In September, the UK's National Air Traffic Services (NATS) faced a significant IT failure that disrupted air traffic and resulted in a substantial economic impact. According to a report by the Cyber Monitoring Centre (CMC) released on November 4, the incident cost the UK economy approximately £33 million, affecting 70 domestic organizations. This financial toll could have reached as high as £42 million if considering the full range of affected UK services, including airlines, airports, ground operations, and tour operators. The outage also had a wider impact when considering overseas airlines, potentially raising the cost to £76 million due to 1800 canceled flights. The failure affected around 450,000 passengers who faced cancellations or delays exceeding two hours. The disruption was not the result of a cyber attack but instead stemmed from an unrecognized defect in the legacy software of the National Airspace System. This defect led to a collision between a routine aircraft identification request and a high-priority system message, causing corrupted flight data and triggering a major incident declaration. Although the automated system was restored within a few hours, flight operations were not normalized until later in the evening. The CMC emphasized that such outages highlight the need for improved resilience in critical sectors, as current regulations may not prevent similar incidents. The reliance on legacy systems by NATS poses a heightened risk, reinforcing the need for organizations to assess risks in systems they depend on, not just those they own.