International Journal of Sustainable Aviation (8 papers in press)

Regular Issues

• Calculations of internal heat gain from occupants affecting the energy consumption of airport buildings  
  by Okan Kon, İsmail Caner 
  Abstract: In complex structures such as airports, when calculating metabolic heat gains from humans, convection and evaporation heat gains taken into account, and then heat gains by convection, radiation, and evaporation from the skin surface are taken into account. In the study, three different metabolic energy production has been taken into account for a person sitting, standing or resting, doing light work and using a small hand tool. In the heat gain calculations from the skin surface, the lowest thermal resistance of the clothing was accepted. Based on the number of passengers, overall heat gain value calculated for one person was found for various airport buildings. As a result, the lowest overall heat gain has been calculated as 406.862 W for 0.2 m/s indoor air velocity and 70 W/m2 metabolic heat production, and the highest is 596.854 W for 5 m/s indoor air velocity and 115 W/m2 metabolic heat production.
  Keywords: airport buildings; indoor heat gain; convection heat transfer; radiation heat transfer; evaporation heat transfer.
  DOI: 10.1504/IJSA.2023.10054178
   
  
• The influence of environmental knowledge on green purchase intention in the air travel industry: The mediating role of green attitude  
  by Mahmut Bakır 
  Abstract: The air travel industry, which is a significant contributor to greenhouse gas emissions, has placed environmental concerns at the forefront of its operations and marketing efforts. This study aims to examine the influence of environmental knowledge on green purchase intention while considering the mediating effect of green attitude. To this end, conceptual model was tested using the partial least squares path modelling (PLS-PM) technique and ADANCO, with 156 valid responses from Turkey collected via a structured questionnaire administered to passengers. The results indicated that both environmental knowledge and green attitude have positive and significant impacts on green purchase intention. Additionally, green attitude mediates the relationship between environmental knowledge and green purchase intention. These findings suggest that an increase in consumers' environmental knowledge has both direct and indirect effects on their inclination to purchase environmentally friendly air travel products.
  Keywords: green purchase intention; environmental knowledge; PLS-PM; air travel industry; sustainable aviation.
  DOI: 10.1504/IJSA.2023.10054766
   
  
• Comparative analysis of using diesel/JP-8 fuel blends and JP-8 for the exergetic sustainability performance of an UAV turbojet engine  
  by Cem Tahsin Yücer, Yavuz Nacakli 
  Abstract: In this study, it is aimed to analyse the effects for the partial use of diesel fuel with kerosene-based JP-8 on the jet engine’s performance by using exergetic sustainability parameters. Three fuel types were defined as 100% JP-8, 75% JP-8/ 25% Diesel and 50% JP-8/ 50% Diesel. Firstly, the exergy analysis was implemented to the jet engine components. Then five exergetic sustainability parameters: waste exergy ratio (WER), environmental effect factor (EEF), exergetic sustainability index (ESI), ecological effect factor (EcoEF) and sustainability efficiency factor (SEF) were calculated. The exergetic sustainability parameters showed that the increase in diesel fuel use caused slightly higher WER, EEF and EcoEF values, as well as slightly lower ESI and SEF values for the combustion chamber and overall jet engine. It was concluded that partial use of diesel can be an alternative for low altitudes under obligatory conditions in small UAV turbojet engines.
  Keywords: exergy analysis; sustainability; jet engine; unmanned aerial vehicle; UAV.
  DOI: 10.1504/IJSA.2023.10056113
   
  
• TRIAD aided adaptive Kalman filter for fault tolerant attitude estimation of a nanosatellite  
  by Hasan Kinatas, Chingiz Hajiyev 
  Abstract: In this study, a fault tolerant attitude estimation system is proposed for a nanosatellite, combining the TRIAD algorithm, a vector-based attitude determination method, with an adaptive extended Kalman filter. As the first step of the estimation system, the TRIAD algorithm produces an initial coarse attitude estimation using three-axis magnetometer and sun sensor measurements. Then, this coarse estimation is filtered via an adaptive extended Kalman filter to obtain the final estimation. Besides filtering and providing more accurate estimations, the adaptive filter also makes the system fault tolerant by maintaining the estimation accuracy in cases where sensor faults exist and measurements become unreliable. This is made possible by tracking the filter's innovation history and re-adjusting the Kalman gain using appropriately calculated fading factors. In order to verify the performance of the proposed system, two different simulations are performed where the attitude sensor outputs are disturbed by additional measurement noise.
  Keywords: nanosatellite; attitude estimation; adaptive Kalman filtering; fault; magnetometer; sun sensor.
  DOI: 10.1504/IJSA.2023.10053674
   
