Progress in Sustainable Aviation

Airports typically have many facilities spread out over an extensive area, sometimes several kilometers apart. These facilities often house specified systems critical for the smooth operations of an airport. The seamless tracking of these facilities, the systems they house, and their service, maintenance, and operational status are critical in ensuring efficient and uninterrupted airport operations.

CMMS is designed to track, monitor, and manage the service, maintenance, and life-cycle of these systems/assets to ensure reliable and uninterrupted airport operations and avoid expensive flight delays and potentially adverse passenger experiences that can cause the absence of such systems. Therefore, proper design and implementation of the CMMS are crucial for achieving intended objectives.

Tagging of airport assets is the key to the successful and efficient implementation of the CMMS. This paper aims to provide a method and a process for successfully implementing a CMMS functionality that ensures standardization, consistency, and the required level of specificity in tagging airport assets while minimizing human errors during the tagging process.

In recent years, unmanned aerial vehicles have been used in all areas of our lives. The prevalence of UAVs is gradually increasing compared to manned platforms in terms of ease of use and the advantages they bring on task type diversity. Unmanned platforms in every field, from space systems to terrestrial and marine systems, are becoming widespread in terms of cost-effectiveness and not risking human life.

The swarm UAV concept is used in commercial areas such as petroleum and pipeline checking applications (Hausamann et al., Aircraft Eng Aerospace Technol 77(5):352–360. https://​doi.​org/​10.​1118/​0002266051061707​7, 2005; Katrasnik et al., IEEE Trans Power Deliv 25(1):485–493. https://​doi.​org/​10.​1109/​TPWRD.​2009.​2035427, 2010), cargo applications (Palunko et al., Robot Autom Magaz 19(3):69–79. https://​doi.​org/​10.​1109/​MRA.​2012.​2205617, 2012), and the movie sector (Galvane, Automated cinematography with unmanned aerial vehicles. In: Eurographics workshop on intelligent cinematography and editing, pp 23–30. https://​doi.​org/​10.​2312/​wiced.​20161097, 2016). In addition, the use of UAVs in light shows and show areas has increased recently. The development of new relative navigation methods of UAV has a financial aspect. Because of these factors, some academic studies are focused on UAV formation subjects. In addition to the civilian use of UAVs, the diversity of military usage areas and parallel to the development in unmanned aerial vehicle technology has brought the necessity of transition from single UAV use to multiple UAVs. Unmanned aerial vehicles (UAVs) contribute to the development of military power due to their success in missions such as surveillance, reconnaissance, attack, and defense, as well as economic and political power. In addition, due to low development costs compared to manned aircraft, unlimited manoeuvrability, and low risk of loss of life, private sector UAV applications, including manned reconnaissance, weather, forestry, agriculture, and photogrammetry, perform civil and military tasks beyond the capabilities of a manned aircraft (Dongwoo et al., Aerosp Sci Technol 76:412–420. https://​doi.​org/​10.​1016/​j.​ast.​2018.​01.​026, 2018). However, a single UAV can only operate in a limited area and is ineffective compared to multiple drones on a mission. Swarm with the approach and multitasking can be performed. The swarm UAV operation does not require any change in the limits and performance of each drone, as well as allowing them to perform an assigned task through collaboration between all or part of the UAVs that make up the swarm to take advantage of the accuracy and efficiency allowed by diversity in the swarm approach (Dongwoo et al., Aerosp Sci Technol 76:412–420. https://​doi.​org/​10.​1016/​j.​ast.​2018.​01.​026, 2018). In addition to this, many researchers are interested in flying UAV platforms in cluster architecture in near or distant formation geometries and performing their tasks.

