Table of contents

13th EASN International Conference

The 13^th EASN International Conference on Innovation in Aviation & Space for Opening New Horizons was successfully held in University of Salerno, Italy, from September 4^th to 8^th, 2023. The EASN Association and the University of Salerno would like to cordially thank all the participants of the 13^th EASN International Conference. Many thanks are also due to the Keynote Speakers, Session Chairs, Authors and Presenters, the International Scientific Committee, and the local Organizing Committee for making this Conference a big success.

The event included 8 Keynote Speeches, more than 380 technical presentations and feedback slots distributed in 65 sessions and workshops.

Moreover, 65 Aviation & Space Projects disseminated their latest research results as well as the future trends in the respective technological fields. In total, 410 participants from 39 countries attended the 13^th EASN International Conference.

Like its predecessors, the conference proved to be a major European dissemination event for research in Aviation & Space, providing a forum for EU funded project activities, where innovative ideas, breakthrough concepts, and disruptive technologies are presented and discussed, also with the aim to establish new research partnerships and possible synergies. In addition, a number of European policy development projects found the floor to present future strategic priorities.

List of International Scientific Committee is available in this pdf.

All papers published in this volume have been reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

1. Type of peer review: Single anonymous

2. Conference submission management system: Conference Submission Platform

3. Number of submissions received: 149

4. Number of submissions sent for review: 147

5. Number of submissions accepted: 103

6. Acceptance Rate (Submissions Accepted / Submissions Received × 100): 69.12 %

7. Average number of reviews per paper: 1.96

8. Total number of reviewers involved: 75

9. Contact person for queries:

Name: Dr. Apostolos Chamos

Affiliation: Managing Director

Email: apostolos.chamos@easn.net

* means value has been edited

Electrification through hydrogen-based fuel cells as well as hydrogen combustion in gas turbines is a key strategy in aviation for achieving substantial reduction of emissions. However, this transition presents multifaceted challenges. Besides the development and improvement of technologies required for such hydrogen-fuelled aero engines, the safety of hydrogen storage and distribution systems on aircraft is paramount. Challenges associated with hydrogen in terms of its material properties, the design and selection of components for the conditioning and distribution, as well as the system design are being presented and discussed in this work. This includes the consideration of high diffusivity, flammability and reactivity of hydrogen and the consequences of these traits: hydrogen embrittlement, hydrogen-induced cracking and leakage, for instance. The challenges elaborated in this work are pertinent to both hydrogen fuel cell-based propulsion systems and hydrogen combusting gas turbines. Design considerations were derived and are being outlined in this work. These are transferable to applications in other industries such as automotive and stationary power plants. The need for novel rigorous safety protocols to enable a sustainable future in aviation is being highlighted.

Due to global warming concerns, the Aviation industry is trying to reduce its carbon footprint. Electric propulsion (EP) is one way of doing this, where the power is obtained from electrical sources. The concept of distributed electric propulsion (DEP) is in the focus now. NASA's X-57 Maxwell, a high winged, all-electric experimental aircraft, uses this concept. The present work aims at developing a CFD model (ANSYS Fluent) to evaluate aerodynamic performance of two configurations of NASA's X-57 aircraft wing; (i) wing and nacelle (clean wing) and (ii) wing, nacelle and one electric propeller under cruise condition; and compare it with the results of wind tunnel experiment performed by NASA/Armstrong X-57 research program. Parameters like lift, drag and pressure coefficients (CL, CD, CP) are compared for both cases. A good match is observed for CL, CD and CP, thus validating the model. The unsteady RANS solver is very efficient in capturing the effects of propeller slipstream on the wing. After validation, this model is further used to simulate aerodynamic performance of a wing with multi-propeller (DEP) configuration.

The design task for distributed propulsion (DP) aircraft is more complex than conventional twin-engine designs due to the pronounced propeller wing interaction. DP concepts rely on a beneficial and robust interaction of propulsion and lifting surface. Additionally, a good DP design is optimised as a system such that each element is not optimised by itself (i.e. η_prop and C_L/C_D), but with consideration of the close coupled interaction. The evaluation of such an interaction driven setup is scope of this work. Thrust and torque of a periodic co-rotating DP wing are measured simultaneously with airfoil coefficients. Thereby the influence of propeller on the wing and vice versa are identified.

Two different sets of propeller geometries with a diameter of D = 0.6 m are studied. One propeller set is designed for minimum induced propeller loss (MIL). The second propeller set is designed to have a constant induced axial velocity over the radius (CIV). We shall compare how the different strategies perform in the DP system.

The two element wing has a span of B = 2.4 m and a reference chord of c = 0.8 m, operating at Re = 2.1 × 10⁶. For this study, the propellers are pitched to meet a constant c_T, J and Ma_tip. The results focus on the system performance for the combined setup in take-off configuration. While the isolated propeller efficiency benefits from the integration in front of the wing by > Δη_prop = 12%, the system efficiency suffers from increased drag on the trailing wing that is roughly tripled over the clean wing. Depending on the propeller position relative to the wing, interaction losses can be minimised so that a system efficiency gain over the isolated wing and propeller of > Δη_sys = 4% is achieved.

Distributed propulsion (DP) configurations are a promising concept for future aircraft systems. The main objective of the presented experiment is to investigate aerodynamic interactions of such configurations in detail and compare DP results to a single propeller configuration. The experimental setup at the Propulsion Test Facility, TU Braunschweig, features three co-rotating propellers. These are not attached directly to the wing, but are mounted on a separate carrier. This decoupling allows the forces and moments acting on wing and propeller to be considered separately. Additionally, different relative propeller positions are set up easily. In order to eliminate side wall effects, only the centre propeller and the centre wing element are subject of investigation for the distributed configuration. The periodically repeating outboard propellers reduce the wind tunnel interference while providing a true DP setup for the instrumented centre. Additionally to the DP setup, tests for conventional propeller wing configurations (only centre propeller installed) as well as isolated propeller and clean wing tests were performed. Thus, the DP effects on wing and propeller and the effect of the downstream wing on the propeller are clearly identified. The comparison between single propeller and distributed propulsion configurations shows that with distributed propulsion the drag increase is reduced from 326% to 216% compared to a clean wing. This effect is intensified by a greater thrust level and higher angles of attack. In order to identify the distributed propulsion effects, the forces acting on the propeller as well as the resulting efficiency of the propeller are compared between the distributed and single propeller configuration for two different relative propeller positions. The efficiency of the centre propeller is increased due to the outer propellers by approx. 2% to 3%.

This paper presents a numerical procedure for studying the interaction between the wake generated by a propeller and the wing, considering a tiltrotor model framed within the T-TECH Italian project, which has the scope to develop innovative technologies for a flight demonstrator. A tiltrotor is an aircraft that generates lift and propulsion by way of powered rotors mounted on rotating shafts or nacelles at the ends of a fixed wing; in which, in contrast with conventional aircraft, the dimension of the propeller is comparable with the vehicle one. The procedure proposes to couple a 3D low-order unsteady Boundary Element Method (BEM) approach, to evaluate the performance of the isolated propeller, and a Reynolds-Averaged Navier-Stokes (RANS) solution for the analysis of the flow field interaction between the propeller (simulated as actuator disk) and the wing.

This work has been carried out within ESTRO Clean Sky 2 CfP project, whose goal was to develop an innovative future green regional aircraft configuration based on several new technologies able to match the very demanding and challenging objectives ACARE 2020 in terms of environmental impact. In details, an automatic numerical procedure for the evaluation of the detrimental effect of the propeller on transition location of a laminar turbo-prop wing is proposed here. The evaluation of transition location is based on a well-known procedure, based on the use of e^N method implemented in a Linear Stability (LST) solver. The input data for the LST solver are represented by the pressure distribution as derived from high-fidelity Reynolds-Averaged Navier–Stoke (RANS) solutions and the velocity profiles in the boundary layer derived from a conical formulation of the boundary layer equations.

Over the past decade numerous novel concepts for electric flight have been elaborated. Each unique in its own way and based on various assumptions and technological advances projected for the future. Within each concept design decisions have to be made on component level, propulsion system level and aircraft level. In order to be able to evaluate and analyse both, advanced components technologies and innovative propulsion system architectures, as well as to understand the effect of each design decision, a common baseline platform has been developed to allow for comparative analyses.

This work presents such a platform with the hydrogen-based electrified regional aircraft concept called H₂Electra. The iterative design process developed for this purpose is presented. It allows for a holistic approach to the development of an aircraft, its electrified propulsion system as well as the sizing of the components therein. Two propulsion system integration concepts are being considered in the evaluation: one partially fuselage-integrated and one nacelle-integrated. Challenges and trade-offs between the two concepts were analysed and evaluated, with safety and reliability being key design and decision-making metrics, alongside block-fuel efficiency and power density. In particular, the design decision on a suitable bus voltage and its effect on the powertrain sizing and integration were investigated.

The presented work examines the aerodynamic challenges of podded ultra high-bypass engines installed on a short/mid range low noise hybrid wing body configuration. After assessing the initial engine integration design, sensitivity studies regarding the impact of the freestream Mach number, engine position, and the engine incidence angle on the interference drag are discussed. Then, shape modifications of the nacelle and the center-body based on 2D RANS optimizations are presented. The results indicate that in order to reduce the initially massive interference drag, the overall aircraft design either has to allow for a modified engine position or for reshaping of the center-body's upper surface. With the latter, an overall drag reduction of –44 % was achieved.

Several studies have shown that flying electric between the so-called ABC-islands in the Caribbean (i.e., Aruba, Bonaire and Curaçao) is feasible with the upcoming first generation of battery-electric aircraft. This paper presents a real-world case study that deals with the technical and operational characteristics of electric flight in that region. With that purpose, the Aruba Airport Authority (AAA) commissioned this investigation, which involved numerous local stakeholders, such as airlines, energy providers and navigation services. This study involves two commuter electric aircraft under development, aiming to investigate how they fit in the current operational scheme of three local airlines and three conventional aircraft types in terms of technology, capacity, schedule, performance, CO₂ emissions and fuel costs. Conclusions indicate that a transition to batter-electric aircraft is feasible with regards to the aforementioned criteria and with the current technology and energy density of batteries.

Due to the need to mitigate global warming, there is a growing interest in alternative fuels for various means of transport, including aviation gas-turbine engines. The work aimed to check the impact of hydrogen co-combustion on the performance and emissions of aircraft engines. Zero-dimensional models of JetCat P140 RXI and DGEN 380 engines developed in the GSP (Gas Turbine Simulation Program) program were used in the research. Combustion calculations in GSP are based on the real gas model and NASA Chemical Equilibrium Applications (CEA) equations. The performance of the engines fueled by Jet A-1 and blends containing hydrogen or methane were calculated. The simulations were performed at the design point on the ground, and then in flight for selected altitudes and flight speeds. With an increase in the gas content in the blend, the thrust and temperature behind the turbine slightly increase, and the specific fuel consumption decreases, because hydrogen and methane have a higher calorific value. The performance of JetCat and DGEN 380 engines was calculated for blends of kerosene with methane or hydrogen. This knowledge will be used to convert these engines to gaseous fuels. In terms of fuels and emissions, GSP has limitations related to the set of available chemicals and the zero-dimensional model of the combustor.

The objective of this work is to perform a comprehensive system analysis of a liquid-cooling thermal management system for a hybrid-electric aircraft using fuel cells for general aviation by sizing and optimizing the system with respect to a given objective. A sensitivity analysis on the different design parameters and model assumptions is also performed and their impact on the aircraft and its performances will be assessed. Firstly, the case study is defined and an optimization is run with some initial assumptions leading to a feasibility study for the implementation of this system. The sensitivity analysis is then undergone for the chosen coolant type and fuel cell stack temperature selected after the first optimization. Incorporating the findings of this analysis, a second optimization is run on the thermal management system with improved inputs in order to demonstrate a scenario with reduced penalty on the aircraft. Preliminary results show that implementing this hybrid propulsion system along with its thermal management is feasible with a reduction in payload and range. In addition, it can be concluded that initial assumptions and design choices are shown to have a significant impact on the system's sizing and should be considered in aircraft sizing design loops.

One of the main concerns of the aviation industry is the reduction of dependence on fossil fuels, the reduction of emissions, and, ultimately, the development of a more sustainable air transport system. Emerging technologies, new operational concepts, and research will be essential to achieve this. Batteries are one of the emerging technologies that will play a key role in the electrification of aviation in the coming years. To ensure the scalability of this technology, an analysis of its possibilities, current status, and limitations is essential. The aim of this study is to carry out such an analysis, answering five key questions related to this technology: i) what is a battery?, ii) what are the key parameters of batteries?, iii) what are the possibilities of battery technology to electrify aviation?, iv) what are the main challenges to overcome?, and finally, v) how can batteries be classified? The answers to these questions will make it possible to present the state of the art of this technology, and to identify the main challenges to be addressed in its future development.

