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Aerospace
Volume 13
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Aerospace, Volume 13, Issue 1 (January 2026) – 110 articles

Cover Story (view full-size image): Advances in additive manufacturing are enabling a new generation of aerospike engines, and Pangea Propulsion’s Demo P1 demonstrator showcases how these innovations can overcome long-standing cooling and manufacturability challenges. Building on this progress, our study evaluates the altitude-adaptive behaviour of the truncated aerospike geometry through CFD simulations and introduces a simplified method to estimate its upper bound on base thrust performance, supporting the wider resurgence of aerospike propulsion. View this paper
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22 pages, 3110 KB  
Article
Data-Driven Predictive Maintenance for Aircraft Components Through Sparse Event Logs
by Fulin Sezenoğlu Çetin, Ufuk Üngör, Emre Koyuncu and İbrahim Özkol
Aerospace 2026, 13(1), 110; https://doi.org/10.3390/aerospace13010110 - 22 Jan 2026
Viewed by 298
Abstract
Effective predictive maintenance is crucial for ensuring aircraft reliability, reducing operational disruptions, and supporting spare part inventory management in airline operations. However, maintenance data is often sparse, with irregular observations, missing records, and imbalanced failure distributions, making accurate forecasting a significant challenge. This [...] Read more.
Effective predictive maintenance is crucial for ensuring aircraft reliability, reducing operational disruptions, and supporting spare part inventory management in airline operations. However, maintenance data is often sparse, with irregular observations, missing records, and imbalanced failure distributions, making accurate forecasting a significant challenge. This study proposes a data-driven framework for maintenance prediction under sparse observational data. We implement and compare two distinct methodologies: survival analysis via DeepHit for time-to-event prediction, and a latent space classifier with autoencoder backbone. Each method is evaluated on historical aircraft maintenance logs and component installation records, addressing challenges posed by limited and imbalanced datasets. Both models are trained and tested on ten years of maintenance logs and component installation records sourced from an airline MRO (Maintenance, Repair and Overhaul) company that services a fleet of more than 500 aircraft, offering a realistic and scalable setting for fleet-wide maintenance analysis. The latent space classifier demonstrates superior overall performance and consistency across diverse components and prediction horizons compared to DeepHit, which is constrained by its sensitivity to probability thresholds. The encoder-based method effectively transfers knowledge from high-data components to those with sparse maintenance histories, enabling reliable maintenance forecasting and enhanced inventory planning for large-scale airline operations. Full article
(This article belongs to the Collection Air Transportation—Operations and Management)
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19 pages, 772 KB  
Article
Throughput and Capacity Analysis of a Vertiport with Taxing and Parking Levels
by Samiksha Rajkumar Nagrare and Teemu Joonas Lieb
Aerospace 2026, 13(1), 109; https://doi.org/10.3390/aerospace13010109 - 22 Jan 2026
Viewed by 222
Abstract
Amidst the increasing aerial traffic and road traffic congestion, Urban Air Mobility (UAM) has emerged as a new mode of aerial transport offering less travel time and ease of portability. A critical factor in reducing travel time is the emerging electric Vertical Take-Off [...] Read more.
Amidst the increasing aerial traffic and road traffic congestion, Urban Air Mobility (UAM) has emerged as a new mode of aerial transport offering less travel time and ease of portability. A critical factor in reducing travel time is the emerging electric Vertical Take-Off and Landing (eVTOL) vehicles, which require infrastructure such as vertiports to operate smoothly. However, the dynamics of vertiport operations, particularly the integration of battery charging facilities, remain relatively unexplored. This work aims to bridge this gap by delving into vertiport management by utilizing separate taxing and parking levels. The study also focuses on the time eVTOLs spend at the vertiport to anticipate potential delays. This factor helps optimise arrival and departure times via a scheduling strategy that accounts for hourly demand fluctuations. The simulation results, conducted with hourly demand, underscore the significant impact of battery charging on operational time while also highlighting the role of parking spots in augmenting capacity and facilitating more efficient scheduling. Full article
(This article belongs to the Special Issue Operational Requirements for Urban Air Traffic Management)
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45 pages, 1326 KB  
Article
Cross-Domain Deep Reinforcement Learning for Real-Time Resource Allocation in Transportation Hubs: From Airport Gates to Seaport Berths
by Zihao Zhang, Qingwei Zhong, Weijun Pan, Yi Ai and Qian Wang
Aerospace 2026, 13(1), 108; https://doi.org/10.3390/aerospace13010108 - 22 Jan 2026
Viewed by 181
Abstract
Efficient resource allocation is critical for transportation hub operations, yet current scheduling systems require substantial domain-specific customization when deployed across different facilities. This paper presents a domain-adaptive deep reinforcement learning (DADRL) framework that learns transferable optimization policies for dynamic resource allocation across structurally [...] Read more.
Efficient resource allocation is critical for transportation hub operations, yet current scheduling systems require substantial domain-specific customization when deployed across different facilities. This paper presents a domain-adaptive deep reinforcement learning (DADRL) framework that learns transferable optimization policies for dynamic resource allocation across structurally similar transportation scheduling problems. The framework integrates dual-level heterogeneous graph attention networks for separating constraint topology from domain-specific features, hypergraph-based constraint modeling for capturing high-order dependencies, and hierarchical policy decomposition that reduces computational complexity from O(mnT) to O(m+n+T). Evaluated on realistic simulators modeling airport gate assignment (Singapore Changi: 50 gates, 300–400 daily flights) and seaport berth allocation (Singapore Port: 40 berths, 80–120 daily vessels), DADRL achieves 87.3% resource utilization in airport operations and 86.3% in port operations, outperforming commercial solvers under strict real-time constraints (Gurobi-MIP with 300 s time limit: 85.1%) while operating 270 times faster (1.1 s versus 298 s per instance). Given unlimited time, Gurobi achieves provably optimal solutions, but DADRL reaches 98.7% of this optimum in 1.1 s, making it suitable for time-critical operational scenarios where exact solvers are computationally infeasible. Critically, policies trained exclusively on airport scenarios retain 92.4% performance when applied to ports without retraining, requiring only 800 adaptation steps compared to 13,200 for domain-specific training. The framework maintains 86.2% performance under operational disruptions and scales to problems three times larger than training instances with only 7% degradation. These results demonstrate that learned optimization principles can generalize across transportation scheduling problems sharing common constraint structures, enabling rapid deployment of AI-based scheduling systems across multi-modal transportation networks with minimal customization and reduced implementation costs. Full article
(This article belongs to the Special Issue Emerging Trends in Air Traffic Flow and Airport Operations Control)
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16 pages, 2564 KB  
Article
Dynamic Analysis of the Rod-Traction System for Ship-Borne Aircraft Under High Sea States
by Guofang Nan, Chen Zhang, Bodong Zhang, Sirui Yang and Jinrui Hu
Aerospace 2026, 13(1), 107; https://doi.org/10.3390/aerospace13010107 - 22 Jan 2026
Viewed by 132
Abstract
The transfer of aircraft on deck relies on the traction system, which is easily affected by the offshore environment. Violent ship motion in the complex marine environment poses a great threat to the aircraft traction process, such as the tire sideslip, off-ground phenomena, [...] Read more.
