The Federal Aviation Administration believes it has identified the source of a computer failure that forced planes to be grounded last week.
The agency says a preliminary review determined that “contract personnel unintentionally deleted files while working to correct synchronization between the live primary database and a backup database.”
According to the FAA, there is no proof of a hack or malevolent intent.
Most airports in the United States detained planes at the gate for around two hours on Jan. 11 until the problem was sorted. Planes were still allowed to land.
The system that has been affected is known as the Notice to Air Missions System. NOTAMs were once available by a hotline, but with the advent of the internet, this service was phased away. The notifications range from banal information about airport development to critical flying restrictions or faulty equipment. All aircraft, including commercial and military flights, must use the system.
The FAA said that it has made efforts to make NOTAM “more robust” to prevent a similar occurrence from occurring again.