Tamer Saraçyakupoğlu

Purpose: This study aims to evaluate the impact of cockpit instrument layout philosophy on pilot operational efficiency and cognitive workload within the context of EASA CS-27 regulations and future urban air mobility (UAM) requirements. It seeks to integrate “Human-in-the-Loop” criteria into multidisciplinary design optimization (MDO) frameworks to inform safer interface designs for next-generation rotorcraft. Design/methodology/approach: A virtual reality simulation using the HTC Vive Pro Eye system was developed to test three instrument panel configurations: shuffled (random placement), mission-based (functional grouping) and importance-based (criticality ranking). Data was collected from seven highly qualified aviation experts, primarily test pilots with approximately 10,000 flight hours each. Performance was assessed through automated task completion timing (quantitative) and semistructured expert interviews (qualitative). Findings: Quantitative analysis revealed that structured layouts provided substantial performance gains over the baseline. The importance-based layout achieved the fastest performance (14.8% improvement), followed by the mission-based layout (11.2% improvement). Furthermore, structured layouts reduced performance variability (standard deviation) by approximately 50%, indicating higher predictability and safety. Expert feedback suggests that while importance-based layouts favor emergency response, a hybrid design is optimal for maintaining procedural flow in UAM operations. Practical implications: The findings provide actionable design guidelines for avionics manufacturers, suggesting that cockpit interfaces for single-pilot UAM operations should prioritize importance-based hierarchy to mitigate cognitive saturation, independent of extensive pilot training. Originality/value: Unlike studies relying on novice participants, this research leverages expert-based heuristic evaluation from high-experience test pilots to provide high-fidelity insights. It offers empirical evidence connecting abstract MDO principles with practical certification standards (CS-27), proposing a validated pathway for designing intuitive cockpits for the emerging eVTOL and UAM sectors.

This study presents a detailed metallurgical analysis of the fracture failure that occurred at the hinge of the refueling door assembly located on the upper fuselage of the F-16 aircraft. The findings revealed that the fracture of the hinge’s auricle section resulted from a monotonic overload caused by an impact between the refueling boom and the door assembly due to improper alignment during in-flight refueling operations. Optical and Scanning Electron Microscopy (SEM) were used to characterize the fracture surface, enabling the identification of brittle cleavage features, river patterns, and the absence of fatigue striations, all indicative of a single overload event rather than cyclic fatigue. The study further observed visible evidence of mechanical distress, such as paint removal, dents, and scratches, corroborating the overload-induced impact mechanism. The findings underscore that even components designed to stringent aerospace standards may experience catastrophic failure when subjected to off axis loads and operational misalignment. Future studies may include finite element modeling to assess hinge redesign strategies under off-axis loading, as well as investigations into alternative materials and design modifications to enhance durability.

Carbon fiber-reinforced polymer (CFRP) laminates are extensively utilized in aerospace and advanced engineering fields because of their outstanding strength-to-weight ratio and superior fatigue durability. However, despite their high in-plane strength and stiffness, CFRP laminates are inherently susceptible to delamination. This weakness stems from the relatively low interlaminar strength of the resin-rich interfaces between layers compared to the much stronger in-plane fiber reinforcement. During mechanical processes such as drilling and punching, out-of-plane stresses and interlaminar shear forces develop, concentrating at these weak interfaces. This study investigates the delamination behavior of CFRP laminates with 3 to 7 plies under drilling and punching, focusing on the effects of ply count and drilling speed. Experimental tests were conducted using an 8 mm punch and drill bit at 2500, 3000, and 3500 rpm, reflecting typical workshop practices for M8 fastener holes. Scanning electron microscopy (SEM) analyses at different magnifications were used to quantify delamination extent. A three-dimensional finite element model was created in ABAQUS/Explicit, integrating the Hashin failure criterion to predict damage initiation within the plies and cohesive surfaces to simulate interlaminar delamination. The analyses show that with proper support, punching can approach the damage levels of drilling for thin CFRP plates, but drilling remains preferable for thicker laminates due to better integrity and tool longevity.

In today’s aviation industry, research and studies are carried out to manufacture and design lightweight, high-performance materials. One of the materials developed in line with this goal is glass laminate aluminum-reinforced epoxy (GLARE), which consists of thin aluminum sheets and S2-glass/epoxy layers. Because of its high impact resistance and excellent fatigue and damage tolerance properties, GLARE is used in different aircraft parts, such as the wing, fuselage, empennage skins, and cargo floors. In this study, a survey was carried out and a low-velocity impact model for GLARE materials was developed using the ABAQUS (2014) version V6.14 software and compared with the results of low-velocity impact tests performed according to the American Society for Testing and Materials (ASTM) D7136 standard. This article introduces a novel integrated approach that combines detailed numerical modeling with experimental validation of GLARE 4A FMLs under low-velocity impact. Leveraging ABAQUS, a robust FEM featuring explicit analysis, cohesive resin interfaces, and custom VUMAT subroutines was developed to accurately simulate energy absorption, dent depth, and delamination. The precise model’s predictions align well with test results performed according to ASTM D7136 standards, exhibiting less than a 0.1% deviation in the displacement (dent depth)–time response, along with deviations of 4.3% in impact energy–time and 5.2% in velocity–time trends at 5.5 ms.

