The aviation industry's journey toward sustainability increasingly depends on how air traffic is organised, governed, and digitally transformed. This paper provides a comprehensive assessment of the evolution of air traffic management (ATM) through the lens of environmental performance and innovation strategy, namely the development of communication, navigation, and surveillance (CNS) systems and examines how digital transformation initiatives are redefining efficiency and safety, within environmental sustainability. Using a comparative and integrative approach, the study identifies strategic enablers and bottlenecks in the transition to a network-centric, data-driven 'green ATM'. These include challenges in data interoperability, cybersecurity, and cross-border regulatory alignment. The paper proposes a conceptual framework defining green ATM as a coordinated, global system-of-systems that leverages digital intelligence, policy harmonisation, and multi-stakeholder collaboration to achieve climate-neutral aviation. It concludes that the next competitive advantage in aviation will emerge not from fleet renewal alone but from managerial and policy innovations.
The aviation industry aims to achieve net-zero emissions by 2050, but widespread adoption of hydrogen propulsion is limited by the lack of aviation-specific standards and certification processes. Although numerous hydrogen standards exist, their suitability for aviation safety, certification, and sustainability has not been fully assessed. This study systematically reviews 24 international hydrogen standards and regulations, evaluating their applicability across seven aviation lifecycle stages: fuel quality, storage, fuelling infrastructure, certification, aircraft operation, continuing airworthiness, and end-of-life management. Findings show that most standards focus on early stages, with around 70% coverage for fuel production and quality and 60% for fuelling infrastructure. A key gap is the absence of a dedicated qualification process for hydrogen aviation fuel. Most existing standards originate from road and industrial sectors and require adaptation for aviation. This research provides a comprehensive lifecycle mapping of hydrogen standards for aviation and identifies priority areas for future standardisation efforts.
The increasing number of unmanned aerial vehicles (UAVs) in commercial operations has underscored the need for precise operational safety measures. Within the specific operations risk assessment (SORA) framework, the ground risk buffer (GRB) defines horizontal safety margins to limit harm to people on the ground in loss-of-control scenarios. This study systematically compares two established GRB calculation methods, the SORA 1:1 rule and a simplified ballistic model, using rotary-wing agricultural UAVs (DJI Agras series) across a range of altitudes (10-100 m) and speeds (5-20 m/s). The results demonstrate that horizontal speed is the dominant factor affecting GRB values. The 1:1 approach provides a simple conservative estimate for low-speed missions but becomes restrictive at higher speeds, while the ballistic model remains an idealised approximation needing refinement. The study provides a model-by-model comparison on representative UAV platforms, demonstrating the operational implications and trade-offs of conservative GRB assumptions.
The study presented in this paper compares the performance of active control techniques to mitigate the excited modes of the wing. In particular, a comparison between the optimal static output feedback (SOF) controller and the robust controller is presented in this paper. The purpose of these controllers is to send the optimised feedback signal to the control surface to actively reduce the vibrations and redistribute the aerodynamic loads. The multiple input multiple output (MIMO) state-space is derived by considering the structural properties of the aircraft wing, availability of control surfaces and sensors on the wing. The results are presented in terms of frequency response function (FRF) and power spectral density (PSD) for open and closed loop systems. The deflection of the control surface has also been presented for both controllers. The results have shown that both of the controllers demonstrated considerable attention of the excited modes.
The aviation industry is actively pursuing the '2050 net zero goal' to mitigate petroleum-based fuel consumption and carbon emissions. A promising approach to achieving this target involves the use of sustainable aviation fuels, usage of bio-based materials and the adoption of lightweight components. This study explores the application of additive manufacturing (AM) to produce lightweight polylactide based parts for aircraft cabin interiors, which allows the creation of complex geometries in a cost-effective manner. Although flammability regulations present challenges for polylactide based components, small parts may qualify for exemption. We developed PLA/TPU blends, compatibilised with Joncryl 4468, using a twin-screw extruder and then produced filaments for 3D printing of small components in commercial airplanes. Mechanical and thermal properties of the additively manufactured blend samples were characterised in order to find an optimal formulation. An ecological and economic assessment demonstrated that this blend appears as a highly cost-effective and sustainable alternative.
Understanding the main factors driving urban air mobility (UAM) demand is essential for better planning of operations for this emerging air transport mode in large cities. Using New York City as a case study, this research aims to analyse the geographic distribution of potential UAM passengers by income and demand for air taxi services through exploratory data analysis. The results show that during the initial phase of operations, airport shuttle services connecting high-income and high-demand areas, such as the route between Manhattan and John F. Kennedy International Airport, can serve as a reference for experimental business cases in operational planning. The theoretical and practical implications of this study offer insights for the development of new air transport services and infrastructure in UAM.
Flap deflection monitoring plays a significant role in flight safety of the fixed-wing UAVs. The proposed research lies on a low-cost, lightweight framework with high-fidelity sensing capability of flap aerodynamics using LiDAR. Experimental validation of the system is carried out in a controlled environment in a laboratory where the LiDAR monitors the motion of the flaps by means of a variation in a known flat. It is small, has a wide horizontal FOV which makes it suited to on-board and real-time monitoring. A Python calibration algorithm takes care of the offset bias, sensor tilt, noise, based on distance normalisation, symmetry, outlier removal and smoothing. A post-calibration of the LiDAR data leads to a smoothing and a symmetrical data, which enables a separation of the flap deflection and noise on the sensors. The method will make the UAV safer by recognising faults that can be detected using lightweight and non-redundant sensors.
