## 7 Conclusions  
The article's main objective was to provide an overview of the logistics planning methodology for securing the operation of a military aircraft and, in particular, to find a way of generating the need to fill the depot with spare parts in the event of unplanned damage. This is important from the point of view of minimizing losses due to the unavailability of the aircraft for flight training. Planning the purchase of spare parts in military aviation is related to long-term planning. First, the logistics needs are defined, then, the budget is estimated, the appropriate contracts with subcontractors are signed, and, finally, the order is completed in the form of the delivery of parts. Often, this process takes a minimum of 15 months. The biggest problems were with the estimation of logistic needs related to the occurrence of accidental damage. Therefore, there was a need to develop a method of logistical planning that considers the occurrence of accidental damage to aircraft. As a tool, one of the available reliability indices--the mean time to failure (MTTF) determined from the collected data from past operations--was proposed. The next step was to determine the mean time to failure using available probability distributions. The results obtained were compared with the MTTF obtained from Formula (1). The values of the indices obtained are comparable. The developed method was verified by comparing the size of the calculated logistic needs with the actual exchanges of a given device. In total, 70% of the results obtained were consistent with the real exchanges. Therefore, it can be concluded that it is possible and effective to predict failing spare parts based on the MTTF reliability index. This method does not require complex computer programs or in-depth mathematicalknowledge. It is a method that can be used by any engineer, provided that failure data from a previous operation is available.  
Summarizing, it would be appropriate to highlight once again that reliability is of the utmost importance in aviation, especially when it comes to safety. The reliability of aircraft and their components is crucial to ensure safe flight operations, as well as readiness to perform them. A thorough reliability study can identify potential failure modes and implement preventive measures to reduce the risks associated with these failures. The use of advanced data collection and analysis techniques can also help to identify potential problems before they occur and to maintain a high level of reliability and safety in flight operations. Therefore, a comprehensive reliability study can significantly affect the safety and readiness of the aircraft for flight operations.  
Conceptualization, A.Z., M.Z., J.T., N.G. and G.K.; methodology, A.Z., M.Z., J.T., M.J., N.G. and G.K.; software, N.G. and G.K.; validation, M.Z., J.T. and N.G.; formal analysis N.G. and G.K.; investigation, A.Z., M.Z., J.T. and N.G.; resources, N.G. and G.K.; data curation, N.G.; writing--original draft preparation, M.Z., J.T., M.J. and N.G.; writing--review and editing, A.Z., M.Z., J.T. and N.G.; visualization, N.G. and G.K.; supervision, M.Z. and J.T.; funding acquisition, J.T. and M.Z. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The authors declare no conflict of interest.