Relative navigation is used in different platforms for rendezvous, formation flight, and stereo imaging, which aims with UAVs and terrestrial or naval autonomous vehicles (Murtazin and Budylov, Acta Astron 67:900–909. https://​doi.​org/​10.​1016/​j.​actaastro.​2010.​05.​012, 2010; Ma et al., Acta Astron 81:335–347. https://​doi.​org/​10.​1016/​j.​actaastro.​2012.​08.​003, 2012). In this study, UAV formation flight methods are focused on and compared. In the UAV formation architecture, criteria such as method, sensor selection, and the effect of the mission on the flight path and formation geometry effect. Relative navigation is looking for the most optimal state estimates about the position and velocity of one platform relative to the other one (Alonso et al., Vision-based relative navigation for formation flying of spacecraft. In: AIAA-2000, p 4439. https://​doi.​org/​10.​2514/​6.​2000-4439, 2010).

There are navigation and relative navigation methods that are traditional as GNSS & INS integrated or ground-based methods. However, within these methods, the platform that makes up the flock requires extra connectivity between the platform components and the sensor fusion subsystems (Erkec and Hajiyev, Traditional methods on relative navigation of small satellites, 2019. In: 9th international recent advances in space technologies conference (RAST), Istanbul, pp 869–874. https://​doi.​org/​10.​2514/​RAST.​2019.​8767777, 2019). In addition, the other method approach is visual sensor-based fully autonomous freedom of movement using optical and image processing sensors and sensing and tracking models in parallel with the developing image processing and computing technologies (parallel programming, high-capacity processors) and is visual sensor-based methods independent of external systems. The new relative navigation models aim to avoid complexity and incremental errors.

The main highlights of the paper can be summarized as follows. The main focussing subject of this study is the Guidance, Navigation, Control (GNC) architecture of UAV’s formation. Control approach requirements are denoted. Second, target UAV’s state vector tracking, estimation, and control models are explained. Collision avoidance can be executed by the relative state vector estimation and control signals during formation. Algorithms used for relative state vector estimations of UAVs within the formation are highlighted. Third, the comparisons of relative models are defined with different aspects within one hand (Erkec and Hajiyev, Int J Aviation Sci Technol 1(2):52–65. https://​doi.​org/​10.​23890/​IJAST.​vm01is02.​0202, 2020).

This study is about the relative navigation systems of UAVs within formation/cluster flight. First, the concepts and methods in cluster UAV technology and architecture are explained. The relative navigation model comparison of UAVs is based on other systems (Inertial Navigation Systems (INS) and Global Navigation Satellite Systems (GNSS)). Sensors placed in UAV platforms are used separately or integrated to solve relative navigation problems. Their areas of use differ according to the platform type and environment. This study aims to estimate the algorithms of UAVs during flight and the effects of relative navigation systems.

The environmental problems caused by fossil fuels have bolstered the need for research and development of “clean” propulsion systems to power future transport. Both academia and industry are focusing their research on alternative fuels and sustainable resources for developing effective, efficient, and clean future vehicle propulsion systems to reduce their effect on the environment. The aviation industry is closely following the development of electrical vehicle technology in the automotive sector, but many challenges remain, such as those related to certification. Many prototypes for electric aircraft have already been built and tested. However, restrictions due to technological limitations, as well as development costs, have imposed significant constraints on proposed designs. One way to reduce these initial costs is via mathematical models that can simulate the entire system before any real hardware is built so that designs and parameters can be optimised cost-effectively. This chapter describes the state of the art on hybrid propulsion component modelling for two key components: a high-temperature superconducting permanent magnet synchronous motor and a lithium-air battery. It is based on an examination of current published literature. These components could be essential in delivering a clean and efficient energy source for propelling an electric aircraft in the future. The work also gives information about literature studies of fault detection in batteries.

The global aviation fleet numbers rise as a result of increase in flight numbers and hours. Aviation transportation industry causes the environmental degradation and global warming effect. In this regard, greener and sustainable aviation issues have been more interested in researchers, engine manufacturers, and society in recent years. This study presents a model about sustainable aviation for finding the environmental effects and sustainable level of aero-engine systems. These metrics consist of the general aviation metrics, energy-based metrics, exergy-based aviation metrics, environmental-based metrics, and sustainability-based metrics. These aviation metrics are applied to a real turbofan engine to assess the engine’s sustainability level and its main components.

