ICAS 2024: Impulses for Innovative Flight Operations Concepts in Air Transport

The DLR Institute of Air Transport from the German Aerospace Center (DLR) participated in the ICAS Congress 2024 in Florence with six presentations. The congress, organised this year by the International Council of the Aeronautical Sciences (ICAS) and the Italian Association of Aeronautics and Astronautics (A.I.D.A.A.), is an important platform for international exchange on research and development in aeronautical sciences. The institute’s presentations aim to make the future of air transport more efficient, safer, and more climate-compatible.

Urban Air Mobility (UAM) and maintenance infrastructure

One contribution focused on the planning and optimisation of maintenance infrastructure for a network of Urban Air Mobility (UAM) vertiports¹. This study draws on insights from the UAM Vertiports and i-LUM projects and extends existing approaches from the HorizonUAM project. The method presented allows for analysis of maintenance capacity requirements to determine infrastructure needs for landing, parking, and electric charging of air taxis.

Key findings of the study:

• Decentralised maintenance locations reduce empty flights to maintenance centres and improve the availability of eVTOL (electric Vertical Take-Off and Landing) aircraft within the network.
• Simulated traffic scenarios of the urban Hamburg airspace showed that distributing maintenance processes evenly throughout the day significantly reduces the required capacity (e.g. maintenance stations, charging infrastructure, and parking spaces).

Reducing climate impact through adjusted flight trajectories

Another presentation outlined an operational approach to mitigating the climate impact of aviation by adjusting flight trajectories². Building on results from the EU ClimOP project, the method allows for comparison of different trajectory adjustments under various meteorological conditions, with a focus on reducing contrails and other non-CO₂ emissions.

Key findings of the study:

• Vertical, lateral, and temporal adaptations of flight trajectories can achieve significant reductions in climate impact.
• The greatest potential for climate impact reduction was found in flights under winter weather conditions and in missions with high contrail intensity.
• The method provides a relatively simple assessment of the climate impact of flight trajectories under different meteorological conditions.

Flight route calculation for unmanned drones – optimising in-situ measurement flights

Another study dealt with the optimisation of flight routes for so-called RPAS (Remotely Piloted Aircraft Systems), which can be used for flight missions in contaminated airspaces to measure air pollution, such as volcanic ash or radioactivity³. This research, conducted as part of the LuFo (Aviation Research Programme) collaborative project MEASURE with the German Weather Service (DWD) and enviscope GmbH, uses a genetic algorithm combined with the Kriging method to collect precise data, thereby optimising measurement flights in contaminated airspaces. The optimised routes enable shorter and more targeted measurement flights, reducing the time needed for efficient data collection during flights and advancing environmental measurement in crisis situations.

Key findings of the study:

• The method allows for flexible and efficient measurement routes, supplementing traditional dispersion calculations with more precise data collection.
• This approach can be applied to RPAS flight missions for effective monitoring of contaminated airspace, such as following environmental disasters.

Communication systems in aviation: "Airborne Ad-hoc Networks" (AANETs)

The DLR Institute also presented its research on the further development of the "L-Band Digital Aeronautical Communication System" (LDACS) data link as part of the IntAirNet project⁴. The project focused on extending the data link by introducing an air-to-air component, allowing direct communication between aircraft, thereby enabling new applications in aviation operations. The study explored how AANETs, particularly in regions without ground infrastructure, such as oceanic airspaces, could support new procedures and applications, complementing existing communication infrastructures. Technological and operational requirements and challenges important for the development of this technology were identified.

Key findings of the study:

• Potential applications include the transmission of flight trajectories, decentralised conflict resolution, and the sharing of information in the event of special incidents or emergencies.
• Direct air-to-air communication can support formation flights (Wake Energy Retrieval; WER), contributing to reduced fuel consumption and mitigating the climate impact of the participating flights.
• Additionally, the transmission of passenger data (internet, phone) could be improved through these networks.

Position verification in "Flying Ad-hoc Networks" (FANETs)

Another study presented a method for verifying the position data of drones within the framework of the VEREDUS project. Based on technologies developed within the project for direct drone-to-drone communication and the establishment of FANETs, the plausibility of the GNSS (Global Navigation Satellite System) position data of network participants is checked⁵. This verification is conducted using independent distance measurements between drones via the data link. Traffic and network simulations were conducted to assess the suitability of the method, and key performance parameters were determined.

Key findings of the study:

• The presented method can be used to verify the plausibility of GNSS position data in FANETs.
• Simulation results show that even when accounting for measurement errors, sufficiently high sensitivities regarding plausibility can be achieved.
• This method has the potential to contribute to increased safety in future urban air traffic scenarios.

About the ICAS congress

The International Council of the Aeronautical Sciences (ICAS) was founded in 1957 by Theodore von Kármán, aiming to promote global exchange of research and technology in aviation. With over 30 participating countries, the ICAS congress brings together leading experts from research, industry, and academia to discuss the latest developments in aviation. The research results presented at the congress are accessible online for all participants and the international aviation community.

¹ _{M. Swaid (DLR Institute of Air Transport), S. Papakonstantinou, D. Kloock-Schreiber, and V. Gollnick (Hamburg University of Technology, Institute of Air Transportation Systems), "Design of a UAM Ground Infrastructure Network with Respect to Maintenance Capacity Requirements," 34th International Council of the Aeronautical Sciences (ICAS) 2024, Florence, Italy.}

² _{Z. L. Zengerling, M. Mendiguchia Meuser, A. Lau (DLR Institute of Air Transport), and V. Gollnick (Hamburg University of Technology, Institute of Air Transportation Systems), "Mitigating the Climate Impact of Aviation by Operational Means – A Comparative Study for Different Weather Situations," 34th International Council of the Aeronautical Sciences (ICAS) 2024, Florence, Italy.}

³ _{K. A. Buchtal, A. Lau (DLR Institute of Air Transport), D. Ebert, J. Richters, and K. Schneiders (German Weather Service, DWD), "Route Planning for Volcanic Ash and Radioactivity In-Situ Drone Measurements Using a Genetic Algorithm and Kriging," 34th International Council of the Aeronautical Sciences (ICAS) 2024, Florence, Italy.}

⁴ _{T. Marks, A. Hillebrecht (DLR Institute of Air Transport), and M. A. Bellido-Manganell (DLR Institute of Communications and Navigation), "Applications and Challenges for Airborne Ad-Hoc Communication Networks in ORP Airspaces Using the L-Band," 34th International Council of the Aeronautical Sciences (ICAS) 2024, Florence, Italy.}