On a Friday evening in mid-November, the nation's skies went quiet for roughly five hours, as the Federal Aviation Administration held every departing flight on the ground after an aging private communications network that links air traffic control began to fail. Officials trace the break to a software update that appears to have overwhelmed routers already worn by decades of service, and they have been firm that no attacker was behind it. The episode lays bare a deeper fact of modern life: the machinery that moves millions of people through the air still rests on infrastructure built a genera
FAA Lifts Rare Nationwide Ground Stop After Five-Hour Halt Disrupts Thousands of Flights
Thousands of travelers faced more than 10,000 delays and over 4,000 cancellations as about 3,100 aircraft bound for U.S. airports were affected.
An incredibly old air traffic control system
Mark
Five hours with no departures anywhere in the country. Why does this one stand out?
Mimi
Because of how rarely it happens. Robert Sumwalt pointed back to 9/11 as the last major ground stop of this kind, with a shorter one in 2023. Friday sits in that company.
Mark
And the cause?
Mimi
Officials say a telecommunication outage. Routers overloaded with data, giving inconsistent readings, so the system was shut down. Mullin said new security patches seemed to overwhelm the older equipment.
Luke
I'd separate who said what there. The patches-and-routers account comes from officials at the briefing. The reboot-and-crash after a network update comes from unnamed sources speaking to CBS. L3Harris hadn't responded, so the operator's version isn't in the reporting yet.
Mark
Officials also said it wasn't a cyberattack.
Mimi
Mullin said so plainly, and said there was no connection to the Microsoft outage. He also said they were still working through the process.
Luke
That's worth noticing. It's no indication so far, not a finished investigation. The statement is firm, but the work behind it isn't described as complete.
Mark
What about the human toll?
Mimi
More than 10,000 delays and over 4,000 cancellations on FlightAware, with about 3,100 aircraft already airborne when it began. Mullin said all were accounted for.
Luke
And the $50 billion figure is an estimate attributed to the administration's plan, not an audited cost. The 2023 review warned about this kind of failure, but it doesn't prove this outage came from that exact weakness.
The Pulse
- A nationwide ground stop halted every departing U.S. flight for about five hours, leaving roughly 3,100 aircraft in the air to be brought down safely.
- Airports scrambled as more than 10,000 delays and over 4,000 cancellations rippled through travel plans just before a holiday rush.
- Officials insisted there was no cyberattack and rejected any link to the recent Microsoft outage, even as the fallout unsettled public confidence.
- Investigators point to an obsolete network, overloaded routers, and security patches that appear to have overwhelmed an outdated system.
- Duffy and Mullin are pressing Congress for emergency funding to replace the system at an estimated $50 billion, warning that more outages will follow without it.
On a Friday evening in mid-November, the nation's skies went quiet for roughly five hours, as the Federal Aviation Administration held every departing flight on the ground after an aging private communications network that links air traffic control began to fail. Officials trace the break to a software update that appears to have overwhelmed routers already worn by decades of service, and they have been firm that no attacker was behind it. The episode lays bare a deeper fact of modern life: the machinery that moves millions of people through the air still rests on infrastructure built a generation ago, and its fragility now asks whether the country will rebuild it before the next failure arrives.
At 8:15 Friday night Eastern time, Transportation Secretary Sean Duffy announced that the nation's airspace was open again. For about five hours the Federal Aviation Administration had held every departing flight in the country on the ground. Duffy was careful not to promise a quick return to normal. Recovery would be slow, and travelers were urged to check with their airlines.
The cause, officials said, lay in the private network that links air traffic control. An update reportedly caused the system to reboot, which led to a crash and a loss of communications. L3Harris operates that network. Duffy said routers had been overloaded with data and began giving inconsistent readings, and Homeland Security Secretary Markwayne Mullin said new security patches appeared to overwhelm them.
The scale was enormous. About 3,100 aircraft bound for U.S. airports were in the air when the stop began, and by evening FlightAware counted more than 10,000 delays and over 4,000 cancellations. Mullin insisted there was no sign of an attack and rejected any link to the recent Microsoft outage, while admitting that a nationwide ground stoppage made the moment a crisis.
