Solutions for Maintenance Repair and Overhaul

Advanced composite materials have been adapted to several applications in the aerospace industry. The main advantages of advanced composites are reduced weight, superior strength, and high corrosion resistance. Apart from these advantages, vibration and thermal insulations are the other important areas that benefit from composite materials for aerospace structures. At this point, as a natural product, cork comes to the fore that today’s air and space vehicles have already been benefiting from cork-based products. However, apart from its mechanical and thermal properties, cork deserves much more attention from the sector as an environmentally friendly composite material. In this chapter, a brief discussion will be given regarding cork composites in aerospace applications.

In this study, single-lap bonding joints were prepared using aluminum alloy 2024-T3 (AA2024) plates and eight-layer carbon fiber-reinforced epoxy hybrid composite (CFREC) plates. Epoxy glue was used for the bonding process, and in order to remove the brittleness of the epoxy by forming a second interface, Nylon 6.6 nanofiber reinforcement by electrospinning was produced and reinforced to the epoxy adhesive. Thus, single-lap bonding joints, which are both glued with pure epoxy and reinforced with epoxy and N6.6, have been obtained. Low-speed impact tests of 1.04 m/s under five different temperatures (−50, −20, 0, 23, and 50 °C) were applied to all single-lap bonding joints produced. Tensile tests were applied to the non-breaking samples in accordance with the ASTM D1002-10 standard, and the loading status after low-speed impact was examined. It was determined that while 1.5 J of the 3 J energy given by low-speed impact was absorbed in common in all samples, the rest was returned, and there were some separations in the adhesion area due to this impact.The highest tensile force of pure epoxy samples and N6.6 reinforced samples after low-speed impact was obtained, 2230.27 N and 2992.74 N, respectively, at 23 °C, and it was determined that N6.6 reinforcement increased the impact force by 34% at room temperature. For the tensile force, the lowest values were reached at −50 °C. For pure epoxy and N6.6 reinforced samples obtaining 585.15 N and 618.61 N values, respectively, an increase of 5.7% was determined. In addition, the rupture surfaces of the samples, which were completely destroyed by the tensile test, were examined with a scanning electron microscope (SEM) for damage analysis.

It has been very important to determine the flow pattern on the surface of any object. Many times, understanding the flow pattern on the surface of the body has been a priority. With flow visualization techniques, separation points, separation lines, streaklines, and surface shear stress patterns can be examined. A surface oil flow visualization study is carried out on NACA 0020 airfoil with a leading-edge tubercle at a Reynolds number of 200,000. The purpose of this study is to find the optimum oil mixture that gives the best results on the airfoil profile. Flow visualization experiments are conducted at 5°, 10°, 15°, and 20° angles of attack on the NACA 0020 airfoil model using five different oil mixtures. The tubercle leading-edge of the model has double amplitude (a1 = 0.05c, a2 = 0.0125c) and double wavelength (λ1 = 0.5c and λ2 = 0.125c). As a result, it is observed that there is no definite mixing ratio, and the oil mixture should change according to the flow parameters.

The scope, content, and frequency of maintenance performed to keep aircraft in airworthy conditions vary. Airline companies are trying to complete the maintenance activities within the optimum time and include them in flight operations. Therefore, it is necessary to plan maintenance activities and optimize the time allocated for maintenance. In addition to planning, technology should be used well to save personnel numbers and time devoted to maintenance. Also, the effective use of technology will bring along more regular and accurate maintenance processes, which can be multicomponent and complex. In this research, traditional and new technologies utilized during aircraft maintenance were examined in the largest maintenance, repair, and overhaul company operating in Turkey. Innovations in aircraft maintenance, improvements in maintenance processes, and time, environmental, and economic gains of airlines were evaluated.

In machining, especially in ductile materials, continuous chip formation is a major problem. The ability to remove chips from the cutting zone is an important constraint for machining without human intervention. In this study, traditional chip breaking approaches and methods used to measure the effectiveness of chip breaker forms are presented. In addition, the effects of the process parameters in the turning process on the chip control method are emphasized. The studies about chip control are summarized, and an approach to control the continuous chips is proposed. The potential of the methods developed for this purpose to be used in aviation applications has been investigated.

Nanosatellite attitude angles are estimated using vector measurements of star trackers in this chapter. As an estimation method, a nontraditional filter is used based on only the kinematics model which is propagated using rate gyro measurements. The issue related to gyro drifts is overcome by adding the bias terms into the state vector in order to estimate them. As a first stage, singular value decomposition (SVD) is used for determining the attitude measurements. As a second stage, an extended Kalman filter (EKF) is designed based on linear attitude measurements. These two stages are integrated for the whole estimation algorithm in order to have estimations with high accuracy, and it is called SVD-aided EKF.

