United States airports have begun to progressively recover normality this Saturday, November 14, after a computer failure caused on Friday the greatest stoppage of United States air traffic since the September 11, 2001 attacks. The Federal Aviation Administration (FAA) ordered suspending takeoffs across the country for more than four hours due to problems in the communication and radar systems used by air traffic controllers, an incident that has left thousands of flights cancelled and delayed and has affected a large number of passengers.
The suspension was lifted at the 20:15 hours of Friday, U.S. east coast time, after technicians managed to restore the systems and confirmed that operations could be resumed safely. However, the reopening has not made it possible to immediately recover normal activity, since airlines need to reorganize their schedules, reposition aircraft and crews, and offer alternatives to travelers who have been left stranded in airports.
According to the latest figures released this Saturday, the cancellations accumulated during Friday and Saturday had already exceeded 12,500 operations, while thousands of additional flights had suffered delays. The impact also extends to international connections, although these show a proportion of cancellations lower than that of domestic routes.
The U.S. Transportation secretary, Sean Duffy, has assured that operations are gradually recovering and defended that flying is once again safe. However, he has warned that cancellations and delays will continue while airlines reorganize their schedules. The U.S. Administration is confident that a large part of the traffic can normalize before the weekend ends.
A failure during modernization work and no evidence of a cyberattack
The initial investigations point to a problem in the communication equipment used by air traffic control centers, which began experiencing failures around 15:36 hours on Friday. The instability affected both voice communications and the information transmitted by radars, which led the FAA to halt departures for safety reasons.
At a later appearance, Duffy said that the incident coincided with work carried out by the company L3Harris, responsible for certain maintenance and infrastructure technology update tasks. The technicians were replacing old copper cables with fiber-optic connections at a remote installation when the problems began to occur.
The Secretary of Transportation explained that the investigation is aimed at determining whether there was an error during installation or whether one of the devices used had a defect. The authorities have not yet established what the exact cause was of the overload that ended up affecting the system.
According to the first technical explanations, several old communications systems and routers began to receive an amount of information that they were unable to manage properly. This situation would have caused unsynchronized data, interference in communications for controllers, and radar screens that flickered or temporarily went black.
The U.S. Government has for the time being ruled out signs of malicious interference. Both the Department of Transportation and the Department of Homeland Security have stated that there is no evidence pointing to a cyberattack, while no connection to artificial intelligence tools has been identified either. The investigation remains open to determine responsibilities and prevent an interruption of these characteristics from happening again.
Thousands of passengers stranded and airports with no space for more planes
The impact of the suspension has been especially intense at the main U.S. airports, where aircraft have piled up with no possibility of taking off and passengers waiting to be rebooked. At facilities such as the Ronald Reagan Washington National Airport, the concentration of planes caused problems with space to park them, while the airlines had to cancel new operations to reorganize their activity.
The situation has also affected international flights, although to a lesser extent than domestic ones. According to data released by the aviation consultancy Cirium, by the morning of Saturday, fewer than 10% of the approximately 2,000 departures scheduled to foreign destinations had been canceled. However, passengers with connections in the United States continue to be exposed to delays and changes to their itineraries.
Recovery will depend on the ability of airlines to return the aircraft and crews to their usual positions. Restrictions on pilots’ and cabin crew working hours also make reshuffling harder, since companies must respect mandatory rest periods before scheduling new flights.
The malfunction, moreover, arrived just two weeks before Thanksgiving, one of the busiest seasons for air traffic in the United States. The incident has highlighted the consequences that a similar disruption could have during days of peak demand.
Systems from the 1980s and diskettes: obsolete air traffic control technology
Beyond the cancellations, the incident has reopened the debate about the age of the infrastructure used to manage U.S. air traffic. The FAA has been trying for decades to modernize its systems, but numerous control centers still rely on technologies developed in the eighties and on equipment for which it is increasingly difficult to find spare parts.
On the past November 5, just eight days before the suspension of flights, the Department of Transportation announced the gradual withdrawal of the diskettes used to store weather information and other essential data for air controllers. Its replacement will be carried out using the new E-IDS display system, designed to replace four old technologies present at more than 400 FAA facilities.
The deterioration of the equipment had already been flagged by oversight bodies. In September, the U.S. Government Accountability Office (GAO) published a report in which it questioned the planning of the air traffic control modernization program. The agency noted that the FAA was accelerating the renewal of its facilities without having a sufficiently detailed integrated schedule or a complete cost estimate.
The GAO warned that poorly coordinated modernization could lead to air traffic disruptions, delays, and even new security incidents, by forcing controllers to work simultaneously with old and new technologies.
The problem takes on a considerable dimension if it is taken into account that, according to a 2024 assessment, more than 75% of the 138 air traffic control systems analyzed by the FAA were unsustainable or potentially unsustainable. Obsolescence affects both communications and surveillance and information transmission systems.
A million-dollar investment that does not prevent failures
In 2025, the U.S. Congress approved an appropriation of $12.5 billion to drive the modernization of air infrastructure, although those responsible for the industry consider that the economic needs are greater.
The Donald Trump Administration has defended the need to accelerate these investments. During his appearance after the breakdown, Duffy called for an additional $50 billion to completely renew the air traffic control system, considering that maintaining current technologies represents an increasing risk to the continuity of service.
The FAA says that it has already made progress in replacing copper wiring with fiber optics and in modernizing communications equipment. However, the main challenge consists in renewing an infrastructure that must remain operational while the work is carried out, without interrupting a network that can handle up to 45,000 flights per day.
The president of the National Air Traffic Controllers Association, Nick Daniels, had already warned about the difficulties involved in carrying out this transformation in facilities subject to high operational pressure and that, in addition, face personnel problems.
For now, U.S. authorities keep the investigation open into the exact causes of the failure and possible responsibilities for the work carried out by L3Harris. The immediate priority is to fully restore operations, while the Government and oversight bodies must determine how to prevent the renewal of an aging infrastructure from again causing a nationwide stoppage of air traffic.