FAA issues national ground stop

A national ground stop was issued by the Federal Aviation Administration (FAA) on Friday, abruptly halting much of the air traffic across the United States. The unexpected alert, issued at 3:54 p.m. ET, was due to "extraordinary circumstances" and prioritized safety. At the time of the alert, 4,042 flights headed to U.S. destinations were already airborne.

Homeland Security Secretary Markwayne Mullin stated there was "no indication as of yet" of any nefarious cause for the ground stop, which he attributed to a telecommunications outage. President Trump was briefed on the situation, but officials are not ruling out any potential causes at this point.

Multiple agencies involved in the investigation told NBC News that there is no evidence of malicious activity behind the incident, and they have not observed behavior associated with a cyberattack. However, they cautioned that their assessment could change as the investigation progresses.

Reagan Washington National Airport in Arlington, Virginia, and Chicago O'Hare International Airport in Chicago were both at capacity by 6 p.m., meaning there was no room for additional planes to park. This situation increased the likelihood of some planes being diverted to other airports.

Air Space Intelligence, an AI technology vendor for the FAA's new SMART system for air traffic control, denied any responsibility for the nationwide ground stop. Aviation safety expert Jeff Guzzetti described the outage as "extraordinary" and noted that pilots are trained to operate in such conditions, with various redundancies in place to ensure safe landings.

The communications outage affected high-altitude, mid-level, and ground-level control centers, causing significant disruptions at airports across the country. At Newark Liberty International Airport, personnel in the control tower reported being "out of space" and dealing with "significant gate issues." One Newark controller expressed uncertainty about the situation, stating that they were "not getting any information from anybody."

Before the FAA's alert, both major airports in Chicago, O'Hare and Midway International Airport, were also under a ground stop due to an "equipment outage." Deveren Werne, a consultant on AI technology, was on an American Airlines flight from Indianapolis to Chicago when the pilots announced all flights were grounded. Werne described the event as unprecedented for him and shared a mixture of emotions with his fellow passengers.

United Airlines acknowledged the ground stop, stating that flights already airborne would continue, while new domestic flights would not depart while the FAA ground stop remained in place.