Maintenance cost analysis under different inspection levels for aircraft structure

According to the MSG-3 analysis, because the degradation of SSI has the characteristics of a delay-time, the threshold and repeated intervals should be considered together. So the variables to be optimized are the inspection level, threshold and repeated intervals, and an optimal inspection model for aircraft structure is developed to minimize the maintenance cost rate subject to a required reliability. In the model, it is considered that different inspection levels have different effects on the maintenance cost and decision-making, and the renewal probability of aircraft structure is studied. Then using Monte Carlo simulation, the initiation and growth of the crack is researched. Finally, an example is presented based on a case study.