The civil applications of UAV, UAS, and drones, as well as the integration of their operations into flight schedules with the urban environment or smart city total transportation system are attracting researchers. This study introduces the developed operational concept for drone flight operations in an urban area, including the airspace design, the recommended construction of the airways, and the essential safety requirements. It also investigates the applicable management system that must be highly automatized, with central observation/supervision, and permit fully autonomous flights of drones using GPS and active marker systems being integrated into the infrastructure as well as defined in a GIS environment. The proposed option is based on the definition of routes as desired and commanded trajectories and their autonomous execution. The airspace structure and fixed routes are given in the global GPS reference system with supporting GIS mapping. The concept application requires a series of further studies and solutions as drone trajectory (or corridor) followed by an autonomous trajectory tracking control system, coupled with autonomous conflict detection, resolution, safe drone following, and formation flight options.

The current problem of the maintenance, repair, and overhaul (MRO) organizations is competitiveness in the environment of aircraft maintenance, which is the main task is to improve the quality of the maintenance and reduce aircraft downtime. This study examines how the MRO can improve the procedures of individual aircraft maintenance task cards by implementing Lean tools, in the combination of the Six Sigma methods. The aim is to minimize downtime of the aircraft and analyze the processes to determine the existing problems in this area. Applying the data collected from the experts of the MRO, airlines, and equipment manufacturers, an analysis was made on engine replacement using a modern hydraulic lift engine hoist. The result shows this approach allowed to eliminate unnecessary tasks from the aircraft maintenance manual (AMM) and also reduce turnaround time by more than 4 h. The measurement based on the final results validates the main contributions o MRO organizations through savings in finance and human resources, thereby reducing maintenance costs and satisfying the customer.

This chapter presents the flexural behavior of low-density stitched polymer foam core sandwich composites. The stitching was made into PVC foam core materials to reinforce the core through the thickness direction. Once the PVC foam core materials were predrilled, E-glass fiber yarns with 600 tex were used to stitch the sandwich cores. The stitching effect was investigated on the sandwich structures with carbon fiber and glass fiber face sheets. The sandwich composites were manufactured with the vacuum bagging method, and the whole face sheets and the sandwich were co-cured. The sandwich panels were cut to obtain flexural test specimens according to ASTM C393 standard. The flexural tests were carried out with three-point bending loading. The effect of core stitching on the flexural characteristics of sandwich composites was revealed. A significant increase in bending load capacity and sandwich rigidity was obtained.

The air transport industry is one of the key industries focused on sustainability issues due to its environmental impacts. Airports, which provide infrastructure for air transport operations, are the main stakeholder responsible for environmental sustainability. This study focuses on the environmental impacts of certain airports and the practices they implement to reduce these impacts. Sample airports to be evaluated were selected from international airports, and they were examined under the titles of greenhouse gas emissions, water management, waste management, energy management, and noise. Evaluations are based on the results of sustainability reports and annual reports of airports and publications of national and international organizations. Three airports were selected among the airports that won the “Best Airports 2020 by Global Region” award, and Istanbul Airport was also included in the study for comparison in the national field.

Developing transport systems has been a continuous challenge to satisfy all preferences of stakeholders. The high strategic level decision-making process must be done using multi-criteria decision-making (MCDM) like analytic hierarchy process (AHP) since it requires building a model based on the current conditions, particularly in transportation engineering. This chapter is based on a survey carried out from a questionnaire that involved 20 passengers and 20 experts specifying the analysis of the supply quality in Budapest city. This reshapes the public transportation system in the city and makes the public transportation system more efficient and effective by evaluating and improving customer satisfaction with public transportation. This also provides some recommendations in order to improve the quality of services as well.

Aircraft maintenance technician (AMT) is the most essential part of the maintenance system that ensures the aircraft to fly for many years by performing the necessary maintenance. The slightest mistake made by the technician while performing tasks in aircraft maintenance causes serious risk in flight safety. For this reason, it is very important to identify the mistakes AMT will make and develop suggestions to prevent or correct these errors. With this study, it is aimed to present a solution for determining the human errors probability (HEP) with the human error evaluation and reduction method (HEART). The HEART approach is given in an application example in critical aircraft maintenance.

This study aimed to observe the effects of fuel performance on the environmental performance indicators of an aircraft engine. For this purpose, three different fuels have been selected: JET-A, AVGAS, and natural gas. Afterwards, the performance of the fuels on three environmental sustainability performance indicators (environmental effect factor, sustainability index, and ecological effect factor) was obtained. According to the results, environmental indicator values were calculated with a value of 4.53 for the Jet-A fuel, 4.71 for the natural gas fuel, and 4.55 for the AVGAS fuel. Exergetic sustainability index values were obtained with a value of 0.22 for the Jet-A fuel, 0.21 for the natural gas fuel, and 0.22 for the AVGAS fuel. Ecological effect factor values were estimated with a value of 5.53 for the Jet-A fuel, 5.71 for the natural gas fuel, and 5.55 for the AVGAS fuel.

Ground-handling services contribute the enabling ground and flight-related activities to be carried out effectively. This study presents ergonomic risk factors which have impact on operational performance of ground-handling services. Identified performance fields are including risk factors which have considerable potential to impact on corporate performance. Ergonomic-related identified performance fields are presented with a taxonomy which is basically focused on ground-handling services may create available conditions for errors. This taxonomy helps to improve awareness level of performance fields to improve corporate sustainability in airport ground operations. Classifying risk factors can be a valuable tool for managers to efficiently allocate resources and timely address potential issues. It also helps create an operational environment that is conducive to identifying all sources of risk.

