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 about the problem the way many people did: they looked up at the departure screens and saw delays across the board. Some phoned 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 "extraordinary circumstances" caused by communications problems at regional air traffic control centers.

At the moment of the stoppage, 3,500 airplanes were in the sky. Transportation Secretary Sean Duffy later said fewer than 400 remained in the air. At least 600 flights were diverted, according to the analytics firm Cirium. As of 5:50 p.m. Eastern, 496 had returned to the airports they left, and 104 had landed somewhere else. Chicago O'Hare, Denver International, Dallas Fort Worth and Reagan National were among the airports that absorbed many of them. About 11,000 flights carrying more than 1.5 million passengers were scheduled to depart after 4 p.m. Eastern, which made further cancellations and diversions likely.

Later in the evening, the FAA lifted the ground stop and said departures could resume. 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 had been cleared earlier, including those within Alaska and Hawaii and certain international flights leaving U.S. airspace. San Francisco's airport said Pacific-bound flights, including to Hawaii and Asia, began leaving around 5 p.m. Eastern.

At a White House briefing, Homeland Security Secretary Markwayne Mullin said there was no indication of an attack. "It's just a telecommunications outage," he said, adding that no lives or flights were ever at risk and that the grounding was done out of an abundance of caution. He acknowledged the conspiracy theories circulating online. He described a "major engineering defect": new technology introduced into an old air traffic control system had overwhelmed it. A complete overhaul, he estimated, would cost $50 billion. Duffy called the system "incredibly old," said it relies on an analog setup overloaded with data, and told Congress, "This is an emergency," asking for emergency funding. He warned that getting traffic back to normal would be slow.

Officials said the failure did not appear tied to the FAA's new AI-powered SMART system, which analyzes flight schedules, weather forecasts and hundreds of other data streams from a single location near Washington, D.C. Its designer, ASI, said the ground stop was not based on or a result of SMART or any ASI product. Microsoft said it had no indication of a link to the Outlook outage a day earlier, and the National Weather Service said its radar and website were fully operational, correcting false reports.

Airlines felt it immediately. 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 and said some routes through U.S. airspace to the Caribbean and South America could be affected. Alaska Airlines said its in-state and Hawaii inter-island flights were unaffected, though it canceled or diverted some other flights. Europe's aviation agency, which manages air traffic for 42 countries, suspended U.S.-bound departures from 5 p.m. Eastern until midnight at the FAA's request. Mexico grounded its flights to the U.S.

Cargo was caught too. FedEx, with nearly 700 aircraft and an average of 17 million packages a day, said it was ready to activate contingency plans and would resume as soon as the FAA permitted. U.S. airlines move about 61,000 tons of goods daily, according to Airlines for America.

Sports teams were stranded. The Nets had just boarded in New Orleans for Memphis when their flight was halted. Five NBA teams were due to fly, and 14 NHL games were scheduled Saturday. The Panthers reached St. Louis, but the Sharks were waiting to leave for Utah. College football teams, including No. 2 Utah, eighth-ranked Texas and No. 9 Tennessee, were stuck as well.

For individual travelers, the uncertainty was personal. Amber McQuilkin, a Seattle software engineer, feared missing the League of Legends world finals in New York, where her friends had already arrived. She said little information was reaching her. Austin Curtis and his wife, bound from South Bend to a Denver baby shower, were told to get off their plane at O'Hare; with their children cared for at home, they might "make the most of it" and stay the weekend.

With departures resuming, the question shifts to how fast the system recovers and whether Congress answers Duffy's call for funding.