This article introduces an optimization-based energy management strategy developed and validated for electric vertical take-off and landing (eVTOL) aircraft. The primary objective of this strategy is to minimize hydrogen consumption while accounting for resource constraints, such as the battery and fuel cell, to enhance energy efficiency and sustainability while adhering to performance and safety requirements. The eVTOL employed in this research is an essential component of our "Viable" research project, featuring a hybrid propulsion system that combines batteries and fuel cells.

To accomplish this, mathematical and computational techniques were employed using the equivalent consumption minimization strategy method to determine the optimal operational parameters for the eVTOL aircraft, considering the available energy resources. These techniques were implemented for the first time in MATLAB, enabling simulations of the aircraft's performance under various conditions. The results demonstrate the efficacy of the energy management strategy in significantly reducing hydrogen consumption while maintaining optimal performance and safety. Graphs and comparative analyses are presented to highlight the evolution of hydrogen consumption compared to different parameters and to compare the approach with alternative methods.

Furthermore, the article explores an alternative solution that offers related results and performance as MATLAB, utilizing the open-source software OpenModelica (OM). Energy management experiments using ECMS were conducted on OM, yielding highly satisfactory outcomes in terms of simulation accuracy and cost-effectiveness. The method was also evaluated in simulations of propulsive system resources, developed on OM, validating the results concerning energy distribution, compliance with constraints, and real-time feedback.

In summary, this article presents a comprehensive strategy for effectively managing energy consumption in eVTOL aircraft. By leveraging simulations conducted in MATLAB and OM, the strategy's effectiveness was assessed, with potential implications for advancing the sustainability of electric eVTOL aircraft.

This paper carries out a sensitivity analysis on the recently proposed hybrid-electric range equation [1]. The proposed hybrid-electric range equation is based on an efficiency-based definition of the degree of hybridization and the efficiencies of respective drivetrains on the range estimation of the hybrid-electric aircraft. The ATR 72 turbo-prop aircraft is chosen as the case study for the sensitivity analysis. The sensitivity analysis done in this paper shows the effects of parameters such as lift to drag ratio, efficiencies, energy densities, payload weight, etc. on the aircraft range. It was observed that variation in aircraft range due to each parameter was distinct and unique. The analysis also depicted the implications of the changes in the above-mentioned parameters from an aircraft designer's viewpoint. The changes were carried out using the predictions for the year 2050. The sensitivity analysis performed in this work successfully narrowed down the parameters that had the maximum impact on the aircraft range.

The objective of this paper is to assess the environmental benefits arising from the introduction of hybrid-electric propulsion on regional and commuter turboprop aircraft. A great focus is put on the propulsion based on a turbine engine coupled with batteries, combining mature technologies. The introduction of novel propulsion architectures on aircraft deployed on regional and commuter networks allows a substantial reduction of the fuel needed by airlines. In this work, scenarios based on real airline networks are presented, in order to quantify the reduction of greenhouse gas emissions possible considering the expected technological advancement for 2035 and 2050. This analysis is conducted by retrofitting the hybrid-electric propulsive system onto existing aircraft that can carry 19 passengers (Dornier DO228) or 70 passengers (ATR72-600). For the 19-seat class, a clean sheet design is also considered to overcome some limitations of the reference aircraft. A precise assessment of the peculiarities linked to the chosen propulsive configuration shows that networks that have shorter flights are better suited to the introduction of this technology, as the restriction on the design payload is less stringent. The proposed propulsive architecture allows a reduction of the operators' yearly fuel budget of up to 50% in 2035 and 80% in 2050. At last, the taxi phase is of particular importance for regional aircraft that perform several rotations a day, therefore a further analysis of this phase is carried out. The result shows that the considered aircraft are capable of completing a full Landing & Take-Off (LTO) cycle without resorting to the thermal part of the propulsive system, reducing considerably the impact of the aircraft on the airport area.

Hydrogen fuel cell-powered electrified propulsion systems hold great promise for the development of sustainable aircraft. However, the integration of fuel cells into aircraft presents unique challenges, particularly in the context of air inlet systems. Key development priorities are to ensure a constant supply of air to the fuel cells and to efficiently manage the transfer of waste heat from the fuel cells. This paper investigates different air inlet systems using analytical methods. Firstly, concepts are identified by analysing the state of the art in air inlet design. Secondly, promising concepts are selected through a qualitative evaluation. Finally, the most promising concept is sized for the given topology. The results of this research highlight the importance of careful air inlet design in order to achieve operability and acceptable performance with fuel cell powered aero engines. The performance and sizing data obtained from the performed analytical calculations can serve as a general basis for the preliminary design of scoop inlets and annular inlets for fuel cell-powered aircraft.

Emission-free aerial propulsion can be achieved with a proton-exchange membrane fuel cell (PEM-FC). In the present investigation, this potential is addressed by designing a hybrid electric power system with fuel cells for an ultralight aerial vehicle to be retrofitted from a conventional fossil-fuelled piston engine configuration. The proposed power system includes a fuel cell, a lithium battery, and a compressed hydrogen vessel. A procedure is proposed to find the size of these components that minimizes the total mass and satisfies the target of a size below 200L and uses performance data of commercially available components. A comparison of different energy management approaches, with and without on-board charge of the battery, is performed. The results underline that the optimal solution is to select the size of the fuel cell to meet the cruise electric request and point out that the maximum discharge current of the battery must be regarded as a key issue in sizing this component, because of the very high take-off power.

This paper compares onboard Energy Storage Solutions (ESSs) for a Kinetic Energy Recovery System (KERS) from a landing aircraft. Energy is stored temporarily and reused so that it enables engine-less taxiing. This paper evaluates the choice of onboard Energy Storage Solutions (ESSs) (flywheels, batteries and supercapacitors) for recovering energy during the landing roll and storing it in the device. A design of an ESS with each of the three technologies was made, using commercially available products. The resulting devices are compared on the basis of weight, charging time, discharging time and complexity in retrofitting to existing systems. Results shows that while batteries have the highest energy density and will have the lowest weight, they are unable to charge/discharge quickly enough to satisfy this application. Conversely, supercapacitors have this ability but their low energy density make them heavy which in turn would offer penalty to the aircraft in flight. Flywheels emerge as the most interesting proposition due to their high energy density and fast charging ability, which satisfy the requirements for application.

Parallel hybrid-electric propulsion systems for small scale unmanned aerial systems (UAS) when tested with an internal combustion engine are susceptible to damage due to increased torque compared to all-electric configurations. The University of Victoria Centre for Aerospace Research has conducted testing and identified several locations in the system for potential upgrades. One of the largest issues identified was the electromagnetic clutch's inability to handle the torque of the Corvid-50 engine. Thus, a new clutch and powertrain system was specified which is better rated for combustion operation. Similar findings are reported based on testing performed at Ł-Institute of Aviation, where a hybrid-electric powertrain stand experienced torque spikes. The spike amplitude was several times higher than the nominal momentum of the ICE, given in the specification sheets. In result, at some working modes, a strong slippage of the clutch has been observed. It is also of highest importance to propose and test potential methods to minimize momentum influence to the powertrain. The goal is to increase robustness of such hybrid systems, and decrease the overall mass of the system.

Electrical motors are key components in the electrical transition required for greenhouse gas reduction programs. Future aircraft will certainly employ electrical motors for primary and secondary surface control, for landing gear and for other actuations such as high-lift systems, and they will also need electrical motors for propulsion. The motors pose the hardest challenge due to the high-power density required. Hybrid-Electric propulsion represents one of the most important topics in the aerospace industry and offers an opportunity to pursue the electrification change especially in light aircraft segments. The focus of this paper is the comparison among permanent magnet synchronous motors for Hybrid Light Aircraft propulsion with traditional and additive winding technologies.

Hybrid-electric power is an appealing technology for multirotor platforms due to its ability to enhance the range of the vehicle while providing low emissions and the precise thrust control required for vehicle stability. The development of a multirotor utilizing hybrid propulsion is an essential step for CfAR as it will be the basis of research on this technology in flight. The designed multirotor, MIMIQ (Modular Inertia Matching Quadcopter), is a 32kg quadcopter with a motor-to-motor diameter of 2.7m which will require a total of 3,700W of power to hover. This demand is primarily met by the series hybrid generator onboard which requires the battery to only supplement a portion of that power. At peak thrust however, the motors will demand 12,000W from the system. During these rapid bursts of energy the battery plays a critical roll in providing an immediate response to the power demand which the generator would not be able to provide otherwise.

This multirotor is designed to accommodate a wide range of propulsion configurations to optimize performance. In addition, the mechanical characteristics are also intended to be easily adjustable. Parameters such as center of mass, inertia, and motor distance can be adjusted to mimic characteristics of future flight vehicles that implement hybrid systems. Before integration, ground tests were performed on various off-the-shelf hybrid generators in order to evaluate their performance and reliability to ensure that they are well suited for the MIMIQ. To characterize the different modes of operation an extensive performance map was pursued. A number of parameters were measured over time with the most important being load, power, and fuel consumption. It has been proven that at low loads the generator can provide power to the propulsion system while charging the onboard batteries. However, at higher loads both the generator and the battery pack are required to provide power. The tests demonstrated that the integration of a hybrid system into MIMIQ is possible. It was also verified that when the engine is integrated into MIMIQ, both the generator and batteries have to provide power simultaneously in all flight phases.

Including production considerations in the early design stages of aircraft structures is challenging. Production information is mostly known by experts and rarely formally documented such that it can be effectively used during the design process. Producibility is mostly considered after completing the design, resulting in increased cost and development time due to the late discovery of production issues. This paper presents a new model, called the Manufacturing Information Model (MIM), which supports the automatic inclusion of production considerations into the design process. The MIM provides a single source of truth and a generic structure to capture and organize production-related information in a product system. Furthermore, it provides compatibility analyses to automatically warn for or exclude infeasible designs. Analysis tools use the information stored within the MIM to calculate the mass, costs, and production rate of the product. To show the functionalities of the MIM, it has been applied to the conceptual design of a wing box at a Tier 1 company. This use case shows how the MIM supports trade-off decisions, as it allows for the identification of trends and the ranking of different manufacturing concepts. Overall, the MIM provides a structured and formal approach to include production information in the conceptual design, improving the decision-making process.

The T-WING project is a research project aimed at designing, manufacturing, qualifying and testing the new wing of Leonardo Next Generation Civil Tilt-Rotor technical demonstrator (NGCTR-TD), as part of Clean Aviation Fast Rotorcraft activities.

The methodology proposed in this paper encompasses the development of high-fidelity modelling and simulation procedures in support to virtual certification methods for crashworthiness requirements of tiltrotors. Finite Element Analysis (FEA) of an aircraft drop test is a complex and detailed process that aims to simulate the structural behaviour during an impact or drop event. This type of analysis is critical for assessing the safety of an aircraft in emergency landing situations. Wing crashworthiness requirement is specific for tilt rotors: during a survivable crash event, the wing design must ensure a pre-defined rupture with the purpose of alleviating the inertial load acting on the fuselage to preserve the occupants from injuries and fire, guaranteeing the escape paths. Thus, the highly integrated T-WING wing box concept has been designed with the specific feature of frangible sections near the wing-fuselage intersection. The activation of fracture of the external semi-wings in correspondence of frangible section is triggered by the achievement of a well-defined crash vertical load factor.

The objective of the methodology is to simulate the crash effects on the whole wing, using explicit non-linear and time-dependent FE analysis, to verify the wing spanwise placement of the frangible sections, the failure mode, the loads acting at the fuselage links, and the acceleration transmitted to the structure. This work is focused on a standalone analysis of the wing plus a lumped scheme of the fuselage, and it is part of a wider activity which will comprise, in the crash simulation, the most relevant vehicle systems (e.g. fuselage model). Moreover, this numerical activity has been compared with experimental results obtained on a different but similar structure, in terms of global acceleration at wing centre of gravity. Good agreement in terms of acceleration has been found between numerical model and experimental relevant test.

The selection of the most critical load conditions is an extremely important topic as it allows the design and structural verification to be limited to a limited subset of conditions that envelop the operational thousands of the Design Limit Load (DLL) book without necessarily having to apply a direct approach. Often, thousands of analyses are performed by a Detailed Finite Element Model (DFEM, including model loading, post-processing and full stress and buckling analysis) taking a long time with a higher probability of error. This work describes the effort to set up a surrogate model of a composite wing, which aims to supply, accurately and efficiently, the structural response of the wing to several solicitation loads that populate the DLL. The surrogate model is defined by employing the Proper Orthogonal Decomposition technique (POD), trained on partial knowledge of data. The snapshots collected are composed of load solicitations and, limited to a subset of wing elements, stress and strain states resulting from the structural response to the relative load solicitation in a numerical analysis. Gappy-POD algorithm is set up to deal with this lack of data in the querying stage when only the solicitations are known. The surrogate model training starts with a selection of loads from the DLL, while its reliability is increased by iteratively adding further FEM analyses based on error maps opportunely defined.

