# Immersive Virtual-Reality System for Aircraft Maintenance Education: A Case Study
## 2 Literature Review  
Learning by doing [11] is a methodology that has been demonstrated as efficient in the learning process. It is based on learning from experiences that result directly from one's own actions. In other words, it is a method by which learners obtain the most out of their education through active participation. The goal is to give future professionals a chance to apply the knowledge and skills they have learned in a real-world setting, which can help them become more proficient and confident in their abilities. Additionally, learning by doing can help reduce the time and cost associated with traditional training methods. Regarding professional training, the usual problem for learners is that accessing the physical material or environments where obtaining knowledge is generally very difficult and expensive. In these cases, the digital representation of the training environments can be the solution. Some papers related to this topic support this assertion, such as the one presented by [PERSON] et al. [12]. In this work, they presented an application of VR technologies to create virtual training simulations addressing assembly or maintenance tasks. The paper suggests a methodology to create an interactive virtual space in which operators can perform predefined tasks in a realistic way, with dedicated instructions to support the learn-by-doing based on key training features. The results show that operators generally appreciate this new training process, enabling faster and more intuitive learning. Aircraft maintenance is one of the fields that have more difficulties because the learners have to demonstrate a high level of expertise to access the planes. Therefore, beginners are not generally allowed to access the hangars to practice their knowledge, although they have to obtain competencies to ensure error-free maintenance. [PERSON] et al. presented in [13] a work that measured the degree of immersion and presence felt by subjects in a virtual environment simulator. Specifically, it conducted two controlled studies using the VR system developed for the visual inspection task of an aft-cargo bay. The results of this study indicated that the system scored high on the issues related to the degree of presence felt by the subjects. In 2008, [PERSON] et al. presented [14] work on training aircraft maintenance inspectors. The purpose of their study was to develop a simulated aircraft cargo bay in a virtual reality (VR) environment to explore VR as a training tool and examine differences between general and detailed inspection under paced and unpaced conditions. [PERSON] et al. presented in [15] a concept to evaluate the potential of inspection and maintenance processes in the aviation industry regarding the use of mixed reality systems. Four different use cases were discussed applying augmented or virtual reality devices in an industrial context. More recent works in this field were presented by [PERSON] et al. [16]. They proposed a system that incorporates virtual reality methods into the classroom to compensate for the shortcomings of the existing remote models of practical education. Based on the proposed system, the authors developed an aircraft maintenance simulation and conducted an experiment comparing their system to a video training method. Some retention tests were conducted, and presence was investigated via survey responses. The ones given to the presence questionnaire confirmed a sense of spatial presence felt by the participants, and the usability of the proposed system was judged to be appropriate. In the same year, [PERSON] et al. [17] presented in their work an aircraft maintenance virtual reality system. For a Dornier-228 aircraft, a walk-around visual inspection of its fuel system was designed in a virtual environment. The environment was tested by students to validate the effectiveness of using the system in training.