Jet pumps are widely used in various industrial and commercial applications, including aircraft fuel jettison systems, chemical plants, refineries, and water treatment facilities. This study examines the correlation between laboratory experiments on jet pumps and computer-based analyses. We conducted a total of 108 fuel flow experiments under pre-assigned parameters for suction lifts, pressures, and nozzle lengths, using water as the testing medium. Each measurement was taken in three separate trials to ensure the results were averaged mathematically. In the computer-based tests, Bernoulli’s principle and the mass continuity law were expertly translated into code. The results from these simulations were then compared with the experimental measurements to verify their accuracy. The study concluded that there is a linear relationship between the nozzle length, suction lift, and flow rate, as anticipated in accordance with the Venturi effect. Additionally, it was observed that the flow rate increased with a decrease in suction lift, an increase in nozzle length, and an increase in pressure. Conversely, the lowest flow rate was recorded when the highest suction lift, the shortest nozzle length, and the lowest pressure were employed.

Hydrogen embrittlement (HE) poses a critical safety risk in the aviation industry, causing unexpected failures in high-strength metals and alloys used in essential components. This study focuses on detailed analyses of multiple aviation incidents and accidents where HE played a significant role, particularly concerning failures in helicopter drive systems and fixed-wing aircraft crankshaft bolts. Investigations revealed that these failures were primarily caused by hydrogen introduced during manufacturing processes, such as electroplating and surface treatments, which were insufficiently mitigated by post-processing techniques like dehydrogenation. These incidents led to Airworthiness Directives (ADs), which mandated corrective actions to prevent similar occurrences, such as improved manufacturing protocols and enhanced material testing. By presenting concrete evidence from metallurgical analyses and documented aviation failures, this paper highlights the critical need for robust manufacturing controls, stringent post-treatment procedures, and continuous monitoring to address hydrogen embrittlement risks effectively and enhance aviation safety.

Hydrogen embrittlement (HE) poses a significant risk in the aviation industry, leading to unexpected failures in high-strength metals and alloys used in critical components. This paper investigates multiple aviation incidents where hydrogen embrittlement contributed, notably in helicopter drive systems and fixed-wing aircraft crankshaft bolts. The failures were attributed mainly to hydrogen introduced during manufacturing processes, particularly electroplating and surface treatments, which left residual hydrogen despite dehydrogenation procedures. These incidents led to the issuance of Airworthiness Directives (ADs), which mandated stricter manufacturing controls and post-processing treatments, such as baking, to eliminate residual hydrogen and prevent future embrittlement. While the paper briefly covers traditional mitigation strategies like cathodic protection and surface coatings, its primary focus is on the need for improved quality control in manufacturing processes to reduce hydrogen-related failures, thereby enhancing the safety and reliability of aviation systems.

Aviation has come a long way since its early days, and as technology has advanced, air vehicles have become even more advanced and effective, especially on the battlefield. In addition, in-depth research and discoveries in the field of aviation have a significant impact on the aviation industry, especially in the field of munitions. In this context, aerial ammunition is an important component of aviation and is widely used in combat. Because a malfunction that may occur during separation or premature detonation during separation from the aircraft may cause fatal effects on the crew. That’s why the bomb must be safely separated from the air vehicles. Modern bombs are therefore equipped with advanced safety features that guarantee a precise and safe separation from the aircraft before explosion. In addition, the determination of the ballistic coefficient according to the size of the desired effect reveals the importance of the choice of munition types. Otherwise, it will not be possible to achieve the desired level of target destruction. The aim of this study is to provide a comprehensive understanding of the basic characteristics of aerial munitions, including the composition and operation of generic aircraft bombs.

The use of additive manufacturing (AM) has a lot of potential for manufacturing geometrically challenging parts, components, and even assemblies. To ensure the effective adoption of additive manufacturing by the aviation industry and to expedite the standardization process, a certification roadmap is essential. This study offers a thorough analysis of the issues facing the qualification and certification of additively made parts, components, and assemblies that could be used on commercial passenger air vehicles. It also provides information regarding the general standards of AM process. After outlining the principles of technical application for the AM process, the current status of the regulations, and rules created by national/international airworthiness authorities and communities are then summarized and analyzed in terms of the manufacturing of aviation-grade parts, components, and assemblies.