The transfer of aircraft on deck relies on the traction system, which is easily affected by the offshore environment. Violent ship motion in the complex marine environment poses a great threat to the aircraft traction process, such as the tire sideslip, off-ground phenomena, the aircraft overturning, traction rod fatigue fracture, and so on. Therefore, it has merits in both academia and engineering practice to study the dynamic behaviors of the ship-borne aircraft towing system under high sea states. Considering the intricate coupling motions of the hull roll, pitch, and heave, the dynamic analysis of the towing system with rod are carried out based on the multibody dynamics theory. The influence of the sea state level and the traction speed on the dynamic characteristics of the towing system is investigated. The results indicate that noticeable tire sideslip occurs under sea state 3, with the peak lateral tire force increasing by approximately 250% compared with sea state 2. Under sea state 4, intermittent off-ground phenomena are observed, accompanied by a further increase of about 22% in lateral tire force. These findings provide quantitative insights into the dynamic characteristics and operational limits of rod-traction systems for ship-borne aircraft in rough marine environments. Full article
(This article belongs to the Section Aeronautics)
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15 pages, 5355 KB  
Article
High-Energy Detonation Based Lunar Regolith Simulation for Resource Utilization
by Junyue Tang, Antong Zhao, Shengyuan Jiang, Yang Li, Yu Li, Yi Yang, Zongquan Deng, Xi Wang, Xiangrun Zhao and Tifei Han
Aerospace 2026, 13(1), 106; https://doi.org/10.3390/aerospace13010106 - 22 Jan 2026
Viewed by 175
Abstract
As international lunar exploration shifts from mainly understanding the Moon to equally prioritizing its utilization, the requirement for highly similar lunar regolith simulants has grown. Current simulants, produced mainly by mechanical crushing and sieving, reproduce mechanical properties but lack space-weathered microstructures. However, this [...] Read more.
As international lunar exploration shifts from mainly understanding the Moon to equally prioritizing its utilization, the requirement for highly similar lunar regolith simulants has grown. Current simulants, produced mainly by mechanical crushing and sieving, reproduce mechanical properties but lack space-weathered microstructures. However, this absence results in significant discrepancies in critical properties such as thermal conductivity and adsorption–desorption behavior, which undermine the reliability of ground-based resource utilization tests. To address this issue, this paper proposes a new preparation method for lunar regolith simulants, which simulates the micrometeorite impact process by utilizing the instantaneous high temperature, pressure, and high-velocity impact generated from the detonation of high-energy explosives in a sealed container. Preliminary experiments confirm that the method produces agglutinates, glass spherules, and porous structures resembling those in lunar regolith. The thermal conductivity of the modified simulant decreases significantly, approaching that of lunar regolith. Further refinement of the process, supported by quantitative 3D characterization, will enable the production of even more similar simulants, providing a reliable material foundation for lunar exploration, in situ resource utilization, and lunar construction activities. Full article
(This article belongs to the Special Issue Lunar Construction)
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17 pages, 2940 KB  
Article
Loss-Driven Design Methodology for MHz-Class GaN QSW Buck Converters with a PCB Air-Core Inductor in SWaP-Constrained Aerospace Applications
by Jinshu Lin, Hui Li, Shan Yin, Xi Liu, Chen Song, Honglang Zhang and Minghai Dong
Aerospace 2026, 13(1), 105; https://doi.org/10.3390/aerospace13010105 - 21 Jan 2026
Viewed by 172
Abstract
Aerospace power systems, including satellites in low earth orbit (LEO) and geostationary earth orbit (GEO), face stringent thermal constraints to minimize size, weight, and power (SWaP). Gallium nitride (GaN) devices offer superior radiation hardness—critical for the harsh space environment—and MHz-level switching capabilities. This [...] Read more.
Aerospace power systems, including satellites in low earth orbit (LEO) and geostationary earth orbit (GEO), face stringent thermal constraints to minimize size, weight, and power (SWaP). Gallium nitride (GaN) devices offer superior radiation hardness—critical for the harsh space environment—and MHz-level switching capabilities. This high-frequency operation minimizes passive components, particularly magnetics, thereby reducing the overall volume. However, above 10 MHz, magnetic cores become impractical due to material limitations. To address these issues, this article proposes a design methodology for a GaN-based quasi-square-wave (QSW) buck converter integrated with a PCB air-core inductor. First, the impact of the switching frequency and dead time on the zero-voltage switching (ZVS) condition is elaborated. Then, a power loss model accounting for various loss mechanisms is presented. To overcome high GaN body diode reverse conduction loss, an auxiliary diode is employed. Based on the model, a design procedure is developed to optimize the inductor for 10 MHz operation while maximizing efficiency. To validate the design, a 28 V/12 V, 18 W prototype was built and tested. Experimental results demonstrate a peak efficiency of 86.5% at 10 MHz. The auxiliary diode improves efficiency by 4%, verifying reverse conduction loss mitigation. Thermal analysis confirms a full-load case temperature of 62.2 °C, providing a 47.8 °C safety margin compliant with aerospace derating standards. These findings validate the solution for high-frequency, space-constrained aerospace applications. Full article
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21 pages, 746 KB  
Review
Nitrous Oxide-Hydrocarbon Liquid Propellants for Space Propulsion: Premixed and Non-Premixed Systems
by Eunwoo Jung, Eun Sang Jung and Minwoo Lee
Aerospace 2026, 13(1), 104; https://doi.org/10.3390/aerospace13010104 - 21 Jan 2026
Viewed by 335
Abstract
Nitrous oxide (N2O) has attracted increasing attention as an oxidizer for space propulsion systems due to its non-toxic nature and favorable handling characteristics. Its relatively high vapor pressure allows self-pressurization, while its wide storage temperature range makes it attractive for a [...] Read more.
Nitrous oxide (N2O) has attracted increasing attention as an oxidizer for space propulsion systems due to its non-toxic nature and favorable handling characteristics. Its relatively high vapor pressure allows self-pressurization, while its wide storage temperature range makes it attractive for a range of space applications. In parallel with broader efforts to identify alternatives to conventional toxic propellants, numerous studies have investigated liquid propulsion systems based on N2O combined with hydrocarbon fuels, spanning both premixed fuel blends and non-premixed bipropellant configurations. This review summarizes experimental and system-level studies on N2O–hydrocarbon propellant combinations, including ethylene, ethane, ethanol, propane, acetylene, methane, dimethyl ether, and propylene. Results reported by different research groups reveal clear differences among propellant combinations in terms of vapor pressure, thermal stability, chemical reactivity, and ignition delay. These differences have direct implications for injector design, mixing strategies, ignition mechanism, and system safety. By bringing together recent results from the literature, this paper aims to clarify the practical trade-offs associated with fuel selection in N2O-based premixed and bipropellant systems and to provide a useful reference for the design and development of future space propulsion concepts. Full article
(This article belongs to the Section Astronautics & Space Science)
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22 pages, 8359 KB  
Article
Unsteady Aerodynamics of Continuously Morphing Airfoils from Transonic to Hypersonic Regimes
by Linyi Zhi, Renqing Zhai, Yu Yang, Xintong Shi and Zhigang Wang
Aerospace 2026, 13(1), 103; https://doi.org/10.3390/aerospace13010103 - 21 Jan 2026
Viewed by 237
Abstract
Designing high-speed aircraft for wide-speed-range operation remains a major aerodynamic challenge. This study investigates the unsteady aerodynamics of a continuously morphing airfoil from transonic to hypersonic regimes. A smooth morphing trajectory is constructed among transonic, supersonic, and hypersonic baseline shapes, and analyzed via [...] Read more.
