TL;DR
The FAA halted departures nationwide on Nov. 13 after officials reported unstable radar and communications data at air traffic facilities. Transportation Secretary Sean Duffy blamed overloaded legacy telecom equipment, while officials said they had seen no evidence of a cyberattack; no written root-cause report has been released.
The Federal Aviation Administration halted departures from airports across the United States for about four hours on Nov. 13 after officials reported instability in radar and communications systems at air traffic facilities nationwide. Transportation Secretary Sean Duffy said overloaded legacy telecom equipment delivered inconsistent data; officials have not published a written report establishing the 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 issued its nationwide ground-stop advisory at 3:54 p.m. Eastern Time, directing departing aircraft to remain on the ground. The advisory cited extraordinary circumstances and safety. Its cancellation notice was timestamped 8:16 p.m.; Duffy said the airspace reopened at 8:15 p.m. The difference between those times leaves the precise end time slightly unclear in the public accounts.
Duffy said the issue began at about 3:36 p.m. and affected en route centers and terminal radar approach control facilities. He described overloaded analog telecom switches and routers delivering inconsistent data. He said the event was not a complete loss of radar or telecommunications. FAA advisories had already cited equipment and communications problems around Chicago O’Hare and Midway before the national order.
Duffy said more than 3,500 aircraft were airborne when the stop began, falling to fewer than 400 by 8 p.m. Exceptions were made for medevac flights, life-saving cargo and law enforcement flights. FlightAware counted 9,159 cancellations within, into or out of the United States on Friday, and 3,515 more by 7:58 a.m. Saturday. Those totals cover all cancellations in those periods and do not establish how many were caused by the ground stop.
How the Ground Stop Disrupted Travel
A nationwide halt to departures can quickly disrupt airline schedules because aircraft and crews are positioned around a network of connected flights. Even after a stop is lifted, airlines may need time to reposition planes and crews, and passengers can face delays or cancellations beyond the period when departures were held. The FAA’s order applied across the country, making the reported system instability a national operational issue rather than a problem limited to one airport.
The cancellation figures show the scale of disruption on those dates, but they include cancellations unrelated to the FAA action. Travelers and businesses should treat them as daily totals, not a count of flights directly lost to the ground stop. Duffy warned that similar events could occur without investment in updated systems, but that is his forecast, not a finding in a published technical investigation.
Products Worth Considering
Amazon Kindle Paperwhite (2024, 16 GB) – 7-inch Display, Black
Bose QuietComfort Wireless Bluetooth Headphones – Active Over‑Ear Noise Cancelling with Mic, USB‑C Charging, Deep Bass, up to 24 h Playtime,
Bose TV Speaker Compact Soundbar with Bluetooth and HDMI-ARC, Black
As an affiliate, we earn on qualifying purchases.
Warnings Before the National Order
FAA advisories point to problems emerging first around Chicago. At 3:21 p.m. ET, the Command Center cited equipment issues in arrival delays and airborne holding at O’Hare. At 3:28 p.m., it stopped departures to O’Hare from US airports and several Canadian airports, citing communications issues; Midway followed at 3:31 p.m. The nationwide order came at 3:54 p.m.
The FAA’s event times indicate a stop lasting about four hours and 23 minutes. BBC News described it as the longest nationwide ground stop since the Sept. 11, 2001, attacks. The only other nationwide stop since then, in January 2023, lasted about one hour and 40 minutes, according to the source material’s comparison of FAA advisory times.
During the disruption, speculation included a cyberattack, a Microsoft outage the previous day and the FAA’s newer SMART air-traffic tool. Duffy and the tool’s maker said SMART was not connected to the equipment involved. The source material does not provide technical records independently confirming the system path or the final cause.
““We didn’t lose all telecom we didn’t lose all radar.””
— Transportation Secretary Sean Duffy
The Cause Still Awaits a Report
Officials have described the equipment behavior, but the available material does not include a written root-cause report or a detailed technical account of what overloaded the switches and routers. The exact chain from the initial Chicago advisories to the nationwide instability has not been established publicly.
Mullin said officials had seen no evidence of a cyberattack and that the incident appeared mechanically driven, while leaving that possibility open. Duffy and the SMART tool’s maker said the AI traffic tool was not connected to the failed equipment. These statements address specific possibilities but do not, on their own, establish a final cause.
Flight cancellation totals also cannot show how many disruptions resulted directly from the stop. They include all reported cancellations for the relevant periods, and the source material does not supply a baseline or a breakdown by cause.
Investigation and System Funding
The next key development is a technical account from the FAA or transportation officials identifying the failure mechanism and any corrective steps. No release date for a written root-cause report is provided in the source material, so the timing remains uncertain.
Duffy has asked Congress for $50 billion for a new system and warned that further events may occur without investment. Congress’s response, the scope and schedule of any replacement, and the FAA’s interim measures have not been specified in the reporting cited here. For travelers, airlines’ recovery from the Nov. 13 disruption continued into Saturday, when FlightAware was still recording additional cancellations.
Key Questions
Why did the FAA stop departures nationwide?
Duffy said radar and communications became unstable at en route centers and approach control facilities, with overloaded legacy telecom switches and routers delivering inconsistent data. A final written cause has not been published.
How long did the ground stop last?
FAA advisory times put it at about four hours and 23 minutes, from roughly 3:53 p.m. to 8:16 p.m. ET on Nov. 13. Duffy said the airspace reopened at 8:15 p.m.
Was the disruption caused by a cyberattack?
Homeland Security Secretary Markwayne Mullin said officials had seen no evidence of a cyberattack and that the incident appeared mechanically driven. He also said officials would not rule that possibility out.
How many flights were cancelled because of the stop?
The exact number caused by the ground stop is not established in the source material. FlightAware counted 9,159 cancellations within, into or out of the United States on Friday, but that total includes cancellations from all causes.
Could a similar disruption happen again?
Duffy warned that there could be more events without funding for a new system. That is his warning; officials have not released a technical report specifying the likelihood of recurrence or the measures planned to prevent it.
Source: Thorsten Meyer AI
