US aviation halted nationwide by major communication outage

UPDATE - follow-up to FAA issues nationwide ground stop citing communication issues affecting 'multiple' air traffic control facilities: The Federal Aviation Administration stopped all departing flights across the United States on Friday afternoon due to a temporary telecommunications outage.

What Happened

The rare nationwide ground stop hit multiple Air Route Traffic Control Centers, which guide high-altitude planes. Homeland Security Secretary Markwayne Mullin stated at the White House that officials found no indication of any threat to the United States. Alaska Airlines noted in an internal message that the trouble involved communications and radar problems. The FAA reported that technicians are currently investigating the issue.

Impact

Planes already airborne will stay in the air, while inbound international flights are handled individually. Flight-data firm Cirium reported that 11,000 flights were scheduled to leave U.S. airports after 4 p.m. ET on Friday. United Airlines announced plans to help customers reach their destinations after the problem is solved. Officials warned that delays tend to grow worse if ground stops last long enough for flight crews to hit their daily duty hour limits.

Context

Nationwide ground stops in the United States are extremely rare occurrences that disrupt thousands of travelers. Similar systemwide halts happened previously during the September 11 terror attacks and during a pilot alert system failure in January 2023.