Designing high-speed aircraft for wide-speed-range operation remains a major aerodynamic challenge. This study investigates the unsteady aerodynamics of a continuously morphing airfoil from transonic to hypersonic regimes. A smooth morphing trajectory is constructed among transonic, supersonic, and hypersonic baseline shapes, and analyzed via high-fidelity unsteady Reynolds-averaged Navier–Stokes (URANS) simulations with a radial basis function (RBF) dynamic mesh. Two processes are examined: pure geometric morphing at fixed Mach numbers (Ma), and morphing coupled with flight acceleration. Key findings reveal two distinct adaptation features: (1) Transonic flow is highly sensitive to morphing (28.8% drop in lift-to-drag ratio), while supersonic flow is robust (<5% variation). (2) During coupled acceleration, the flow transitions smoothly—the shock evolves from a detached bow wave to an attached oblique structure, and the adaptive airfoil maintains a lift-to-drag ratio above 4 across Ma = 0.8–6. Additionally, wake vorticity transitions from organized shear layers to multi-scale clusters. These results elucidate the flow physics mechanism of continuous morphing and provide a framework for designing adaptive wide-speed-range aircraft. Full article
(This article belongs to the Special Issue Aerodynamic Analysis of a High-Speed Aircraft: From Hypersonic Down to Subsonic Speeds)
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26 pages, 15170 KB  
Article
Numerical Investigation of Recirculation Bubble Dynamics in Extremely Under-Expanded Jet Impingement with Non-Uniform Inflow Conditions
by Zixi Zhao, Ruiyang Xu and Guosheng He
Aerospace 2026, 13(1), 102; https://doi.org/10.3390/aerospace13010102 - 21 Jan 2026
Viewed by 159
Abstract
During lunar landing and takeoff, an extremely under-expanded jet from retrorocket engines generates a complex impingement flow, including multiple shocks and a near-field recirculation bubble, posing critical risks to lunar missions. To clarify the formation and evolution of the recirculation bubble, numerical simulations [...] Read more.
During lunar landing and takeoff, an extremely under-expanded jet from retrorocket engines generates a complex impingement flow, including multiple shocks and a near-field recirculation bubble, posing critical risks to lunar missions. To clarify the formation and evolution of the recirculation bubble, numerical simulations under non-uniform inflow conditions over a range of nozzle heights are performed using a compressible Navier–Stokes solver. The shock structures depend on the distance available for inflow development. Non-uniform total pressure ahead of the surface shock is the primary driver of the adverse pressure gradient that initiates the bubble. This non-uniformity originates from shock interactions at high nozzle heights and directly from the inflow conditions at low heights. Furthermore, the flow stabilizes rapidly at high nozzle heights, while strong unsteadiness persists at low heights. A dimensionless coefficient, CRB, defined as the ratio of pressure difference to dynamic pressure along the recirculation bubble boundary, is proposed to characterize the interaction between the recirculation bubble and surface shock. Its steady-state variation with nozzle height reveals a distinct threshold below which both bubble size and intensity increase sharply, indicating a flow pattern transition. Full article
(This article belongs to the Section Astronautics & Space Science)
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16 pages, 7955 KB  
Article
Measurement and Adjustment of the Membrane Reflector Antenna Surface Considering the Influence of Gravity
by Yongzhen Gu, Mengtian Wang and Haoxin Wang
Aerospace 2026, 13(1), 99; https://doi.org/10.3390/aerospace13010099 - 20 Jan 2026
Viewed by 208
Abstract
Accurately characterizing the structural state of membrane reflector antennas (MRA) remains challenging due to the difficulty in determining stress distribution through geometric measurement alone. Although photogrammetry provides high-precision geometric data, it falls short of capturing mechanical pre-tension and is notably influenced by gravity, [...] Read more.
Accurately characterizing the structural state of membrane reflector antennas (MRA) remains challenging due to the difficulty in determining stress distribution through geometric measurement alone. Although photogrammetry provides high-precision geometric data, it falls short of capturing mechanical pre-tension and is notably influenced by gravity, which limits its utility in guiding surface accuracy adjustments. This paper proposed an integrated approach combining photogrammetry with a nonlinear finite element method (NFEM) to achieve high-fidelity imaging and effective shape adjustment of electrostatically formed MRA, explicitly accounting for gravity effects during ground-based measurement and shape control. The proposed method establishes a mechanical model that incorporates real-world geometric data under gravity and performs force–shape matching to reconcile discrepancies between physical and simulation models. Experimental validation demonstrates that the gravity-corrected NFEM model closely aligns with the physical antenna, with a deviation in surface accuracy within 9.9%. Using this refined model, we successfully optimized electrode voltages and cable tensions, improving the surface accuracy of the physical model from an initial 0.7033 mm to 0.5723 mm. This work provides a reliable and efficient strategy for the shape control and adjustment of membrane space structures under gravity, with potential applications in large deployable antennas, solar sails, and other tension-controlled flexible systems. Full article
(This article belongs to the Section Astronautics & Space Science)
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22 pages, 3108 KB  
Article
Cell-Based Optimization of Air Traffic Control Sector Boundaries Using Traffic Complexity
by César Gómez Arnaldo, José María Arroyo López, Raquel Delgado-Aguilera Jurado, María Zamarreño Suárez, Javier Alberto Pérez Castán and Francisco Pérez Moreno
Aerospace 2026, 13(1), 101; https://doi.org/10.3390/aerospace13010101 - 20 Jan 2026
Viewed by 151
Abstract
The increasing demand for air travel has intensified the need for more efficient air traffic management (ATM) solutions. One of the key challenges in this domain is the optimal sectorization of airspace to ensure balanced controller workload and operational efficiency. Traditional airspace sectors, [...] Read more.
The increasing demand for air travel has intensified the need for more efficient air traffic management (ATM) solutions. One of the key challenges in this domain is the optimal sectorization of airspace to ensure balanced controller workload and operational efficiency. Traditional airspace sectors, typically static and based on historical flow patterns, often fail to adapt to evolving traffic complexity, resulting in imbalanced workload distribution and reduced system performance. This study introduces a novel methodology for optimizing ATC sector geometries based on air traffic complexity indicators, aiming to enhance the balance of operational workload across sectors. The proposed optimization is formulated in the horizontal plane using a two-dimensional cell-based airspace representation. A graph-partitioning optimization model with spatial and operational constraints is applied, along with a refinement step using adjacent-cell pairs to improve geometric coherence. Tested on real data from Madrid North ACC, the model achieved significant complexity balancing while preserving sector shapes in a real-world case study based on a Spanish ACC. This work provides a methodological basis to support static and dynamic airspace design and has the potential to enhance ATC efficiency through data-driven optimization. Full article
(This article belongs to the Special Issue AI, Machine Learning and Automation for Air Traffic Control (ATC))
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16 pages, 2082 KB  
Article
Adaptive Robust Cubature Filtering-Based Autonomous Navigation for Cislunar Spacecraft Using Inter-Satellite Ranging and Angle Data
by Jun Xu, Xin Ma and Xiao Chen
Aerospace 2026, 13(1), 100; https://doi.org/10.3390/aerospace13010100 - 20 Jan 2026
Viewed by 172
Abstract
The Linked Autonomous Interplanetary Satellite Orbit Navigation (LiAISON) technique enables cislunar spacecraft to obtain accurate position and velocity information, allowing full state estimation of two vehicles using only inter-satellite range (ISR) measurements when both their dynamical states are unknown. However, its stand-alone use [...] Read more.
