FAA Nationwide Ground Stop Halts US Flights, Backs Up Air Cargo

The Federal Aviation Administration (FAA) halted departing flights at every airport in the U.S. on Friday afternoon after a telecommunications outage disrupted communications at air traffic control centers across the country.

The order took effect at 3:54 p.m. Eastern time and was listed to run to 11:30 p.m., although the advisory directed departing traffic to remain ground stopped until further notice.

In a ground stoppage, planes can land at airports but cannot take off. By about 6:40 p.m., about 3,000 flights in the U.S. had been canceled and more than 10,000 had been delayed, according to FlightAware. The count covered Friday flights within, into or out of the country.

In an advisory, Expeditors International warned that export cargo would be delayed or canceled and rolled to later flights. Import flights could be held at origin, delayed or diverted.

A backlog would continue after departures resume, with disruption likely through the weekend, the company said. Airlines may apply booking restrictions or cut capacity in the short term while they reposition aircraft and crews.

“A ground stop can have a significant ripple effect on air cargo, particularly for time-sensitive shipments like medical supplies, pharmaceuticals, perishables and critical manufacturing components,” Justin Crabbe, founder and CEO of private jet rental company Jettly, told Sourcing Journal. “Cargo networks operate on tightly coordinated schedules, so even a relatively short disruption can cause missed connections, aircraft and crews being out of position, and delivery delays that continue well after flights resume.”

UPS posted a service alert saying all flight operations had been paused until further notice, while FedEx released a statement saying it was monitoring the stoppage.

“We are prepared to activate contingency plans to minimize service disruptions and will resume normal flight operations as soon as the FAA permits,” FedEx said in a statement. “Customers can monitor the status of their shipments on fedex.com.”

Transportation Secretary Sean Duffy posted the first official explanation on X at 4:16 p.m.

“The FAA issued a nationwide ground stop for all U.S. airports following a communication issue impacting all Air Route Traffic Control Centers,” Duffy wrote. “FAA technicians are investigating the issue. We will provide immediate updates as we have them.”

Flights already in the air were allowed to continue and land, while inbound international flights were to be managed on a case-by-case basis. Just after 5 p.m. Eastern, the FAA posted on X that all flights had been halted out of an abundance of caution amid a temporary telecommunications outage and that every flight had been accounted for.

The FAA had halted traffic in Chicago before the nationwide order. Homeland Security Secretary Markwayne Mullin told reporters outside the White House that officials had found no sign the stoppage threatened the U.S.

“There is no prior indication as of yet that this was nefarious attack against us,” Mullin said. “It’s just a telecommunication outage as of right now.”

The agency has not named the system that failed. Advisory 120, issued at 5:46 p.m. Eastern, said the stop remains in effect, with departures allowed as facilities recover.

By early evening, telecom issues at some FAA air-traffic facilities were coming back online, according to a report from The Wall Street Journal.

The outage appears to be affecting a telecommunications network overseen by L3Harris Technologies, that report said. The network handles crucial radio frequencies that controllers use to communicate with pilots, and it was not immediately clear whether the outage also affected radar feeds.

Air Space Intelligence, the company behind the FAA’s SMART airspace planning system, said its technology did not cause Friday’s ground stop.

“The current ground stop is not based on or a result of the SMART system, any product of ASI or our integration with FAA and ATC,” the company said in a statement on X. Mullin said DHS was examining a possible link through its Cybersecurity and Infrastructure Security Agency.

Mullin also said officials were not ruling out a cyberattack or an AI intrusion.

“We don’t want to get ahead of ourselves,” Mullin said. “We’re not ruling anything out at this point.” He also downplayed any connection to the recent Microsoft Outlook issues, in which platforms were down intermittently since early Thursday.

American Airlines expects its schedule to be disrupted for the rest of the day, depending on how long the ground stop remains in place.

“It will be all hands on deck across American to get customers on their way as soon as possible when the FAA lifts this ground stop,” the airline said in a statement.

The occurrence of a nationwide ground stoppage is rare, with this being only the second time one has been put in place since the Sept. 11, 2001 attacks. The other came on Jan. 11, 2023, when a contractor unintentionally deleted files from the FAA’s Notice to Air Missions system, forcing a pause in departures that lasted less than two hours.

The outage is the latest sign of strain on the air traffic control system, which has been beset by equipment failures, communications problems and shortages of controllers. The FAA and the White House asked lawmakers on Friday for another $30.1 billion for the overhaul.

Friday’s stoppage was not the first time a technology failure backed up air cargo. A global IT outage in July 2024 canceled 6,855 flights globally that day, according to Cirium. Xeneta chief air freight officer Niall van de Wouw warned at the time that such incidents can take three times as long to resolve as they last.