequences across the country on November 13, when problems spread through air route traffic control centers and terminal radar approach control facilities.

The FAA ordered a nationwide ground stop while more than 3,500 aircraft were already airborne. Officials said controllers managed to bring every one of those planes safely to the ground.