The Linked Autonomous Interplanetary Satellite Orbit Navigation (LiAISON) technique enables cislunar spacecraft to obtain accurate position and velocity information, allowing full state estimation of two vehicles using only inter-satellite range (ISR) measurements when both their dynamical states are unknown. However, its stand-alone use leads to significantly increased orbit determination errors when the orbital planes of the two spacecraft are nearly coplanar, and is characterized by long initial convergence times and slow recovery following dynamical disturbances. To mitigate these issues, this study introduces an integrated navigation method that augments inter-satellite range measurements with line-of-sight vector angles relative to background stars. Additionally, an enhanced Adaptive Robust Cubature Kalman Filter (ARCKF) incorporating a chi-square test-based adaptive forgetting factor (AFF-ARCKF) is developed. This algorithm performs adaptive estimation of both process and measurement noise covariance matrices, improving convergence speed and accuracy while effectively suppressing the influence of measurement outliers. Numerical simulations involving spacecraft in Earth–Moon L4 planar orbits and distant retrograde orbits (DRO) confirm that the proposed method significantly enhances system observability under near-coplanar conditions. Comparative evaluations demonstrate that AFF-ARCKF achieves faster convergence compared to the standard ARCKF. Further analysis examining the effects of initial state errors and varying initial forgetting factors clarifies the operational boundaries and practical applicability of the proposed algorithm. Full article
(This article belongs to the Special Issue Space Navigation and Control Technologies (2nd Edition))
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20 pages, 6615 KB  
Article
Numerical Analysis of Shock Control Bumps for Delaying Transonic Buffet Boundary on a Swept Wing
by Shenghua Zhang, Feng Deng and Zao Ni
Aerospace 2026, 13(1), 98; https://doi.org/10.3390/aerospace13010098 - 19 Jan 2026
Viewed by 190
Abstract
Transonic shock buffet is a complex flow phenomenon characterized by self-sustained shock oscillations, which severely limits the flight envelope of modern civil aircraft. While Shock Control Bumps (SCBs) have been widely studied for drag reduction, their potential for delaying the buffet boundary on [...] Read more.
Transonic shock buffet is a complex flow phenomenon characterized by self-sustained shock oscillations, which severely limits the flight envelope of modern civil aircraft. While Shock Control Bumps (SCBs) have been widely studied for drag reduction, their potential for delaying the buffet boundary on swept wings has yet to be fully explored. This study employs numerical analysis to investigate the efficacy of three-dimensional (3D) contour SCBs in delaying the buffet boundary of the NASA Common Research Model (CRM) wing. The buffet boundary is identified using both the lift-curve slope change and trailing-edge pressure divergence criteria. The results reveal that 3D SCBs generate streamwise vortices that energize the boundary layer, thereby not only weakening local shock strength but, more critically, suppressing the spanwise expansion of shock-induced separation. Collectively, the reduction in shock strength and the containment of spanwise separation delay the buffet boundary, thereby improving the aerodynamic efficiency of the wing. Two configurations, designed at different lift conditions (SCB-L at CL=0.460 and SCB-H at CL=0.507), demonstrate a trade-off between buffet delay and off-design drag reduction. The SCB-H configuration achieves a buffet boundary lift coefficient improvement of 6.3% but exhibits limited drag reduction at lower angles of attack, whereas the SCB-L offers a balanced improvement of 4.0%, with a broader effective drag-reduction range. These results demonstrate that effective suppression of spanwise flow is key to delaying swept-wing buffet and establish a solid reference framework for the buffet-oriented design of SCBs. Full article
(This article belongs to the Special Issue Advancing Fluid Dynamics in Aerospace Applications)
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27 pages, 13508 KB  
Article
Investigating XR Pilot Training Through Gaze Behavior Analysis Using Sensor Technology
by Aleksandar Knežević, Branimir Krstić, Aleksandar Bukvić, Dalibor Petrović and Boško Rašuo
Aerospace 2026, 13(1), 97; https://doi.org/10.3390/aerospace13010097 - 16 Jan 2026
Viewed by 417
Abstract
This research aims to characterize extended reality flight trainers and to provide a detailed account of the sensors employed to collect data essential for qualitative task performance analysis, with a particular focus on gaze behavior within the extended reality environment. A comparative study [...] Read more.
This research aims to characterize extended reality flight trainers and to provide a detailed account of the sensors employed to collect data essential for qualitative task performance analysis, with a particular focus on gaze behavior within the extended reality environment. A comparative study was conducted to evaluate the effectiveness of an extended reality environment relative to traditional flight simulators. Eight flight instructor candidates, advanced pilots with comparable flight-hour experience, were divided into four groups based on airplane or helicopter type and cockpit configuration (analog or digital). In the traditional simulator, fixation numbers, dwell time percentages, revisit numbers, and revisit time percentages were recorded, while in the extended reality environment, the following metrics were analyzed: fixation numbers and durations, saccade numbers and durations, smooth pursuits and durations, and number of blinks. These eye-tracking parameters were evaluated alongside flight performance metrics across all trials. Each scenario involved a takeoff and initial climb task within the traffic pattern of a fixed-wing aircraft. Despite the diversity of pilot groups, no statistically significant differences were observed in either flight performance or gaze behavior metrics between the two environments. Moreover, differences identified between certain pilot groups within one scenario were consistently observed in another, indicating the sensitivity of the proposed evaluation procedure. The enhanced realism and validated effectiveness are therefore crucial for establishing standards that support the formal adoption of extended reality technologies in pilot training programs. Integrating this digital space significantly enhances the overall training experience and provides a higher level of simulation fidelity for next-generation cadet training. Full article
(This article belongs to the Special Issue New Trends in Aviation Development 2024–2025)
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25 pages, 5117 KB  
Article
Multidisciplinary Design Optimization for the Conceptual Design of Supersonic Civil Aircraft Based on Full-Carpet Sonic Boom/Aerodynamic Characteristics Employing Differential Evolution
by Yuyu Duan, Chonweng Wan, Runze Li and Haixin Chen
Aerospace 2026, 13(1), 96; https://doi.org/10.3390/aerospace13010096 - 15 Jan 2026
Viewed by 308
Abstract
Reducing the sonic boom intensity and increasing the cruise lift-to-drag ratio are pivotal technologies for the successful development of supersonic civil aircraft. To address the limitation that sonic boom research primarily focuses on characteristics directly beneath the flight track, a full-carpet sonic boom [...] Read more.
