Major airlines on Saturday canceled more than 3,700 US flights and delayed 2,000 more as the United States sought to recover from the longest nationwide shutdown of flights since the September 11, 2001, attacks. The disruption followed a Federal Aviation Administration ground stop on Friday that halted nearly all departing flights for almost five hours, forcing airlines to cancel nearly 10,000 flights and delay more than 7,000 others in what was described as one of the worst travel days in US history.
Although the FAA lifted the ground stop on Friday night, tens of thousands of passengers remained stranded at airports across the country. Airlines worked to clear congestion and position flight crews and other personnel for recovery. United Airlines and Delta Air Lines announced ground stops for their own flights at Chicago O'Hare Airport and New York LaGuardia Airport, respectively, to manage congestion and gate issues, while many major airports said they could not accept further diversions. American Airlines said it was prioritizing flights to international destinations and to smaller cities outside its major hubs to reposition aircraft and crews more quickly.S2
The FAA issued the ground stop because of an outage that appeared to affect a network handling critical radio frequencies used by air traffic controllers to communicate with pilots, according to two airline officials. The contractor that oversees the network, L3Harris, did not respond to a request for comment. Transportation Secretary Sean Duffy said the trouble began at 3:36 p.m. ET when air traffic control centers experienced instability in radar and communications systems, adding that switches and routers were overloaded with data and produced inconsistencies that led officials to shut the system down.S2
The outage is the latest and most dramatic sign of strain on a US air traffic control system burdened by aging technology, equipment and communications problems, and a shortage of several thousand controllers. Duffy called for $50 billion to upgrade air traffic control systems, up from the $30 billion he had sought earlier, describing the situation as an emergency. He said the immediate problem had been fixed and that flying was safe, but warned that a broader overhaul was needed to prevent similar failures. Before the outage, the White House and Department of Transportation had urged Congress to approve $30.1 billion to upgrade aged airports and air traffic systems.S2
