A Rare Nationwide Ground Stop Halts U.S. Flights, and the Mess Spills Into the Weekend

If your travel plans ran into trouble over the weekend, you were not alone. On Friday, November 13, the Federal Aviation Administration ordered a rare nationwide ground stop, telling airports across the country to hold departing flights. The order went out in the late afternoon, Eastern time, and lasted more than four hours before it was lifted around 8:15 p.m. Public radio station KPBS reported it was only the second nationwide ground stop since the attacks of September 11, 2001, and the longest such pause in that time.

The cause was a problem with the system that carries flight and radar information, not bad weather or any attack. KPBS reported that Transportation Secretary Sean Duffy pointed to aging equipment, saying the system runs on old switches, old routers, and 1980s copper lines, and that it got overloaded. The trouble began as a contractor, L3Harris, worked on older communication lines, part of a long effort to switch from copper wire to fiber. A router then started flooding other routers with connection attempts, which disrupted some radar feeds and communication with aircraft and forced controllers to slow traffic for safety. Officials said the root cause was still under investigation.

Homeland Security Secretary Markwayne Mullin said there was no sign the outage was tied to a cyberattack or a terror threat. Duffy said the department did not believe anything harmful or intentional was involved.

The effects were large and spilled into the weekend. As of Saturday night, November 14, ABC News reported figures from the tracking site FlightAware showing more than 9,000 flights canceled on Friday and more than 6,400 canceled on Saturday, with thousands more delayed. About 3,500 planes were in the air when the ground stop began, and all of them landed safely.

Several airlines tried to ease the pain for stranded passengers, changing tickets at no extra fee or fare difference for travelers caught in the mess. FAA Administrator Bryan Bedford said he expected airlines to be back on a full schedule by the end of Sunday.

The episode renewed long-running concern about the aging equipment behind the nation's air traffic system. For older travelers heading out for the holidays, the lesson is simple. Build in extra time, keep your airline's app or phone number handy, and ask about fee-free changes if a delay upends your trip.