Reducing the sonic boom intensity and increasing the cruise lift-to-drag ratio are pivotal technologies for the successful development of supersonic civil aircraft. To address the limitation that sonic boom research primarily focuses on characteristics directly beneath the flight track, a full-carpet sonic boom and aerodynamic characteristics prediction software (AERO-BOOM) was independently developed. This software is based on the Panel Method, Modified Linearized Theory, the Waveform Parameter Method, and the Stevens Perceived Noise Evaluation Method. AERO-BOOM can efficiently assess the lift-to-drag ratio and the full-carpet sonic boom characteristics of supersonic civil aircraft. Building upon this software, a Multidisciplinary Optimization design platform for full-carpet sonic boom and aerodynamic characteristics of supersonic civil aircraft was established, utilizing an in-house hybrid surrogate-aided differential evolution optimization algorithm. For a supersonic civil aircraft, both fuselage optimization and overall aircraft optimization were conducted. The optimization objectives were the lift-to-drag ratio and the full-carpet sonic boom loudness (FBL). The optimization results demonstrate that fuselage optimization (e.g., employing a downward-cambered nose) increased the lift-to-drag ratio by 0.26 and reduced the FBL by 0.62 PLdB. Furthermore, the overall aircraft optimization (involving modifications to the wing planform and increasing the tail sweep angle) yielded a 1.51 increase in the lift-to-drag ratio and a 1.09 PLdB reduction in the FBL. Full article
(This article belongs to the Special Issue Aircraft Conceptual Design: Tools, Processes and Examples)
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27 pages, 2279 KB  
Article
Sustainability-Driven Design Optimization of Aircraft Parts Using Mathematical Modeling
by Aikaterini Anagnostopoulou, Dimitris Sotiropoulos, Ioannis Sioutis and Konstantinos Tserpes
Aerospace 2026, 13(1), 95; https://doi.org/10.3390/aerospace13010095 - 15 Jan 2026
Viewed by 274
Abstract
The design of aircraft components is a complex process that must simultaneously account for environmental impact, manufacturability, cost and structural performance to meet modern regulatory requirements and sustainability objectives. When these factors are integrated from the early design stages, the approach transcends traditional [...] Read more.
The design of aircraft components is a complex process that must simultaneously account for environmental impact, manufacturability, cost and structural performance to meet modern regulatory requirements and sustainability objectives. When these factors are integrated from the early design stages, the approach transcends traditional eco-design and becomes a genuinely sustainability-oriented design methodology. This study proposes a sustainability-driven design framework for aircraft components and demonstrates its application to a fuselage panel consisting of a curved skin, four frames, seven stringers, and twenty-four clips. The design variables investigated include the material selection, joining methods, and subcomponent thicknesses. The design space is constructed through a combinatorial generation process coupled with compatibility and feasibility constraints. Sustainability criteria are evaluated using a combination of parametric Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) regression models, parametric Finite Element Analysis (FEA), and Random Forest surrogate modeling trained on a stratified set of simulation results. Two methodological pathways are introduced: 1. Cluster-based optimization, involving customized clustering followed by multi-criteria decision-making (MCDM) within each cluster. 2. Global optimization, performed across the full decision matrix using Pareto front analysis and MCDM techniques. A stability analysis of five objective-weighting methods and four normalization techniques is conducted to identify the most robust methodological configuration. The results—based on a full cradle-to-grave assessment that includes the use phase over a 30-year A319 aircraft operational lifetime—show that the thermoplastic CFRP panel joined by welding emerges as the most sustainable design alternative. Full article
(This article belongs to the Special Issue Composite Materials and Aircraft Structural Design)
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19 pages, 5793 KB  
Article
Computational Study of Hybrid Propeller Configurations
by Mingtai Chen, Tianming Liu, Jack Edwards and Tiegang Fang
Aerospace 2026, 13(1), 94; https://doi.org/10.3390/aerospace13010094 - 15 Jan 2026
Viewed by 281
Abstract
This study presents the first computational investigation of hybrid propeller configurations that combine toroidal and conventional blade geometries. Using Delayed Detached Eddy Simulation (DDES) with the Shear Stress Transport (SST) k−ω model for flow analysis and the Ffowcs Williams and Hawkings [...] Read more.
This study presents the first computational investigation of hybrid propeller configurations that combine toroidal and conventional blade geometries. Using Delayed Detached Eddy Simulation (DDES) with the Shear Stress Transport (SST) k−ω model for flow analysis and the Ffowcs Williams and Hawkings (FW–H) formulation for aeroacoustic prediction, five hybrid propeller designs were evaluated: a baseline model and four variants with modified loop-element spacing. The results show that the V-Gap-S configuration achieves the highest figure of merit (FM), producing over 10% improvement in propeller performance relative to the baseline, while also exhibiting the lowest turbulence kinetic energy (TKE) levels across multiple radial planes. Aeroacoustic analysis reveals quadrupole-like directivity for primary tonal noise, primarily driven by blade tip–vortex interactions, with primary tonal noise strongly correlated with thrust. Broadband noise and overall sound pressure level (OASPL) exhibited dipole-like patterns, influenced by propeller torque and FM, respectively. Comparisons of surface pressure, vorticity, and time derivatives of acoustic pressure further elucidate the mechanisms linking blade spacing to aerodynamic loading and noise generation. The results demonstrate that aerodynamic performance and aeroacoustics are strongly coupled and that meaningful noise reduction claims require performance conditions to be matched. Full article
(This article belongs to the Section Aeronautics)
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21 pages, 1065 KB  
Article
GC-ViT: Graph Convolution-Augmented Vision Transformer for Pilot G-LOC Detection Through AU Correlation Learning
by Bohuai Zhang, Zhenchi Xu and Xuan Li
Aerospace 2026, 13(1), 93; https://doi.org/10.3390/aerospace13010093 - 15 Jan 2026
Viewed by 179
Abstract
Prolonged +Gz acceleration during high-performance flight exposes pilots to the risk of G-induced loss of consciousness (G-LOC), a dangerous condition that compromises operational safety. To enable early detection without intrusive sensors, we present a vision-based warning system that analyzes facial action units (AUs) [...] Read more.
Prolonged +Gz acceleration during high-performance flight exposes pilots to the risk of G-induced loss of consciousness (G-LOC), a dangerous condition that compromises operational safety. To enable early detection without intrusive sensors, we present a vision-based warning system that analyzes facial action units (AUs) as physiological indicators of impending G-LOC. Our approach combines computer vision with physiological modeling to capture subtle facial microexpressions associated with cerebral hypoxia using widely available RGB cameras. We propose a novel Graph Convolution-Augmented Vision Transformer (GC-ViT) network architecture that effectively captures dynamic AU variations in pilots under G-LOC conditions by integrating global context modeling with vision Transformer. The proposed framework integrates a vision–semantics collaborative Transformer for robust AU feature extraction, where EfficientNet-based spatiotemporal modeling is enhanced by Transformer attention mechanisms to maintain recognition accuracy under high-G stress. Building upon this, we develop a graph-based physiological model that dynamically tracks interactions between critical AUs during G-LOC progression by learning the characteristic patterns of AU co-activation during centrifugal training. Experimental validation on centrifuge training datasets demonstrates strong performance, achieving an AUC-ROC of 0.898 and an AP score of 0.96, confirming the system’s ability to reliably identify characteristic patterns of AU co-activation during G-LOC events. Overall, this contact-free system offers an interpretable solution for rapid G-LOC detection, or as a complementary enhancement to existing aeromedical monitoring technologies. The non-invasive design demonstrates significant potential for improving safety in aerospace physiology applications without requiring modifications to current cockpit or centrifuge setups. Full article
(This article belongs to the Special Issue Human Factors and Performance in Aviation Safety)
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22 pages, 8501 KB  
Article
Study on Thermophysical Properties and Electrical Conductivity Characteristics of Combustion Products from Propellants with Ionization Seeds
by Chunlin Chen, Lei Chang, Baoquan Mao, Qijin Zhao, Renbin Li and Xianghua Bai
Aerospace 2026, 13(1), 92; https://doi.org/10.3390/aerospace13010092 - 15 Jan 2026
Viewed by 343
Abstract
Detailed knowledge regarding the thermophysical properties and electrical conductivity of the combustion products derived from solid propellants is essential for the optimized design and operation of solid-fuel rocket engines employing magnetohydrodynamic drive technology. However, the high-temperature and high-pressure environment prevailing during rocket operation [...] Read more.
