Why did the FAA suddenly ground flights across the US? Officials reveal what went wrong

The Federal Aviation Administration (FAA) has lifted a nationwide ground stop after communications problems at regional air traffic control centers disrupted flight operations across the United States on Friday afternoon. The agency confirmed that airplane departures could resume following the disruption, which resulted in hundreds of flights being diverted. Officials cited ‘extraordinary circumstances’ linked to communications problems at regional air traffic control centers as the reason for grounding flights nationwide.

The incident marked the first nationwide ground stop since January 2023, when a malfunction in a key FAA computer system disrupted air travel. It was also the second such incident since the aftermath of the September 11, 2001, attacks. The nation's top homeland security official attributed the disruption to a telecommunications outage and said there was no indication that the communications failure was connected to a cyberattack. The ground stop affected potentially thousands of scheduled flights through at least late Friday night, disrupting travel plans for passengers across the country.

Homeland Security Secretary Markwayne Mullin emphasized that the public was never in danger during the nationwide ground stop. Speaking to reporters at the White House, he said the decision was made out of an abundance of caution.

“I just want to reiterate this: the public was never at danger through this process,” Mullin said. “There was there was never any lives at risk. There was no flights at risk. FAA was able to handle it. We did it out of an abundance of caution.”

Mullin also ruled out any connection between Friday's disruption and Thursday's Microsoft outage. “There is no connection between this and Microsoft. I know a lot of people are making that jump,” Mullin said off the top of the briefing at the White House. Addressing speculation surrounding the incident, Mullin reiterated that the communications failure was not linked to the Microsoft outage. “I do understand the internet traffic and where all these conspiracies start running towards. I just can’t say this enough,” Mullin later said: “All your loved ones are safe.”

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More than 3,500 aircraft were in the air

Transportation Secretary Sean Duffy said more than 3,500 airplanes were in the air when the FAA issued the nationwide ground stop earlier Friday. “We had over 3,500 airplanes in the air. They all engaged, and last time I looked, we had less than 400 in the airspace as they were all coming in to safely land. And we navigated it with our well-known procedures that that we have when these incidents happen,” Duffy said during a press briefing late Friday.

Duffy explained that the decision to halt flights followed instability in radar systems and communication centers across the country. “We started to have inconsistency in the data from the radars and our communication with airplanes, and we have procedures for this,” he said.

Outdated technology and overloaded routers behind FAA ground stop

Duffy said outdated air traffic control technology and routers overloaded with data were responsible for the nationwide ground stop. “What we have is an incredibly old air traffic control system,” Duffy said at a news conference. “The president, for the last year, has been asking Congress to fully fund a full build of a brand new air traffic control system.”

He further explained that overloaded routers started producing inconsistent data, prompting officials to shut down the system. “Our routers actually got overloaded with data, and… they started to give us inconsistency in the data from those routers. And because of that, we shut the system down,” he added. Duffy said some routers had been replaced during his tenure, but the older hardware experienced failures.