Composites have been widely used lately because of their high specific stiffness and strength characteristics. In this study, the impact resistance of sandwich structures with carbon fiber-reinforced polymer (CFRP) face sheet and polyvinyl chloride (PVC) foam core material, which is frequently used in areas requiring high specific stiffness, such as aviation and sports equipment were investigated. Kaolin micro-particles, which are generally used in the structure of laminated composites in the literature, were added to the face sheets in various proportions such as 0%, 2%, 5%, and 10%. Four different sandwich configurations were tested under 10 J, 17.5 J, and 25 J impact energy with a low-velocity drop weight impact test device. Maximum impact load, absorbed energy, and indentation depth values were given comparatively.

In the United States, FAA started to evaluate the environmental impacts of airports by launching the “Airport Sustainability Plan” application in 2011. The plans, which achieved quite successful results in 2014, were again evaluated within the framework of FAA’s Airport Development Plan. Within this plan, first, airports have expanded their master plans with a sustainability perspective, and as a second step, they have planned what they will do only about sustainability within the framework of airport sustainability plans. Each plan includes various types of sustainability focus areas. As a result of the Airport Sustainability Plan applications of the airports in the United States, various positive results have been achieved in the sustainability components such as economic viability, operational efficiency, natural resource conservation, and social responsibility. Airport sustainability plans and other sustainability regulations being analyzed according to EONS components.

An optimized configuration of electrically powered propellers, modelled as actuator disks, for a novel canard aircraft design has been found using numerical methods by determining the improvement in aerodynamic characteristics of the aircraft for varying angles of attack. The aircraft was placed in a freestream, and its aerodynamic effects for various propeller configurations were noted. Four propeller configurations, namely, pushers, tractors, tractors with a tail rotor, and tractors with tail and tip rotors have been studied. It has been observed that the use of tractors with a tail rotor provides the highest increase in the lifting capacity of the aircraft for positive angles of attack, while the tractors-only configuration has the highest lift-to-drag ratio when placed at a vertical offset to the lifting surface.

In this study, effects of cruise flight conditions on exhaust gas emissions regarding PW4000 engine are scrutinized. For this aim, parametric cycle equations are encoded by considering PW4000 input values. Also, cruise flight regime is selected Mach between 0.6 and 0.7 and altitude 10 and 11 km. Based on ICAO database for NOx emissions at LTO cycle, cruise NOx emissions are calculated by employing BFF2 and DLR methods. Furthermore, after fuel flow of PW4000 engine is computed from cycle equations at defined flight conditions, CO2 and H2O emissions are calculated from combustion equations. According to emission results, average NOx emission index (EINOx) decreases from 28 g/kg to 25 g/kg due to rising altitude, whereas NOx value per unit second decreases from 0.03 kg to 0.024 kg. It could be highlighted that quantifying EINOx without using mentioned methods leads to wrong calculations.

Solar-powered high-altitude long endurance unmanned aerial vehicles can be utilized for a variety of aerial surveillance applications. This chapter presents the key outcomes of a study involving conceptual design and sizing of such a UAV for collection of data using LiDAR, while flying over some ground stations located near the coastline of India. This UAV was designed to meet the requirements of geologists for their scientific studies of the coastal habitats over a period of time. The design methodology involves an iterative process resulting in a converged solution to meet the mission requirements. A CAD model of the UAV was created using the OpenVSP tool developed by NASA, and utilized to arrive at estimates of wetted area and drag polar. It was seen that the designed UAV was able to meet all the specified operational and mission requirements.

In the study, the sky emissivity (εsky) and sky temperature (Tsky) values were determined and the heat loss by radiation from the exterior surfaces required for the heating and cooling energy consumption calculations of the airport buildings was investigated. While the outdoor dew point is determined, the outdoor temperature and relative humidity are used. The outdoor dew point temperature value was used while calculating the sky emissivity value. When determining the outdoor sky temperature values, both sky emissivity and cloudiness factor values are used. Sky temperature is required to calculate the heat loss with radiation from the exterior surfaces of the airport buildings. Twenty cities in different climate zones around the world are selected in the study. The heat loss by radiation from the external surfaces of the airport buildings in these 20 cities has been calculated. For the 0.0 value of the completely cloudless for cloudiness factor, the highest external surface radiation heat loss difference depending on the 0.9 surface emissivity values was obtained in Moscow with 68.580 W/m2 and for the 1.0 value of completely cloudy for cloudiness factor and for the 0.5 surface emissivity value, the lowest external surface radiation heat loss difference was calculated as 8.874 W/m2 for Lisbon.

