The innovative capacity and weather-based procedures rolled out this summer by the EUROCONTROL Network Manager Operations Centre (NMOC) clearly contributed to better tackling severe weather disruptions and traffic bottlenecks this summer and beyond.
Flights are now avoiding trouble zones more smoothly due to rerouting scenarios that have been pre-agreed with aviation partners across the network using CDM, the well-established Cooperative Decision-Making process. Overall, they played a significant role in reducing en-route delays, which were down in Summer 2025 by 31% compared to the previous summer, with all delay categories showing major improvements, of which reduced weather delays – an impressive 41% fewer – was the standout figure. This fresh approach has boosted predictability, kept traffic flowing better, which also helps to ensure safety across the skies by metering the traffic according to available capacity– and is proving to be a real game-changer for operators, airports and air navigation service providers (ANSPs).
The need for these new procedures was triggered by the growing impact of adverse weather events on network traffic observed in 2024, with their effects extending well beyond national borders, where air traffic delays increased due adverse weather by 48% in Summer 24 versus Summer 23, and capacity delays were up by 91% in the same period.
For Summer 2025 therefore, the decision was taken to pursue a network-centric approach which would better mitigate the impact of weather on air traffic and support improved capacity management for all operational actors. The outcome of this was the recruitment of weather specialists in the NMOC team, where they have been working in close collaboration with EUMETNET and national MET providers to produce a European wide Network weather assessment to help the decision-making process within the NMOC. Based on this new network weather assessment, the potential impact of adverse weather is assessed in combination with traffic demand and capacity together with other events in the network (such as airspace closures, industrial action, runway closures, etc.), supporting early and consistent situational awareness for aircraft operators, airports, and area control centres.
Besides the pre-agreed scenarios, EUROCONTROL also has the possibility to temporarily lift constraint related restrictions to potential flight routeings. These relaxations of the rules and restrictions are centralised in the EUROCONTROL Network Manager’s Route Availability Document (RAD), which governs how aircraft can file flight plans across European airspace. Removing restrictions as needed improves airspace efficiency by shifting traffic into newly available airspace.
Next steps
Although globally significant network challenges persist with delays remaining above EU targets, the excellent results delivered by the new capacity and weather-based procedures have led EUROCONTROL’s NMOC to start working on creating with ops partners, following the CDM approach, a new set of additional scenarios that will deliver further flexibility and granularity for 2026 particularly for the key summer peak period. The idea is that more scenarios will support network throughput by using less saturated airspace as air traffic continues to rise. The goal is to have these new scenarios reviewed by Spring 2026, enabling their implementation during peak traffic in Summer 2026.
