Project results are expected to contribute to the following expected outcomes.

• Environment: the proposed solutions are expected to contribute to the achievement of the objectives of a 55 % reduction in greenhouse gas emissions by 2030 and net-zero greenhouse gas emissions by 2050, by maturing concepts enabling optimal and optimum green trajectories, thus reducing CO₂ and non CO₂ emissions, as well as contributing to new and up-to-date models to tackle emissions and noise and improve local air quality.
• Capacity: the proposed solutions are expected to improve airspace capacity through the identification of optimal and environmentally friendly flight trajectories, taking also into consideration the new entrants (e.g., U-space flights).
• Cost-efficiency: saving fuel for airspace users will reduce CO₂ emissions and related costs for emission allowances.

The challenge is to design and develop concrete innovative applications (that are already TRL1, achieved within SESAR programme or outside) that aim at achieving the objective of net-zero greenhouse gas emissions by 2050 set by the European Green Deal, in line with the EU’s commitment to global climate action under the Paris Agreement. The proposed solutions shall demonstrate their potential to accelerate the shift to smarter and more sustainable mobility, to improve the fuel efficiency and reduce the emissions (both CO₂ and non-CO2) generated by ATM operations and increase the understanding of the climate impacts of aviation to better anticipate them and take adaptation measures. The challenge includes the adaptation of the route charging scheme to take into consideration the green deal objectives and how to enable the definition of globally harmonised policies and regulations to support climate-friendly flight operations. The challenge includes as well the development of innovative ideas to accelerate decarbonisation of ATM through the integration of energy, transport and digitalisation platforms that are at the base of the green transition.

The SESAR 3 JU has identified the following innovative research elements that could be used to achieve the expected outcomes. The list is not intended to be prescriptive; proposals for work on areas other than those listed below are welcome, provided they have already successfully achieved TRL1 (within SESAR programme or outside) and include adequate background and justification to ensure clear traceability with the R&I needs set out in the SRIA for the aviation green deal flagship.

• Multi-scale multi-pollutant air quality systems. Development of solutions for the evaluation of the impact that the air traffic regulation policy options can have on the environment and climate. The proposed solutions should be able to follow the fate of aircraft emissions in the atmosphere on both the global/regional scale (e.g., transport of pollutants from the troposphere to the stratosphere, impact onto the radiative properties of the atmosphere, ozone production, etc.), and on the local scale (e.g., impact close to an airport area during landing and take-off phases). The main area of applicability of such a solution is to support the aviation community in estimating the extent of the environmental impacts that current and future air traffic movements might have. Research shall address integration and optimization aspects to reduce the overall computational time and human errors (R&I need: optimum green trajectories). Research shall take into account the output of project CREATE.
• Greener long-haul flights. Long-haul flights contribute the most to aviation CO₂ emissions and other environmental impacts. Europe has a big contribution to this market sector and therefore it is essential to explore innovative coordination and interoperability actions with ATM systems of destination/origin regions of European long-haul flights in order to reduce the overall environmental impact of these operations. Research aims at developing applications that will contribute to the green improvement of long haul flight operations e.g., increasing the level of ATM automation, air-ground collaboration (R&I need: optimum green trajectories).
• Validation of novel metrics in support of environmental impact assessment in ATM. The collaborative management of environmental impacts and the implementation of strategies to reduce them require the development of indicators/metrics that will enable, on one hand, all ATM decision-makers to make informed decisions at different levels and, on the other hand, to communicate on ATM community efforts towards environmental sustainability. Research aims at developing and validating new environmental metrics for use in R&I and/or operations. The areas for development include use of EPP data for environmental performance assessment, development of meaningful operational proxies that can support ATM decision making in ATFM or ATC operations, development of methodologies for providing an accurate estimation of CO₂ and non-CO₂ emissions and noise with minimal input data (e.g., based only on surveillance data combined with flight plan data), etc. The research can also investigate the adaptation to ATM of software and methodologies currently in use by airlines to optimise their environmental performance (R&I need: accelerating decarbonisation through operational and business incentivisation).
• Explore the concept of “green flag” flights. Making operations greener needs a real boost based on realisable operational frameworks and incentives for the ATM actors. These incentives encompass all phases of flight and start from strategic and pre-tactical phases, where ATM decision-makers have to make informed decisions towards higher environmental sustainability. In ATM process terms, this means an environmentally responsible ATFCM, an E-ATFCM. An enabler of this E-ATFCM framework is to explore new environmental indicators oriented to facilitate decisions to ATM actors. The concept of “green flag” seeks the establishment of a methodology for environmental scoring of flight plans, analysing all aspects derived from the plans that may have an impact on environment. This includes all type of emissions, contrails and noise. The concept may also include the consideration of whether there is availability of alternative means of transport for the same route, e.g., train, so that requirements for a flight to be “green flagged” are higher where there are viable alternatives. The low impact “green flagged” flight plans may benefit from having priority in slot allocation, lower route charges and other advantages linked to pre-tactical and tactical operational decisions. The concept of “green flight” needs to be grounded in a careful review of environmental impact aspects and the validation of the proposed scoring against reference measurements of impact. The research must also address the impact of the concept in the SES performance scheme, including the consideration of trade-offs with other key performance areas (R&I: Accelerating decarbonisation through operational and business incentivisation).
• Automated stepless aircraft high-lift device management. The research activities shall aim at supporting the development of a concept for the stepless management of aircraft high-lift devices with automated support. The objective is to support pilots in managing the energy of the aircraft during the last (e.g., 10,000 ft.) part of the descent phase, in order to reduce fuel consumption and noise perception on the ground. The improved high-lift device management shall improve the adaptability of the flight to the prevailing approach conditions in terms of current aircraft mass and weather conditions. The ability of the aircraft to apply speed changes as required by ATC or potentially by an on-board airborne separation assistance system (ASAS) such as interval management will also be improved, and the environmental impact of such speed changes will be reduced. The research shall take into account both classic 3-degree approach paths and increased glide-slope paths. Research shall take into consideration the results of project DYNCAT (R&I need: environmentally optimised climb and descent operations (OCO and ODO)).
• Green applications to reduce ATM impact on non-CO₂ emissions, noise and air quality. Research aims at developing innovative applications that could contribute to reduce the impact of ATM on non-CO₂ emissions, noise and air quality pollutants. The air quality pollutants (nitrogen oxides (NO_X), particulate matter (PM), volatile organic compounds (VOCs), sulphur dioxide (SO₂), carbon monoxide (CO) and unburnt hydrocarbons (HC)) not only concern the airport local area: their potential impact may affect a substantial area around the airport and other ATM stakeholders could collaboratively work with the airport to design, implement and operate solutions to minimise these aviation impacts. For non-CO₂ emissions, these green applications could consist of different ATC support tools (automated advice to adapt pre-tactical and tactical flight planning to reduce non-CO₂ emissions, monitoring tools on environmental impact, improved capabilities to ensure that traffic minimize non-CO₂ emissions in different phases of flight, etc.). The proposed solutions may use AI for optimising trajectories, creating ‘green’ routes and increasing prediction accuracy. Research could also consider applications for greener network operations e.g., DCB with a lower monitor value per sector to ensure not only safety but also to enable optimal environmental efficiency to be facilitated for each flight (R&I need: non-CO₂ impacts of aviation).