Aviation Twin Transition Cluster Event: Sustainability Challenges in Aviation Panel

Below you will find the abstracts and full videos of the presentations made during the Sustainability Challenges in Aviation Panel at the Aviation Twin Transition Cluster Event held in Athens on July 29-30. To see all of the different panels held, click here.

Progress in psychoacoustic modelling of drone noise

Speaker: Prof. Antonio J Torija Martinez (University of Salford, RefMap project, ImAFUSA)

Abstract

This presentation will overview the current state-of-the-art methods to model and assess aircraft noise, with a particular focus on conventional practices used in regulatory and operational contexts.

It will highlight key research gaps in extending these approaches to assess noise from emerging innovative air mobility (IAM) technologies, such as electric vertical take-off and landing (eVTOL) aircraft. These gaps include challenges related to novel vehicle configurations, complex noise signatures, and particular operational conditions with IAM aircraft operating closer to communities.

The presentation will also showcase recent work at the University of Salford aimed at advancing modelling tools and assessment methods for IAM noise, including integrated efforts within an innovative framework of perception-driven engineering. Progress in auralisation and psychoacoustic methods for IAM noise will be presented and discussed.

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Smart Use of Sustainable Aviation Fuels and Climate-Optimized Routing Toward Mitigating Contrail-Induced Environmental Impacts

Speaker: Abolfazl Simorgh (UC3M, RefMap project)

Abstract

Aircraft CO2 and non-CO2 emissions contribute significantly to climate change. Sustainable aviation fuels (SAFs) and climate-optimized flight planning are among the most immediate measures to mitigate these impacts.

However, SAFs are more production-intensive and costly than conventional kerosene fuel, limiting their short-term scalability. Moreover, climate-optimized routing incurs additional costs and may lead to operational issues such as capacity-demand imbalances and increased complexity.

In this work, we present a framework that strategically combines these two measures in a targeted manner to maximize climate benefits while accounting for the challenges associated with limited fuel availability and operational constraints.

We conducted a year-long analysis of the 150 most-traveled European routes in 2023. Results indicate that smartly allocating only 2% SAF to business-as-usual trajectories, specifically targeting flights that form strongly warming contrails, can deliver contrail-related climate benefits comparable to those achieved with uniform 100% SAF usage, yielding approximately 40% mitigation.

This effectiveness is attributed to the reduction in soot particle emissions from SAF combustion, which shortens contrail lifetime and reduces associated radiative forcing. Furthermore, the strategic allocation of SAF on climate-optimized trajectories can achieve an additional 30-40% reduction in contrail-related climate impact compared to operating the same routes with kerosene alone.

Notably, these benefits saturate at around 5% SAF usage, indicating that increased SAF availability does not necessarily yield proportional additional mitigation for contrail impacts.

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How does the turbulence affect the drone trajectory?

Speaker: Gerardo Zampino (KTH, RefMap project)

Abstract

The overall aim of RefMap is to promote a new approach for a greener aviation using AI for the trajectory optimisation. Although RefMap focuses on both commercial aircrafts and UAVs, only the latter cases are presented.

The neural network with Deep Reinforcement Learning (DRL) is employed to track and chooses the drone trajectory in a simplified urban environment simulated using the high-fidelity LES. Here we follow the entire development from the setup of the simulations used to identify and physically understand the motivations behind the setup of the DRL.

The analysis of the turbulent structures around the buildings, here modelled as wall-mounted, square cylinders shows that the most hazardous region for a drone corresponds to the detached-flow region that envelops the rear obstacle. This region also displays the highest stress gradient for which the NN has been trained to avoid.

The navigation of the drone in the 2D slice is a significant example of the potentiality of this tool as, in real time, the path proposed avoids the hazardous region until reaching the target.

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Holistic Assessment and Design Approaches Towards Sustainable Aviation

Speaker: Angelos Filipatos (Department of Mechanical Engineering & Aeronautics, University of Patras)

Abstract

Global sustainability targets are steering the aviation sector toward practices that reach well beyond isolated environmental-impact evaluations. Community-driven insights underline the importance of embedding sustainability thinking from the earliest design sketches through to final material choices. This abstract consolidates key findings from research undertaken at the University of Patras and illustrates how a holistic sustainability perspective can be integrated across the aviation design related activities.

First, the investigations show how material selection for aircraft structures can be assessed using a sustainability framework that takes into account on structural performance, environmental performance, cost efficiency, and circular-economy potential. A dedicated decision-support tool was developed to benchmark candidate materials against these three dimensions and to flag combinations that satisfy stringent sustainability thresholds.

Second, a suite of multi-criteria decision-making (MCDM) algorithms and normalization technique was systematically compared, revealing that methodological choices can significantly influence overall sustainability scores. Quantifying this sensitivity enables design teams to just the robustness of the rankings generated.

Third, the MCDM framework was scaled to whole-aircraft assessments. A hybrid analytic-hierarchy- process and weighted-addition model ranked aircraft incorporating novel fuels or propulsion concepts under varying stakeholder priorities, demonstrating how changes in weighting schemes can reorder preferred options.

Fourth, a sustainability-driven component-design workflow was formulated and validated on a composite aviation structure demonstrator. The method interweaves technological, environmental, economic, and circularity criteria into a single conceptual level, ensuring that trade-offs become visible before irreversible design commitments are made.

Collectively, the studies highlight a comprehensive yet pathway for embedding holistic sustainability assessment and design into aviation engineering, providing actionable guidance for industry as it charts a credible course toward greener flight. A composite sustainability index enables alternative designs to be optimized on this broader basis.

Main Message:

Performance, environmental, economic, circular and social metrics merge in a n holistic framework, guiding early design teams to choose designs, materials and concepts that can meet aviation requirements.

Summary

In this work, results of a group of studies from University of Patras, relevant with the sustainability-oriented design in the aviation industry, will be presented. Sustainability definitions, assessment frameworks and practical design campaigns of aviation components will be the core results of the presented studies. Overall, our aim is to highlight the need for a holistic and comprehensive approach to sustainability assessment and sustainable design aviation with practical examples and robust proposals for the industry’s way forward.

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What Seaplanes Can Teach Us About UAM’s Future

Speaker: Constantin Tzembelicos (Element Aerospace Limited, Mediterra Holdings, Di-Pegasus project)

Abstract

As aviation explores greener, more digitally integrated solutions, both legacy and emerging platforms face complex challenges. This presentation compares the historical yet niche operations of seaplanes with the rapidly evolving domain of Urban Air Mobility (UAM) and highlights opportunities for cross-sectoral learning.

Despite differing trajectories, both aviation segments grapple with non-traditional infrastructure, regulatory uncertainty, and sustainability expectations. The comparison offers valuable insights for stakeholders navigating the path toward scalable, sustainable, and digitally enabled aviation systems.

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The Aviation Twin Transition Cluster Event hosted by RefMap project took place on 29 and 30 July, 2025, in Athens, Greece bringing together experts, industry leaders, researchers, and policymakers to discuss challenges and opportunities in the green and digital transitions in aviation and urban air mobility.

To see all the panels and more about the event click here

For more about the event and the Book of Abstracts click here: https://www.refmap.eu/clustering-event-in-athens