The prediction of aircraft vibrations is necessary for identifying possible design optimization points of each on-board system. In this context, the authors investigated the dynamic response of a Main Landing Gear (MLG) conceived for a fast helicopter when exposed to flight vibrations arisen from the engine propellers. The research activity falls within the Racer program of Clean Sky 2 framework, which aims to develop a novel high-speed rotorcraft. Relying on Airbus Helicopters operative requirements, this paper deals with the numerical procedure description of the MLG dynamic response assessment (resonance frequencies, accelerations amplitude, generalized masses) with respect to the expected in-flight vibrations levels. In particular, an equivalent combined load (sine and random spectrum) based on the normal modes and the corresponding modal mass distribution is employed for investigating the relevant effects on structural endurance. The central themes focus on the possible numerical modelling strategies and vibration loads analysis, which led safely to the qualification. This method could allow for performing sensitivity dynamic analyses in case of further design stiffness or weight changes.

The landing gear system is one of the most critical systems of the aircraft. The need to design a landing gear with high performance, longer life and with a significant reduction in terms of weight, production and maintenance costs represents a real challenge for a sustainable future that Europe is heralding.

This paper presents the results of the experimental campaign of vibration tests performed on the main and side landing gear system, in both extended and retracted configurations, to be installed on the AIRBUS Group/Helicopter RACER compound helicopter demonstrator and it is part of the Project ANGELA within the European Research Program Clean Sky 2 Fast-Rotorcraft.

Furthermore, in this paper will be described the tailoring of the standard. The hybrid nature of the RACER, not envisaged in any of the categories of the standard, required a tailoring phase to test the landing gear systems in a conservative condition. Thus, it will be shown how this phase led to defining a test sequence, a test setup and the vibration loads. The test campaign, conducted with RTCA DO 160-G tailoring, is part of a wider experimental activity aimed at the development, production and qualification of processes and materials that will allow the landing gear system to achieve the "Permit to Flight".

Turboprop aircraft should be improved as they are more environmentally friendly aircraft compared to turbojet aircraft but noise and vibration are often too high for passengers. A simple and uncomplicated way to carry out experiments is using a demonstrator. To determine whether the demonstrator represents the reality, it must be validated. In this project, real flights were first conducted in a turboprop aircraft. During two 70-minute flights, 94 subjects answered questions about symptoms, mood or comfort levels related to noise and vibration, among other things. In the next step, investigations will be carried out in the demonstrator under the same conditions as the real flights. Both results will be compared with each other. If the data from the demonstrator corresponds to that of the real flights, the demonstrator is considered to have been successfully validated. The requirement for this is that the demonstrator data lies within the confidence intervals of the results from the real flights. The aim is to validate a full-scale on-ground demonstrator of a regional turboprop aircraft cabin that will be used for multiple tests like subject tests and comfort evaluation, composite materials and structures, systems and energy consumption.

Innovative studies on morphing wing structures with the highest potential to improve aerodynamic performance on large aircraft are running under the CleanSky2 platform to validate the morphing architectures on true-scale demonstrator through ground and wind tunnel tests. Research activities have been conducted to develop a revolutionary multi-modal camber morphing flap to enhance the aerodynamic behaviour of a new generation of regional aircraft within this challenging framework. The design and validation of the intelligent architecture capable of different morphing modes required for low-speed (take-off/landing) and high-speed (cruise)conditions. To enhance the significance and applicability of the wind tunnel test campaign, a significant scale factor of 1:3 was selected for the test article. In this study, general layout of the mechanical model and FE analysis performed both inner and outer flap will be presented. A comprehensive structural analysis of the flap test article was conducted to ensure the safety and effectiveness of the conceived mechanical solutions. Linear static analyses were performed using the finite element (FE) method within the Ansys Workbench® environment. These analyses aimed to assess the adequacy of the mechanical solutions and validate the test article's structural integrity.

This paper provides an insight into ongoing research aimed at designing a morphing wing with the ability to continuously adapt its aerodynamic shape. The wing is targeted at a general purpose unmanned aerial vehicle. The morphing wing concept outlined in the paper is based on continuous camber changes of the wing leading and trailing edges, allowing optimal performance in different flight regimes. The aeroelastic tailoring method is used to design the load carrying structure of the wing in order to define the optimal stiffness and strength of the structure, which are considered as fixed in subsequent design steps. The research proposes a novel modular design approach that combines aerodynamic shape optimisation and aeroelastic considerations for designing morphing wing surfaces.

This paper presents a rapid iterative design approach, used to develop a preliminary configuration of an Unmanned Aerial Vehicle (UAV), which is to perform a High-Altitude, Long Endurance (HALE) mission. First, based on a set of requirements, an initial aircraft concept is developed.

The rapid iterative design approach revolves around an energy-based flight profile simulation, which is updated with an improved aerodynamic model of the aircraft during every iteration. An aircraft configuration is defined by a set of constant parameters. A corresponding flight profile consists of an altitude and velocity profile, as a function of time. The behaviour of the aircraft is simulated based on the specified flight profile.

For sizing the aircraft components exposed to the airstream, the aerodynamic design phase aims to create an airframe which achieves the performance outlined in the flight performance simulation, utilizing the obtained aircraft parameters. Using the geometric data, a 3D-model of the aircraft is created, which is essential for the aircraft's weight and balance calculations and for determining the airframe shape exposed to the airflow. A Computational Fluid Dynamics (CFD) simulation is conducted to obtain the actual aerodynamic characteristics of the airframe. If the performance requirement of the flight performance simulation is not met, another iteration of the aerodynamic design phase is required.

The design framework stands out due to its rapid iteration capability, accessibility, and straightforward application, making it particularly advantageous for educational settings in which students engage with aircraft design. The approach aims to offer satisfactory results for an initial aircraft conceptualization.

This design framework emerged from the DLR Design Challenge 2023, an annual competition hosted by the German Center for Aerospace Research, where student teams develop preliminary aircraft designs. This years challenge tasked the teams with designing an aircraft system to restore internet coverage over a disaster-affected region. The described approach was used to develop the Sentinel System of the DHBW Ravensburg team. However, the simulation and development process is not limited to applications within this challenge.

This work is part of a research program aimed at finding new approaches and design solutions for helicopter main rotor modelling using multidisciplinary optimization. It is the fourth stage of an individual research program that includes preliminary tasks such as parametric modelling of a single blade, CFD modelling of a full main rotor for different flight conditions, and preliminary structural modelling of a blade. The main goal of this work is to present the parametric modelling of the rotor blade body and structure as an application for complex simulation. The paper demonstrates the method of advanced analysis of the entire rotor and provides exemplary results obtained from complicated analyses. The analytical foundation for combined fluid-structure analysis is presented. The parametric design method is shown to be applicable for different blade planform shapes and various section airfoils. The blade CFD fluid domain is also prepared using the parametric method, as well as the blade's inner structure. The simulation parameters from the previous stages of research, which serve as inputs to the FSI analysis, are outlined. These previously obtained parameters are combined and introduced into an FSI simulation to assess their compatibility and applicability. The configuration procedure of the analysis and the boundary conditions are presented. The obtained numerical results are then compared with analytical assumptions. The simulation products, which serve as inputs for further analysis, are presented with graphical representations. The time and memory consumption of the simulation are outlined. The application of the described work in an optimization loop is proposed. As a result of this research, new options for main rotor optimization are developed. The paper demonstrates some crucial possibilities of FSI analysis in the described simulation cases. The use of combined parametric modeling with fluid-structure interaction analysis for different flight conditions is presented as a new perspective for multidisciplinary design optimization of a helicopter rotor system.

The rapid growth of the commercial aviation sector in recent years, as well as the ambitious emission reduction targets, necessitate the investigation of novel methods to improve the aerodynamic efficiency of future airliners. With increasing passenger demand and evolving industry requirements, innovative designs, like the Box-Wing aircraft configuration, and flow control techniques, such as riblets, are essential to enhance efficiency, reduce fuel consumption and emissions, and meet future aviation needs. In this work, the performance enhancement of a novel Box-Wing airliner with the application of riblets is investigated through CFD modeling. The riblets are small, streamwise grooves aligned with the airflow, which when applied correctly, can reduce the turbulent skin friction drag. The riblets installed on the aircraft are modeled through a dedicated surrogate model, based on the cross-section area of their groove. In this study, both optimal size riblets, as well as constant size riblets, have been examined, assessing the performance degradation associated with the practical application limitations. The results show that the riblets can improve the aircraft's aerodynamic characteristics, with a maximum drag reduction of 60 drag counts, as well as the overall flight performance, providing a maximum increase of 6.4% in payload and 13.3% in range.

This paper studies the effect of lightning impact on aircraft fuselage made of innovative Carbon Fibers Reinforced Composites (CFRC) panels, as an alternative to traditional metal structures. Metal layers are able to dissipate the current generated by lightning impacting the structure, whereas the multilayer CFRC panels are less conductive and therefore have limited capacity for current dissipation. This study presents a time-varying thermal simulation coupled with an electromagnetic simulation, considering different lightning currents that represent both short strokes (i.e., impulses), and long strokes (i.e., square pulses). In order to compare different stoke shapes, the temperature increment resulting from the lightning impact will be assessed through Finite Element Analysis. This approach allows for an assessment of the impact of different strokes on CFRC panels. The model serves as a starting point for future analyses aimed at comparing different technological solutions, beginning with experimental laboratory tests.

This study aims to provide an in-depth characterization of the intelligent behaviour exhibited by structures fabricated using fused deposition modelling (FDM) printing technology. The primary objective is to understand the variability in the shape-morphing behaviour of additively manufactured PLA structures. A comprehensive analysis is conducted to shed light on the impact of various factors on shape transformation, encompassing both working and printing parameters. To establish the relationship between the printing and working parameters with the shape morphing characteristics, the experimental procedure employs Taguchi's method design of experiments. Notably, the study quantitatively reveals the extent of these parameters' impact on the characteristics.

Sol-Gel is a "bottom-up" synthesis method that enables the production of films, nano/microparticles, fibers, gels, and bulk materials, both glassy and crystalline. Sol-Gel chemistry can be a vital tool for solving problems in several industrial applications where nanotechnology is necessary to overcome constraints. Here, various examples involving silicate-based materials are discussed. Silicatic materials with a variety of morphologies and applications, e.g., monodisperse SiO₂ particles ranging in size from a few nanometers to a micron, can be synthesized through hydrolysis and polycondensation reactions of silicon alkoxide precursors. Using an environmentally friendly electrospinning process, silica nanoparticles can be incorporated into polyvinylpyrrolidone (PVP) fibers to create novel, fire-resistant sound absorbers. Additionally, by employing hybrid techniques based on Sol-Gel, the flame retardance of nanocomposites made of silica and epoxy resin as well as epoxy-based composites including hemp, even cured with cycloaliphatic hardeners, can be enhanced. The development of novel materials beneficial for aviation applications, such as hydrophobic (potentially self-anti-icing) coatings, is a further proof of the effectiveness of Sol-Gel chemistry.

The design and technological demonstration of a Landing Gear architecture were addressed for Airbus fast rotorcraft end application within the Clean Sky 2 Racer project. Numerical activities including advanced modelling approaches were carried out to substantiate the feasibility of structural concepts in compliance with industrial standards and CS-29 applicable airworthiness requirements. In order to demonstrate the goodness of design strategies, a true-scale prototype was manufactured and tested for demonstrating its capability to withstand static loads representative of the limit and ultimate cases expected in service. The paper will focus on the qualification of the Nose and Main Landing Gear systems. Sizing process was validated and verified by test whose results allowed for validating/calibrating the FE model. In such a way, the design database could count on a reliable tool available for analysing the effect of any further load condition change.

Within the ecoTECH project, a new fuselage section was designed based on an existing business jet panel, aiming to incorporate innovative technologies and environmentally friendly approaches. The Metallic Fuselage Panel Demonstrator developed in this project integrates the most promising technologies previously developed in the areas of manufacturing methods, including mechanical milling and friction stir welding, as well as surface treatments such as sol-gel and thin film sulphuric acid anodizing, along with a Chrome-free primer applied on a new Al-Cu-Li alloy structure. Two types of full-scale testing were performed to mature the newly developed technologies and assess the performance of the demonstrator. The first was a Static Full-Scale Test Demonstrator, designed and manufactured to undergo static full-scale testing. This testing evaluated the structural integrity and performance of the panel under various load conditions, representative of an operational aircraft, including compression, shear, pressure, tension, and combinations of these forces. The second type of testing conducted concerned endurance. Similar to the static test demonstrator, this demonstrator was subjected to fatigue to assess its durability and long-term performance by simulating representative flight loading spectrum of a business jet aircraft and providing valuable insights into the panel's ability to withstand prolonged operational conditions. The successful completion of these phases in the ecoTECH project represents a significant milestone, demonstrating the effective integration of innovative manufacturing methods and environmentally friendly surface treatments for new aluminum alloys in the development of innovative environmentally friendly technologies. The project's outcomes contribute to the advancement of sustainable and efficient technologies in the aerospace industry, providing a foundation for the future development of aircraft structures with improved performance, durability, and reduced environmental impact.

