The air conditioning system is one of the most important life support systems in an aircraft, therefore the assessment of technical condition and maintenance of reliability at an appropriate level are of great importance in ensuring flight safety. Thesis evaluates the technical condition of the air conditioning system of short flight passenger aircraft. To solve the tasks, the author has developed a prototype of a short flights passenger transportation aircraft and proposed an air conditioning system scheme and calculated the structural reliability of the air conditioning system for one flight shift. This work has practical application and the approaches described can be used to assess the reliability and technical condition of the aircraft during exploitation.