In the design of multi-rotor vehicles, it is very important to predesign the overall layout from the perspective of fluid dynamics and flight and control performance. However, currently there is no unified guiding principle. This research discusses the predesign procedure of an overall layout of multi-rotor vehicles based on particle swarm optimization (PSO) algorithm. First, the rotor dynamics model based on the blade element momentum theory is introduced. Then the proper parameter setting of the PSO algorithm is discussed considering rotor-number and payload mass. Finally, by using the PSO algorithm, some results of proper rotor sizes and positions are showed according to different rotor numbers and takeoff weights as well as blade numbers and angles of rotors.

The purpose of the project is to develop a solar sail and improve the maneuverability of solar sail by developing a control mechanism to enhance the maneuverability of the solar sail. The solar sail is modeled using CATIA V5 and SolidWorks. Considering the solar sail design parameters from the previous work. The size of the solar sail is 150 m × 150 m. The materials chosen for the boom is M5 fiber and for the sail is mylar. The control mechanism is designed. The overall design of the solar sail can perform various manipulations to more effectively avoid space debris, astronomical objects, and corrections and changes in direction.

Documents that affect the aircraft load and balance calculations are kept in the trip file for the period specified according to the applicable local regulations and airline requirements. Ground-handling companies consume many papers to fulfill the custom and airline procedures to accept and release the aircraft. This consumption significantly affects the handling companies’ headcount and environmental effects via time-consuming, environmental effects and useless financial investments every day. From beginning to end, the environmental effects of a paper production process, combined with the unconscious and endless use of paper as a resource, have a devastating effect. This study investigated how much paper was used during daily routine operations in the operation department of a handling company at a busy airport in Turkey. The extent to which this paper appraises necessary and unnecessary printouts, alternative methods of paper use have been considered, and printers’ environmental and financial effects have also been addressed by the same method.

This chapter investigates benefits and associated safety concerns imposed by new technology and innovative process of aircraft inspection using drones. The assessment of related risks is conducted by using HAZOP (hazard and operability) method in correlation with safety risk assessment matrix. The results of research show that the aircraft inspection using drones have a lot of benefits both for airlines and MRO (maintenance, repair, and overhaul) organizations including improving efficiency of process and cost savings, but also improving the safety of inspection process by means of better working conditions for engineers. It is recommended to adopt some of preventive measures in order to mitigate associated safety risks.

This chapter provides an overview of the initial sizing procedure of a single-seat tandem helicopter whose intended useful payload is 100 kg together with the basic analyses of power performances in hover and progressive flight. In the beginning, following the definition of the initial requirements, the essential advantages of tandem configuration are mentioned and some similar air vehicles are briefly described. This is followed by the total mass decomposition (into empty, useful and fuel mass) and estimation of its individual components as well as the definition of the main geometric features of the two rotors. By assuming a piston engine of 80 kW continuous power, it is possible to estimate the required and available power in hover and progressive flight as well as make an estimation of optimal velocities and possible range and endurance. Obtained results are presented graphically and numerically. In the end, some conclusions and recommendations for further research are given.

The usage of 3D printers in the production of parts is becoming widespread. Parts used in many different fields are produced with these printers. One of these fields is the aviation industry. It is desirable that the drones be as light as possible. 3D printers can respond to this demand. In this study, surface roughness optimization of the drone propeller produced on a 3D printer was performed. Layer height, infill rate, and printing speed are set as parameters. Compared to other parameters, it was seen that layer height was more effective at 90%. Optimum parameter levels are 0.1 mm layer height, 25% infill rate, and 50 mm/min printing speed.

Advanced polymers are extensively used in several sectors including defense and aerospace industries. In recent applications, smart polymers are adapted in different structures to control the structural response. Shear-stiffening gels are one of smart polymers that exhibits thickening texture under loading. Upon removal of the loading from the medium, the gel turns into viscous state that fluidic behavior predominates the material. In this work, we deal with the synthesis of a shear-stiffening gel by using various chemical components. In addition to the neat gel, additive particles were included into the gel and mechanical behavior of the reinforced gel was enhanced.

This chapter determines that the urgent task is the timely detection of dangerous condition of machinery. A brief review and analysis of modern means of measuring vibration and noise by vibroacoustic parameters of the working area is conducted. A system for monitoring the vibroacoustic parameters of the working area is proposed, which can measure the parameters of noise and vibration and analyze the measured data, signal the exceeding of the permissible ranges for human work, and display the measured data. The measuring channels are linked to the main board using a Bluetooth module, which lets you to place sensors to measure noise and vibration in any part of the work area.

As the importance of data security increases day by day, the new encryption method developments are also becoming more complex. Although logical and operational operators increase data security by complicating the algorithm, it can sometimes create disadvantages. Therefore, encryption algorithms must be chosen very accurately; research in this area has also generally been shaped around this focus. In the field of cryptology, the most important parameter is the encryption key. Generating, distributing, and hiding this key is one of the most important problems. Random number generators in cryptography should meet some requirements. For this purpose, we realized a new true random number generator. ESC-50 sound dataset is selected as a seed for random number generator. Applied design is approved by NIST 800-22 test suite, Ent test, UACI, and NPCR tests. All of these successful test results showed that our design can be implemented in encryption system as a key generator.

