Latest FAA Ground Shutdown Updates: Thousands More Flights Canceled Saturday; officials blame overloaded routers; no sign of cyber attack

Airlines canceled thousands more flights Saturday as they struggled to recover from a nationwide shutdown that halted departures across the United States for more than four hours Friday, the longest since the Sept. 11, 2001, attacks.

More than 3,600 U.S. flights were canceled Saturday and more than 1,800 were delayed as of 9:10 a.m. ET, according to FlightAware. This is in addition to thousands of cancellations on Friday.

The Federal Aviation Administration lifted the ground shutdown at 8:15 p.m. ET Friday. Transportation Secretary Sean Duffy said at a news conference late Friday that airspace had reopened, but warned that “it would be slow.”

“It’s going to take us some time to understand what happened this afternoon,” he said.

Duffy said the “instability” of radar communications at air traffic control centers began just after 3:30 p.m. ET, when more than 3,500 planes were in the air. He blamed this on an “incredibly old air traffic system”.

“We have old switches, old routers, we use little copper lines from the 1980s,” Duffy said. “It’s an old system that broke down. It broke down everywhere. It was overloaded.”

Citing multiple sources, CBS News reported that “an update to the private communications network that links the U.S. air traffic control system caused the system to reboot, leading to a crash and communications outage.” He said the system is operated by L3Harris Technologies.

Asked if he could say with certainty that the problem was not caused by a cyberattack, Homeland Security Secretary Markwayne Mullin said: “There’s nothing for certain at this time. It doesn’t appear to be the case.” Mullin also said the outage was not related to Microsoft’s global outage.

On Friday, Duffy requested $50 billion from Congress to modernize the nation’s air traffic control system, on top of the $12.5 billion approved by lawmakers last year. He also does not rule out another breakdown. “You’re going to get more unless the American people and Congress tell us to build, and I can’t wait for that to happen,” Duffy said.

Travelers whose flights have been canceled must be refunded if they choose not to travel, and Delta and United are offering travel waivers. But a Transportation Department rule that took effect Oct. 19 states that “government system failures” are no longer considered within an airline’s control, which could make it more difficult to obtain other compensation.

Sen. Tammy Duckworth, an Illinois Democrat and ranking member of an aviation subcommittee, called for an investigation. “Whatever the reason for this nationwide ground check is, it will warrant a thorough and complete investigation,” she wrote on X.