The Federal Aviation Administration (FAA) said on Thursday a preliminary review found that contract personnel “unintentionally deleted files” disrupting a critical computer system and prompting a nationwide groundstop on Wednesday, January 11 that disrupted more than 11,000 flights.
The FAA said the error occurred while personnel were working “to correct synchronization between the live primary database and a backup database.” The FAA said it “has so far found no evidence of a cyber-attack or malicious intent.”
Outbound flights slowly began to resume roughly after 9am Eastern Time on January 11 after a nationwide two-hour groudstop that the FAA had blamed on a “damaged database file.” No inbound flights already en route to their destinations were impacted by the groundstop.
It was the first nationwide grounding of departing flights since 9/11.
The FAA says it has since made necessary repairs to the Notice to Air Missions (NOTAM) messaging system which had suffered a procedural error related to a corrupted data file. The NOTAM system provides pilots, flight crews and other users of U.S. airspace with critical safety notices.
The system outage occurred on January 10, but the FAA groundstop was not issued until the following morning.
Last week, a group of more than 120 members of Congress told the FAA that the computer outage was “completely unacceptable” and demanded the agency explain how it will avoid future incidents.
Senate Commerce Committee Chair Maria Cantwell (D-WA) has said her panel plans to investigate the FAA’s groundstop. It follows Cantwell saying earlier this month that the Commerce Committee would hold hearings on the Southwest Airlines meltdown that led to nearly 16,000 flight cancelations over the holidays.