- 6,600 flights were cancelled and 8,600 delayed, while another 1,500 flights had already been cancelled for Sunday
The United States reopened its airspace on Friday after a communications failure at air traffic control centres triggered a nationwide flight suspension, causing widespread disruption at airports and leaving thousands of passengers stranded.
The Federal Aviation Administration (FAA) lifted the ground stop at 8:15 pm Eastern Time (1:15 am GMT on Saturday), but Transportation Secretary Sean Duffy warned that flight departures would resume gradually and airlines could take days to restore normal operations.
According to FlightRadar24, more than 6,600 flights were cancelled and 8,600 delayed, while another 1,500 flights had already been cancelled for Sunday. Aviation analysts warned that the four-hour nationwide grounding could disrupt airline schedules for several days. Duffy said tens of thousands of passengers had been stranded at airports across the country.
The disruption began at 3:36 pm on Friday when air traffic control centres experienced instability in radar and communications systems. Duffy said overloaded switches and routers produced inconsistencies in data, prompting officials to shut down the system as a safety precaution. He stressed that radar and communications were never completely lost and that thousands of aircraft were able to land safely.
Duffy said the immediate technical problem had been resolved and flying was safe, but warned that the incident highlighted the urgent need to modernise the country’s ageing air traffic control infrastructure. He criticised Congress for failing to provide sufficient funding for a replacement system and called for $50 billion to upgrade the network.
Earlier on Friday, the White House and the Department of Transportation had urged Congress to approve $30.1 billion for improvements to ageing airports and air traffic control infrastructure.
“What we have is an incredibly old air traffic control system,” Duffy said, urging lawmakers: “Give us the money to fix it.”
Homeland Security Secretary Markwayne Mullin said there was “zero evidence” so far that the outage had resulted from a cyberattack or a rogue artificial intelligence system, although investigators had not ruled out either possibility.
“It appears this was mechanically driven, however, we’re still looking,” Mullin said, adding that the National Security Agency was assisting the Department of Homeland Security with the investigation.
The outage appeared to involve a telecommunications network overseen by L3Harris Technologies, according to two airline officials. The network handles critical radio frequencies used by air traffic controllers to communicate with pilots. The company did not immediately respond to a request for comment.
Despite the lifting of the ground stop, passengers continued to face significant disruption, with delays and cancellations mounting at airports from Boston and New York to Seattle and Los Angeles. Aircraft remained parked at gates, while thousands of travellers faced the prospect of spending the night at airports.
The disruption also affected international travellers. US airlines will not be required to compensate stranded passengers because the carriers were not responsible for the FAA system failure.
The incident marked the longest nationwide flight shutdown since the September 11, 2001 attacks. The only other nationwide ground stop since then occurred in January 2023, when the FAA suspended domestic departures for approximately 90 minutes.
The disruption also affected airline stocks, with shares of American Airlines, United Airlines and Delta Air Lines falling between one and two percent in after-hours trading, while JetBlue Airways dropped around three percent.
American Airlines said it was prioritising flights to smaller cities outside its major hubs and international destinations to reposition aircraft and crews and accelerate the recovery of its operations.
