The Federal Aviation Administration (FAA) ordered a nationwide ground stop of all departing flights at 3:54 p.m. Eastern Time on Friday 13 November 2026 and lifted it at 8:15 p.m., according to Transportation Secretary Sean Duffy as reported by ABC News and NBC News. The FAA said the stop followed communication issues affecting multiple Air Route Traffic Control Centers. As of 14 November 2026, officials have offered explanations, but the FAA’s own written statement says only that technicians are investigating, and Lens found no final cause report.

What the FAA and officials said

The FAA’s statement, marked preliminary and subject to change, says it issued a ground stop for all US airports following communication issues affecting multiple Air Route Traffic Control Centers, that technicians are investigating, and that it will provide updates. After the evening briefing, the FAA said on social media that it tested its systems to confirm they were stable before clearing flights to resume, according to CBS News.

Duffy said the instability in radar and communications at control centers and Terminal Radar Approach Control (TRACON) facilities began around 3:30 p.m. (ABC News) or 3:36 p.m. (NBC News), and that about 3,500 aircraft were in the air when the stop began. ABC News says it was the second nationwide ground stop since 11 September 2001. The last was in January 2023.

Explanations given so far

  • Duffy, at a White House briefing: an old air traffic control system, in which switches and routers became overloaded with data and gave inconsistent readings, so the FAA shut the system down. He asked Congress for $50 billion to rebuild it, The Hill reports.
  • Homeland Security Secretary Markwayne Mullin: it did not appear to be a cyberattack, though he said nothing was completely certain (ABC News). CBS News reports he said new security patches added to the older system appeared to overwhelm its routers. CNN describes his explanation as FAA updates to the aging systems.
  • Unnamed sources told CBS News that an update to the private communications network linking air traffic control caused the system to reboot, crash and lose communications. CBS says the network is operated by L3Harris, which had not responded to its request for comment.

SMART and Microsoft

On 10 November 2026 the FAA said its SMART system (Strategic Management of Airspace, Routes and Trajectories) would be used in the airspace of all 22 centers, after a September rollout in the National Capital Region. Air Space Intelligence (ASI), the contractor, said in a post on X: “The current ground stop is not based on or a result of the SMART system, any product of ASI or our integration with FAA and ATC.” Duffy said at the briefing that SMART is not connected to the equipment that failed and that there was no possible way it affected the outage. Asked earlier about a possible link, Mullin said officials were looking at that, according to ABC News.

Microsoft reported its own outage the same day (see Lens’s earlier post). Futurism reports that Microsoft said it had no indication the ground stop was related to any of its services. Mullin said at the briefing that there is no connection to Microsoft, CBS News reports.

Where reports differ

  • Duration: 3:54 p.m. to 8:15 p.m. is 4 hours 21 minutes (Lens arithmetic). NBC News and ABC News say more than four hours, The Hill says around four, and CBS News says about five.
  • Flights: NBC News says more than 7,000 flights were canceled. CNN, citing FlightAware, says more than 7,700 canceled and more than 8,000 delayed on Friday. CBS News, in a story updated at 11:03 p.m. ET on Friday, cited FlightAware for more than 4,000 cancellations and more than 10,000 delays.
  • Aircraft airborne: Duffy said 3,500. NBC News cites Flightradar24 at 4,042 flights headed for US destinations; CBS News cites the same service at about 3,100.
  • Centers affected: Duffy’s post on X, as quoted by The Hill, said all Air Route Traffic Control Centers. The FAA statement says multiple.
  • SMART cost: Futurism says just under $1 billion. The Hill says $875 million. Lens found no published cost for the ground stop itself.

Sources and notes

This post draws on the FAA’s ground stop statement and general statements page (read for its 13 November and 10 November SMART entries), and on ABC News, CBS News, NBC News (main report read), The Hill, CNN’s live page (read in part) and Futurism; the FAA statement page and the other outlets were read in full. The posts on X by Duffy, ASI and Microsoft were not opened and are quoted through these outlets. Reuters and AP wire copy on the stop was not opened, and no FAA update after the 13 November statement was found. Futurism describes Mullin as a Homeland Security “administrator”; ABC News, CBS News, CNN and The Hill give his title as Homeland Security Secretary. The cause accounts above are officials’ statements and unnamed-source reports, not findings. The story is still moving.

Image: The FAA air traffic control tower at Minneapolis-St. Paul International Airport, Minnesota, 17 August 2020. Photo: Tony Webster (CC BY-SA 2.0), via Wikimedia Commons. Stand-in image: not a photo of the 13 November ground stop or of the facilities involved in it.