The United States lifted a nationwide ground stop late on Friday 13 November 2026, but airlines said delays and cancellations would continue into the weekend.
A ground stop is a Federal Aviation Administration (FAA) order that keeps planes on the ground. Planes already in the air may keep flying and land normally.
What happened
The FAA issued the order on Friday afternoon. It said a “temporary telecommunications outage” had affected Air Route Traffic Control Centers. These regional centres guide planes across the country.
The FAA lifted the order at 8:15pm Eastern Time (01:15 GMT on Saturday), after about four hours.
Sean Duffy, the US transport secretary, said old network equipment caused the failure. He said overloaded switches and routers gave inconsistent readings.
“Our routers actually got overloaded with data, and they started to give us inconsistency in the data from those routers. And because of that, we shut the system down,” Duffy told reporters at the White House.
He also said: “What we have is an incredibly old air traffic control system.” And: “We use 1980s little copper lines. It’s an old system that went down, and went down everywhere. It got overloaded.”
This is the government’s account, not an independent finding. CNN reported, from an airline source, that the problem is believed to have started at Chicago Midway International Airport.
No evidence of an attack
Markwayne Mullin, the US homeland security secretary, said there was no sign of an attack. Mullin said there was zero evidence of a cyberattack or an AI attack, but officials had not ruled one out.
Mullin said the outage was not linked to the Microsoft outage the day before, on 12 November. He said it was a telecommunications outage, not a repeat of the 11 September 2001 attacks.
How big it was
Duffy said more than 3,500 aircraft were in the air when the stop was issued. That number fell below 400 as they landed.
Cirium, an aviation data firm, said about 11,000 flights carrying more than 1.5 million passengers were due to leave US airports after 4pm on Friday.
The figures kept changing and sources disagree. Euronews reported that FlightAware counted more than 8,800 cancelled flights to or from the United States on Friday, and about 2,650 more for Saturday. Earlier counts were lower. AFP, filing on Saturday, reported a first tally of almost 6,000.
Nationwide ground stops are very rare. The FAA had ordered only two before in recent history: after the 11 September 2001 attacks, and in January 2023, when the system that sends safety notices to pilots failed.
Money and politics
Duffy and White House budget director Russ Vought asked Congress for an extra $30.1 billion to modernise air traffic control. CNN reported the letter was sent on Friday morning, hours before the ground stop.
At the White House briefing on Friday night, Duffy said he wanted more. “This is an emergency. I want Congress to give us emergency funding. This is bipartisan. This is American. I want $50 billion,” he told reporters.
Maria Cantwell, the senior Democrat on the Senate commerce committee, said the committee would look at the technology issues.
Ray LaHood, a former transport secretary, told CNN affiliate WEEK that ageing equipment was probably to blame, and called the stop “a national calamity”.
Airlines and a new AI tool
United, Delta and American all said they were resuming flights. American said it was working to run “as many remaining flights as possible this evening”.
The FAA expanded an AI-assisted flight planning tool, SMART, to all its air traffic control centres on 10 November. Air Space Intelligence (ASI), the company that built it, said on X the ground stop was “not based on or a result of the SMART system, any product of ASI or our integration with FAA and ATC”. Duffy denied the SMART system caused the outage. Mullin said officials were still looking into whether new technology played a part.
What to watch
Duffy said it would “take us some time to get back to capacity”, but he expected operations to be “back up and operational as we come into the heat of travel during Thanksgiving”. Thanksgiving, later in November, is one of the busiest US travel periods. The other open question is money: Congress has not approved the extra funding Duffy asked for.
Sources: Euronews, 14 November 2026; CNN, 13-14 November 2026; NPR, 13 November 2026; The Hill, 13 November 2026; Roll Call, 13 November 2026; ABC News 4, 13 November 2026; The Washington Post, 13 November 2026; The New York Times, 13 November 2026. Full URLs are listed in the front matter.