Washington: The United States has lifted a nationwide flight restriction imposed after a communications failure disrupted air traffic control operations, although airlines continued to face widespread cancellations and delays on Saturday.
The Federal Aviation Administration (FAA) ordered the ground stop on Friday, November 13, as a safety precaution after instability affected radar and communications systems used by air traffic controllers. The restriction prevented departing aircraft from taking off at airports across the country, while international arrivals were handled on a case by case basis.
US airspace reopened at approximately 8:15 p.m. Eastern Time on Friday after Transportation Secretary Sean Duffy confirmed that the immediate technical problem had been addressed. However, the resumption of flights did not immediately restore normal airline operations, as carriers continued working to manage disrupted schedules, reposition aircraft and assist affected passengers.
According to figures from flight tracking company Flightradar24, more than 6,600 flights were cancelled and approximately 8,600 were delayed during the disruption. Another 1,500 flights had already been cancelled for Sunday, November 15, highlighting the continuing impact on airline operations.
At least 827 flights were also diverted to other airports, according to aviation analytics company Cirium. Aircraft were redirected to airports including Washington Dulles International Airport, Los Angeles International Airport and Nashville International Airport. Some passengers also experienced long waits after landing because gates were unavailable.
Speaking at a White House briefing on Friday, Duffy said the technical problems began at approximately 3:36 p.m. Eastern Time, when air traffic control centres experienced instability in radar and communications systems. He explained that switches and routers in the ageing air traffic control network had become overloaded with data, resulting in inconsistencies in the information being transmitted through the system.
Duffy said the FAA had taken action to address the immediate problem before allowing flights to resume. He also called for major investment to modernise the country's air traffic control infrastructure, including a proposed $50 billion investment.
Homeland Security Secretary Markwayne Mullin said investigators had found no evidence that the disruption was caused by a cyberattack or a rogue artificial intelligence system. He described the incident as appearing to be mechanically driven. However, the investigation was continuing, with the National Security Agency assisting the Department of Homeland Security.
The incident also raised questions about the introduction of new technology into the country's ageing aviation infrastructure. The FAA had expanded its Strategic Management of Airspace, Routes and Trajectories system, known as SMART, to all 22 air traffic control centres on November 10. The cloud based system uses information about weather, flight routes and traffic conditions to help controllers manage airspace more efficiently.
However, Duffy denied that the new artificial intelligence powered system was responsible for the November 13 disruption. Officials had not established a definitive technical cause for the failure.
The disruption has renewed concerns about the condition of the US air traffic control network, which continues to depend on older communications equipment alongside newer technology. The system has also faced longstanding challenges, including equipment problems and shortages of air traffic controllers.
The administration has previously sought $30.1 billion for improvements to airport and air traffic control infrastructure. Duffy's latest call for a $50 billion investment has added urgency to the debate over modernising the country's aviation system.
Although the nationwide ground stop has ended, the FAA continued to report individual airline ground stops and possible airport delays on Saturday. Airlines were also working to restore schedules and accommodate passengers whose journeys had been disrupted.
The incident has highlighted the importance of reliable communications infrastructure in maintaining aviation safety and the challenges of managing one of the world's busiest air transport networks.