Accurate estimation of wind distribution plays a vital role in modelling more efficiently and minimizing theoretical computation errors in terms of practical applications. This research strives to conduct elaborately an assessment of the wind behavior and features of an international airport based on various heights from the ground level. Wind speed at each height, composed of 10 m, 20 m, 30 m, 40 m, and 50 m, is computed by applying the power-law equation. After that, the wind profile at each height is comparatively estimated based on the graphical, empirical, and maximum-likelihood method. Several statistical tools, namely, root mean square (RMSE) and R-squared (R2), are performed to make a fair comparison among the methods that help estimate the Weibull parameters. The results of this study reveal that the empirical and maximum-likelihood methods exhibit better performance than the graphical method in estimating the shape and scale parameter, irrespective of heights. Moreover, the findings of the study imply that the airport has a moderate potential to make use of generating electricity and hydrogen from wind power.

The aim of this chapter is to present the changes occurred in teaching the subjects of strength of materials and aeronautics, relating them both to flight safety by introducing in class the use of simulation and simulators. To this end, the teaching methodology on the aforementioned subjects will be briefly documented to show how physics and aeronautics can further enhance an effective flight training to prevent aviation accidents and educate cadets on how to best deal with a number of possible critical incidents during the flight; accordingly, the difference between the teaching approach before and after the utilization of the simulations and simulators to the Laboratories of Strength of Materials and Aeronautics will be evident. A detailed discussion will highlight the changes that the simulation and simulators brought to the educational process in relation to the lecturers, as well as to the cadets.

This chapter is devoted to the analysis of relative satellite vector estimations with extended Kalman filter (EKF) using the target and follower satellite positioning approach obtained by the Newton-Raphson method (NRM). In this study, target and follower satellite baseline values were determined as derived simulation data. Position states due to Earth-centered inertial (ECI) reference frame were obtained by Keplerian orbital parameters and Global Positioning System (GPS) receiver. The Pseudo-ranging model was used to determining the position of target and follower satellites. To simulate GPS receiver, random measurement errors were added to the actual distance between the target and follower satellites. With this study, satellite relative state vectors are obtained within the analysis scenario.

This chapter summarises the results of 2D CFD simulations of a 30P30N aerofoil section (without a leading edge slat) equipped with a morphing trailing edge flap (TEF). Numerical simulations are carried out at a fixed angle of attack of 8°, with f lap deflections of 5° and 15°. Results demonstrate that at the lower angle of attack case, the morphing TEF is able to reduce noise without reducing aerodynamic efficiency. However, at the higher angle of attack case, the overall performance is similar to that of a flapped conventional configuration, except at the highest frequencies where the conventional configuration is slightly quieter.

In this chapter, the parameters affecting the design of the windshield constructions of the aircraft in the “community aircraft” status are discussed. In the analyses, deformations that may occur under different conditions were examined by using existing constructions for pilot window design in side-by-side aircraft. In the analysis, the bird strike in the glass construction with a layered structure is modelled with ANSYS-LS Dyna, and the total amount of deformation that may occur in different geometries is discussed. Besides, the solution of the problem with the TRIZ approach is discussed, and the solutions proposed in the analysis made according to the area of the fixed body in the pressure-stress recovery property condition are evaluated, and the use of transparent wood material on the outer surface of the glass is evaluated. According to this approach, the analyses were repeated for glass and transparent wood, and it was found that there could be a significant reduction in total deformation. In addition, it was concluded that the transparent wooden structure could allow for a larger glass construction due to its thermal properties.

At the beginning of 2020, Covid-19 has had serious negative effects on the aviation sector around the globe. Many aviation enterprises suspended their activities, and some faced bankruptcy. In 2021, while the sector is trying to normalize with economic and political support, passengers follow the developments carefully and try to adapt. However, the variability of human behavior appears to be one of the obstacles to normalization. In the chapter, the behavior of passengers in Turkey during the Covid-19 process was investigated, and the risk perception of Covid-19 was measured according to demographic differences. Although age is the main factor, it has been observed that gender, education, and income show different results for participants due to the risk of contracting Covid-19. The findings reveal the importance of acting one step beyond the standard solution suggestions to increase the confidence of the passengers or reduce their concerns.

In this chapter, hydrogen fuel cell (HFC) technology is investigated as a solution for the general aviation industry. A modified Cessna 172 installed with poly-membrane fuel cells (PEMFCs) was modelled through MATLAB/Simulink software with Hydrogen (H2) as fuel. Under different scenarios, a model was produced in Simulink investigating hydrogen in the gaseous state at 350 and 700 bars, and in liquid at 5 bars. The maximum reduction obtained in fuel required was over 80%. However, the mass comparisons between the original Cessna 172 and HFC-powered Cessna model indicate that the HFC system brings an extra 6.9–30% mass. For a modified one-pilot Cessna 172, only four of the seven test scenarios allowed it to take-off. Power densities obtained were between 213 and 403 Wh/kg for the scenario runs, which were lower than expected. The greatest drawback of HFC-powered aircraft is the additional mass that they bring, specifically the tank mass. Overall, the data produced show that PEMFCs are a strong candidate for clean propulsion on small general aviation aircraft. There is therefore an opportunity for researching how to reduce hydrogen tank mass, to further increase the capabilities of HFCs for the general aviation industry.

