Transportation Secretary Sean Duffy said Saturday that work by FAA contractor L3Harris to replace copper telecommunications lines with fiber at a remote facility was underway when Friday’s nationwide flight ground stop began. Duffy said investigators have not determined whether a contractor error or faulty router triggered the disruption.

The update adds a specific maintenance operation and contractor to the investigation. The Federal Aviation Administration’s Friday statement described communications issues affecting multiple air traffic control centers but did not identify a cause. Duffy’s account is an official explanation of the suspected sequence, not a published final investigation finding.

What the FAA outage update adds

At a Saturday briefing, Duffy said the work involved changing old copper lines to fiber at at least one remote FAA site. He named L3Harris as the contractor and said a router being replaced may have flooded other routers in the system. That account fits the government’s earlier description of overloaded legacy switches and routers, but officials have not released a technical report identifying the failed component or the precise error.

The FAA ordered the ground stop after communications and radar data became inconsistent. The Department of Transportation said the precaution allowed controllers to use established procedures while aircraft already in the air landed safely. Officials said the new airspace-planning tool was separate from the equipment involved.

What remains unresolved

Duffy said the investigation was weighing whether the installation work went wrong or the router itself was faulty. That distinction matters: naming the contractor and describing the work does not establish fault or show that a final cause has been confirmed. The FAA has not published a final investigation report in the material available Saturday.

The outage also revived questions about how legacy telecommunications equipment is modernized without disrupting systems used by air traffic controllers. The Department of Transportation has called for additional funding to modernize air traffic control, but the cause review and any accountability decisions are separate from that policy debate.

What travelers should check

For a specific itinerary, check the operating airline’s app or website for current flight status and rebooking details. The FAA’s National Airspace System Status page provides system-level notices. The Globuzz’s earlier FAA ground-stop report covers the initial order and passenger guidance; see also the site’s Travel coverage.

Sources

The Wall Street Journal: Air-Travel Outage Linked to Contractor Replacing Copper Wire (Nov. 14).

The Washington Post: Work to replace old wiring led to ground stop, transportation secretary says (Nov. 14).

U.S. Department of Transportation: Duffy’s updates after the nationwide ground stop.

Federal Aviation Administration: Friday statement on the nationwide ground stop.