--- title: "Over 10,000 flights delayed in the US due to an air traffic control system failure" description: "On November 13, flight departures were suspended in the US due to an air traffic control system failure: over 10,000 flights delayed, over 1,100 canceled. The FAA has not named the exact cause." date: 2026-11-13T23:59:47.975Z lang: en url: https://xab.info/en/posts/us-air-traffic-control-failure-10000-flights tags: [usa, aviation, faa, flight-delays, air-traffic-control] author: "Roman V." publisher: "XAB.info" --- # Over 10,000 flights delayed in the US due to an air traffic control system failure ![United Airlines plane standing on an airport tarmac on a cloudy day](https://xab.info/media/2026/11/13/ssha-sboj-upravleniya-vozdushnym-dvizheniem-10-tysyach-reysov/ssha-sboj-upravleniya-vozdushnym-dvizheniem-10-tysyach-reysov-1.webp) ## Key Points - On November 13, flight departures were suspended in the U.S. for safety reasons; over 10,000 flights delayed, over 1,100 canceled. - The FAA has not named the exact cause; the failures simultaneously affected ATC radars and radio frequencies. - WSJ links the failure to an overload of the FAA's private network (L3Harris), while CNN points to a router problem starting at Chicago Midway. - U.S. President Donald Trump has been informed of the situation. On November 13, 2026, flight departures were suspended across the United States for security reasons. By the evening, this decision had already led to the delay of more than 10,000 flights. This was reported by RBC-Ukraine with reference to CNN and The Wall Street Journal. ### Scale of the failure Flight cancellations began on Friday afternoon at 15:53 Washington time. According to FlightAware, as of 17:40, more than 1,100 flights in the U.S. had been canceled and nearly 10,000 had been delayed. The aviation analytics company Cirium estimated that about 11,000 flights were still scheduled from U.S. airports as of 16:00; CNN provided comparable figures. ### What is known about the cause According to a CNN source in the aviation industry, the nationwide outages simultaneously affected air traffic control radars and radio frequencies, and controllers have no clarity regarding the cause or what exactly is happening. Another source told the publication that the U.S. Federal Aviation Administration (FAA) also does not yet know what is happening: "Ten minutes ago they were in an emergency meeting, and there was still no clear answer regarding the cause." ### Technical failure theories Sources for the WSJ claim that an update to the FAA's private communication network led to its overload and failure, which disrupted communication with air traffic control agencies; according to them, this network is maintained by the company L3Harris. Parallel to this, a CNN source points to a network router problem, which, according to his information, originated at Chicago Midway International Airport and spread across the entire country. ### Government reaction and consequences According to CNN, top aides to U.S. President Donald Trump are monitoring the situation, and the head of the White House has already been informed about the incident. The publication also notes that some airports are already reporting congestion due to the large number of aircraft that are on the ground and unable to take off. ## Accounts differ ### Cause of the air traffic control system failure - **The Wall Street Journal sources:** An update to the FAA's private communication network caused an overload and failure, disrupting communication with ATC; the network is maintained by L3Harris. ([rbc.ua](https://www.rbc.ua/ukr/news/ssha-cherez-masshtabniy-zbiy-zatrimano-ponad-1794613857.html)) - **CNN aviation industry source:** The failures were caused by a network router problem that originated at Chicago Midway International Airport and spread across the country. ([rbc.ua](https://www.rbc.ua/ukr/news/ssha-cherez-masshtabniy-zbiy-zatrimano-ponad-1794613857.html)) *Where they agree:* The FAA has not identified the exact cause of the failure; the disruption affected ATC radars and radio frequencies, leading to nationwide flight suspensions/delays. ## Fact-Check & Sources - [В США из-за масштабного сбоя задержаны более 10 тысяч авиарейсов, - CNN](https://www.rbc.ua/ukr/news/ssha-cherez-masshtabniy-zbiy-zatrimano-ponad-1794613857.html) - The numbers for delays (10k+) and cancellations (1100+) align with data from FlightAware, Cirium, and CNN. The cause is not definitively confirmed; the FAA does not know the exact reason, and theories from the WSJ (L3Harris network) and CNN (routers, Chicago Midway) differ. ## FAQ ### How many flights were delayed and canceled in the U.S.? According to FlightAware, by 17:40 Washington time, more than 1,100 flights were canceled, and nearly 10,000 were delayed. Cirium estimated the number of flights scheduled by 16:00 to be around 11,000. ### What is the reason for the flight suspension? The FAA has not named the exact cause. The WSJ links the outage to an overload of the FAA's private communication network (maintained by L3Harris), while a CNN source points to a network router issue that originated at Chicago Midway airport and spread nationwide. ### Who has been informed about the situation? According to CNN, top aides to U.S. President Donald Trump are monitoring the situation, and the head of the White House has been informed.