Major events, for example Olympic Games or FIFA World Cup, are very popular with people from all over the world. The demand for air travel noticeably rises at these periods. In that case, research has to be carried out in order to forecast the traffic flow to make all members of ATM system (airlines, airports, ATC and etc.) ready for it. In this paper the method to figure out the possible structure of air traffic flows will be described. This method also can be used to estimate the optimal aircraft fleet to transport the additional passengers or the optimal usage of available aircrafts. The focus will be on minimizing airline's expenses. The main goal of this study is to transform the task of people transportation into math problem. The way to state optimization problem will be represented. This paper also considers different types of research conditions and suitable constraints for each of them.