TL;DR
The FAA halted departures nationwide on Nov. 13 after radar and communications became unstable, according to Transportation Secretary Sean Duffy. He attributed the problem to overloaded legacy telecom equipment, while Homeland Security Secretary Markwayne Mullin said officials had seen no evidence of a cyberattack. The FAA has not published a written root-cause report, and Friday’s flight cancellation totals include causes beyond the ground stop.
The Federal Aviation Administration halted departures at airports nationwide on Friday, Nov. 13, after radar and communications became unstable at air traffic control facilities, Transportation Secretary Sean Duffy said. The stop lasted just over four hours, disrupting flights across the country; officials have not released a written report identifying the failure’s root cause.
Get everyday essentials delivered free with Prime
- Fast, free delivery on millions of items
- Prime Video, Amazon Music and more included
- Member-only deals all year
The FAA Air Traffic Control System Command Center began reporting equipment problems in Chicago before the national order. At 3:21 p.m. Eastern Time, it cited equipment issues in an advisory about arrival delays and airborne holding at O’Hare. At 3:28 p.m., it restricted departures bound for O’Hare and listed communications issues; Midway followed with a departure restriction at 3:31 p.m.
Duffy said the nationwide instability began at 3:36 p.m. ET at en route centers and terminal radar approach control facilities. At 3:54 p.m., the Command Center ordered all airports to hold departing traffic, citing extraordinary circumstances and safety. The FAA’s cancellation advisory took effect at 8:16 p.m.; Duffy said the airspace reopened at 8:15 p.m. The advisory times indicate a stop of about four hours and 23 minutes.
Duffy said more than 3,500 aircraft were airborne when the stop began and fewer than 400 remained aloft by 8 p.m. ET. Medevac flights, life-saving cargo and law enforcement flights were permitted to continue, according to the source material. The FAA expected airborne holding at airports during the disruption, and flights resumed gradually after the order was lifted.
Disruption Across U.S. Flights
A nationwide departure halt can disrupt travel well beyond the period when the order is active. Aircraft and crews may be out of position, and passengers can face delays or cancellations as airlines work through the backlog. The scale of the response also put attention on the reliability of air traffic control systems used across the country.
FlightAware counted 9,159 cancellations within, into or out of the United States on Friday, and 3,515 more by 7:58 a.m. ET on Saturday. Those figures cover all cancellations recorded for those periods, not just flights affected by the ground stop. They show the broader disruption but do not establish how many cancellations the FAA order itself caused.
Popular right now
De'Longhi Magnifica Duo Fully Automatic Espresso Machine with Milk Frother, Silver
Bose QuietComfort Headphones (2nd Gen), Wireless Over-Ear Noise-Cancelling Headphones, Black
Bose QuietComfort Wireless Headphones – Twilight Blue (Limited Edition)
As an affiliate, we earn on qualifying purchases.
From Chicago Delays to Nationwide Halt
The FAA’s public advisories show the first equipment-related warning of the afternoon at O’Hare, followed by restrictions at O’Hare and Midway. The Command Center also activated its diversion recovery tool for all airports at 3:30 p.m., according to the source material. The shift from local notices to a nationwide order came within minutes of the 3:36 p.m. instability Duffy described.
The source material, citing BBC News, describes the event as the longest nationwide ground stop since the Sept. 11, 2001 attacks. It says the only other such stop since then occurred in January 2023 and lasted about one hour and 40 minutes. Those comparisons are attributed to BBC News; the FAA advisories establish the event times used to calculate the 2026 duration.
““We didn’t lose all telecom we didn’t lose all radar.””
— Transportation Secretary Sean Duffy
Root Cause Still Unreported
Duffy attributed the instability to legacy analog telecom switches and routers that became overloaded with data and delivered inconsistent information. That is his account of the failure; the FAA has not published a written root-cause report in the source material. It is not clear which specific equipment failed, what triggered the overload, or how the problem spread from the initial Chicago advisories to facilities nationwide.
Mullin said officials had seen no evidence of a cyberattack but did not rule one out. Duffy and the maker of the FAA’s new SMART traffic tool said that system was not connected to the failed equipment. The available material does not identify the precise technical failure or provide a completed investigation’s findings.
The cancellation counts also have limits: FlightAware’s totals include cancellations for all reasons, so they cannot be treated as a count of flights caused to cancel by the ground stop. The number of travelers directly affected was not specified in the source material.
Investigation and System Funding
The next key development is a written FAA account of the failure, including its root cause and any corrective steps. The source material does not give a publication date for such a report. Officials may also provide further information about whether cyber-related explanations were ruled out after the initial review.
Duffy said Congress should provide $50 billion for a new air traffic control system and warned that disruptions could recur without funding. The source material does not establish whether Congress will approve that request, when any replacement would be completed, or what immediate changes the FAA plans to make to the equipment implicated in the incident.
Key Questions
Why did the FAA halt departures nationwide?
Transportation Secretary Sean Duffy said radar and communications became unstable at air traffic control centers and approach facilities nationwide. He attributed the issue to overloaded legacy telecom equipment delivering inconsistent data.
When did the ground stop begin and end?
The FAA Command Center issued the nationwide order at about 3:54 p.m. ET on Nov. 13. Its cancellation advisory took effect at 8:16 p.m.; Duffy said airspace reopened at 8:15 p.m.
Was the disruption caused by a cyberattack?
Homeland Security Secretary Markwayne Mullin said officials had seen “zero evidence” of a cyberattack, while adding they would not rule it out. The source material does not include a final investigation finding.
How many flights were cancelled?
FlightAware counted 9,159 cancellations within, into or out of the United States on Friday and 3,515 more by 7:58 a.m. ET Saturday. Those totals include cancellations for all causes, not only those linked to the ground stop.
Could another nationwide halt happen?
Duffy warned that similar disruptions could occur again without funding for a new air traffic control system. The source material does not provide an official forecast or a timeline for replacing the existing equipment.
Source: Thorsten Meyer AI
