The Federal Aviation Administration (FAA) issued a nationwide ground stop, the longest since 9/11, after an update to a telecommunications system managed by contractor L3Harris Technologies caused significant disruptions across U.S. air travel. Transportation Secretary Sean Duffy indicated that a router “flooded” the air traffic control system, leading to communication and radar feed issues, though officials confirmed no foul play. This event, which left hundreds of thousands stranded and impacted major sports events, has intensified calls for urgent modernization of the nation’s aging air traffic control infrastructure.
A critical update to a telecommunications system managed by contractor L3Harris Technologies led to the longest halt in flight departures to U.S. airports since 9/11, leaving hundreds of thousands of travelers stranded amidst widespread disruptions. Transportation Secretary Sean Duffy confirmed that the nationwide ground stop was a direct result of upgrades moving from a copper wire system to fiber at “at least” one remote location.
During a press conference with Duffy, Federal Aviation Administration (FAA) head Bryan Bedford stated there was “zero evidence” of any nefarious activity or artificial intelligence involvement. The issue stemmed from a router that “flooded” other routers within the air traffic control system, attempting over 1,000 connections every five seconds. This overload caused severe problems with airplane communications and radar feeds, necessitating the unprecedented grounding of flights.
The incident has sharply brought to light the vulnerability of America’s aging air traffic control infrastructure and the challenges of modernizing it while managing the world’s busiest airspace. Duffy questioned whether the problem pointed to “incompetence, meaning was it user error, installator error from L3 Harris, or did they install a faulty router.” L3Harris Technologies confirmed it is “supporting the FAA in its investigation” and noted it has completed more than 70% of the copper-to-fiber conversion.
Secretary Duffy used the opportunity to urge lawmakers to approve billions more in funding to modernize the nation's air traffic control system. FAA Administrator Bedford explained that while no FAA facilities lost power, flights were grounded due to “instability” in information feeds to air traffic control centers, to prevent any risk of centers losing connectivity with aircraft. Officials were unsure of the cause for about 45 minutes.
Flight disruptions mount
The travel chaos extended into the weekend, with nearly 6,500 U.S. flights canceled and over 8,000 delayed by Saturday evening, according to FlightAware. These figures followed more than 9,000 U.S. flight cancellations and over 7,000 delays on Friday, though some disruptions were also attributed to adverse weather. Friday’s cancellations marked the second-highest tally since a severe blizzard in January, as reported by aviation-data firm Cirium.
A significant challenge in recovering from the ground stop involved repositioning aircraft, which had been diverted to various airports, and managing limited gate space. Airlines operated lighter schedules on Saturday, deploying all available spare planes and crews to prepare for the critical upcoming Thanksgiving holiday travel season.
Extra pay for flight crews
American Airlines responded by offering extra pay to flight attendants to take on additional trips. Similarly, Delta Air Lines provided double pay and confirmed seats on flights to help crews get into position, while United Airlines offered extra compensation to pilots and flight attendants for flights through Sunday. Airlines like American also committed to changing customer tickets without fees or fare differences for affected travelers and capping certain airfares.
Approximately 3 million people were scheduled to fly on Saturday. The FAA's ground stop, initiated around 4 p.m. ET on Friday, lasted over four hours, making it the longest pause on departing flights in 25 years.
Aging infrastructure
Secretary Duffy emphatically linked the problem to outdated U.S. infrastructure and reiterated the necessity for Congress to approve more funding for the country's air traffic control overhaul. Airline executives have long expressed frustration over aging equipment and a shortage of air traffic controllers, citing the significant costs of resulting disruptions.
This incident marked only the second time the FAA had issued a nationwide ground stop since the September 11, 2001, terror attacks. Officials from the Trump administration repeatedly confirmed that there was no indication of a cyberattack. The U.S. operates the world's busiest airspace, and the FAA assured that systems were thoroughly tested and confirmed stable before resuming flights. The disruption also significantly affected travel plans for NBA, NHL, and college sports teams, which struggled to reach their destinations for weekend games.
College games postponed
Duffy indicated that college football teams on charter flights could potentially receive priority. He advised teams to contact the FAA to schedule their flight times. The Southeastern Conference (SEC) announced on X that some games had been moved to Sunday due to the flight disruptions. The SEC stated it was in close communication with member institutions to coordinate responses.
The National Football League (NFL) responded by assigning three backup referees to games on Sunday, reassigning officials to games within driving distance of their hometowns to mitigate travel impacts. April Roach and Jessica Golden contributed to this article.
