All flights in the United States were grounded for hours after a nationwide computer outage.
The Federal Aviation Administration posted a notice on its website announcing that its Notice to Air Missions (NOTAM) system had "failed" Wednesday morning, which delayed more than 4,000 flights and resulted in nearly 700 canceled flights, according to the online flight tracker FlightAware.
"Technicians are currently working to restore the system and there is no estimate for restoration of service at this time," the FAA notice said. "Operations across the National Airspace System are affected."
The White House said that no evidence of a cyber attack had been detected, but the Department of Transportation will conduct a full investigation of the outage and its causes.
Flights resumed starting about 9:45 a.m., but NBC aviation analyst Capt. John Cox told MSNBC's "Morning Joe" that domestic flights would not likely return to their normal schedules until Thursday or Friday due to the outage.
"There's a domino effect to this — airplanes move around the world, and consequently, as an example, an airplane that's trapped in New York, in four hours, is expected to be in Los Angeles, in five hours, and so the people in Los Angeles that are depending on that airplane, their flight will be either delayed or canceled, and the airplane would then say, 'Go to Hawaii, and then come back,'" Cox said. "So you've got all of these airplanes moving around throughout the day."
"I think it'll certainly be tomorrow at the earliest, and potentially the day after, before the system's back to 100 percent," he added.