Abstract. Development of the best economic parameter inspection program of fatigue-prone aircraft under limitation of airline failure intensity is discussed. Calculation of aircraft failure probability, airline failure intensity and airline gain are considered using Markov Chains and Semi-Markov process theory for the case when parameters of exponential fatigue crack growth are known. 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.