The report, submitted earlier this week to the Civil Aviation Authority, identified an issue with a flight plan processing sub-system called Flight Plan Reception Suite Automated – Replacement (FPRSA-R).
A small but important part of NATS’ overall air traffic control technical infrastructure, it was found to have encountered an extremely rare set of circumstances presented by a flight plan that included two identically named, but separate waypoint markers outside of UK airspace.
This led to a ‘critical exception’ whereby both the primary system and its backup entered a fail-safe mode.
This scenario had never been encountered before, with the system having previously processed more than 15 million flight plans over the 5 years it has been in service. Steps have been taken to ensure the incident cannot be repeated.