This paper presents an approach to the development of condition-based maintenance of aircraft to improve aircraft maintenance in the limits and conditions of small countries and in accordance with global technological achievement. For the aircraft were under a limited lifespan maintenance concept, a new condition-based maintenance model is developed. This model applies a technical diagnostic method that brought us to decreasing numbers of failures in the ageing period of those technical systems and at the same time decreases the time when it is out of use and lowers maintenance expenses. An analysis based on this model showed its applicability, preservation of operational readiness, and potential for decreasing the cost of aircraft maintenance.