The anthropic activities, starting from the early industrial development phases, are pointed-out as concurrent causes affecting the environmental conditions of planet Earth as well as people life quality. Evidences of these influences have been observed even in the remote territories like North and South poles. Every day news report about extreme meteorological events affecting vast geographical areas with heavy loss in terms of victims and damages to infrastructures. In these potential risk scenarios, it is extremely important to support emergency management with timely and accurate geo-spatial information and also to restore minimal communication services. In these severe conditions a relevant role may be played by High-Altitude Platform Systems (HAPS) operating at high altitudes, ranging from 17 to 22 kilometres, typically in the stratosphere, extending coverage for large areas and improving connectivity in remote or underserved areas, bridging the digital divide and providing connectivity to rural or isolated regions, carrying remote sensing instruments, such as imaging sensors or atmospheric sensors, to gather data about the Earth's surface, weather patterns, or atmospheric conditions. To analyse their sustainability, the proposed work presents the definition of a Life Cycle Assessment (LCA) for two distinct "lighter than air" configurations: an "innovative blimp airship" (IBA) and a classical blimp airship (CBA) as baseline. While IBA configuration is considered as an unmanned, the CBA airship is a manned configuration. The goal of this activity is to support the characterization and validation of the environmental contribution in terms of CO₂ emissions due to innovative technologies, concepts and industrial processes adopted for the development of such HAPS configurations. For this assessment SimaPro tool has been used. The applied methodology has adopted the ISO standards: ISO-14040:2006 and ISO-14044:2018 as guidelines to estimate the collectable benefits due to the adoption of innovative eco-design solutions. Specifically, this paper is focused on the identification of materials and on inventory development in order to support the LCA process.

Over the past few decades, composite materials, and specifically carbon fiber reinforced plastics (CFRPs), are finding increasing use in the automotive, aerospace, and aeronautics industries. As a result, the production of CFRPs has been significantly increased, thus leading to a corresponding increase in waste production. In the near future, landfill and incineration disposal of waste will likely be prevented due to legislation, thereby bringing forward the need to develop efficient recycling processes for CFRPs. However, recycling of CFRPs is very challenging, mainly due to the difficulty in removing the thermosetting matrix. This paper reports a pre-screening of the solvolysis recycling process for CFRPs on the basis of the mechanical properties of the recovered fibers. To this end, solvolysis tests were conducted on unidirectional CFRP samples under supercritical and subcritical conditions using acetone and water. The solvolysis tests were conducted for various conditions of temperature, pressure, and reaction time. The efficiency of the recycling processes has been evaluated by means of single-fiber tension tests on the recovered fibers, which were conducted according to the ASTM C 1557-14 standard. In most cases, the decomposition efficiency of the epoxy resin in the CFRP, measured in terms of mass, ranged between 90 and 100%. Moreover, the mechanical tests showed that the recovered fibers retained more than 58% of their initial Young's modulus and tensile strength.

To respond to the current climate crisis, hydrogen-powered aircraft are seen as a promising solution in the aviation sector to cut down CO₂ emissions. Hydrogen-fueled aircraft present however huge challenges, especially due to the complex storage of hydrogen. To achieve a reasonable fuel energy density for medium- to long-range missions, hydrogen must indeed be stored in liquid form in big and heavy pressurized tanks. Tank design must so be included in conceptual design, which now has an important impact on the aircraft. This study proposes a structural sizing methodology for a liquid hydrogen tank for a commercial aircraft. A parametric model of a cylindrical cryogenic tank placed at the back of the cabin in a conventional aircraft is created and sized to withstand pressure, bending, torsion and shear loads. The process integrates sizing standards for pressurized structures of the current CS-25 regulation in its methodology and remains general enough to consider both integral and non-integral tanks of any dimensions or materials. Initial analyses show a clear dependency of the tank's performance as well as the optimal stiffening structure configuration on the design pressure.

The objective of the Clean Sky 2 Technology Evaluator project GREENPORT2050 is to assess the environmental impact up to 2050 at airport level of technologies developed in Clean Sky 2 for fixed-wing aircraft. To not only facilitate computational processes and improve their efficiency, but also to ensure quality and configuration-management tasks are automatically and well taken care of, Royal NLR develops a versatile computation platform for conducting these assessments. This paper provides an overview of the platform's implementation (adopting modern, widely-accepted and proven technologies) and its key features (especially in relation to the mechanism of defining and integrating models).

The development of sustainable hydrophobic composite coatings is of high interest for aircraft applications. Currently, the use of natural derived functionalized microparticles as filler to obtain hydrophobic epoxy-based coatings was not deeply investigated. In this scenario, a novel hydrophobic epoxy-based composite including waste hemp microparticles functionalized with silica layer, 3-aminopropyltriethoxysilane, polypropylene-graft-maleic anhydride and silanes (hexadecyltrimethoxysilane and 1H,1H,2H,2H- Perfluorocotyltriethoxysilane) is presented. The resulting coating was casted on typical aeronautical panel, based on carbon-fiber-reinforced polymers, to achieve an improved hydrophobicity and anti-icing property induced by functionalized hemp microparticles.

The wettability and anti-icing property were investigated. Compared to unfilled epoxy resin, the obtained composite coating achieved a greater water contact angle of 30° and doubled increase in icing time. Despite the low content (2 wt.%) of hemp particles, DSC analysis displayed a relevant increase in Tg value, confirming an efficient interaction between the epoxy matrix and the functionalized hemp filler. AFM analysis proved how the presence of hemp filler leads to an increase in roughness due to the hierarchical structure formed by the long chains of silane molecules. The combination of silane activity and rough morphology allows the development of hemp composite coatings with enhanced hydrophobicity, anti-icing behavior and thermal stability for aircraft applications.

Aircraft are composed of many electronic systems: sensors, displays, navigation equipment and communication elements. These elements require a reliable interconnection, which is a major challenge for communication networks as high reliability and predictability requirements must be verified for safe operation. In addition, their verification via hardware deployments is limited because these are costly and make difficult to try different architectures and configurations, thus delaying the design and development in this area. Therefore, verification at early stages of the design process is of great importance that has to be supported via simulation. In this context, the present work presents an event-driven link level framework and simulator for the validation of avionics networks. The presented tool supports communication protocols such as Avionics Full-Duplex Switched Ethernet (AFDX), which is a common protocol in avionics, as well as Ethernet, which is used with static routing in such scenarios. The simulator also uses realistic element models to provide accurate results. The proposed platform is evaluated in Clean Sky's Disruptive Cockpit for Large Passenger Aircraft architecture scenario. The speed of the verification is a key factor, so the computational cost is analyzed, proving that the execution time is linearly dependent on the number of messages sent.

On-board systems represent an important part of an aircraft having a noticeable impact on mass and fuel consumption, among others. New innovative systems might increase the performance of the new generation of aircraft. Aircraft on-board system architectures are defined by the different subsystems, components and connections among them. The big amount of possible combinations usually creates a huge architectural design space that requires automation in order to be properly explored. Certification aspects can be used as a filter in early design stages of on-board systems, this allows to discard some architectures if they are not compliant with the certification specifications. The discarded architectures do not need to be sized and calculated, saving computational time. The proposed methodology shows how to create this link between on-board system architectures generation and certification rules. Results show an application case regarding the modelling of a flight spoiler system. Several architectures are automatically generated from the design space and then automatically filtered by the certification specification rules. This achieves a preliminary certification of innovative on-board system architectures and allows certification aspects to also drive the design process.

This paper investigates the state-of-the-art of graphene-based technologies for the prospective use cases of end-to-end terahertz (THz) communication systems, such as industrial Internet of Things (IoT) applications and unmanned aerial vehicles (UAVs). THz communications offer ultra-high throughput and enhanced sensing capabilities, enabling advanced applications like UAV swarms and integrated sensing, localization, and mapping. The potential of wireless THz communication can be unlocked by graphene technology. Graphene, owing to its remarkable electrical, thermal, and mechanical properties, emerges as a promising candidate for a multitude of applications in aerial wireless communications in the THz band, including high-speed electronic devices, tunable metamaterials, and innovative antennas. However, reliable tools for the simulation-based design of graphene components, able to account for the fabrication-related uncertainties, are still missing. This paper presents the envisaged possibilities of wireless communications in THz bands, overviews graphene devices for RF applications at THz, and discusses the open issues of modelling THz devices and THz channel.

In the framework of the COAST (Cost Optimized Avionics SysTem) project, the Integrated Mission Management System (IMMS) has been developed, a technology aimed to automatically optimize the trajectory of Small Air Transport (SAT) vehicles considering, among possible obstacles, weather conditions, air-traffic and terrain. It is based on the interaction of the evolved versions of three systems, realized within COAST, including the Advanced Weather Awareness System (AWAS), devoted to provide on-board data regarding weather hazards monitored and forecast. The Evolved-AWAS technology has been developed by introducing several enhancements to its baseline version, in order to generate additional information required by IMMS for trajectory optimization. The current work describes the latest developments of Evolved-AWAS and the tests carried out to validate the prototype. All the new functionalities were tested verifying the correct generation of output data needed by IMMS and their visualization into the HMI (Human Machine Interface). The positive results of the performed tests ensured the proper functioning of the software, allowing its integration in the IMMS technology. Finally, the paper reports the outcomes of the last COAST flight demonstration campaign held in June 2023, which revealed the correct behaviour of the Evolved-AWAS, as well as of the overall IMMS.

The paper describes research and development activities under Clean Sky 2 Cost optimized Avionic System (COAST) program. The main goal of this development was to deliver technology enablers at TRL 5 for affordable cockpit and avionics. The target segment for the technology enablers is aircraft with 1 to 19 passengers and small cargo aircraft belonging to CS-23 category. The main aim is to provide overall summer during the whole COAST program development per individual technology. Sections are divided per each technology with their results and overall contribution to the program. The Clean Sky 2 COAST program covered the development of following technologies: Cockpit Architecture SAT avionic system architecture, Flight Management Tactical Separation System (TSS), Advanced Weather Awareness System (AWAS), Flight Reconfiguration System (FRS), Navigation and Surveillance Dual Frequency Multi-Constellation GNSS Receiver (GNSS), Low-cost Integrated Navigation System (NAV), Affordable Integrated Surveillance System (SURV), Platform technologies Compact Computing Platform (CCP), High Integrity Electronics for health monitoring (HIE), Integrated Mission Management System Integrated Mission Management System (IMMS). These technologies were part of several flight test campaigns which took place in the Czech Republic with Evektor company using EV-55 aircraft.

The effective transport of cargo across the globe by aircraft, termed strategic airlift, is foundational to the success of humanitarian aid/disaster relief (HA/DR) missions and even military operations. Due to the variable extremity of these events, it is essential for aircraft and operations to be designed with a high resilience, factoring in performance in a plethora is scenarios. This work aims to provide a framework that enables the coupling of aircraft, fleet and concepts of operations (CONOPS) design to a mission effectiveness in a strategic cargo airlift. Through agent-based modelling, the complex interaction and emergent behaviors of the different systems in the dynamic airlift environment is better captured and evaluated. Unexpected events, such as cargo requirement reformulation, aircraft servicing and changing airbase accessibility, are employed to emulate the dynamic and spontaneous nature of rapid cargo airlift missions. The impact of these events is stochastically modelled, promoting an analysis of a variety of scenarios. By creating a theoretical disaster relief mission, a trade-space exploration is conducted so that aircraft designs and operational objectives can be evaluated for their mission effect. The framework demonstrates the ability to evaluate aircraft and operational performance holistically, enabling a more robust design procedure for a variety of potential design scenarios and metrics.

In this contribution, the development of a novel two-way 3D printed soft actuator actuated with shape memory alloys (SMAs) is presented, considering all the stages from the design, manufacturing, control, and implementation. The SMAs are integrated into the 3D printed composite using thermoplastic polyurethane (TPU). In order to measure the deflection of the soft actuator a computer vision system was implemented. With these measures and using system identification techniques, a mathematical model was developed, which describes the dynamics of the prototype and helps to design of a controller. However, precise control of deflection in systems actuated by SMAs is challenging due to their inherent nonlinearities and hysteretic behavior. To face this challenge, a proportional-integral (PI) controller was designed based on robust stability conditions. The effectiveness of the designed PI controller was validated through experimental results.

