LONDON – The US Federal Aviation Administration (FAA) has now conducted a preliminary review into the causes of a widespread system outage last week which saw the grounding and disruption of flights across the continental United States.
In their statement issued January 19, the aviation regulatory body advised:
“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 agency has so far found no evidence of a cyber-attack or malicious intent. The FAA continues to investigate the circumstances surrounding the outage.”
“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.”
The NOTAM system
A Notice to Air Missions (NOTAM) is a notice containing information essential to personnel concerned with flight operations but not known far enough in advance to be publicized by other means.
It states the abnormal status of a component of the National Airspace System (NAS) – not the normal status.
- NOTAMs indicate the real-time and abnormal status of the NAS impacting every user.
- NOTAMs concern the establishment, condition, or change of any facility, service, procedure or hazard in the NAS.
- NOTAMs have a unique language using special contractions to make communication more efficient.
Given the importance of the NOTAM advisory system to flight operators, flight crews and associated operational staff, the outage of the system resulted in a widespread precautionary grounding of commercial flight services last week.
For operational safety reasons, the FAA requires flight crews and flight operators to review NOTAM’s relevant to the operation as part of the pre-flight briefing process.
The system outage resulted in approximately 7000 flights being cancelled after the system went off-line on the evening of January 10. A telephone-based backup system initially allowed movement of late-night flights, however the stopgap measure could not keep up with the rising flight frequencies through the morning of January 11.
As a result, the decision was made to ground commercial flights across the continental United States.
Initial response work by the FAA on January 11 traced the outage problem to a damaged database file, and the agency disclosed that there was no evidence of a deliberate cyber attack.