The Federal Aviation Administration (FAA) said a “damaged database file” was likely to blame for a computer system outage that halted domestic departures on Wednesday morning and led to thousands of delayed and cancelled flights throughout the day.
“The FAA is continuing a thorough review to determine the root cause of the Notice to Air Missions (NOTAM) system outage,” the agency said in a statement on Wednesday evening. “Our preliminary work has traced the outage to a damaged database file.”
The NOTAM system provides pilots with real-time information about flight hazards and cautions. Following technical issues on Tuesday, FAA officials decided to reload the system early Wednesday morning.
However, the reboot took longer than expected, and the agency paused all domestic departures around 7:30 a.m. as it continued working to restore the NOTAM system. The ground stop was lifted just before 9 a.m.
“At this time, there is no evidence of a cyber attack,” the agency added Wednesday evening. “The FAA is working diligently to further pinpoint the causes of this issue and take all needed steps to prevent this kind of disruption from happening again.”
As of Wednesday night, about 9,700 flights had been delayed and another 1,300 had been canceled in the wake of the outage, according to the flight tracker FlightAware.