This article presents a soft SMA-driven actuator capable of achieving desired bending angles. To create the actuator, flex sensors and Shape memory alloy (SMA) wires were embedded into the thermoplastic polyurethane (TPU) matrix of the sample during the 3D printing process. By deactivating and activating the two SMA wires according to sensing signals from the flex sensors, the actuator sample can track the input bending angle. This approach enabled closed-loop control and improved the overall efficiency of the system. Additionally, the proposed manufacturing process provides a simple and cost-effective solution for the rapid prototyping and custom design of smart materials with complex structures and high resolutions.

This paper describes some important aspects of the development of a cup anemometer performance simulator. This tool aims to simulate the different phenomena which affect the different subsystems of the anemometer, in order to develop different strategies to improve the accuracy of the data obtained through post-processing or design changes. Bearing in mind that the cup anemometer is the most widely used wind speed sensor in the wind energy sector (to control wind generators and to analyse the future economic revenue of wind farms in certain locations), the relevance of the present study should be highlighted. The software is designed in Simulink® and is divided in 4 modules representing the different subsystems of an anemometer from the actual wind speed to the output data. The first two modules of the simulator are detailed in this paper, which consist of the Rotation Rate Module and the Pulse Generating Module. The first module outputs the anemometer's rotor angular position with time, which depends on the wind speed of the anemometer. Oscillations of the rotation rate caused by steady state harmonic accelerations are taken into account. The Pulse Generating Module simulates the optoelectronic system of the anemometer and creates the pulse train signal based on the rotor's angular position, taking into account the manufacturing and eccentricity errors of the system. The architecture of the modules is detailed, and related with the phenomena which is intended to simulate.

The contemporary design of flight control systems demands the utilization of intricate models for the in-depth analysis of individual components or subsystems. Conversely, there is a parallel need for more foundational and synthetic models that offer sufficient accuracy, specifically tailored for preliminary design, monitoring, or diagnostic purposes.

This paper centers on electro-hydraulic servomechanisms designed for aeronautical applications, emphasizing their contemporary significance. These systems play a crucial role, particularly in primary flight commands characterized by precise position servo control.

The great variety of configurations and applications, their complexity and the criticality that characterizes this servomechanisms, deemed appropriate to devote particular attention to their modeling and the development of numerical simulation systems models that are versatile and reliable (flexible and easily applicable to different real systems but capable of providing realistic simulations). In particular, in this work are presented two innovative Coulomb friction models which are applied through MATLAB/Simulink block diagram structure to the model of the electrohydraulic servomechanism. The two friction models are foreseen to overcome the problematic of standard models for the friction, giving more realistic results, increasing the accuracy of the simulations.

Due to their high reliability and precision, piston valves are frequently used for pressure regulating applications. Particularly in the aerospace industry, where cryogenic fluids such as liquid hydrogen are frequently used, the design and operation of piston valves become crucial. The current state of advancement of this technology in the cryogenic field is still in its early stages, owing to the difficulties in designing such complex systems in harsh environments. This justifies the need for further in-depth studies and analysis using CFDs tools and predictive models. In order to ensure an optimal and efficient use of a piston pressure regulating valve in cryogenic environment, it is necessary to understand the strengths and limitations of this technology in an extreme thermal and mechanical condition. The presented work concentrates therefore on a preliminary analysis and optimization of a piston valve operating in liquid hydrogen flow field, for pressure regulating applications. Particular focus will be dedicated to the overall dynamics of the main body of the piston, in terms of robustness and controllability of the desired response of the system. The dynamics of the piston within an extremely low-viscous flow, as well as the thermodynamic and fluid dynamic aspects of the valve system, will be discussed. Simulations of the flow field will be performed through CFD tool, crossing the results with the dynamics of the simulated system response through and implemented Simulink model. The obtained results will be then critically analysed in order to suggest possible optimization of the valve in the locations where the system is most affected from a thermal and mechanical standpoint.

The environment in the cockpit of commercial aircraft is becoming increasingly complex due to the introduction of automation systems. This complexity is especially evident when malfunctions take place, making it difficult for pilots to comprehend the interconnectedness of the systems and potentially leading to loss of control. This paper investigates a novel method for creating an Artificial Intelligence-based stall recovery assistant using Reinforcement Learning by training the agent to generate a stall and subsequently recover from it. This enables training in a large training space with a simple reward function, where the agent has the ability to develop a deep understanding of the environment. Tests show that the agent is able to recover from stall at a variety of altitudes while experiencing unreliable airspeed information originating from a blocked Pitot tube system and with a better response than all baseline agents. The results indicate that restricting AI is not always necessary and, further, that too many restrictions can lead to a system that learns only shallow features, causing it to be unreliable in unforeseen circumstances.

The expansion of Unmanned Aircraft Systems (UAS) is creating new markets, particularly in Urban Air Mobility (UAM), which presents unique challenges. Beyond the risk of mid-air collisions, UAM services in urban areas introduce ground risks to buildings, traffic routes, and pedestrians. This research explores trends in Ground Risk models for different operation planning stages: strategic, pre-tactical, and tactical. It offers a logical pipeline for UAS operators, emphasizing detailed analysis and data source considerations, along with the importance of model interoperability. Using a Naples case study, the research provides practical steps for national authorities to streamline the UAS authorization process.

UAVs are currently conquering the skies as prominent tools for various data-intensive applications, in the economic, transport, military and civil sector. While initially found application in the military sector, technology progression allowed them to enter the recreational sector and are now gaining ground in the fringes of the commercial environment. In parallel, technical components and subsystems that are application-optimised focus on highly automated drones, benefit from expertise in other domains, especially when it comes to Electronic Components and Systems (ECS), such as the automotive one, to operate beyond the visual line of sight (BVLOS) with a rather high degree of autonomy. Such technological developments, as well as currents trends and societal needs have opened the way for an unparalleled expansion in the use of UAS for a great number of applications, where humans cannot reach or are unable to perform in a timely and efficient manner. This work aims to present a in-depth analysis of the current market trends that shape the existing landscape for the development of safe and reliable BVLOS operations.

Nowadays, Unmanned Aerial Vehicles (UAVs) are widely used in heterogeneous contexts and, thanks to a continuous technological evolution, are going to be used for several applications such as, for example, Beyond Visual Line of Sight (BVLOS) operations. Since in BVLOS flights the UAV and the ground control center may not have a direct visibility with each other, a robust communication system is needed to provide reliable connectivity. Although a cellular (4G/5G) network is the current best candidate to enable BVLOS applications, there are still some limitations to overcome, as 4G (LTE) and 5G (NR) cellular networks are natively designed for terrestrial use. In this paper, we first investigate current cellular communication limitations for UAV-based applications, in particular taking into account both results available in the literature, as well as experimental performance campaigns. Then, a viable solution for mitigating these drawbacks exploiting selective on-board antennas is proposed, whose performance is experimentally investigated with a preliminary prototypical architecture.

Without the need for an on-board pilot, drones are designed to accomplish dull, dangerous and dirty missions. However, if a mission exhibits a large operative area and/or several objectives, it may entail poor performance when executed by a single drone. Drone teams may overcome this issue by acting as mobile sensor networks for proximal sensing. In such networks, cooperative autonomy is a key enabling behaviour for achieving resilient and cost-efficient systems. This work implements cooperative autonomous behaviour in the form of a dynamic and decentralized mission planner for a multi-drone inspection mission. The proposed design exploits multi-agent task allocation, distributed route planning and game theory for the assignment of inspection tasks and for the processing of optimal routes in reasonable time frames and with limited communication. In detail, it applies the learning-in-games framework for the coordination within the inspection team, by studying some ad-hoc variants of best response and of log linear learning. Moreover, this work presents some numerical results of model-in-the-loop tests for a comparison between the learning-in-games approaches.

In recent years the increasing use of drones has raised significant concerns on safety and make them dramatic threats to security. To address these worries Counter-UAS Systems (CUS) are capturing the interest of research and of industry. Consequently, the development of effective drone detection technologies has become a critical research focus. The proposed work explores the application of edge computing to drone classification. It tunes a Deep Learning model, You Only Look Once (YOLO), and implements it on a Field Programmable Gate Array (FPGA) technology. FPGAs are considered advantageous over conventional processors since they enable parallelism and can be used to create high-speed, low-power, and low-latency circuit designs and so to satisfy the stringent Size, weight and Power (SWaP) requirements of a drone-based implementation. In details, two different YOLO neural networks YOLO v3 and v8 are trained and evaluated on a large data set constructed with drones' images at various distances. The two models are then implemented on a System-on-Chip (SoC). In order to demonstrate the feasibility of a drone on board image Artificial Intelligence processing, the evaluation assesses the accuracy of classification and the computational performances such as latency.

The development of a future transportation concept in cities may also include transportation of passenger and cargo at various altitudes in order to reduce the load on the ground infrastructure. This is known as urban air mobility (UAM), facilitated by the application of electrical vertical take-off and landing (eVTOL) vehicles. Public acceptance is required with regard to safety aspects in densely populated areas, but also in terms of noise emissions. As with almost any aircraft, the propulsion systems, in most cases the propeller blades, are the main source of noise generation. In literature, experimental and numerical results for geometric blade modifications for the purpose of noise reduction are provided only for small diameter propellers. This paper investigates the individual features at larger diameter propellers by means of numeric aeroacoustic simulations with OpenFOAM. The modifications include serrations of the trailing edge, leading edge tubercles and blade tip adaptations. Moreover, the combination of those features is investigated in a parameter study for various rotational velocities and several flight modes. The key effect, namely a reduction of broadband noise, can be observed for several cases, but the strength of it varies. An optimization process is necessary to obtain an efficient noise reduction for all operating conditions of a particular aircraft design.

Experts worldwide agree that development of operations of Unmanned Aircraft Systems (UAS, commonly known as drones) above populated areas, to remain socially acceptable, must satisfy a set of crucial criteria: safety, security, environmental sustainability (including noise and pollution reduction) and compliance with legal requirements (encompassing liability, privacy and alignment with urban land use regulations). However, for both commercial organisations and entities carrying flights in the public interest, these operations need to also be economically sustainable. This article considers two illustrative scenarios: (1) the urgent transport of medical equipment (e.g., defibrillators) on an ad-hoc basis, precisely when and where required, rather than on a routine schedule; (2) security or plant safety applications, where a drone remains on standby, recharging its batteries in a designated 'nest,' ready to take-off for capturing imagery or sensory data when triggered by security personnel or by automatic alerts (e.g., a camera detecting an individual penetrating a perimeter). Deploying one remote pilot for each 'sleeping' drone 24/7 would lead to enormous service costs, difficult to be sustained by any organisation. The drone hence needs to be completely autonomous, meaning that a remote pilot would no longer be necessary. The concept, often referred to as 'Drones in the Box,' is technically feasible and currently exists. Organisation of the operations, however, goes beyond technical feasibility. According to the Automation Concept by the Joint Authorities for Rulemaking on Unmanned Systems (JARUS), this falls under level 5 of automation. In this highest level, there is neither involvement of a remote pilot in aircraft flight functions, both on the ground and in the air, nor any human awareness of dynamic operational parameters. In essence, to ensure economic sustainability, the 24/7 operations must entirely eliminate the need for remote pilots. Nonetheless, a UAS operator would still exist as the legal entity responsible for organising and overseeing operations, securing necessary approvals and being accountable for the process. Therefore, a professional job profile would still be necessary, to possibly trigger the flight, receive the collected information and act upon or activate the Emergency Response Plan (ERP) when required. This professional would neither need to be trained nor licenced as Remote Pilot but the position should be 24/7. In scenarios such as the two mentioned examples, security personnel may already be on duty 24/7 to safeguard certain facilities (e.g., hospitals) or provide emergency medical services (e.g., 118 in Italy). These operations could thus become economically viable if these personnel were trained by the operator for this on-demand duty. The Flying Forward 2020 (FF2020) project has coined this role as the 'Fleet Manager' and intends to standardise it through ISO (International Organisation for Standardisation), for global harmonisation.

Unmanned Air Vehicles (UAVs) are becoming increasingly popular and widely used in a variety of industries. They can be used for tasks such as agriculture, construction, delivery, surveillance, rescue operations, mapping, wildlife tracking and many more. With the advancements in technology, UAVs are becoming more autonomous and able to perform tasks with minimal human intervention, so are widely used for military and law enforcement purposes. V-tail configurations are commonly used on UAVs due to their advantages in control and stability performance, as well as their ability to reduce drag and improve overall efficiency. However, research on V-tail design and sizing is limited, particularly for Class I mini-UAVs. The objective of this paper is to identify a methodology for a V-tail sizing of a Class I Mini UAV (NATO classification), which refers to the Conceptual and Preliminary Design of the UAV. The methodology will follow the design of a V-tail from the characteristics of the conventional tail of the UAV. Once the characteristics of the conventional tail were extracted, V-tail geometric characteristics (reference area, aspect ratio, mean aerodynamic chord, tail span, dihedral angle), were computed. Therefore, the aerodynamic characteristics of the V-tail have to be extracted, first as an isolated tail, and then as an installed tail. The stability derivatives of the V-tail are then calculated. The methodology for the analytical aerodynamic characteristics and stability derivatives, is a combination of NACA Report No.823 and Marcello R. Napolitano methodologies. Paul E. Purser and John P. Campbell provide design methods for V-tail on a NACA report, which include some of the desired stability derivatives. The rest of them will be calculated with Napolitano's method. Marcello R. Napolitano gives a methodology for conventional tail sizing; thus, the equations of its methodology have to convert for a V-tail configuration. Furthermore, the aerodynamic characteristics and stability derivatives of the designed V-tail will be verified by Low Fidelity Aerodynamics simulation (XFLR5 software), and then by High Fidelity Aerodynamics by means of CFD. The results between low fidelity analytical values and High-Fidelity Aerodynamics values indicate a relative error lower than 20%.

