The Federal Aviation Administration said Friday afternoon that a "temporary telecommunications outage" led it to halt departing flights at every airport in the United States. The ground stop remained in effect at 3:25 p.m. Mountain time.

"There has been a temporary telecommunications outage - out of an abundance of caution all flights have been halted," the agency said in a post on X at 3:02 p.m. "Every flight has been accounted for and international flights will be handled on a case by case basis."

The FAA did not say what failed or when departures would resume. An advisory from the agency's Air Traffic Control System Command Center described the problem as a "nationwide comms failure."

Image

The ground stop took effect at 1:53 p.m., as the Kiowa County Press reported earlier Friday. The FAA's order said all airports were stopped "due to extraordinary circumstances and for reasons of safety" and that departing traffic "should remain ground stopped until further notice."

Transportation Secretary Sean Duffy said in an earlier post on X that the problem was "a communication issue impacting all Air Route Traffic Control Centers." Those centers manage high-altitude traffic between airports. Colorado is handled by the Denver center in Longmont.

At Denver International Airport, 284 departures had been delayed and 22 canceled Friday as of 3:22 p.m., according to the flight-tracking service FlightAware. Nationally, FlightAware counted 9,917 delays and 768 cancellations of flights within, into or out of the United States. Those totals include delays from earlier in the day, when wind and low clouds were already slowing traffic at airports including San Francisco, Boston and New York.

Flights already in the air were allowed to continue. A separate FAA advisory told pilots to expect to circle in holding patterns before landing at airports across the country because of equipment outages.

The trouble appeared first in Chicago. About 35 minutes before the national order, the FAA halted flights headed to Chicago Midway International Airport from across the country because of an equipment outage, according to FAA advisories.

Travelers should check with their airline before leaving for the airport. The FAA posts current airport conditions at nasstatus.faa.gov.

Nationwide ground stops are rare. The last one came in January 2023, when the failure of the FAA's Notice to Air Missions system held departures across the country for about 90 minutes. Before that, the FAA cleared the skies after the September 11, 2001, terrorist attacks.

This is a developing story and will be updated.