Abstract: To solve the problems of harsh maintenance training conditions of civil aviation aircraft and the difficulty for operators to understand complex maintenance manuals, a dual-mode simulated maintenance system of a certain type
civil aircraft is designed and developed based on virtual reality (VR) technology. Firstly, dual-mode system of
desktop and VR are developed based on Unity3D platform and HTC Vive virtual device, and interactive research
on ray dynamic collision detection algorithm and geometric transformation are carried out. Then， a data manage
ment and scheduling scheme based on B/S architecture is proposed, and the sub query search engine is studied.
Finally, the test verification of dual-mode system is carried out respectively, taking the landing gear maintenance
as well as winding inspection and maintenance of civil aircraft as case studies. The research results show that the
space segmentation technology based on dynamic collision detection algorithm is more conducive to ray detection,
and the search that is divided into sub queries according to logical steps is more efficient. The developed system
meets the virtual learning and training needs of trainees for different simulated maintenance.

Key words: civil aircraft maintenance, virtual reality (VR), ray collision, data management, simulated maintenance