Robert Sumwalt, a former NTSB chair and a pilot for 24 years, called the event absolutely unprecedented, noting that the last comparable stop came on 9/11. The network at the center of the failure is old. It was awarded to Harris Corp. in 2002, and a 2023 safety review had already called it obsolete and warned that an unexpected failure could cut off facilities or entire regional centers.
Duffy used the moment to call again for emergency funding, warning that more such events would come unless Congress acted. Mullin argued that piecemeal fixes were not enough and that the administration wants the whole system replaced at an estimated $50 billion.
For now the work is clearing the backlog. The FAA moved as many flights as crew capacity allowed, with airlines resuming the rest Saturday morning. Duffy expects normal service to return in time for the heavy Thanksgiving travel later this month.
At 8:15 Friday night, Eastern time, Transportation Secretary Sean Duffy announced that the nation's airspace was open again. For about five hours, the Federal Aviation Administration had held every departing flight in the country on the ground, a step it said it took because of extraordinary circumstances and for reasons of safety. Duffy was careful not to promise a quick return to normal. It would be slow, he said, and travelers at airports should check with their airlines.
Officials described the cause as a telecommunication outage. Multiple sources told CBS News earlier in the day that an update to the private communications network linking America's air traffic control system caused the system to reboot, which led to a crash and a loss of communications. L3Harris operates that network, and it did not immediately respond to CBS News' request for comment. Duffy's account at the briefing was that the routers were overloaded with data and began giving inconsistent readings, so the system was shut down. Homeland Security Secretary Markwayne Mullin added that new security patches introduced into the older system appeared to overwhelm those routers.
The scale was large. When the ground stop began, Flightradar24 counted about 3,100 aircraft in the air bound for U.S. airports. Mullin said all flights were accounted for and that those in the air would be brought down safely. By Friday's end, FlightAware listed more than 10,000 delays and over 4,000 cancellations. Before releasing departures, the FAA said, it tested its systems to confirm they were stable and reliable.
Mullin said repeatedly that there was no sign of an attack. Earlier outside the White House, he said there was no indication the outage was a nefarious act or a threat to the United States. At the evening briefing he repeated that there was no cyberattack, and he rejected any link to the recent massive Microsoft outage, saying he knew many people were making that leap. He also conceded the gravity of the moment: he did not want to call it a crisis, he said, but a nationwide ground stoppage made it one. Federal agencies, he said, were working together on the response.
Robert Sumwalt, a former chair of the National Transportation Safety Board and a CBS News transportation safety expert, called the event absolutely unprecedented. A pilot for 24 years, he was in the air on 9/11, which he identified as the last comparable major ground stop. He noted a shorter one in 2023, lasting a few hours, and said it was unbelievable that this could happen today. That January 2023 stop followed the overnight failure of the FAA's flight personnel alert system.
The network at the center of Friday's failure is old. The FAA Telecommunications Infrastructure, or FTI, connects air traffic control centers and other FAA facilities and carries the voice communications and operational data used to manage traffic. The FAA awarded Harris Corp., the predecessor to L3Harris, the contract to modernize, operate and manage it in July 2002, more than 24 years ago. A November 2023 safety review commissioned by the FAA called the network obsolete and noted its reliance on older TDM technology. The review warned that this technology was no longer supported by the telecommunications infrastructure beneath it, and that an unexpected failure could cut off individual FAA facilities, or an entire regional control center, from the wider network.
Duffy used the moment to renew his call for emergency funding from Congress. You will have more of these, he said, unless the American people and Congress tell the department to build. Mullin said the incident showed why piecemeal modernization is not enough; the Trump administration wants the whole system replaced, at an estimated cost of $50 billion.
The immediate task is clearing the backlog. Duffy said the FAA would move as many flights as crew capacity allowed Friday night, with airline partners resuming the rest Saturday morning, and that unwinding the disruption would take time. He said he expects flights to be back up and running for the heat of Thanksgiving travel later this month.
Notable Quotes
You will have more of these unless the American people and the Congress tell us to build.— Transportation Secretary Sean Duffy
There is no indication, as of yet, that this was a nefarious act; it was a telecommunication outage.— Homeland Security Secretary Markwayne Mullin
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