UK air traffic control outage grounded 2,000 flights

A UK air traffic control outage on September 8, 2026, grounded more than 2,000 flights and disrupted hundreds of thousands of passengers, with reports attributing the cause to a military aircraft's flight plan containing spurious data. The National Air Traffic Services (NATS) system shut down for approximately four hours, causing widespread cancellations, delays, and diversions across major airports including Heathrow, Gatwick, Manchester, and several Scottish airports. The disruption continued to cause knock-on effects for days as airlines struggled to reposition aircraft and crews. According to four people briefed on the incident, the outage was triggered by a flight plan submitted by a UK military aircraft that contained spurious data, which caused a meltdown in the NATS flight processing system. NATS operations director Kathryn Leahy informed industry bosses during a briefing that the affected system did not have a dedicated backup, as NATS was in the midst of a major overhaul of its systems and the volume of data made duplication prohibitively expensive.