FAA Halts Flights Nationwide in Rare Ground Stop; Officials Say Telecom Outage, Not Attack

On Friday evening, runways across the United States emptied. The Federal Aviation Administration issued a nationwide ground stop, citing "extraordinary circumstances" and "reasons of safety." Hundreds of flights were affected. On a flight-tracker graphic shown on the PBS NewsHour, the aircraft across the country and the surrounding region were marked in yellow, which meant they were not moving.

A nationwide ground stop is rare. PBS NewsHour anchor Amna Nawaz said this was only the third such grounding in recent decades. The most recent came in January 2023, after a pilot communications system failed. The one before that was the grounding that followed the September 11 attacks.

That history is why Homeland Security Secretary Markwayne Mullin spoke to reporters soon after the stop began. He said he did not believe it was tied to a specific attack. "This isn't another 9/11," he said, adding that he could not repeat that enough and that the public had no reason to be afraid for their loved ones. People were drawing the comparison, he said, because the last nationwide ground stoppage of this kind was that one. He described tonight's event as a telecommunications outage, which he called very different.

The cause had not been confirmed. Aviation correspondent Miles O'Brien told NewsHour that there was a lot of speculation and that no one really knew for sure, or at least no one was saying. What he saw was a systemwide problem in a system built on redundancy, which raised the question of what single points of failure existed and why.

O'Brien pointed to one possibility. Twenty-two regional en route centers manage aircraft at cruise altitude as they cross the country, and they are linked to each other by old-fashioned landlines. Some people were speculating that the connections between those centers had failed. He said that was speculation, and he did not say what might have broken them. He raised two open questions: whether a hacking event could have been involved, or whether the problem was tied to the ongoing modernization of a system that still relies on floppy disks, paper strips and radars dating to the 1940s. His image for the modernization effort was attaching a rocket booster to a horse and buggy.

Nawaz also asked whether the stop could be connected to the massive Microsoft outage the program had been covering. O'Brien did not answer that directly. He said the system should not be this vulnerable, and that if one layer can be taken down, another should be behind it.

He placed the blame on years of deferred investment. Congress and Washington, he said, had kicked the can down the road on air infrastructure while travel hit an all-time record despite high costs. He called for serious investment in something more resilient and more redundant.

He also stressed that, as of that moment, everyone was safe, though extremely inconvenienced. He credited the air traffic controllers who keep the aging system working every day.

The open questions are the root cause and when flights will resume. Mullin's telecommunications explanation is an official statement, not a confirmed finding, so the next thing to watch is what investigators determine failed and whether it revives the debate over modernizing the nation's air traffic systems.