The aim of this study is to design L₁ adaptive controller, which is one of the robust control methods that can overcome model uncertainties, disturbances and noises, for a fixed-wing unmanned aerial vehicle (UAV) with tail fin controlled. In this context, first of all, the decoupled equations of motion of the six-degrees-of-freedom system are derived for the roll, pitch and yaw channels of the UAV. Then, the performance of the controller is demonstrated by simulation results for linearized system representation. By adding parameter errors to the system in question, the feature of tracking the given angle commands are analyzed. It has been observed that the L₁ adaptive control structure exhibits rapid adaptation even in presence of system uncertainties. Finally, the controller is applied to the nonlinear system and operated throughout the entire flight envelope.

In the recent years a rapid increase of multirotor UAVs in the commercial market is observed resulting in a large number of motor/propeller concepts and thrust architectures. The limited availability of data for the aerodynamic performance of the motor/propeller system often leads to a non-optimal operation on multirotor UAVs design points. Since experimental investigations are both cost- and time-demanding, the accurate CFD modeling of UAV propellers is crucial and highly supportive in the early design phases of multirotor UAVs. In the current study, a CFD framework is employed for the performance investigation of a small-scale three-blade propeller on a lightweight micro quadrotor UAV, designed for indoor search and rescue operations. More specifically, two widely implemented methods for propeller modeling are examined, namely the Multiple Reference Frame (MRF) and the Sliding Mesh (SM). Several operating points are investigated, corresponding to different propeller rotating speeds (RPM) and Reynolds numbers. The accuracy of each method is evaluated by comparing the CFD results with those obtained from literature experimental data. Finally, the uncertainty of the computational methods is quantified through Richardson's extrapolation method.

The research described was conducted by a student team dedicated to finding sustainable and long-endurance systems and outlines an innovative solar panel UAV aircraft solution. Our prototype demonstrated the feasibility of the concept, while the second aircraft, currently in the design phase, aims to improve performance further and allow for extended self-powered flight time. The sustainable approach of our project addresses the growing need to reduce the environmental impact of transportation technologies. The main objective of this study is to address the requirements of the Specific Category - Civil Drones regulation, promulgated by EASA, regarding the risk associated with the impact of the aircraft on the ground in case of an in-flight failure. To address this issue, we conducted an in-depth analysis of possible failure scenarios and their consequences on the safety of the aircraft and people on the ground. Furthermore, the team developed models for risk assessment to evaluate the risk associated with solar panel UAV operation. To mitigate the risk of impact, we considered using a parachute, the effectiveness of which was analysed using a dynamic model implemented in Simulink. The analysis allowed us to evaluate the semi-controlled descent of the aircraft with the parachute attached, providing valuable information to optimize the safety system further. In conclusion, our study significantly contributes to ensuring the safety of our model in flight and on the ground through ground-impact risk management while promoting the development of sustainable and innovative solutions in the aviation field.

Designing an efficient and optimized multirotor UAV requires laborious trade-off analyses, involving numerous design variables and mission requirement parameters, especially during the early conceptual design phase. The large number of unknown parameters, as well as the associated design effort often leads to non-optimal designs, for the sake of time efficiency. This work presents the implementation of a machine learning (ML) framework to assist and expedite the conceptual design phase of multirotor UAVs. The framework utilizes information from a comprehensive database of commercial lightweight multirotor UAVs. The database contains an extensive collection of crucial sizing parameters, performance metrics, and features associated with foldability and indoor guidance (e.g., obstacle avoidance sensors). These attributes specifically pertain to multirotor UAVs weighing less than 2kg, which exhibit diverse design and performance characteristics. The proposed ML framework employs multiple regression models (e.g. k-nearest neighbors regression, multi-layer perceptron regression) to predict the sizing parameters during a multirotor UAV's conceptual design phase. This enables designers to make quick informed decisions, while also significantly reducing computational time and effort. Finally, the ML framework's predictive capability is validated by comparing the predicted values with real-world data from an "unseen" test dataset.

Multirotor UAVs have become an essential tool in a wider range of applications, including among others disaster management, and search and rescue (SAR) operations. Typically, these systems operate outdoors, with their guidance and positioning being based primarily on GPS. This work is focused on the design and optimization of a multirotor UAV specifically tailored for indoor SAR applications, where GPS signal is unavailable, and obstacles are prevalent. The design incorporates a lightweight frame structure, in order to increase the UAV's payload capability. This is necessary, since the UAV requires multiple obstacle recognition and avoidance sensors, as well as thermal and optical cameras, to successfully accomplish its mission objectives in a GPS-denied environment. Towards this goal, various trade studies were conducted including different motor/propeller configurations and airframe FEM analyses. The aerodynamic performance of the UAV is evaluated also, using dedicated CFD analyses that incorporate the effect of propellers. Lastly, a prototype of the designed configuration is produced using additive manufacturing methods and initial flight tests of the UAV are performed.

This study presents an experimental investigation of blade-shaped riblets for drag reduction in unmanned aerial vehicle (UAV) applications. UAVs have gained significant attention since they can perform various missions, including surveillance, reconnaissance, and package delivery. However, their aerodynamic performance, specifically the high drag associated with their exposed surfaces, remains a key challenge for enhancing their efficiency and extending their flight endurance. To address this issue, riblet geometries are proposed as a potential solution, which can reduce the turbulent skin friction drag by up to 8%. The experimental investigation involves wind tunnel testing of blade-shaped riblets, with various spacing-to-height (s/h) ratios and constant groove cross-sectional area (A_g). The riblets are designed for application on the wing, empennage, and fuselage surfaces of a UAV. The investigations are performed on a flat plate for various flow conditions, including different freestream velocities, to evaluate the drag reduction effectiveness of the riblet configuration. The drag force is measured using a force balance system and flow visualization techniques are employed to assess the position where the boundary layer has transitioned to fully turbulent. The results demonstrate the drag-reducing effect of blade-shaped and trapezoidal riblets and the different performances observed for the various s/h ratios. The cases with s/h=1 result in the smallest drag coefficients, while the cases with s/h=2 have significantly increased drag values, compared to the smooth flat plate, due to the increased wetted surface area. These findings highlight the potential of riblets as an effective drag-reduction technique for UAV applications, enabling increased endurance and/or enhanced payload capacity.

The current study focuses on the development of a prototype BWB UAV for highway traffic monitoring by supporting a Cooperative Intelligent Transport System (C-ITS). This system allows the monitoring of traffic conditions at large roads and highways. Having determined the mission requirements and concluded the aerodynamic conceptual and preliminary design phases, high fidelity CFD simulations are performed, aiming to calculate the key aerodynamic and stability characteristics of the platform and to optimize its performance throughout the mission. More specifically, regarding the aerodynamic vehicle design, results concerning the calculation of stability derivatives, control surfaces sizing, trim analysis and flight envelope (V-n diagram) are presented, along with the respective methodologies. Considering the structural design of the aircraft, a combination of layout, FE simulations and parameterized design tools were employed, allowing the design and sizing of the skin and the internal structural parts. The parts are mainly made of composite and additively manufactured nylon materials. Coupled interaction loops are conducted among the aerodynamic and structural analyses to optimize the overall performance of the aerial vehicle, maximizing the aerodynamic efficiency, and reducing the structural weight. Finally, the study is concluded by the presentation of the manufactured prototype of the UAV, which satisfies all the structural, aerodynamic, stability and performance requirements for the established highway traffic monitoring mission.

Drone intrusions pose a growing threat for the airports as their expansion is sponsored by the widespread availability of their technology and by the ongoing U-space implementation. Counter-drone systems traditionally employ a reactive policy, which implies the closure of the overall airport following an intrusion, penalizing the continuity and the resilience of airport operations. Instead, a drone intrusion management system shall ensure a resilient behaviour against drone intrusions with a proactive policy, supported by specific procedures to mitigate the impacts of intrusions. ASPRID (Airport System PRotection from Intruding Drones) is an exploratory research project to develop an innovative operational concept for managing both careless and malicious drone intrusions in airports. This work demonstrates the positive impact of the ASPRID solution for the resilient protection of airport operations against drone intrusions. Such impact is assessed by means of real-time simulations, including a gaming exercise with experts representing aerodrome stakeholders and Law Enforcement Agencies. We present here the main results of the quantitative assessment and the main feedbacks received by the experts.

Operational pressure refers to pressure, whether induced or self-induced, that can affect the (flight) operation and may also impact safety. It is a hot topic in many sectors, being an important reason for multiple personnel strikes - the aviation sector is no exception here. Given the rapid evolution of these different operational pressures as the world adapts, continuous attention will be necessary for addressing the concept of operational pressure and discovering new mitigation strategies. Therefore, this paper delves deeper into both current and future factors influencing operational pressure, as well as mentioning some potential mitigating measures. Moreover, the case of operational pressure is structured and visualised using NLR's Safety & Human Performance (SHP) framework. The result provides a structured overview of the impacts of different operational pressures on safety, which can aid in developing mitigations to lessen the effect of such pressures.

This paper explores the potential of eye-tracking technology in adaptive human-machine interfaces for pilots in aviation. We argue that an interface able to adjust its layout and elements based on pilots' real-time eye-tracking data can prevent errors and enhance their performance. The study presents a literature review on the use of eye-tracking for various pilot cases, including flight simulator games, drone pilots, and cockpit pilots. Results in most cases showed that eye-tracking has been employed to improve interactions, enhance spatial awareness, guide pilots' gaze to relevant areas, and provide insights into pilots' information processing and task load. The paper discusses two sample cases demonstrating the potential of eye-tracking in adaptive human-machine interfaces. In the first case, during challenging drone simulations, eye-tracking identified areas where an adaptive human-machine interface could aid navigation and reduce cognitive load. In the second one, based on real drone flights, when signal loss incidents occurred, eye-tracking data showed that the interface should adapt to pilots' needs by providing critical information to help them to improve situational awareness. The paper concludes that eye-tracking technology has significant potential in adaptive human-machine interfaces for aviation, emphasising the importance of refining these technologies to meet pilots' specific needs and enhance flight safety.

The study of human performance of air traffic controllers (ATCOs) is an interesting line of research to improve operational safety. In recent years, there has been an increase in the number of techniques available to develop this research based on massive data analysis. This study presents the use of certain electroencephalography (EEG) parameters to study the human performance of ATCOs. Although software and applications are now available to calculate these parameters, there are often problems in understanding the detailed process used to calculate them. The parameters presented in this study are intended to overcome this limitation and are applicable in real air traffic control (ATC) situations. Six parameters are analysed: excitement, stress, relaxation, boredom, engagement, and attention. As an application case for the parameters, a total of 50 data samples obtained during the development of real-time simulations on a highly realistic ATC platform are analysed. From these data, the above-mentioned EEG parameters and their trends are calculated. In addition, the evolution of these parameters is studied in relation to two other variables that characterise the operational situation of the sector during the simulations: the taskload based on ATC events and the number of simultaneous aircraft in the sector per minute.

This paper presents a comprehensive review of haptic feedback in light aircraft control. It provides an overview of the results and experiences gained from a previous research project focused on the design and testing of pilot haptic feedback hardware. The objective of this paper is to outline a roadmap for the future development of "More Haptic Aircraft," incorporating principles of human-centred design into light aircraft cockpits equipped with the presented haptic feedback device. The roadmap provides general requirements for pilot-aircraft interaction and highlights three specific levels of functions. These functions aim to reduce the pilot's workload and enhance situational awareness.

The aviation industry is moving towards single-pilot operations due to increased operating expenses and a shortage of pilots. The necessity of developing a digital cockpit assistant leads to discovering methods to assess the stress and mental workload of pilots. This study used twenty-eight healthy volunteers to conduct preliminary computerised cognitive tasks while recording their physiological data for PPG, EDA, and temperature under four different stress and workload situations. The results highlight how they are sensible to a binary classification between a relaxed and more cognitively demanding condition.