Detailed knowledge regarding the thermophysical properties and electrical conductivity of the combustion products derived from solid propellants is essential for the optimized design and operation of solid-fuel rocket engines employing magnetohydrodynamic drive technology. However, the high-temperature and high-pressure environment prevailing during rocket operation makes the experimental measurement of these characteristics extremely difficult, while the ionization reactions obtained by adding ionization seeds containing cesium to solid propellants for increasing the electrical conductivity of gaseous combustion products makes the theoretical calculation of these characteristics extremely problematic as well. The present work addresses these issues by constructing a minimum Gibbs free energy constraint function in conjunction with the Debye–Hückel correction under the condition of ionization to calculate the equilibrium components of combustion products. The obtained equilibrium components are then applied in conjunction with Lennard–Jones potential energy theory and the Champan–Enskog framework to approximately calculate the specific heat, viscosity coefficient, and thermal conductivity of propellant gases over a wide range of temperatures and pressures. The Kantrowitz model is proposed to solve the electrical conductivity of combustion products. Finally, the accuracy of the numerical calculations is validated through the Langmuir probe experiment. The discrepancy between calculated and measured electron density decreases with increasing temperature and remains within 5% when the combustion product temperature exceeds approximately 1800 K. The validity of the proposed framework is demonstrated by examining the effects of temperature, pressure, and ionization seed content on the thermophysical properties and electrical conductivity of the combustion products derived from tri-base solid propellant with cesium atoms employed as ionization seeds. Full article
(This article belongs to the Section Astronautics & Space Science)
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20 pages, 18283 KB  
Article
Aerodynamic Effects of the Oblique Angle and the Asymmetric Leading-Edge Sweep on an Oblique-Wing Aircraft
by Zhuo Liu, Huajun Sun, Heng Zhang, Jie Li and Weijia Fu
Aerospace 2026, 13(1), 91; https://doi.org/10.3390/aerospace13010091 - 15 Jan 2026
Viewed by 347
Abstract
Compared with conventional symmetric aircraft, the oblique-wing aircraft offers significant advantages across a wide speed range due to the variable oblique angle. However, the asymmetric aerodynamic characteristics will arise from the differential leading-edge sweep between the forward and aft wings during the rotation [...] Read more.
Compared with conventional symmetric aircraft, the oblique-wing aircraft offers significant advantages across a wide speed range due to the variable oblique angle. However, the asymmetric aerodynamic characteristics will arise from the differential leading-edge sweep between the forward and aft wings during the rotation process. This study investigates the aerodynamic effects of a conceptual oblique-wing configuration at transonic (Mach 0.85) and supersonic (Mach 1.40) flight conditions. For the baseline design, peak lift-to-drag ratio occurs at oblique angles of 30° and 60°, respectively. Analysis at Mach 0.85 reveals that the forward wing dominates the aerodynamic performance of the whole configuration. The parameter study of the leading-edge sweep confirms that the configuration combining a smaller forward-wing sweep with a larger aft-wing sweep is an effective design for achieving the balanced aerodynamic performance, namely, the forward wing with a 24° leading-edge sweepback angle and the after wing with 33° yield a high lift-to-drag ratio, achieving an optimal trade-off with rolling moment minimization. This drag reduction is achieved through the simultaneous decrease in both wave drag and induced drag. Furthermore, downwash analysis reveals that the inherent rolling moment originates from asymmetric tail loads induced by uneven downwash distribution. These findings provide guidance for the aerodynamic design of future oblique-wing aircraft. Full article
(This article belongs to the Special Issue Aircraft Conceptual Design: Tools, Processes and Examples)
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24 pages, 6265 KB  
Article
On the Study of Performance Enhancement of 3D Printing and Industrial Application on Aviation Devices
by Hui-Pei Chang and Yung-Lan Yeh
Aerospace 2026, 13(1), 90; https://doi.org/10.3390/aerospace13010090 - 14 Jan 2026
Viewed by 271
Abstract
Three-dimensional printing is the most commonly used method for producing customized or mock-up products for industrial applications. In particular, aviation devices for drones usually require a high spatial resolution to satisfy the small size requirement. In practical applications of drones, the two main [...] Read more.
Three-dimensional printing is the most commonly used method for producing customized or mock-up products for industrial applications. In particular, aviation devices for drones usually require a high spatial resolution to satisfy the small size requirement. In practical applications of drones, the two main tasks are inspection and detection. However, the working environment is often filled with flammable gases, such as natural gas or petroleum gas. Thus, the parts of drones that can easily produce an electrical spark, such as electronic connectors, should be specially protected. In this study, atmosphere control was applied to enhance the printing performance and manufacture of anti-explosion devices. The results demonstrate that atmosphere control can efficiently improve the print quality and that the print resolution of a commercial 3D printer can be enhanced to reach the mm scale. In the anti-pressure testing via a high-pressure smoke experiment, the manufactured anti-explosion devices for drones showed an appropriate intrinsic safety level, suggesting that they can be used in drones used for daily inspections of pipelines in petrochemical plants. The two main contributions of this study are the development of a practical method for improving FDM 3D printers and an anti-explosion device for drones. Full article
(This article belongs to the Special Issue Advances in UAVs: Design Methods, Performance Enhancement Techniques and Technologies)
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24 pages, 3791 KB  
Article
Two-Stage Assumed Mode Method for Flutter Analysis of Supersonic Panels with Elastic Supports and Attached Masses
by Wuchao Qi, Shuai Yuan and Sumei Tian
Aerospace 2026, 13(1), 89; https://doi.org/10.3390/aerospace13010089 - 14 Jan 2026
Viewed by 207
Abstract
During the service life of a supersonic aircraft, panels are susceptible to damaged boundary supports and unexpected attached masses, which can critically alter their flutter characteristics. This paper proposes a novel two-stage assumed mode method to efficiently analyze the modal properties and expanded [...] Read more.
During the service life of a supersonic aircraft, panels are susceptible to damaged boundary supports and unexpected attached masses, which can critically alter their flutter characteristics. This paper proposes a novel two-stage assumed mode method to efficiently analyze the modal properties and expanded flutter envelopes of such compromised structures. In the first stage, the bending modes of a Euler–Bernoulli beam under elastic supports in two orthogonal directions are combined to construct the assumed modes of the intact panel, forming a modal matrix that satisfies geometric boundary conditions and establishing the baseline dynamic model. In the second stage, the method is reapplied to derive the generalized eigenvalue problem for the panel with attached masses, accurately capturing the modified mode shapes and frequencies. Subsequently, based on the principle of virtual work and first-order piston theory, the generalized aerodynamic forces are formulated. These are then incorporated into the flutter equations, which are solved in the frequency domain using the p-k method. The results demonstrate that elastic supports generally lower flutter velocities and frequencies. However, an interesting finding is that a centrally attached mass of 0.03 kg (≈10% of the panel mass) can increase the flutter speed by about 10%, whereas the same mass placed off-center may reduce it by roughly 2%. Furthermore, the proposed 9-point damper layout is shown to raise the flutter speed of an elastically supported panel with an off-center mass by up to 18% and the flutter frequency by over 13%, thereby recovering and even exceeding the design flutter boundary. Full article
(This article belongs to the Special Issue Aeroelasticity, Volume V)
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15 pages, 3495 KB  
Article
Towards More Reliable Aircraft Emission Inventories for Local Air Quality Assessment
by Kiana Sanajou and Oxana Tchepel
Aerospace 2026, 13(1), 88; https://doi.org/10.3390/aerospace13010088 - 14 Jan 2026
Viewed by 223
Abstract
Accurate quantification of aircraft emissions and their uncertainties is essential for well-informed policy-making, air quality management, and the development of sustainable airport strategies. This study addresses uncertainties in aircraft emission estimates implemented for local air pollutants with hourly resolution at six European airports. [...] Read more.
