Clean Sky 2 is currently the largest European research programme developing innovative, cutting-edge technology aimed at reducing CO2, gas emissions and noise levels produced by aircraft. Funded by the EU’s Horizon 2020 programme with €1.8 billion over 10 years, Clean Sky contributes to strengthening European aero-industry collaboration, global leadership and competitiveness by delivering innovative solutions for the aviation sector.
Running from 2014 until 2024, it has recently completed a major milestone in evaluating the progress in terms of technology developments towards greener aircraft: the First Global Assessment 2020. This has been performed under the Technology Evaluator Transverse Activity and is available as a full report and executive summary.
Overview of High Level Objectives
The Clean Sky 2 Joint Undertaking was established by Council Regulation (EU) No 558/2014 of 6 May 2014 to develop cleaner air transport technologies for earliest possible deployment, and in particular the integration, demonstration and validation of technologies capable of:
increasing aircraft fuel efficiency, thus reducing CO2 emissions by 20-30% compared to ‘state-of-the-art’ aircraft
reducing aircraft NOx and noise emissions by 20-30% compared to ‘state-of-the-art’ aircraft
Besides improving the environmental impact of aeronautical technologies, including those related to small aviation, the objective of Clean Sky 2 is also to develop a strong and globally competitive aeronautical industry and supply chain in Europe.
The programme structure is shown in Figure 1. It is composed of three IADPs – Innovative Aircraft Demonstration Platforms – (Large Passenger Aircraft, Regional Aircraft and Fast Rotorcraft), three ITDs – Integrated Technology Demonstrators – (Airframe, Engines and Systems) as well as three ‘Transverse Activities’ or ‘TAs’ (Small Air Transport – SAT, Eco-Design and the Technology Evaluator –TE) with relevance to several ITDs and/or IADPs and requiring coordination and management across the ITDs and/or IADPs. The key demonstrators are shown in Figure 2.
The Technology Evaluator
The Technology Evaluator, as a Transverse Activity, has been established as an independent Technology Evaluator for the entire duration of the Clean Sky 2 Joint Undertaking, i.e. until 31 December, 2024. It is led by the German Aerospace Center (DLR) and has the following tasks (as per Regulation1):
monitoring and assessing the environmental and societal impact of the technological results arising from individual ITDs and IADPs across all Clean Sky activities, specifically quantifying the expected improvements on the overall noise, greenhouse gas and air pollutants emissions from the aviation sector in future scenarios in comparison to baseline scenarios;
providing feedback to ITDs and IADPs in order to enable the optimisation of their performance against their respective goals and objectives;
providing input, through the Executive Director, to the Governing Board on environmental and societal impacts across Clean Sky activities to enable the Governing Board to take all actions necessary to optimise benefits across all Clean Sky programmes, against the respective programmes’ high-level goals and objectives;
providing regular information, through the members, the Executive Director and other bodies of the Joint Undertaking, on the impact of the technological results of the ITDs and IADPs;
Overall Assessment Timeline
To monitor and assess the progress of the ongoing technology developments across all Clean Sky 2 activities, two major reporting milestones have been set: a 1st Global Assessment by end of 2020, i.e. approximately at programme mid-term , and the 2nd Final Global Assessment by mid-2024, at programme closure.
First Assessment – Interim Results
The report reflects the technological achievements of the first five years of the programme which will end in 2024. The report assesses the environmental benefits from CS2 technological achievements, which were considered to have reached, already before programme mid-term, a sufficient level of maturity (TRL) to be included in the overall performance models of the new aircraft concepts.
To date, substantial progress has been made in the development of these technology bricks across all platforms. However, additional technologies, still under development, will be integrated by the programme’s end, when mature enough, and will further improve the current results.
Assessment at three Levels: Mission, Airport and Global Fleet
For the set of concept aircraft, the Clean Sky 2 Technology Evaluator has performed a first assessment based on three major pillars (Figure 7):
Innovation potential at Mission level
Clean Sky 2 Concept Aircraft are compared with 2014 Reference Aircraft on relevant missions regarding emissions and noise. The results are the basis to quantify the success level versus the CS2 environmental goals.
Realistic impact at Airport level
A typical day at representative EU-airports (fleet mix from 2014 historical and 2035/2050 forecast data) is compared for a fleet with and without Clean Sky aircraft and analysed regarding emissions and noise.
Aviation footprint at Air Transport System (ATS) level
A year with all global flights (fleet mix from 2014 historical and 2035/2050 forecast data) is compared for a fleet with and without Clean Sky aircraft and analysed regarding emissions and noise.
Figure 7 – TE Assessment levels.
The detailed performance results of these new aircraft concepts and their impact at airport and fleet level are unveiled in the First Global Assessment full report and summarized also in an executive summary (synopsis report).
1 Council Regulation (EU) No 558/2014 of 6 May 2014.