FAA Attributes Ground Stop to Error in Copper-to-Fiber Upgrade

Transportation Secretary Sean Duffy stated on Saturday that the Friday nationwide ground stop resulted from an error made while a contractor updated a Federal Aviation Administration telecommunication line. L3Harris, a long-time FAA contractor, was performing routine maintenance in at least one remote facility, replacing copper wire with fiber optic cable.

Duffy noted that the routers in these specific facilities were manufactured in 2001. He described the shift from copper to fiber as a standard update that has occurred in American institutions for decades. "Virtually every single institution in America has gone from copper to fiber, from analog to digital," Duffy said. He added that the FAA may be the last major agency to perform this work due to delayed investments, but he called the process uncomplicated.

The FAA is currently investigating the specific error that caused other routers in the air traffic control system to fail. Duffy asked whether the issue stemmed from user error, installer error by L3Harris, or a faulty router installation. L3Harris did not immediately respond to requests for comment regarding the incident.

FAA Administrator Bryan Bedford, who attended the briefing with Duffy, said there was no evidence of a nefarious act or an AI-related issue. Homeland Security Secretary Markwayne Mullin also joined the White House briefing, confirming that there was no indication the outage was caused by an attack. Air Space Intelligence, the company developing the FAA's new AI-enhanced software tool known as the SMART system, stated on social media that the ground stop was not a result of their product.

The disruption grounded flights for approximately four hours on Friday. According to flight tracking site FlightAware, nearly 25,000 flights were delayed and over 9,000 were cancelled on Friday. The impact continued into Saturday, with more than 4,000 cancellations recorded. Data from aviation analytics firm Cirium showed that Saturday's cancellations represented 14% of flights departing the United States.

Duffy reported that air traffic control facilities experienced intermittent outages of radar and communications systems beginning earlier in the afternoon on Friday. He attributed the failures to old switches and routers. The aviation system returned online Saturday morning, but delays and cancellations persisted. Duffy said he believed the system would be back up and operational before the peak of Thanksgiving travel.

Bedford said airline partners believed they would achieve full schedule integrity by the close of business on Sunday. Tens of thousands of passengers remained stranded across the country on Saturday. At Tampa International Airport in Florida, passengers waited in chairs in the main terminal area before security to find a place to rest.

In Washington, D.C., passengers Erin and Jake Britt spent half a day at Ronald Reagan Washington National Airport on Friday. Their flight to Fort Lauderdale, Florida, boarded at 3 p.m., but they deplaned at 5:30 p.m. without leaving the airport. Erin Britt said the pilot and flight attendants had no more information than the passengers. "They seem just as in the dark," she said. The couple cancelled their weekend trip and spent over nine hours on the JetBlue customer service line to process a reimbursement.

Other travelers faced similar disruptions. Joe Romano and Maddie Cabana had a cruise departing from Orlando, Florida, on Saturday. Their JetBlue flight was cancelled, so they booked a Southwest Airlines flight that departed early Saturday morning. Suze DiPietro decided against flying after her flight was affected; her husband drove four hours from Ocean City, New Jersey, to pick her up in D.C., where they stayed with friends.

This event marks the second nationwide ground stop since September 11, 2001. The previous instance occurred in 2023 when contract workers inadvertently deleted critical files in the NOTAM system, an outage that initially raised fears of a cyberattack but was later determined to be a human error.