This review article examines the integration of green technologies in the airline industry, focusing on their categories, developmental status, and prospective trajectories. It delineates four primary domains: sustainable aviation fuels (SAFs), aircraft design and propulsion, cabin and in-flight services, and digital technologies. Hydroprocessed esters and fatty acids - synthetic paraffinic kerosene (HEFA-SPK) and advanced turbofan engines have reached full maturity, whereas alcohol-to-jet-synthetic paraffinic kerosene (ATJ-SPK), the power-to-liquid synthetic paraffinic kerosene (PtL-SPK), hybrid-electric propulsion, and blended wing bodies remain in preliminary development phases. Numerous cabin and digital innovations are presently in broad implementation. Key future priorities include expanding the utilisation of SAFs and advancing hybrid-electric propulsion systems. Overcoming technical, economic, and regulatory challenges will require coordinated efforts to achieve substantial decarbonisation and sustainability.
This paper critically reviews recent advancements in proton exchange membrane fuel cells (PEMFCs) and solid oxide fuel cell (SOFC) technologies for decarbonising aircraft power systems. Using a systematic literature review and comparative analysis, it evaluates technical, economic, and regulatory barriers. Key findings highlight promising innovations such as UCLA's 200,000-hour graphene catalysts, ZeroAvia's 1.5 kW/kg PEMFC, and LH2-powered demonstrators like Airbus ZEROe and H2FLY. Despite progress, challenges remain - low system-level power-to-weight ratios, LH2 storage issues, high costs, and limited hydrogen infrastructure. A phased roadmap is proposed: FC adoption in UAVs/APUs by 2030, regional aircraft by 2040, and larger planes thereafter. The review highlights synergies between hydrogen fuel-cell systems and sustainable aviation fuels (SAFs) - the latter acting as complementary or transitional energy carriers (including drop-in and power-to-liquid e-fuels, and as reformable feedstocks for SOFCs) - and between fuel cells and hybrid architectures (principally fuel-cell-battery hybrids for transient/peak demands and SOFC-gas-turbine hybrids to boost cruise efficiency and system power-density). Its originality lies in synthesising 2024-2025 developments, identifying aerospace-specific trade-offs, and recommending R&D priorities like PGM-free catalysts and cryogenic tank design. Fuel cells show strong potential, but success hinges on green hydrogen expansion and global policy alignment.
Pilot personality traits are among the most critical risk factors contributing to human error in aviation. This study proposes an integrated approach that combines a risk assessment matrix and the analytic hierarchy process (AHP) to prioritise personality traits leading to pilot errors. The proposed framework first identifies unacceptable traits among commercial airline and military pilots and then uses AHP to calculate their relative importance. Findings reveal that for commercial pilots, a lack of self-discipline and rule-consciousness are the most critical traits, while for military pilots, a lack of self-discipline, absence of rule-consciousness, overconfidence, and neuroticism are the dominant traits. The proposed model offers a proactive and systematic method to evaluate pilot personality characteristics, supporting the development of more effective pilot selection and training systems to enhance flight safety.
Unmanned aerial vehicles (UAVs) offer wide operational capability, low environmental impact, and enhanced aerodynamic performance while eliminating pilot risk in military missions; therefore, aerodynamic design optimisation was performed for three different wing configurations in ANSYS Fluent. This study mainly aims to determine the best wingspan that can give the highest CL/CD in different angles of attack. Part of the innovative work of this study was the application of particle swarm and cuckoo search techniques, in modelling CD and CL coefficients obtained from the aerodynamic analysis. These approaches facilitated the creation of the nonlinear predictive models, instead of the traditional computational fluid dynamics (CFD) analysis. Also, the UAV design obtained through optimisation was successfully fabricated, thus confirming the practical relevance of the design. The findings indicate that alternative optimisation techniques would be able to save the computational time and cost considerably without significantly compromising predictive accuracy.
This study adopted the norm activation model (NAM) to investigate the factors influencing air passengers' intentions to purchase the airline's voluntary carbon offsetting (VCO) products. This study explores the role of subjective norms, perceived consumer effectiveness, and serial mediation of the NAM's mechanism, which receives less attention in aviation studies. To do that, 410 airline passengers were surveyed, and structural equation modelling (SEM) was utilised to analyse the activation mechanism between various NAM factors. The findings supported all hypotheses initially posited by the NAM, including the significant impact of subjective norms and perceived consumer effectiveness on VOC purchase intention. Importantly, the study found that subjective norms are critical in shaping personal norms. Moreover, by testing serial mediation, this study supports the norm activation mechanism proposed by the original NAM. Such findings are important to airline managers in setting their VCO policies and providing insights for the passengers regarding future travels.
Global navigation satellite systems (GNSS) are critical for both military and civil aviation, yet their susceptibility to jamming and spoofing poses significant threats to reliable navigation. This paper explores and quantitatively evaluates a centralised error-state Kalman filter (EKF) approach using range-only inter-UAV measurements for cooperative navigation of unmanned aerial vehicle (UAV) fleets operating in GPS-denied environments. The centralised ES-EKF leverages inter-UAV correlations by aggregating data from all UAVs in a central unit, enabling accurate state estimation even when multiple UAVs lose GPS access. Through simulations involving six UAVs with systematically varied GPS availability (from three down to a single GPS-enabled UAV), we demonstrate that the centralised ES-EKF significantly reduces navigation uncertainty and maintains mission integrity by utilising collaborative measurements. Scenarios where up to five UAVs experience GPS jamming illustrate the algorithm's capability to sustain accurate positioning through cooperative data fusion, provided at least one UAV retains GPS functionality. This analysis provides clear performance benchmarks for such a configuration. While centralised ES-EKF offers superior performance in capturing inter-agent correlations, it also presents challenges related to computational load, scalability, and communication reliability in large networks. Therefore, this study established a baseline for future decentralised localisation works.
