The U.S. Federal Aviation Administration reported Thursday that air traffic in the United States was largely back to normal one day after a faulty file in a computer system triggered an outage affecting more than 11,000 flights through delays or cancellations.
The flight-tracking website FlightAware.com also reported delays and cancellations were back to normal levels for Thursday.
FAA officials said they traced the outage to a damaged database file, affecting the Notice to Air Missions System — or NOTAMs, a crucial part in the process of every flight that departs an airport in the United States.
Pilots are required to consult NOTAMS before taking off. The system lists potential adverse impacts on flights, from runway construction to the potential for icing. The system once was telephone-based, with pilots calling dedicated flight service stations for the information, but it has since moved online.
FAA reports say the system stopped working at 8:28 p.m. Eastern time Tuesday, but because there weren’t many departures at that hour, pilots were able to get the information verbally. By dawn Wednesday, the system was still out, and there were too many flights leaving to brief pilots individually.
U.S. Transportation Secretary Pete Buttigieg said it is likely that the main system had a problem, and the backup didn’t work correctly. He said the FAA rebooted the main system around 5 a.m., but it took a while to verify that all the information was validated and available.
Buttigieg said the FAA ordered all flights grounded Wednesday morning and planes were stuck for hours “to make absolutely sure the messages were moving correctly and the information for safety purposes” was “working the way it should.”
The FAA said it is taking steps to ensure a similar failure does not happen again.
Some information for this report came from Reuters and The Associated Press.
