Simple Flying - Jake Hardiman
The company has published its preliminary investigation into the issue.
Just over a week after the disruption began, NATS, which provides air traffic control services in the UK, has published its preliminary report into the matter, which reveals the meltdown's root cause. According to the company, the problems did indeed begin as a result of an issue with a flight plan filed in its system.
Specifically, one of its flight plan processing sub-systems failed when it encountered a plan that, as NATS explains, "included two identically named, but separate waypoint markers outside of UK airspace." This critical exception prompted not only the main sub-system but also its backup to enter a fail-safe mode, meaning that the plan could neither be accepted nor rejected by the system.
This meant that a situation whereby incorrect safety critical information was passed onto air traffic controllers was avoided. However, the fact that the system and its backup were down meant that flight plans could no longer be processed automatically, hence the significant operational disruption.