The massive flight disruption that grounded thousands of planes last week was caused by “contract personnel unintentionally deleting files,” according to the Federal Aviation Administration on Thursday.
Following an outage in the NOTAM system, the FAA halted all departures nationwide on January 11.
According to the FAA, the files were accidentally deleted while the contractors were “working to correct synchronisation between the live primary database and a backup database.”
The investigation is still ongoing, and the review was described as preliminary. According to the FAA, there is no evidence of a cyberattack or malicious intent.
The NOTAM system sends vital information to pilots in order for them to fly. Later that day, the system was restored.
At 7:20 a.m. on Jan. 11, the FAA issued a tweet instructing airlines to halt all domestic departures until 9 a.m.
Around 8:50 a.m., the FAA lifted the ground stop, and normal air traffic operations gradually resumed.
The agency announced on Thursday that repairs have been made to strengthen the system and that additional measures will be taken.
