FAA lifts nationwide ground stop, White House says no indication of "nefarious act"

A rare nationwide ground stop on all departing U.S. flights that lasted several hours Friday has been lifted, the Federal Aviation Administration said. The FAA and White House said the issue appeared to be caused by a "telecommunication outage."

"At 8:15 tonight, Eastern time, we've opened up the airspace," Transportation Secretary Sean Duffy said during a news briefing Friday night. "Now does that mean every flight is going to fly right now? It's going to be slow. So if you're watching, you're at an airport, check with your airline." 

The FAA had issued the ground stop on all departing flights due to "extraordinary circumstances and for reasons of safety." The ground stop lasted about five hours.

Duffy attributed the ground stop to outdated air traffic control technology and routers overloaded by data.

"What we have is an incredibly old air traffic control system," Duffy said in the news conference. "... 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." 

An update to the private communications network that connects America's air traffic control system caused the system to reboot, leading to a crash and a communications outage, multiple sources told CBS News earlier Friday. The system is operated by L3Harris, which did not immediately respond to CBS News' request for comment. 

Duffy said the FAA would try to move as many flights as possible Friday night depending on crew capacity. 

"If not, we're going to start tomorrow [Saturday] morning with our airline partners moving those aircraft. But it's going to take us some time to unwind what's happened this afternoon," Duffy said.

There were more than 10,000 delays and over 4,000 cancellations listed Friday, according to the flight tracking website FlightAware.

Duffy said he thinks flights would be "back up and operational as we come into the heat of travel" during the Thanksgiving holiday.

Homeland Security Secretary Markwayne Mullin told reporters in a briefing outside the White House earlier Friday that "there was no indication, as of yet, that this was a nefarious act against us. It was just a telecommunication outage, as of right now." 

"There is no indication, we had no reason to believe, that as of right now, that this was a threat to the United States," Mullin said. "This was a telecommunication outage throughout FAA. Out of an abundance of caution, we have grounded all the flights. And all the flights are accounted for."

Mullin reiterated Friday night that there was no cyberattack and the ground stop was not related to the massive global Microsoft outage.

"I want to make sure everybody understands that there is no connection between this and Microsoft," Mullin said. "I know a lot of people are making that jump. This is so far what we've seen. There is actually no cyberattack. We're still working through that process."

He also said flights will be able to land safely. 

"We are assured that everybody is safe. Everybody that's going to be in the air, that's currently on the plane, the loved ones, as I said, we're going to get you on the ground and we're doing it in a safe manner," Mullin said.

Federal agencies are all working together on the situation, Mullin added. 

"I don't want to say that this is a crisis, but it is because we're ... we had to do a nationwide ground stoppage," he said.

International flights departing from the East Coast can fly over the Atlantic Ocean, while flights from Jacksonville, Houston, Miami and San Juan can depart southbound over the Gulf and Atlantic, a source told CBS News.

According to the flight tracking site FlightRadar24, there were about 3,100 airborne aircraft bound for U.S. airports when the ground stop began. Mullin said all airborne flights were being dealt with on a "case-by-case" basis. 

The ground stop was posted to the FAA's National Airspace System Status website. Delays began piling up at major airports across the country in Boston, Atlanta, Miami, Pittsburgh, New York City, Los Angeles and Baltimore. 

"This is absolutely unprecedented," said Robert Sumwalt, a former chair of the National Transportation Safety Board and a CBS News transportation safety expert. "I was an airline pilot for 24 years. I was in the air on 9/11. That was the last major ground stop. There was one back in 2023 for just a few hours. This is absolutely unbelievable that this could happen in this day and age."  

Duffy renewed his call in a news conference for Congress to approve emergency funding to modernize the nation's air traffic control system.

"But you will have more of these," Duffy said. "You will have more of them unless the American people and the Congress tell us to build." 

Shortly before the FAA ordered the nationwide ground stop, both major Chicago airports, O'Hare International and Midway International, were issued a ground stop because of an equipment outage. 

In January 2023, a nationwide ground stop was ordered for a few hours, and domestic flights were delayed nationwide due to an FAA system outage. The FAA said at the time that its flight personnel alert system went down overnight.