In this chapter, the effects of porosity on battery performance in a vanadium redox flow battery which can use to charge quickly and efficiently the battery systems of the aircraft systems are explained in a detail. These effects are explored in terms of concentration, ohmic, and activation polarization, all of which have a substantial impact on battery performance. The studies in the literature have demonstrated that while the increment in porosity increases ohmic polarization, concentration polarization decreases. Furthermore, particular scenarios are developed for the electrode having different pore distributions which is one of the battery components. The linear increasing porosity and stepwise increasing porosity designs decrease the concentration polarization and increase the utilization of vanadium species, discharge capacity, energy efficiency, and output power. The increase in the porosity decreases the activation overpotential due to the enhanced electrochemical surface area. Furthermore, this increase caused more oxygen functional groups to develop as well as a higher rate of hydrogen evolution. In addition, the heat sources released by the electrochemical reactions and the temperature distributions in the battery are analyzed for the different electrode porosity in a vanadium redox flow battery. The results show that increasing the electrode porosity increases ohmic heat. Furthermore, the temperature distribution in a VRFB becomes more uniform at lower porosity or a higher flow rate.

Aircraft sequencing and scheduling are significant operations for air traffic controllers and pilots. This study presents a mixed-integer linear programming model to minimize the average delay per aircraft for the single and mixed operations runway. Due to the complexity of the problem, the genetic algorithm, tabu search, and simulated annealing algorithms were applied to solve this problem. In addition, the results of the three different meta-heuristic algorithms were compared with the first-come first-served approach and each other. The results demonstrated that all algorithms could noticeably decrease the average delay per aircraft compared to the first-come first-served approach.

One of the most important requirements for maintaining an aircraft airworthy is that the manufacturer’s recommended maintenance must be completed within the specified periods. Airlines that execute optimally aircraft maintenance planning may minimize maintenance costs, which account for 18–23% of direct operating costs, to a minimum level. Airlines that can maintain their maintenance expenses as low as possible have a competitive advantage. Furthermore, the methodologies developed for the efficient use of resources in aircraft maintenance contribute to future generations’ capacity to satisfy their demands, that is, sustainability. The approaches in aircraft maintenance management are investigated with a historical perspective in this chapter to reveal the relationship between maintenance management and sustainability, depending on the development of the aviation industry.

The current problem of the MRO organizations is competitiveness in the environment of aircraft maintenance, in which 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 by implementing Lean tools, in the combination of Six Sigma methods. The aim is analyzing the maintenance processes to determine the existing problems to minimize downtime of the aircraft in this area. Using the data collected from the experts of the MRO, airlines, and an equipment manufacturer, an analysis was made on engine replacement processes. Consequently, , a novel tool is proposed utilizing hydraulic lift engine hoists. The result shows that this approach allows to eliminate unnecessary tasks from the Aircraft Maintenance Manual (AMM) and also reduces the turnaround time by more than 7 h in a single process. The measurement which is based on the final results validates the main contributions for MRO organizations through savings in time and human resources, thereby reducing maintenance cost and aircraft downtime and satisfying the customer.

In this study, radiation and convective heat loss were calculated from the exterior surfaces of airport buildings in 20 different cities in different climatic zones of the world, depending on the outdoor conditions. Firstly, for radiation heat loss, sky emissivity (ε_sky) and sky temperature (T_sky) are calculated. While calculating the sky emissivity value, the outdoor dew point temperature value is used, and when determining the outdoor sky temperature values, both sky emissivity and cloudiness factor values are used. Secondly, convective heat loss was calculated by using the average outdoor temperature and wind velocity values. The convective heat loss calculation from the exterior surfaces of the airport buildings was calculated with both forced and free convective heat loss. Convective heat loss to be used is determined depending on the Gr/Re² ratio. Finally, by summing both radiation and convective heat loss, total radiation and convective heat loss were determined. As a result, the highest total radiation and convective heat loss were found in Moscow, the capital of the Russian Federation, with 166.511 W/m². The lowest total was calculated in Lisbon, the capital of Portugal, at 37.690 W/m².