The Federal Aviation Administration ordered a nationwide ground stop for departing flights on Friday, November 13, after a telecommunications failure disrupted operations at air traffic control centres across the United States. Transportation Secretary Sean Duffy said the communication issue affected all 22 Air Route Traffic Control Centres, the facilities that manage aircraft movements between airports. The FAA described the measure as a precaution taken “due to extraordinary circumstances and for reasons of safety”.
The precise cause remains under investigation. Homeland Security Secretary Markwayne Mullin told reporters at the White House that there was no indication yet of a malicious attack, while declining to rule out a cyberattack. He also said the disruption was unrelated to the separate Microsoft outage. CNN reported that security sources’ initial assessment did not point to a cyberattack.
The immediate impact was severe and cascading. By 6:40 p.m. Eastern Time on Friday, approximately 10,200 flights within, into or out of the United States had been delayed and more than 3,220 cancelled, according to FlightAware figures reported by Business Insider.
Flightradar24 reported approximately 3,100 aircraft already airborne and bound for US airports when the disruption began. Aircraft already in the air were allowed to continue and land, while incoming international flights were being handled on a case by case basis. Passengers were left waiting aboard aircraft or at departure gates, and major airlines including United and American warned of widespread disruption.
Aviation experts estimated that the cost could quickly run into the millions. “At the very least, thousands of euros per flight,” Joris Melkert, an aviation expert at TU Delft, told Dutch broadcaster NOS. He said costs could rise to tens of thousands of euros per flight depending on the disruption’s duration and expenditure on passenger assistance and hotels. Melkert noted that, with roughly 15 million flights per year in the United States, more than 40,000 per day, missed connections and crew rest requirements could create backlogs that take days to clear.
Friday’s failure prompted the first nationwide ground stop since January 2023, when the FAA suspended departures after its Notice to Air Missions system failed, and only the second since the September 11 attacks. The 2023 departure suspension lasted less than two hours; Friday’s remained in place for several hours into the evening.
The outage has renewed scrutiny of the telecommunications infrastructure connecting air traffic control facilities across the country. The FAA has warned that obsolete technology causes avoidable delays and cancellations and requires extensive modernisation to meet growing demand.
The ground stop came on the same day that the White House and Department of Transportation urged Congress to approve an additional $30.1 billion to modernise airports and the air traffic control system, on top of $12.5 billion approved in July 2025. The request includes $10.1 billion for air traffic control modernisation, including $7.2 billion for a common automation platform and controller workstations and $2 billion for cloud computing, as well as a separate $2 billion to replace or improve control towers. In their letter to lawmakers, Duffy and White House budget director Russell Vought said the FAA had replaced 68 percent of its legacy copper telecommunications network with high-speed fibre.
The cause of Friday’s failure has not been established, but the disruption adds urgency to longstanding concerns about infrastructure resilience. Duffy has warned that, at the existing replacement rate, it would take approximately 300 years to replace all of the nation’s air traffic control towers.
As of Friday evening, the FAA had not announced when the nationwide ground stop would be lifted. Mullin cautioned that restoring normal operations would take time. Technicians were investigating the telecommunications failure, and the agency will face intense scrutiny over how the disruption spread across the national aviation system.
The incident has intensified scrutiny of modernisation funding as the White House presses Congress to approve its request. Airlines, pilot representatives and air traffic controllers have already backed additional investment in the system.