Overview
- A previously unknown defect in a small module of the National Airspace System corrupted aircraft identification (squawk) processing in the space of a millisecond, forcing controllers to impose nationwide restrictions and restart the system after the fault on Tuesday, 8 September.
- The outage halted normal operations for about six hours, disrupted more than 2,000 flights and affected hundreds of thousands of passengers as backlogs took days to clear.
- NATS says safety was never compromised, the immediate fault has been identified, temporary mitigations are in place and a permanent software fix is undergoing safety testing with a fuller technical report due in roughly 60 days.
- Transport Secretary Heidi Alexander has ordered an independent review by the Civil Aviation Authority, which will report within six months, while airlines are pressing for compensation, stronger resilience measures and leadership accountability.
- The incident revives concerns about legacy systems and contingency planning after earlier NATS failures, and industry groups say the episode increases the case for mandated investment to ensure a single software fault cannot trigger nationwide disruption.