  
• PC Air: an extreme case of fleet planning problems  
  by Orawan Nugprachaya, Poowin Bunyavejchewin 
  Abstract: From 2000 to 2019, a total of 31 airline firms were launched in Thailand but then shut down, mostly within a short period of time. Although a vast array of factors could contribute to airline failures, this study focuses on pitfalls in the airline fleet planning process, notably equipment selection and acquisition. Of the 31 defunct airlines, PC Air, a short-lived charter carrier, was selected for analysis since it was an extreme case study, representing a textbook pitfall trap in which airline firms have rarely fallen into in real-world aviation business situations. In the PC Air case, flawed fleet planning was a clear-cut error behind its collapse. This was exemplified through the unsound selection and acquisition of the used aircraft, which mismatched the airline's mission and contradicted the charter carrier business model, and via its ill-advised decision to conduct commercial operations with only one aircraft.
  Keywords: airbus; A310-200; aircraft acquisition; aircraft selection; charter carrier; defunct Thai airlines; fleet management; fleet planning; PC Air; Thailand.
  DOI: 10.1504/IJSA.2023.10052471
   
  
• Model reference adaptive control of a quadrotor: simulation and flight tests  
  by Demet Canpolat Tosun, Yasemin Işık 
  Abstract: The aim of this study is to design and implement a model reference adaptive control system for a quadrotor. The quadrotor model is the Qball-X4, a testbed developed by Quanser Inc. For control purposes, the mathematical model of the quadrotor is examined in detail. The simulation studies are performed using the mathematical model and appropriate controller parameters in the MATLAB/Simulink simulation environment. Different reference models and adaptation rates are tested according to the model reference adaptive control procedure. After obtaining satisfactory results in the simulation environment, the purposed control system is implemented on the real system. The motion of the vehicle in the X, Y, and Z axes is observed and the results are presented with graphics for different flight tests.
  Keywords: model reference adaptive control; MRAC; Qball-X4; MATLAB/Simulink; reference model; adaptation rate; motion control.
  DOI: 10.1504/IJSA.2023.10056322
   
  
• Design, manufacturing and testing of a tail-sitter UAV capable of hovering  
  by Sandro Domitran, Marina Bagić Babac 
  Abstract: There are many different tasks that got revolutionised with the arrival of UAVs in the last couple of years. Most of them are solved either by using multi-rotors or airplanes, which both have some strengths and weaknesses. While multi-rotors can fly precisely and take off and land almost anywhere, they are not as efficient as planes as they are able to generate lift using wings. This work proposed an aircraft that is a combination of those two, so the strengths are preserved, and weaknesses eliminated. The built prototype is a tail-sitter aircraft which is mechanically the simplest VTOL aircraft type. It takes off and lands as a multi-rotor, and it is able to transition into fixed-wing flight while in mid-air. The outdoor experiments verified its behaviour while hovering, while transitions and fixed-wing flight are only verified using simulation. In addition, it was also able to perform a simple task using machine learning.
  Keywords: ArduPilot; machine learning; PID; RealFlight; simulation; software in the loop; SITL; tail-sitter; transition; VTOL.
  DOI: 10.1504/IJSA.2023.10054538
   
  
• Transforming to NextGen air transportation system: a case study for Turkey's national aerospace development  
  by Mehmet Necati Cizrelioğullari, Tapdig İmanov 
  Abstract: Innovation of the air transportation system is crucial on all stages of its development, which requires continuous support. Modernisation of ageing equipment, development of new generation (NG) aircrafts and its systems makes necessary shifts to a next generation (NextGen) aviation industry era. This study compares the existing technologies of the air transportation system used in Turkey's aviation industry with the NextGen concept and its main pillars for the development of new elements. This study also examines the feasibility of leveraging new elements of the NextGen concept that would efficiently use the national airspace, which include satellite-based navigation and surveillance, advanced digital communications, integrated air traffic management, and wide information sharing systems. Taking into account the increasing trend of development of the international and regional air transportation network from/to Turkey in the near future, it is considered appropriate to apply the concept of NextGen in the Turkish aviation industry in order to avoid difficulties in managing airspace. The results of the study state several benefits upon application of NextGen elements, but expected cost issues need to be defined by the government to invest in its implementation and development.
  Keywords: air transportation; next generation; NextGen; airspace; aviation; Turkey.
  DOI: 10.1504/IJSA.2023.10053591