The introduction of artificial intelligence (AI) tools in aviation necessitates more research into human-autonomy teaming in these domain settings. This paper describes the development of a design framework for supporting Human Factors novices in considering human factors, improving human-autonomy collaboration, and maintaining safety when developing AI tools for aviation settings. Combining elements of Hierarchical Task Analysis, Coactive Design, and Types and Levels of Autonomy, the design framework provides guidance in three phases: modelling and understanding the existing system and associated tasks; producing a new function allocation for optimal Human-Autonomy Teaming (HAT); and assessing HAT-related risks of the proposed design. In this framework, designers generate a comprehensive set of design considerations to support subsequent development processes. Framework limitations and future research avenues are discussed.

Air traffic is currently increasing. But the ATC service, which is responsible for providing control of aircraft crossing the airspace, is unable to increase its capacity to cope with this demand. This makes airspace an increasingly complex environment. Complexity is thus becoming an area of interest. This paper aims to develop a complexity indicator based on the behaviour of the main flows of a sector. By means of Exploratory Data Analysis, it is possible to obtain a study that allows the complexity of different sectors to be compared with each other, as well as to analyse in detail the complexity of a sector or its causes. This exploratory analysis carried out for the study of complexity is very extensive, and can allow the ATC service to have a general or specific view of the complexity of the sectors, or even of the behaviour of certain air traffic flows. This is of great help, and can be a tool for optimising human and technological resources within the ATC service.

This study delves into the realm of Air Traffic Management (ATM) and its criticality in ensuring the safety and resilience of aviation systems. Traditionally, safety has been approached reactively (Safety I), but with the complexities of socio-technical systems like ATM, a shift towards proactive measures is essential. This research explores Resilience Engineering (RE) and Safety II, emphasizing learning from a system's adaptability in everyday situations. ATM, a multifaceted system, relies on technology, organization, and human interactions, striving to maintain equilibrium among these pillars for safe and efficient operations. Any changes to these elements can disrupt this balance, necessitating a systemic perspective. Safety in ATM depends on resource availability, timeliness, and coordination among organizations and humans, while resilient performance extends safety beyond the expected operating conditions. To unify safety and resilience, this study introduces the Safety Resilience-Bayesian Network (SR-BBN) model. This model integrates data-driven and knowledge-based approaches, categorizing variables into separations, external factors, nominal conditions, and Air Traffic Controller (ATCO) strategies. The SR-BBN model aids in predicting safety outcomes and identifies influential variables.

The current aim in response to the anticipated growth in air traffic demand is to expand airspace capacity. However, this poses a challenge, as many airspace volumes are nearing saturation. An influential factor in determining airspace capacity is separation minima, which have remained unchanged for more than two decades. It seems that technological developments in recent years, such as new aircraft capabilities and ATC (Air Traffic Control) support tools, may eventually enhance current separation minima standards. Consequently, there is a push to improve separation management by introducing new operational concepts. Ad Hoc separation minima are one such concept, allowing different separation values to be applied within the same airspace volume based on factors such as aircraft models, weights, and wind conditions, among others. These values are computed individually for each aircraft pair in each situation. Implementing different separation minima values within the same airspace volume requires a significant change in certain ATC activities. In addition, new functionalities or ATC support tools are essential, as Air Traffic Control Officers (ATCO) cannot mentally determine the appropriate separation value for each situation. To address this, a new tool, the Ad Hoc Separation Minima Tool (ASMT), is proposed. It aims to integrate this concept seamlessly into an en-route (ENR) sector without increasing ATCOs workload and altering ATC responsibilities. This study provides a high-level overview of the ASMT architecture, and its functional system has been evaluated in a simulated ENR sector using MATLAB®.

The widely used Quality Service Index (QSI) model estimates air traffic by considering attributes such as capacity, connectivity, and travel time, which impact an itinerary market share (MS) in the origin-destination (OD) market. To determine itinerary attractiveness, the conventional QSI model combines these features, weighting them based on their significance and generates a score for each option. The key is therefore to select the optimal combination of weighted attributes that are able to forecast the MS with the desired accuracy. However, traditional QSI models rely on expert knowledge and assume that the traffic generation and allocation is always based in the same market principles, hindering their ability to generalize and identify new features. To address this, the present work, which is part of a research project entitled ERA funded by Red.es, introduces a generalized rationale based on Artificial intelligence using historical data, a challenge that has been faced in the early stages of the project. This approach enables the identification and understanding of key features in the aviation traffic and the development of a forecasting model capable of capturing more complex feature relationships.

To highlight which cardiodynamic adjustments take place in civil aircraft pilots when unexpected mechanical accidents occur while they are in flight, in 8 skilled pilots we detected the mean blood arterial pressure (MAP) and heart rate (HR) while a unexpected failing of one engine occurred when they were engaged in a simulated flight with a homemade Airbus A300 cockpit. Comparing these two cardiovascular variables in a simulated flight test, just as when the accident happened, together with the values assessed in a simulated control flight without accidents, by the non-parametric Wilcoxon test for paired data it has been found a significant increase of MAP's median (+ 20.3%, P = 0.008) without significant increase in HR one. However, in several tested pilots this sudden MAP increase tended to progressively recover baseline values while simulating the flight despite the event triggering this functional response was still present.

We concluded that the cardiovascular apparatus of skilled aircraft civil pilots adapts in such a way of sudden respond to unexpected emergency conditions by adjusting mean arterial blood pressure for adequate blood flow to limb muscles, and this happens without a concomitant tachycardia response in order to maintain an optimal mechanical/metabolic efficiency of the heart.

Within the framework of the European Union's Horizon 2020 research and innovation program, one of the main goals of the Labyrinth project, which ended on May 2023, was to develop and test the Conflict Management services of a U-space-based Unmanned Traffic Management (UTM) system. The U-space ConOps provides a high-level description of the architecture, requirements and functionalities of these systems, but the implementer has a certain degree of freedom in aspects like the techniques used or some policies and procedures. The current document describes some of those implementation decisions. The prototype included, at least in a basic version, part of the services defined by the ConOps, namely e-identification, Tracking, Geo-awareness, Drone Aeronautical Information Management, Geo-fence Provision, Operation Plan Preparation/Optimization, Operation Plan Processing, Strategic and Tactical Conflict Resolution, Emergency Management, Monitoring, Traffic Information and Legal Recording. Besides, a web app interface was developed for the operator/pilot. The system was tested in simulations and real visual line of sight (VLOS) and beyond VLOS (BVLOS) flights, with both vertical take-off and landing (VTOL) and fixed-wing platforms, while assisting final users interested in incorporating drones to support their daily tasks. The three-year experience developing and testing the environment provided many lessons at different levels: functionalities, compatibility, procedures, information, usability, ground control station (GCS) integration and aircrew roles during the mission.

There is a rapid growth of national space launch ambitions and capabilities, e.g. delivering satellites into low-earth and sun-synchronous orbits. With vertical and horizontal delivery methods, and numerous locations under consideration in several continents, the industry has faced early challenges, such as failed launches and licencing timescales. This paper explores the increasing intersection between aviation and air traffic management (ATM) with higher airspace operations (HAOs). It introduces the background and principles of space launches, before addressing the particular impacts on aviation and ATM. The strategic challenges of planning launch windows to align both with orbiting asset congestion and ATM demands, plus promulgating such information to airspace users, is discussed. In the tactical phase, the consequences of impacts on airspace users (such as the re-routing of flights) and on air navigation service providers (such as the demands of coordinating airspace closures in the context of considerable re-entry/splashdown uncertainty) are discussed. A key contribution we make in this paper is the first aircraft-specific, fuel and operating cost analysis of HAO impacts, and the first such European cost assessment, with basic impact geometries. We also propose improved aircraft-specific impact models, which include passenger-centric costs.

Currently there exist a wide variety of models that can be used to assess the fuel consumption of a single flight, from conventional models based on physics and flight performance to more innovative ones based on avant-garde techniques such as artificial intelligence. However, the quality of the fuel consumption estimated by these models usually relies strongly on the quality of data available. As consumed fuel is impacted by a wide variety of features, such as aircraft type, engine family, meteorological conditions, flight path, etc, the more information available, the more accurate the estimations will be.

However, having access to such granulated data is not always trivial and, moreover, the computational cost that could be derived from assembling data coming from different agents in the aviation field (airports, airlines, manufacturers, meteorological stations), plus the processing of the data and afterwards the computation of a refined fuel consumption model will be very high. The work presented here has been developed within the framework of the project E.R.A. (Environmentally Responsible Aviation) funded by Red.es, and it presents an extensive analysis on how consumed fuel and carbon dioxide emissions estimations could be made with limited access to information. Moreover, the aim is to be able to prove that for aggregated metrics, that being a set of flights and not a single flight, the consumed fuel can be easily estimated thus helping accounting for the carbon dioxide emissions that are produced at a global level.

Systems-of-Systems theory is enlarging the perspective that engineers have on the objects of their work. Previously, efforts were focused at the system level, and by managing system inputs and outputs, all interactions between systems were thought to be addressed. With age, a system-of-systems designed individually at different moments in time will degrade as an overall fitness to purpose, will grow to a certain degree of obsolescence. In aviation this is most evident since systems invented and put in place 60 years ago are still operating. The assumptions made originally when the system was created became obsolete, gradually or in quantum leaps. This paper uses examples from air navigation to illustrate that the fitness for purpose for an individual system does change over time and with the changes in the environment the system is working in. The first time a system is established as an industry standard, its first design, and its first architecture presumably best fit the requirements, the specifications. Although these specifications of the system do not change in time, the fitness to the purpose does change and usually decays. This is only obvious in a systems-of-systems analysis, done for the system now part of a system-of-systems. The paper studies the following cases of obsolescence with impact on Air Traffic Management: Radar Altimeters, ILS Glide Slope intercept from above, Continuous Descent Approach effects on turbine engines, and evolution of SSR transponder utility.

Technology adoption depends not only on the development of new technologies, but also on the existence of regulations able to foster the implementation of such technologies. To facilitate the exploration of different policy options aimed at accelerating the adoption of new Air Traffic Management (ATM) technologies, an agent-based model that represents the behaviour of the European ATM system has been developed. This model includes representations of the main stakeholders in the ATM ecosystem: regulatory bodies, technology providers, labour unions and technology adopters, including Air Navigation Service Providers (ANSPs), airlines and airports. New ATM technologies, policies imposed, behavioural biases (e.g., loss aversion) and exogenous variables (e.g., fuel price) drive the actions of the agents, leading to the emergent global behaviour of the system. A calibration and validation process involving historical data, gaming experiments and participatory simulations was performed. The model was used to evaluate various policies that included economic incentives and penalties in two scenarios: one based on past events and another focused on the future. The results allow us to analyse which individual stakeholders benefit the most from each policy and to identify the mechanisms that emerge and drive the path of technology adoption, finding that a combination of economic incentives and penalties provides promising economical and operational results.

This paper presents the outcomes of a study conducted by SALTO team in the framework of the Student Aerospace Challenge, focusing on designing structures to optimize passenger protection against radiation in a suborbital vehicle. The study delves into space radiation characteristics and their potential impact on human health during suborbital flights. Through comprehensive research and the utilization of CARI-7A software, the team evaluated radiation exposure and explored both passive and active shielding solutions. The passive shielding solution involved the design of a multifunctional sandwich panel and a shielding layout for windows, minimizing weight penalties on the vehicle's structure. Additionally, an active shielding concept utilizing high-temperature superconductor material and solenoid layouts was investigated. The study underscores the benefits and challenges associated with both passive and active shielding methods, emphasizing the importance of further exploration to enhance suborbital flight safety and pave the way for future human space exploration endeavors.

Regenerative cooling has been the primary cooling method for every modern launch vehicle engine, except for the Viking: a film-cooled (with ablative throat) N₂O₄ / UH25 engine used on the first stage of the Ariane rockets 2-4. Despite this, film-cooling as a stand-alone cooling method has traditionally been considered insufficient for the high combustion temperatures and long burn times associated with launcher engines. This study explored the feasibility of a solely film-cooled engine at the demonstrator scale (3 kN), as a prototype for a lightweight launcher engine. A wide range of liquid oxygen (LOX)/butane engines were modelled and from this a relationship was determined to predict chamber wall temperature for a given oxidiser-to-fuel ratio (O/F), chamber pressure, and amount of film cooling. Notably, this equation was found to apply to both a 3 kN and a 30 kN engine. Numerical modelling of engine specific impulse (Isp) using this equation then found the conditions yielding optimal engine performance.

Fairing separation is a critical event during a rocket's launch as it generates mechanical shocks that can cause partial or total onboard equipment failure. This study details the experimental results of the fairing separation shock of the launcher RFA ONE and its influence on the supporting structures of RF antennas. Accelerometers were used at multiple points of neighbouring structures to characterise the separation devices' shock during fairing separation tests. Moreover, the shock propagation on different material structures, such as aluminium, carbon fibre, and Viton® elastomer sealant, was investigated. The results showed that the presence of Viton® sealant increased shock transmissibility. Further investigation was conducted to study the influence of applied torque on the separation locks on the shock levels. The study revealed that higher torques lead to increased magnitudes of shock acceleration. Finally, the paper provides recommendations for reducing the shock levels. The experimental results and recommendations presented in this paper provide valuable insights for launcher designers and manufacturers to ensure the safety and reliability of shock-sensitive components during flight.