Accurate quantification of aircraft emissions and their uncertainties is essential for well-informed policy-making, air quality management, and the development of sustainable airport strategies. This study addresses uncertainties in aircraft emission estimates implemented for local air pollutants with hourly resolution at six European airports. Publicly available flight-tracking data were used to determine aircraft movements and types, but they typically lack detailed information on aircraft engine models, thus contributing to uncertainties in emission factors. Times-in-mode for take-off, climb-out, and approach modes followed International Civil Aviation Organization (ICAO) recommendations, while taxi times, known to vary between airports, were modeled using statistical distributions derived from Eurocontrol, and the contribution of taxi time to overall uncertainty in emission estimates was investigated. Monte Carlo simulation combined with Sobol sensitivity analysis identified the relative contribution of each uncertainty source. On average, the results indicate an uncertainty of 23% for CO, 34% for HC, 7% for NOx, and 21% for PM across the airports analyzed. Overall, the proposed methodology introduces a novel framework utilizing publicly available, hourly resolved flight-tracking data with robust uncertainty analysis to estimate airport-level emissions with enhanced reliability, providing crucial information for local air quality assessment and policy development. Full article
(This article belongs to the Section Air Traffic and Transportation)
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33 pages, 4351 KB  
Review
Center of Mass Measurement Technology and Its Research Progress in the Aerospace Field
by Huan Wang, Qilong Jiang, Hanbin Zhu, Wenke Zhou, Chang Liu and Hongchao Zhao
Aerospace 2026, 13(1), 87; https://doi.org/10.3390/aerospace13010087 - 13 Jan 2026
Viewed by 240
Abstract
The center of mass is a key parameter characterizing the mass distribution of an object, and its measurement holds significant importance in high-tech fields such as aerospace, the defense industry, and precision manufacturing. With modern engineering demanding ever-increasing spacecraft flight stability, control precision, [...] Read more.
The center of mass is a key parameter characterizing the mass distribution of an object, and its measurement holds significant importance in high-tech fields such as aerospace, the defense industry, and precision manufacturing. With modern engineering demanding ever-increasing spacecraft flight stability, control precision, and precision measurement requirements, the accuracy, efficiency, and adaptability of center of mass measurement have also become research hotspots. This paper systematically reviews current mainstream measurement techniques, including static and dynamic methods, while analyzing their respective advantages and sources of error. By comparing Chinese and non-Chinese achievements in center of mass measurement equipment development and engineering applications, it identifies existing challenges and issues in the field and outlines future trends in center of mass measurement technology. Full article
(This article belongs to the Special Issue Advanced Manufacturing, Assembly, and Testing Technologies for Spacecraft)
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16 pages, 1705 KB  
Article
Economic Analysis of a ROXY Pilot Plant Supporting Early Lunar Mission Architectures
by Tehya F. Birch, Achim Seidel, James E. Johnson, Georg Poehle and Uday Pal
Aerospace 2026, 13(1), 86; https://doi.org/10.3390/aerospace13010086 - 13 Jan 2026
Viewed by 598
Abstract
The establishment of a sustained human presence on the Moon is critically dependent on the ability to utilize local resources, primarily the production of oxygen for life support and propellant. The ROXY (Regolith to Oxygen and metals conversion) process is a molten salt [...] Read more.
The establishment of a sustained human presence on the Moon is critically dependent on the ability to utilize local resources, primarily the production of oxygen for life support and propellant. The ROXY (Regolith to Oxygen and metals conversion) process is a molten salt electrolysis technology designed for this purpose. This paper presents an economic analysis of a ROXY pilot plant capable of producing over one ton of oxygen per year. We evaluate the economic viability by analyzing development, transportation, and operational costs against the potential revenue from selling oxygen and metals within a nascent lunar economy. A key aspect of this analysis is the perspective of an early customer in habitation life support systems preceding that of much higher propellant production demand. The analysis contextualizes this paradigm by recognizing that the primary economic driver for oxygen production is the larger future market for propellant; however, early life support demand may incentivize a paradigm-shift from Earth-based consumable resupply. Scenarios based on varying transportation costs and development timelines are evaluated to determine the internal rate of return (IRR) and time to break even (TTBE). The results indicate that the ROXY pilot plant is economically viable, particularly in near-term scenarios with higher transportation costs, achieving a positive IRR of up to 47.4% when both oxygen and metals are sold. The analysis identifies facility mass, driven by the robotics subsystem, as the primary factor for future cost-reduction efforts, concluding that ROXY is a technically and economically sound pathway toward sustainable lunar operations. Full article
(This article belongs to the Section Astronautics & Space Science)
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22 pages, 363 KB  
Review
Human Factors, Competencies, and System Interaction in Remotely Piloted Aircraft Systems
by John Murray and Graham Wild
Aerospace 2026, 13(1), 85; https://doi.org/10.3390/aerospace13010085 - 13 Jan 2026
Viewed by 464
Abstract
Research into Remotely Piloted Aircraft Systems (RPASs) has expanded rapidly, yet the competencies, knowledge, skills, and other attributes (KSaOs) required of RPAS pilots remain comparatively underexamined. This review consolidates existing studies addressing human performance, subject matter expertise, training practices, and accident causation to [...] Read more.
Research into Remotely Piloted Aircraft Systems (RPASs) has expanded rapidly, yet the competencies, knowledge, skills, and other attributes (KSaOs) required of RPAS pilots remain comparatively underexamined. This review consolidates existing studies addressing human performance, subject matter expertise, training practices, and accident causation to provide a comprehensive account of the KSaOs underpinning safe civilian and commercial drone operations. Prior research demonstrates that early work drew heavily on military contexts, which may not generalize to contemporary civilian operations characterized by smaller platforms, single-pilot tasks, and diverse industry applications. Studies employing subject matter experts highlight cognitive demands in areas such as situational awareness, workload management, planning, fatigue recognition, perceptual acuity, and decision-making. Accident analyses, predominantly using the human factors accident classification system and related taxonomies, show that skill errors and preconditions for unsafe acts are the most frequent contributors to RPAS occurrences, with limited evidence of higher-level latent organizational factors in civilian contexts. Emerging research emphasizes that RPAS pilots increasingly perform data-collection tasks integral to professional workflows, requiring competencies beyond aircraft handling alone. The review identifies significant gaps in training specificity, selection processes, and taxonomy suitability, indicating opportunities for future research to refine RPAS competency frameworks and support improved operational safety. Full article
(This article belongs to the Special Issue Human Factors and Performance in Aviation Safety)
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24 pages, 14492 KB  
Article
Impact of Groove Manufacturing Errors on Aircraft Skin-Friction Reduction
by Zhaoliang Dou, Yue Du and Fengbin Liu
Aerospace 2026, 13(1), 84; https://doi.org/10.3390/aerospace13010084 - 13 Jan 2026
Viewed by 300
Abstract
This study systematically investigates the effects of manufacturing errors on the drag reduction performance of micro-grooves fabricated using roll-to-roll hot embossing technology. Numerical simulations were conducted to analyze the drag reduction characteristics of spanwise micro-grooves under a 0.4 Ma incoming flow, with a [...] Read more.
