A “previously unknown software defect” caused the air traffic control meltdown last week, which saw more than 2,000 flights affected, tearing up the travel plans of hundreds of thousands of passengers.
The preliminary report on National Air Traffic Services’ (Nats) investigation into the incident, which occurred on Tuesday, 8 September, determined it was caused by a “legacy and previously unknown defect” in a software module within the National Airspace System (NAS), which manages UK airspace and processes requests for the allocation or reassignment of squawk codes.
