https://arstechnica.com/tech-policy/2023/01/faa-outage-that-grounded-flights-blamed-on-old-tech-and-damaged-database-file/

A Notice to Air Missions system outage that grounded flights across the US yesterday morning seems to have been caused by a damaged database file, the Federal Aviation Administration said last night.

"The FAA is continuing a thorough review to determine the root cause of the Notice to Air Missions (NOTAM) system outage," the FAA statement said. "Our preliminary work has traced the outage to a damaged database file. At this time, there is no evidence of a cyber attack. 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."