This chapter presents the overview of the piezoelectric as a vibration energy harvester on airplane seats. It is a method of utilizing vibration on seats for generating electricity to support the need for electricity for simple electrical devices such as laptops, smartphones, tablets, etc. The mechanisms of harvesting energy covered are electromagnetic vibration, piezoelectric vibrations, and electrostatic vibration energy harvesters. The method is to focus on piezoelectricity for the design of airplane seats. The method for implementation of harvesting vibration energy is applied in which leads to the optimal placement of the harvesters. Several concepts are generated and tested by using Minitab 17 software.

In scramjet engine, inlet isolator is used to provide stable compressed flow to the combustors. A series of oblique shocks are used to compress the flow by increasing static pressure. The shock wave/Boundary layer Interaction (SWBLI) is one of the major phenomenon in inlet isolator flow. Intel-Isolator is designed for fixed flow conditions, but flights can face fluctuating condition for various reasons which may affect the compression and separation characteristics inside the isolator. In our present study, a computation on the effect of pulsating flow on the shock wave/boundary layer interaction in supersonic inlet isolator is performed. The inlet flow condition is sinusoidal with different frequencies but with same amplitude with mean Mach number of 4.9. The different flow parameters at different flow conditions inside the isolator are observed. The hysteresis phenomena and dependency on the frequency of the cycle are examined in the study.

Converging-diverging thrust-vectoring micro-nozzle has the potential to become a prominent manoeuvring technique of flight control for small-scale aerospace systems. Present study addresses thrust vectoring in the supersonic micro-nozzle by “bypass mass injection” method. Numerical modelling has been done by the direct simulation Monte Carlo (DSMC) method. Numerical results show that the total mass flow rate, secondary flow percentage, thrust force, thrust coefficient, and specific impulse increase with the bypass channel width. Consequently, a change in thrust direction is obtained which in turn produces a considerable vectoring effect in the supersonic micro-nozzle. The vectoring effect for Pout = 40 kPa peaks at 6-μm bypass channel, whereas a gradual increase of the vectoring angle with the bypass channel width is observed at Pout = 10 kPa.

The more electric auxiliary power unit (MEAPU) can provide electric power for more electric aircraft. Since the starter generator (SG) is used in MEAPU, the optimization of starting process control can be realized through fuel flow and SG torque control. Compared with the auxiliary power unit (APU), the electric load of SG in MEAPU can change abruptly during power generation, resulting in excessive speed fluctuation of MEAPU, which needs to be suppressed. In order to solve the above problems, a model consists of an APU and a SG is established. In the starting process, a variable substitution optimal control (VSOC) method is proposed, and the starting time is shortened by 10 s without over-temperature and surge. An active load fluctuation suppression control (ALFSC) method is used, suppressing the speed fluctuation caused by a sudden load of more than 80%.

Re-entry vehicle is the movement of an object from outer space into and through the atmosphere of a planet. The re-entry vehicles are especially design to withstand extreme heat and aerodynamic forces. In this chapter, the effect of flight altitude on the aerodynamic characteristics of re-entry vehicle is presented. The study demonstrates the importance of understanding the effect of shock wave and illustrates how small change in flight altitude can alter the resulting aerodynamic forces on the re-entry vehicle. Here, the problem of selecting the shape of windward side of the re-entry vehicle is addressed by analysing the flow behaviour over two-dimensional blunt and sharp body. Blunt body are more preferable than sharp body that is decided based on the variation of pressure, velocity and temperature. The flow behaviour over three-dimensional body such as the Dragon and Apollo capsules at supersonic and hypersonic speed is analysed.

Optimal linear Kalman filter, fault detection, fault isolation, and reconfigurable Kalman filter algorithms have been applied to the lateral dynamics of Boeing-747 aircraft in this study. The flight dynamic model of Boeing-747 aircraft in steady-state flight condition is presented and investigated. In nominal case, the OLKF gives fine estimation values. However, when there is a malfunction on the measurement channels, the accuracy of the filter estimations becomes poor, and the filter becomes unreliable. Two faulty cases took place on the system. The first sensor fault is the single-sensor fault, and the second is a simultaneous double-sensor fault. The fault detection algorithm detects the fault, and isolation process ran and calculate the statistics of the rate of sample and theoretical error variances. For fault accommodation process, this chapter presents reconfigurable Kalman filter algorithm to enhance the estimation values of the filter.

This chapter presents a summary of works completed towards the understanding of acoustic emission (AE) and acousto-ultrasonic (AU) monitoring in high-temperature environments. An expanding interest into the development of hypersonic vehicles, operating at Mach numbers greater than five, presents challenges with aerodynamic heating at temperatures exceeding 1000 °C. Monitoring of high-risk systems such as turbojet engines operating at high temperatures present similar challenges for vehicles currently in operation. This work comprises a short review of research into the effects of temperature for AE/AU monitoring as well as the sensors and actuators (S&As) that may be employed in these environments. A discussion is provided regarding considerations and techniques for the future of in situ integrated vehicular health monitoring (IVHM) for AE/AU at high temperatures.

