The Federal Aviation Administration (FAA) has blamed a contractor deleting files for a system outage that led to all US domestic flights being temporarily grounded earlier this month.
Domestic flights within the United States were delayed or canceled on the morning of 11 January, causing travel disruption for passengers across the country.
The incident was related to an issue with the Notice to Air Missions (NOTAM) system, which provides pilots with real-time information about changes and potential hazards on flight routes.
The lack of system availability meant all domestic flights were temporarily grounded for two hours while the system was restored.
Having investigated the issue, the FAA has revealed that the outage was caused by an error made by a contractor.
“A preliminary FAA review of last week’s outage of the Notice to Air Missions (NOTAM) system determined that contract personnel unintentionally deleted files while working to correct synchronization between the live primary database and a backup database,” the aviation agency said in a statement.
“The agency has so far found no evidence of a cyber-attack or malicious intent,” said the statement, adding: “The FAA continues to investigate the circumstances surrounding the outage.”
A previous statement by the FAA said that the issue was caused by a “damaged database file”. President Biden was briefed on the issue when it occurred, while US lawmakers described the outage as “completely unacceptable”.
The FAA is still investigating the issue but has already vowed to take lessons from the incident to avoid it happening again.
“The FAA made the necessary repairs to the system and has taken steps to make the NOTAM system more resilient. The agency is acting quickly to adopt any other lessons learned in our efforts to ensure the continuing robustness of the nation’s air traffic control system,” said the FAA statement.