This study systematically investigates the effects of manufacturing errors on the drag reduction performance of micro-grooves fabricated using roll-to-roll hot embossing technology. Numerical simulations were conducted to analyze the drag reduction characteristics of spanwise micro-grooves under a 0.4 Ma incoming flow, with a focus on the influence mechanisms of groove array straightness error (δ) and bottom corner rounding error (σ) on aerodynamic performance. The results indicate that straightness errors induce periodic pressure pulsations, which disrupt large-scale turbulent structures and lead to a linear degradation in drag reduction performance. In contrast, bottom corner rounding errors modulate small-scale turbulence by altering the local curvature at the groove bottom. Positive deviations in particular cause an upward shift of the vortex core and enhanced energy dissipation, significantly impairing drag reduction. Based on these findings, an optimized processing window is proposed, recommending that the straightness error δ and bottom corner rounding error σ be controlled within −4% to 2% and −20% to 4%, respectively. Under these conditions, the fluctuation in the drag reduction rate can be confined within 20%. This study provides important theoretical insights and practical guidance for the precision manufacturing of drag-reducing micro-groove surfaces on aircraft. Full article
(This article belongs to the Section Aeronautics)
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21 pages, 3877 KB  
Article
Investigation of Cavitation Inception in Aviation Hydraulic Fluid AMG-10 in a Small-Scale Rectangular Throttle Channel
by Volodymyr Brazhenko and Taras Tarasenko
Aerospace 2026, 13(1), 83; https://doi.org/10.3390/aerospace13010083 - 13 Jan 2026
Viewed by 285
Abstract
Cavitation in aircraft hydraulic systems continues to pose a serious problem for the aviation industry. This paper presents a new study on cavitation in aviation hydraulic fluid AMG-10 at its inception condition, corresponding to a relative pressure drop of Δp = 0.58, [...] Read more.
Cavitation in aircraft hydraulic systems continues to pose a serious problem for the aviation industry. This paper presents a new study on cavitation in aviation hydraulic fluid AMG-10 at its inception condition, corresponding to a relative pressure drop of Δp = 0.58, within a small-scale rectangular throttle channel of specified dimensions. Numerical simulations were performed in a quasi-steady-state framework using the realizable k–ε turbulence model combined with the Enhanced Wall Treatment approach, and the results were validated against time-integrated experimental data obtained via the shadowgraphy method. Cavitation was modeled using the Zwart–Gerber–Belamri model. The validated numerical model, which showed a pressure deviation of less than 10% from experimental data on the upper and lower walls, also demonstrated good agreement in the dimensions of the cavitation regions, confirming that the upper region is consistently larger than the lower one. Quantitative analysis demonstrated that regions with high vapor concentration are highly localized, representing only 0.048% of the channel volume at a 0.8 vapor fraction threshold. The analysis reveals that the cavitation regions spatially coincide with local pressure drops to values as low as 214 and 236 Pa near the upper and lower walls. These regions are also associated with wall jets, accelerated by the flow constriction to velocities up to 41.98 m/s. Furthermore, the cavitation region corresponds to a distinct peak in the mean turbulent kinetic energy field, reaching 164.5 m2/s2, which decays downstream. Full article
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36 pages, 1411 KB  
Article
A Novel Stochastic Framework for Integrated Airline Operation Planning: Addressing Codeshare Agreements, Overbooking, and Station Purity
by Kübra Kızıloğlu and Ümit Sami Sakallı
Aerospace 2026, 13(1), 82; https://doi.org/10.3390/aerospace13010082 - 12 Jan 2026
Viewed by 279
Abstract
This study presents an integrated optimization framework for fleet assignment, flight scheduling, and aircraft routing under uncertainty, addressing a core challenge in airline operational planning. A three-stage stochastic mixed-integer nonlinear programming model is developed that, for the first time, simultaneously incorporates station purity [...] Read more.
This study presents an integrated optimization framework for fleet assignment, flight scheduling, and aircraft routing under uncertainty, addressing a core challenge in airline operational planning. A three-stage stochastic mixed-integer nonlinear programming model is developed that, for the first time, simultaneously incorporates station purity constraints, codeshare agreements, and overbooking decisions. The formulation also includes realistic operational factors such as stochastic passenger demand and non-cruise times (NCT), along with adjustable cruise speeds and flexible departure time windows. To handle the computational complexity of this large-scale stochastic problem, a Sample Average Approximation (SAA) scheme is combined with two tailored metaheuristic algorithms: Simulated Annealing and Cuckoo Search. Extensive experiments on real-world flight data demonstrate that the proposed hybrid approach achieves tight optimality gaps below 0.5%, with narrow confidence intervals across all instances. Moreover, the SA-enhanced method consistently yields superior solutions compared with the CS-based variant. The results highlight the significant operational and economic benefits of jointly optimizing codeshare decisions, station purity restrictions, and overbooking policies. The proposed framework provides a scalable and robust decision-support tool for airlines seeking to enhance resource utilization, reduce operational costs, and improve service quality under uncertainty. Full article
(This article belongs to the Collection Air Transportation—Operations and Management)
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25 pages, 5648 KB  
Article
Advanced Sensor Tasking Strategies for Space Object Cataloging
by Alessandro Mignocchi, Sebastian Samuele Rizzuto, Alessia De Riz and Marco Felice Montaruli
Aerospace 2026, 13(1), 81; https://doi.org/10.3390/aerospace13010081 - 12 Jan 2026
Viewed by 523
Abstract
Space Surveillance and Tracking (SST) plays a crucial role in ensuring space safety. To this end, accurate and numerous observational resources are needed to build and maintain a catalog of space objects. In particular, it is essential to develop optimal observation strategies to [...] Read more.
Space Surveillance and Tracking (SST) plays a crucial role in ensuring space safety. To this end, accurate and numerous observational resources are needed to build and maintain a catalog of space objects. In particular, it is essential to develop optimal observation strategies to maximize both the number and the quality of detections obtained from a sensor network. This represents a key step in the assessment of the network through simulations. This work presents the integrated development of sensor tasking strategies for optical systems and a track-to-track correlation pipeline within SΞNSIT, a software environment designed to simulate sensor network configurations and evaluate cataloging performance. For high-altitude low Earth orbit (HLEO) targets, which are fast-moving and widely distributed, tasking strategies emphasize systematic scans of the Earth’s shadow boundary to exploit favorable phase angles and improve observational accuracy, while medium- and geostationary-Earth orbits (MEO–GEO) rely on equatorial-plane scans. The correlation pipeline employs Two-Body Integrals, uncertainty propagation, and a χ2-test with the Squared Mahalanobis Distance to associate tracks and perform initial orbit determination of newly detected objects. Results indicate that the integrated approach significantly enhances detection coverage, leading to greater catalog build-up efficiency and improved SST performance. Consequently, it facilitates the cataloging of numerous uncataloged objects within a reduced timeframe. Full article
(This article belongs to the Special Issue Advances in Space Surveillance and Tracking)
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