More than one million passengers in the US faced travel disruptions because of problems with the country's ageing air traffic control system. The system faced major technical problems on Friday, forcing the Federal Aviation Administration (FAA) to stop flights across the country.
The disruption affected passengers who were already on planes as well as those waiting to board. According to flight-tracking service FlightAware, around 9,200 flights were cancelled on Friday. Another 6,200 flights were cancelled on Saturday, even after the FAA lifted the ground stop, according to CNN.
US air traffic control system uses outdated technology
The US air traffic control system handles a huge number of flights every day despite using outdated technology. The system manages a large amount of US airspace and handles more than 45,000 flights daily.
Deep Dive
What caused the nationwide FAA ground stop?
Why did problems with the FAA’s old technology disrupt flights?
How much funding is the FAA seeking to modernise air traffic control?
Despite its old equipment, major failures are relatively rare. However, the latest disruption has exposed how difficult it has become to maintain the country's ageing aviation technology.
Some parts of the US air traffic control system still depend on technology that is decades old. Air traffic controllers still use paper strips carrying flight details to transfer information from one controller to another, according to CNN.
Some parts of the system also depend on floppy computer discs. Copper wires are still used for communication across nearly one-third of the air traffic control system. These outdated systems make it difficult to maintain operations and introduce newer technology.
{{/usCountry}}Some parts of the system also depend on floppy computer discs. Copper wires are still used for communication across nearly one-third of the air traffic control system. These outdated systems make it difficult to maintain operations and introduce newer technology.
{{/usCountry}}Experts say replacing old technology is difficult because many of its original parts are no longer available.
Henry Harteveldt, president of Atmosphere Research Group and a travel industry analyst, compared the problem to maintaining a 30-year-old car. He said finding replacement parts becomes increasingly difficult as a vehicle gets older, according to CNN.
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Old air traffic control technology caused flight problems
The latest disruption happened while a contractor was upgrading the air traffic control system. On Friday afternoon, a contractor was working to replace some of the existing copper wires with faster fibre-optic cables. However, the newer equipment created problems when it interacted with the older technology.
US Homeland Security Secretary Markwayne Mullin said the new equipment and technology were overwhelming the older system. He said the existing patchwork of old and new technology was not working properly, according to CNN.
The system became unreliable during the disruption. As a result, the FAA could not safely allow existing planes to continue flying or permit additional aircraft to take off. The agency ordered a rare nationwide ground stop, forcing flights to remain on the ground.
The flight cancellations continued even after the FAA lifted the ground stop. The FAA lifted the nationwide ground stop shortly after 8 pm Eastern Time on Friday. However, airlines could not immediately restart all their operations.
Some airlines faced staffing problems, while other aircraft were stuck in cities where they were not needed. This meant airlines could not operate their planned flights even after the technical restriction was removed. FlightAware reported another 6,200 cancellations on Saturday.
US officials said modernising the system while keeping the old one running is a major challenge. Transportation Secretary Sean Duffy said the government was trying to build a modern air traffic control system without shutting down the existing one. He acknowledged that the work was difficult and said previous administrations had not completed it because of the challenges involved, according to CNN.
Duffy warned that doing nothing would create even greater risks for the aviation system. He also highlighted how old the technology is, saying the system uses technology from the 1980s, software from the 1990s and radar from the 1970s. He added that replacement parts for some of the old radar equipment are no longer manufactured.
Earlier problems caused by outdated technology
The latest nationwide flight disruption is not the first time ageing FAA technology has affected air travel. In May 2025, communication problems affected air traffic control systems managing flights around Newark Liberty International Airport.
A separate FAA computer failure grounded flights across the US in January 2023. The system responsible for informing pilots about possible problems and conditions along their flight routes stopped working.
FAA seeks more funding for modernisation
The FAA needs money from the US Congress to replace its old air traffic control technology. The agency depends on government funding to upgrade its systems.
Last year, Congress approved $12.5 billion for these upgrades. Before Friday's flight disruption, Transportation Secretary Sean Duffy had asked Congress for another $30 billion.
However, after the latest technical failure, Duffy said the FAA now needs $50 billion to complete the upgrades. Duffy said the government must continue the work even though replacing the old system is difficult. He also said he could not promise that the same technical problem would not happen again. He said the government should use the latest flight disruption as a reason to speed up the work. Duffy urged Congress to provide the money so the FAA can complete the upgrades, according to CNN.