This work explores the application of the explicit dynamic finite element analysis (FEA) software, LS-DYNA for the simulation of low-velocity impacts upon metallic plates as a preliminary assessment for similar work in fibre-reinforced polymers (FRPs). Impacts are performed on a flat (100 × 100)-mm aluminium plate of 1 mm thickness using a 10-mm spherical steel projectile. Impact events between 2.5 J and 20 J are performed, and the acoustic and modal response of the plate is analysed. The aim of this work is to provide a framework that would allow for the localization and interrogation of impact events for the assessment of barely visible impact damage (BVID) in FRPs. The challenges of BVID are discussed as well as the future work to be undertaken towards the development of an acoustic emission (AE) structural health monitoring (SHM) system.

This opinion chapter discusses the advantages of foresight under a systemic macrocognitive approach for the safe and effective deployment of technological innovations in aviation. Although microcognitive studies aid the understanding of interfaces between innovative systems and their users, this chapter posits that there is a need to address the broader information-driven environment that emerges in organizations through the innovation-driven change process. The chapter argues that a deep understanding of knowledge structures and organizational cognition may aid identifying the prerequisites for the safe preparedness of aviation organizations and their sucessful deployment of innovative systems. Following the critical tenets of the systemic paradigm and naturalistic decision-making, a systemic mapping is presented that extends to higher levels of analysis, complementing the microcognitive approaches.

Recently, it is witnessed a significant increase in the number of controlled missiles for various purposes and specifically for launching satellites. To validate the performance of an air vehicle and to carry out the designing process of the controller and stabilizer, missiles need to be accurately modeled and simulated. The literature is very meager in the simulation of missiles using 6DOF model. Therefore, this project simulates the missile using 6DOF by Simulink. To perform the simulation, dynamical equations using Newton’s second law were derived and then simulated term by term using MATLAB. The resulted dynamical equations were a set of nonlinear time-invariant and coupled differential equations. The missile thrust and inertia tensor were defined using tabular data which function of time, while the aerodynamics and stability derivatives were also determined by tables that function to Mach’s number, angle of attack, and sideslip angles. The simulation process was validated by comparing the resulted trajectory for a case study with a similar one found in the literature. The comparison showed a good agreement. The resulted simulator allowed to design and tune of a PID controller using the Ziegler-Nichols method. This approach showed high flexibility and efficiency in finding missile trajectory and designing controller and stabilizer.

Maintenance optimization has been of high interest in recent years for both the industry and the knowledge institutions. For example, tens of billions of dollars are spent on annual aviation maintenance, repair, and overhaul (MRO) activities. At the same time, the attention also grows in the direction of the advances in data analytics and digital technologies which can enable the next step in maintenance transition from preventive to predictive. The integration and operational deployment of physics-based (domain knowledge) and data-driven (AI, digital twin) innovative technologies can enhance the optimization of lifecycles and processes. Main objectives are the reduction of aircraft downtime and costs as well as a minimal waste in terms of materials and energy.

With the exponential growth of numerous drone operations ranging from infrastructure monitoring to even package delivery services, the integration of UAS in the smart city transportation systems is an actual task that requires radically new, sustainable (safe, secure, with minimum environmental impact and life cycle cost) solutions. This paper deals with the required ATM and dedicated control systems for drones or groups of drones. Drones may follow the fixed trajectories (or corridors) by an autonomous trajectory tracking control system, coupled with autonomous conflict detection, resolution, and formation flight options. Drones will be connected with the agency, designed trajectories to support them with factual information on trajectories and corridors. While the agency will use trajectory elements to design fixed or desired trajectories, drones may use the conventional GPS, infrared, acoustic, and visual sensors for positioning and advanced navigation. The accuracy can be improved by unique markers integrated into the infrastructure.

A new bench test was built in order to analyze at small scales, typically with sample size of a dozen of centimeters, the behavior of composites under a kerosene flame. Compared to standard tests, the small dimension size of the samples makes it possible to install more measurements allowing scrutinizing in more details the fire reaction of composites, and analyses can be done on a larger number of products. During the thermal stress, the test bench allows to monitor mass loss and the temperature at the back face. As for examples, the tests for two carbon fiber-reinforced polymer matrix composites, a thermosetting-based (epoxy 8552) and a thermoplastic-based (polyphenylene sulfide), will be shown, and the results are discussed.

The purpose of this chapter is to determine the impact of aircraft on Europe’s ecology. The focus of this chapter will be on the extent to which aircrafts influence and pollute the environment. The chapter includes various case studies conducted by various authors to estimate the impact of various universal indicators and to determine the level of the impact made by specific factors on the environment, as well as a comparison of EU facts and figures with policies proposed by various governments, including the USA and Australia. The purpose of this chapter is to assess the facts and numbers in order to determine the environmental risks posed by aircraft around the world.

