Departing flights across the United States were grounded Wednesday morning after the Federal Aviation Administration said it had experienced a computer outage.
The FAA said later Wednesday morning it had ordered all airlines to pause domestic departures until 9 a.m. ET.
More than 3,500 flights within, to and out of the U.S. were delayed as of around 8 a.m. Wednesday, according to the online flight tracker FlightAware. Nearly 500 flights were listed as canceled.
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The FAA said on its website that its Notice to Air Missions (NOTAM) system had “failed.” NOTAM contains information essential to workers involved in flight operations.
“Operations across the National Airspace System are affected,” the agency said in a statement.
In an update posted to Twitter just before 7:20 a.m., the FAA said it was ordering airlines to pause all domestic departures until 9 a.m. ET “to allow the agency to validate the integrity of flight and safety information.”
It said it was still working to fully restore the NOTAM system.
In a subsequent update, it said that all flights in the sky were safe to land.
“Pilots check the NOTAM system before they fly. A Notice to Air Missions alerts pilots about closed runways, equipment outages, and other potential hazards along a flight route or at a location that could affect the flight.”
White House press secretary Karine Jean-Pierre said in a tweet that there was “no evidence of a cyberattack at this point,” and added that President Joe Biden had directed the Department of Transportation to conduct a full investigation into the causes.” She added: “The FAA will provide regular updates.”
Transportation Secretary Pete Buttigieg said in a tweet that he had “been in touch with FAA this morning about an outage affecting a key system for providing safety information to pilots.”
“FAA is working to resolve this issue swiftly and safely so that air traffic can resume normal operations, and will continue to provide updates,” he said.
“We are performing final validation checks and repopulating the system now,” the FAA said in an earlier tweet just before 7 a.m.
“While some functions are beginning to come back on line, National Airspace System operations remain limited,” it said.
Southwest Airlines said it was “closely monitoring” the situation and that it “may impact the start of operations” Wednesday.
“An FAA system outage is causing ground stops at AUS and other airports across the country,” the Austin-Bergstrom International Airport said in a tweet.
“Arriving & departing passengers can expect delays this morning & through the day,” it said, adding: “Please stay in contact with your airline & check your flight status before heading to AUS.”
The news came after a number of social media users said they had been affected by the situation. It also appeared to have affected some flights into the U.S.
A number of airports outside the U.S. said operations were continuing as normal, but the international airport operator Aéroports de Paris, or Airports of Paris, said all flights by American airline companies would be delayed until further notice. It said non-American airlines were flying out as normal without interruption.
Air France said all of its U.S.-bound flights were operating as planned and were not affected by the FAA computer outage. The airline said it continued to monitor the situation.
“As far as we are aware, we are still operating to/from the U.S. at the moment,” a spokesperson for Gatwick Airport in London said.
A spokesperson for Frankfurt Airport in Germany said the FAA outage had not affected its operations.
This is a developing story. Please check back for updates.
Sara Mhaidli, Nancy Ing and Austin Mullen contributed.