4.3 Critical path and key milestones to roll out the Digital European Sky by 2045

This section defines the critical path for establishing the Digital European Sky by 2045 so that Europe can become the most efficient and environmentally friendly sky to fly in the world. It puts the transformation of ATM into perspective with the planned introduction of SAF (1) and the next generation of aircraft for zero-emission aviation (2).

The critical path looks beyond completing Common Project 1 (CP1) (3) at the key transformations needed to secure the transition to TBO. Figure 10identifies these elements and their impact on the environment for each technology lever across phases C and D. The Appendix provides further details of the critical pathways for specific ATM domains (TBO, CNS, automation, U-space, civil–military and cybersecurity).

Figure 10: Critical path for roll-out by 2045

Focusing on this critical path will be key to eliminating environmental inefficiencies through enhanced capacity, flight efficiency and predictability, allowing airspace users to fly optimal routes. Interdependencies between performance areas show that inadequate capacity leads to non-optimal aircraft routing and increased environmental impact.

The transition to TBO will result in a progressive reduction of CO₂ emissions. This will be achieved through a more precise and systematic optimisation of each flight’s CO₂ footprint, provided by advanced automation and greater air–ground connectivity. Figure 10 illustrates what the transformational changes will mean in real terms, namely a reduction in CO₂ emissions by a further 1 % by phase C and 7.5 % by phase D.

Reducing the total impact of ATM on the climate, including non-CO₂ emissions (e.g. the effect of contrails), will be addressed in phase D through coordinated strategies and a revision of environmental performance metrics. This will include the definition of precise eco-sensitive areas with the support of advanced prediction tools. In addition, other solutions will improve local air quality and noise mitigation at airports.

In parallel, phase D will also support the integration of zero-emission aircraft thereby accommodating the specific needs and flight profiles of a new generation of vehicles, such as battery-electric vehicles for short flights and hydrogen-powered aircraft, which are expected to enter service from 2035 (4).

Any delays in the deployment of these elements will delay the overall roll-out of the vision and reduce Europe’s ability to deliver the most efficient and environmentally friendly sky to fly in the world.

To achieve this ambition by 2045, the innovation cycle in ATM must be significantly shortened, affecting both the development (time to market) and the deployment (market uptake) of SESAR Solutions, as illustrated in Figure 11. Key milestones include significantly advancing phase D development by 2030, completing phase C deployment by 2035 and, ultimately, completing phase D deployment by 2045.

Figure 11: Development and deployment cycle challenges

To set this transition in motion from 2025 to 2030, key activities include completing CP1 implementation, mobilising resources and investments for phase C and D priorities, updating the EPAS according to the SDOs, launching a reflection on a future common project, securing air–ground connectivity transitions, and ensuring continued EU funding and private investments for SESAR beyond the EU’s current multiannual financial framework (MFF), which ends in 2027.