FAA Lifts Nationwide Ground Stop After Communications Failure Strands Travelers and Teams

Travelers at Chicago O'Hare who had just cleared security on Friday afternoon learned what was happening by looking up. The departure boards showed delays across the line. Some called friends or relatives to decide whether to stay the night or find another way home. The Federal Aviation Administration had grounded every flight in the country, citing what it called extraordinary circumstances: communications problems at regional air traffic control centers.

The stop was later lifted, and departures were allowed to resume. By then the order had diverted at least 600 flights, according to the aviation analytics firm Cirium. As of 5:50 p.m. Eastern, 496 of them had returned to the airport where they took off, and 104 had been sent to a different one. Chicago O'Hare, Denver International, Dallas Fort Worth and Reagan National were among the airports that took in many of the diverted planes. Some 11,000 flights carrying more than 1.5 million passengers were scheduled to depart after 4 p.m. Eastern, so more cancellations and diversions were likely.

It was the first nationwide ground stop since January 2023, when a key FAA computer system malfunctioned. Before that, the last was after the Sept. 11, 2001, attacks. Some flights were cleared early. Flights within Alaska and Hawaii were never held, and some international departures leaving U.S. airspace were let go. San Francisco's airport said Pacific flights, including those to Hawaii and Asia, began leaving around 5 p.m. Eastern.

Homeland Security Secretary Markwayne Mullin said there was no sign it was a malicious attack, calling it a telecommunications outage. He described a major engineering defect: new technology introduced into an old air traffic control system had overwhelmed it. He put the cost of a complete overhaul at about $50 billion. He also said no lives or flights were ever at risk and that the grounding was done out of caution. He acknowledged the conspiracy theories circulating online.

Transportation Secretary Sean Duffy called the system incredibly old, relying on an analog setup that was overloaded with data. "This is an emergency," he said, and asked Congress for emergency funding for upgrades. About 3,500 airplanes were in the sky when the stop began; Duffy said fewer than 400 remained when he last checked. He warned that getting back to normal would be slow.

The FAA's new AI-powered SMART system, which is meant to predict problems in the sky, does not appear to be involved. Mullin said there was no indication of a link, and ASI, the company that designed it, said the ground stop was not based on or a result of SMART or any of its products. Microsoft said it had no indication the stop was related to the outage that took Outlook and other services offline Thursday. The National Weather Service said its radar and website were fully operational and corrected false reports of a disruption.

Airlines and shippers scrambled. JetBlue canceled all remaining domestic flights Friday evening, leaving only Europe-bound departures from Boston Logan and New York's JFK, and warned of more cancellations Saturday. Air Canada canceled all U.S. flights for the rest of the evening. Europe's aviation agency suspended U.S.-bound departures from 5 p.m. Eastern until midnight at the FAA's request, and Mexico grounded its flights to the U.S. FedEx, with nearly 700 aircraft, said it was ready to activate contingency plans.

Sports felt it too. The Nets had just boarded in New Orleans for Memphis when their flight was halted. The Sharks were stuck waiting to leave for Utah, while the Panthers had reached St. Louis in time. College football teams including No. 2 Utah, eighth-ranked Texas and No. 9 Tennessee were stalled on their way to road games.

Among the stranded, Seattle software engineer Amber McQuilkin feared missing the League of Legends world finals in New York, where her friends had already arrived. Austin Curtis and his wife, heading from South Bend to a Denver baby shower, were told to get off their plane at O'Hare and were weighing a weekend in Chicago. What to watch next is whether Congress responds to the emergency funding request and how quickly airline schedules recover.