This study investigated the nanoparticle addition effect on the mechanical properties of DURATEK KLB 75 polyurethane (PU) resin used for bonding sheet metal, galvanized sheet, aluminum, and the sandwich panel. Nanoparticle-reinforced samples were produced by adding 0.5% hexagonal boron nitride nanoparticles (hBNNPs), 0.5% hBNNPs +0.25% multi-walled carbon nanotubes (MWCNTs) in PU resin. Tensile and hardness test (shore D) were conducted for every specimen to determine the effect of nanoparticle addition on the mechanical properties of the samples produced according to ASTM-D638-10 standards, and tests results curves and graphs drawn. Tensile strength for pure PU, 0.5% hBNNP added PU, and 0.5% hBNNP +0.25 MWCNT added samples are 20.80 Mpa, 14.87 Mpa, and 24.80 Mpa, respectively. Moreover, the hardness test result supported the tensile test. While h-BNNP causes a decreased tensile strength and hardness, the addition of CNT and h-BNNP increases these properties.

The steady-state and dynamic design of experiments for 53° sweep lambda wing-unmanned combat aerial vehicles (UCAV) configuration is discussed in detail. The design of the experiments was done in the Universiti Teknologi Malaysia Low-Speed wind Tunnel (UTM-LST) and contains force and moments balance and surface flow visualization with the pitch angle and yaw angle variation for the steady-state experiments and the dynamic oscillatory rig facility with 1 degree of freedom oscillating mechanism was fixed to rotate in yawing axis to focus on the sensitivity for the yaw angle for the dynamic investigations. The steady-state experiments will be capable to give the steady-state aerodynamic derivatives, while the dynamic testing will provide the trainset aerodynamic derivatives. The steady-state and the dynamic measurements will help in studying the unsteadiness and the uncertainties of the flow over the wing configuration.

An experimental study is carried out to investigate the effects of leading-edge tubercle NACA 0015 airfoil at a suction type of wind tunnel. Three different leading-edge tubercles and a baseline NACA 0015 airfoil are utilized. These airfoil dimensions are a mean chord (c) of 150 mm and spanwise length of 450 mm. The Reynolds number based on the mean chord is 5 × 104. The force measurements experiment is performed by using a six-axis load cell at the angle of attack changing from 0° to 30° with an increment of 1°. This study aims to provide important insights about leading-edge tubercle airfoil at low Reynolds number and reveal the aerodynamic performance of these airfoils. Force measurement results reveal that tubercle form at the leading edge is significantly changed common stall characteristic as compared to the baseline airfoil.

This chapter is devoted comparison of stationary user localization estimation by traditional extended Kalman filter (EKF), linear Kalman filter (LKF), and NRM pre-processed LKF. In this study, Şükrü Saraçoğlu stadium’s location was estimated via various types of Kalman filters. Position states due to Earth-centered inertial (ECI) reference frame were obtained by the Global Positioning System (GPS) receiver. Pseudo-ranging model was used to determining the position of Şükrü Saraçoğlu stadium. To simulate GPS receiver, random measurement errors were added to the actual distance between the stadium and GPS satellite. In this study, various filters were compared for stationary user localization estimation.

In this study, the accuracy of the distance measurement, distance difference measurement, and integrated terrestrial radio navigation methods is investigated. To do this, simulations for the aircraft flight dynamics were carried out, and the obtained position values were compared with the actual values. The aircraft position determination methods were evaluated in the sense of accuracy.

A finite element model (FEM) is developed in the commercial software ANSYS© to study the buckling, debonding, and collapse behavior of composite-stiffened panels under uniaxial compression. The main goal of the developed model is to explore, without sacrificing any accuracy of the results, the possibility to overcome the required extremely fine meshes, which are followed by large computation times, when traditional cohesive zone modeling (CZM) is used, for the study of debonded structures. An engineering method from the literature that leads to significantly coarser CZM meshes, as it is proven for simple coupons only, is extended to larger scale structures (stiffened panels). Additionally, progressive damage modeling (PDM) routines are employed to the FEM of the stiffened panel to capture its overall behavior. Eventually, by modifying certain CZ model parameters, a time-efficient yet accurate FE model is obtained with PDM capabilities. This work can provide guidelines for the numerical analyses of even larger and complicated damaged structures.

Although the aviation industry is working on versatile technological transformations, especially unmanned aerial vehicles, alternatives in current engine technologies are quite limited. In the development of areas where the use of innovative engine technologies, strategic evaluation paradigm is need as sectoral requirements, and the sustainability effects of environmental indicators are also important points that need to be addressed. In this process, performance evaluations of engines with different environmental impact processes gain importance. In this study, the effects of environmental sustainability depending on defined indicators are discussed over the performance of a turboprop engine depending on altitude conditions. The performance of the irreversible effects of the sampled PT6-21 turboprop engine at 15000–21000-ft cruising conditions was evaluated. In the analyses, irreversibility effects related to engine performance for three different ambient temperatures were examined and analyzed. At the end of this study, the effects of indicators on environmental performances were examined.