Air-navigation service provider NATS has issued Aeronautical Information Circular Y 087/2026 announcing the start of Exercise Cobra Warrior 26-2, a large-scale multi-national military drill running from 14 September to 1 October 2026. Temporary segregated airspace will be activated across parts of Lincolnshire, the North Sea and designated low-flying areas, with daily activity windows between 08:00 and 17:00 UTC. While commercial routes above Flight Level 245 remain open, traffic below that altitude may be subject to tactical ATC reroutes and minor holding. The Civil Aviation Authority has already published NOTAMs advising operators to plan for up to ten-minute en-route delays on east-west corridors during peak sortie periods. Business-aviation operators to RAF Waddington, Cranwell and nearby GA aerodromes are most affected, facing slot coordination and potential transponder mandatory zone (TMZ) requirements. European carriers operating short-haul services over the North Sea have been asked to upload an additional 200 kg contingency fuel where flight plans intersect exercise areas. Mobility managers moving VIPs or time-critical cargo should verify slot confirmations 24 hours before departure and check Eurocontrol Network Operations Portal for updated tactical flow management measures. Travel insurers have reminded companies that military exercises count as an “extraordinary circumstance” under EU261/UK261, limiting compensation rights for any delay-induced cancellations. Cobra Warrior is the RAF’s premier air-combat exercise and involves participants from at least six NATO partners, underscoring the need for sustained commercial-military airspace coordination in an increasingly congested sky.
Source: NATS AIP Supplements
