The Federal Aviation Administration (FAA) said Thursday that last week's computer system outage that temporarily grounded all U.S. airline departures was caused by the accidental removal of files.
Driving the news: A preliminary review determined that "contract personnel unintentionally deleted files while working to correct synchronization between the live primary database and a backup database," the agency said in a statement.
The big picture: The outage of the system that sends pilots safety alerts and other critical information caused thousands of delays and cancellations and cost airlines billions of dollars.
Details: The FAA, which is still investigating the outage, has so far found no evidence of a cyber-attack or malicious intent, per the agency.
- They've made the necessary repairs to the system and taken steps to make the Notice to Air Missions System system more resilient, according to the statement.
What they're saying: "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," the FAA said.