The paper describes development of the methodology of the choice of aircraft fleet’s inspection intervals. This methodology is verified, using the experimental fatigue crack growth data. Methodology includes in the economic parameters. Using this method it is possible to find safe- enough and the most cost- effective inspection planning programs. In addition the paper includes testing of the methodology at different permissive withdrawal probabilities and their impact on the real probability of withdrawal and the number of inspection intervals for the model with one aircraft and with aircraft fleet. For the case when they are not known the minimax approach is offered if there are results of acceptance full-scale fatigue test and conditions of acceptance are known. Numerical examples are given.