The fairing is an important element of the rocket as it protects the payload from the external environment during the most aggressive phases of the flight. A test campaign was developed with the aim of qualifying the fairing structure of the RFA One. This test is intended to simulate the quasi-static loads of the most critical phase during flight. A FEA model was developed to identify the most critical phase of flight and to identify the quasi-static reactions that replicate the flight loads. Based on these reactions, the loads and test levels were defined. The test results were compared with the FEA data to correlate and improve the model. The static test was successfully performed at acceptance and qualification Level 2. The load and strain results indicate that the DLL was achieved and exceeded by a factor of 1.11, while the fairing maintained its functionality and key performance. This paper presents the most relevant results of the test, discusses the results compared with the FEA model and summarizes some lessons drawn from the test campaign.

Recent advancements in the field of micro combustor research are growing for achieving high-performance systems in micro power generation and microelectromechanical devices. To mitigate the hazardous emissions from carbon fuels, as an alternative, zero-carbon-free fuels ammonia, and hydrogen are being explored in micro combustion processes. The distinctive feature of a micro combustor lies in its significantly higher area to volume ratio in comparison with traditional combustion systems, leading to accelerated combustion reaction rates. However, the small size of micro combustors poses a challenge in achieving efficient mixing of highly reactive fuels like hydrogen and ammonia with oxidizers. The unique properties of micro combustors can lead to differences in the combustion behavior of hydrogen and ammonia compared to larger-scale combustion systems. Hence, examining the performance of carbon-free fuels in micro combustors is crucial for the advancement of clean energy combustion systems. A numerical investigation on a Y-shaped micro-combustor was carried out to identify the aspects of non-premixed combustion of ammonia/air and hydrogen/air. The findings reveal that in the case of hydrogen combustion, stable flames were reached, even at low equivalence ratios. Therefore, the distinct combustion properties of hydrogen and ammonia result in varying NO_x emissions, with hydrogen generally leading to higher NO_x levels due to its higher flame temperature and increased thermal NO_x production.

Future planetary exploration robots need to improve their autonomy to increase mission safety and efficiency. The presented concept achieves this by introducing the learning and usage of ground interaction models, which allow a more precise modelling of the robot's mobility on different terrains. The idea is that a precise prediction of the expected performance will, on the one hand, allow an early detection of changed conditions and, on the other hand, enable a system to appropriately react on it. By classifying the traversed terrain, a robot gains the possibility to replan its path or to change its locomotion behavior to eventually optimize mission success. The paper provides details, on how the ground interaction models are trained, how the required data is collected, and how they are embedded into a physical simulator to use them online on the system.

On-orbit servicing, assembly and manufacturing (OSAM) opens a new frontier for robotic systems. A gripping tool for such applications must meet several requirements of space mechanics, such as safety, precision and reliability, while functioning in space conditions. This paper presents a development cycle of such tools designed for the assembly of a small satellite antenna on the International Space Station. Two different grippers, driven by a common drive unit, are presented, conforming to a Multi-Purpose-Tool (MPT) for orbital robotic systems and meeting the requirements of a defined OSAM mission. Both design drivers and concepts and specific component selection are described. Proposed mechanical solutions for safe gripping of objects including space tribology aspects are covered. To adapted to operations not foreseen, the grippers and the drive unit can be reconfigured. The tool architecture presented promotes modularity, scalability, reusability and convertibility of designs, thus facilitating rapid integration in similar missions. A test campaign for critical requirements will be in place to ensure reliable performance of the tools for use in the space environment.

In many space activities, existing robotic systems are highly mission-specific and cannot be reused. On the other hand, there are several highly modular system designs, that lack the specialized hardware, yet. The MODKOM (Modular Components as Building Blocks for Application-specific Configurable Space Robots) project, aims to create a toolbox that allows to configure and recombine a robot for certain tasks, out of specialized and standardized building blocks; this also includes commercial off-the-shelf components. Therefore, MODKOM also focuses on providing a software framework to compose and configure such systems. Based on the proposed system modeling, all entities (hard- & software) can be represented, handled, and also be stored to reuse sub-systems. By providing adequate (graphical) user interfaces and thereby lowering the need for manually-typed files, this process is simplified benefiting accessibility to non-experts. First tests in parallel projects show already the reduced necessity for manual configuration work and thus, a decrease in mistakes in formerly error-prone tasks. MODKOM also provides a set of modular hardware building blocks, which will be used in the upcoming final demonstration scenario to evaluate the advances made.

With humankind's aspiration of extraterrestrial inhabitation, the need for robotic support is eminent. To master the emerging challenge of providing astronauts with assistive space robots possessing the required adaptability to new situations and tasks under the constraints of severely limited supply chains in extraterrestrial missions, the utilization of existing hardware to its fullest is required. We propose the combination of a concept with an architecture to jointly support context-aware collaboration between humans and robotic systems for implementing effective resource utilization in space missions. The underlying framework is an implementation of a flexible architecture that enables context awareness for robotic systems. It supports processing nodes for retrieval of context information from the raw sensor values as well as further inferences using the output of nodes. Context information spans across three entities and describes the current state of the environment, the astronaut, and the robot itself. This information then can be used to infer the human's current intention as well as influence the behaviour to be executed next. Additionally, dynamic changes in the data processing chains are handled by the framework to facilitate an adequate adaptation of the system to situational events. We combine this architecture with the concept of space robots as a composition from building blocks, which are supported and made accessible by a software toolkit. The modular design approach enables online self-reconfiguration of robotic hardware and software components. In combination with dynamic mission planning, based on ontological descriptions of available resources and functionalities, robots are able to adapt their physical and computational appearance dynamically during a mission according to different tasks and goals. By incorporating these two developments in a joint deployment we envision raising the efficiency of robotic systems in human-machine interaction through the usage of self-reconfiguration as a reactive behavior in order to adapt to a specific task, recognized or derived from a human's intention. Transfer of the proposed idea back to Earth may help to abate resource dissipation caused by deploying specialized monolithic systems with a narrow range of capabilities through utilizing the adaptivity of reconfigurable robots.

Planetary robots must be extensively tested before they can be sent on a mission. Especially on loose soil, there is a need for tests with repeatable surface and soil properties to simulate the planetary use and to obtain reliable results for each test run. To achieve this, a leveling and loosening mechanism for a robotic test track is presented. By leveling and loosening in one motion, it enables easy and fast test preparation. Bio-inspired bear claws were designed and tested as loosening tools, which allow loosening with minimal resistance and a loosening effect of about 45%. The modular design allows the attachments to be easily interchanged to adapt the mechanism to different requirements or add additional functions like measurements of the soil properties. The paper provides details on the design and evaluation of the leveling and loosening mechanism.

This work aims to analyze the feasibility of utilizing hybrid storage systems to enable the operation of high-power payloads during eclipse periods. The main objective of the study is to reach possible configurations with the same performance as traditional designs, but with reduced mass and/or volume, or to maintain the mass and volume while increasing the peak power capabilities. The proposed solution involves the use of supercapacitors and high-energy lithium-ion cells, with the former serving to meet peak loads and the latter supplying the mean power needs. Additionally, a simple architecture for the electrical power system is proposed, and the sizing equations for the supercapacitors and lithium-ion cells are derived from the governing power and energy balance equations. The results allow well-founded decision-making process on the suitability of the hybrid configuration based on the peak power demand and its duration, as well as the mean power demand during eclipse operations.

Satellites dedicated to remote sensing either for the Earth or space, typically require their instruments to be pointing toward the location of their object of study. These satellites can face significant challenges as different components also have its own pointing requirements to be operative or work optimally. For instance, we have the case of solar panels for electrical power generation, where perfect pointing of the panels toward the Sun can affect negatively to payload operation. Common solutions for maximizing power generation include the usage of orientable solar panels. However, this approach increases the complexity of the satellite, raising the cost of the solar panels and their associated mechanism. In this study, we propose a new approach that enables high-consuming remote sensing payloads to operate for extended periods without using orientable solar panels. To ensure maximum power generation without compromising the satellite's pointing constraints, an optimal tracking law is derived. This law maximizes the projected solar array area at each instant, resulting in maximum electrical power generation. The proposed method is validated against an actual mission scenario. This work offers significant benefits for satellite operators, reducing the need for costly orientable solar panels and enhancing the overall efficiency of satellite missions.

Attitude determination is a fundamental task of the Attitude Determination and Control Subsystem (ADCS). It involves determining the spacecraft's orientation with respect to a reference system and calculating its angular velocity, which is essential for understanding where the payload is pointing and the spacecraft's stability. The determination of the attitude is obtained using sensors such as Sun sensors, Nadir sensors, or Star trackers. Regarding the spacecraft angular velocity, gyroscopes or MEMs can be used to measure the angular velocity of the satellite, but in their absence the velocity can be derived from the attitude data of the other sensors. However, this method requires a sampling rate to be twice the frequency of the movement, otherwise the angular velocity cannot be calculated with traditional methods. To address this issue, this study proposes a thermal analysis of the external temperatures of a rotating satellite to obtain its rotation rate. This method is especially useful for satellites with low or limited data sample rates. The proposed methodology is used in the UPMSat-2 case to demonstrate the functionality of its experimental ADCS.

Stratospheric balloon missions have emerged as a cost-effective alternative to space missions for scientific research and technology development. These missions enable the collection of critical data from the Earth's upper atmosphere while reducing financial and logistical burdens associated with traditional space missions. One key challenge in these missions is the accurate measurement of the relative-to-the-gondola wind speed in the tropopause and the stratosphere. This paper explores the viability of using cup anemometers as wind speed sensors in stratospheric balloon missions, offering an easy-to-calibrate, low-cost, and accurate solution. The present paper provides a short overview of stratospheric balloon missions and their relevance in atmospheric research and outlines the challenges and limitations of existing wind speed sensing technologies. The cup anemometer is also described, detailing its working principle, advantages, and limitations, and propose a methodology for incorporating the instrument into stratospheric balloon missions. To validate the proposed methodology, a stratospheric balloon mission (the Tasec-Lab experiment, onboard a B2Space balloon launched in 2021), was equipped with a cup anemometer whose performance was analyzed. The results prove that cup anemometers can provide accurate and reliable relative wind speed measurements in the tropopause and the stratosphere. Furthermore, the low power consumption and the ease of development and calibration of cup anemometers make them an attractive option for stratospheric balloon missions.

Artificial Intelligence (AI) techniques are being used in general-purpose industrial computing systems. There is a great interest in expanding its use across other types of systems. However, they are not immediately applicable to embedded safety-critical systems. In particular, in spacecrafts, there are subsystems with high integrity requirements, which means that their failure could affect the overall behavior of the vehicle or even the loss of the complete mission. This paper deals with the use of some relevant AI techniques onboard space systems. Machine Learning and Neural Networks are potential techniques for these systems. The objective of this paper is to evaluate its applicability, select the most appropriate tools, and determine its feasibility to place onboard the satellite. Through the analysis of standards proposals, and a thermal estimation use case, we identify the issues, challenges, and guidelines to be considered for the use of AI, specifically machine learning, in UPMSat-3.

We explore the risks associated with uncontrolled space debris re-entry and the implications for airspace management and flight safety. With the increasing number of satellites and other objects being launched into space the potential for uncontrolled re-entry events poses a unique challenge for airspace management and public safety. While there have been no recorded instances of aircraft damage or human injury due to re-entering space debris, the increasing frequency of such events necessitates a comprehensive understanding of the associated risks and appropriate mitigation strategies. We briefly examine the current methods for tracking and predicting space debris re-entry, concentrating on the decision-making process for airspace closures, and the risk assessment for ground airborne safety. Our analysis aims to contribute to the ongoing dialogue on space debris management and to inform future policy and operational decisions in the context of civil aviation and public safety.

One of the main objectives of the European Commission (EC) since the 70s has been to coordinate research policies and to enhance the transnational cooperation in order to reach efficiency in terms of funding and to match with Europe's economic ambitions. It has been addressed through a centralized approach managed by the EC and a decentralized approach through the cooperation of member states. Regarding the aviation sector, the centralized financing has been successfully implemented under the EU Research & Innovation Framework Programmes, while the decentralized approach has been less successful through the initiative Air Transport Net (AirTN) ERA-NET. The intention of this paper is to analyse the AirTN case study and its methodology to launch transnational calls, the results, and the reasons why it was not completely successful. Following the identification of these main barriers, we provide a list of suggestions that could have been implemented for a more successful outcome.