Overview
- NATS, which traced the fault to a millisecond error on Sept. 8, says a paused manual request for an aircraft identification code resumed incorrectly and corrupted flight identification data.
- The corrupted data forced a full NAS restart and nationwide flight restrictions that led to roughly 2,000 cancelled flights and disruption to more than 300,000 passengers as the backlog took days to clear.
- NATS published a preliminary report confirming the fault was a software defect in a small subsection of its flight‑data system and said the issue was not linked to the 2023 outage or to military action.
- The operator says temporary mitigations are in place while a permanent fix undergoes safety testing, but airlines are pressing for compensation and some have demanded leadership changes.
- Transport Secretary Heidi Alexander has ordered the Civil Aviation Authority to carry out an independent review with a six‑month deadline, and the incident has intensified calls for faster investment and dedicated backups for critical NAS components.