The method of the stochastic Markov process used for the analysis of operation of a training aircraft-Cessna 150 was presented in the article. In this article, the time changing probability of readiness was determined on the basis of knowledge of the current aircraft operation. Markov stochastic processes have been used as a model to determine aircraft-Cessna 150 readiness for specific tasks. In order to determine the readiness, the probability of being in one of the investigated states is determined. The analysed states included: standby, pre-flight service, flight, interstate service, after-flight service and hangar service.