Аbstract. The article summarizes the theoretical aspects of the processes of calculation and analysis of the cost of air transportation. In Ukraine, planning, accounting and analysis of operating costs is carried out in two main aspects ‒ economic elements and cost items. Aviation enterprises use International Accounting Standards 1 ″Presentation of Financial Statements″ to disclose information on expenses. In particular, this standard provides that an entity must disclose all items of expenses that are recognized in the reporting period in a single ″Statement of profit or loss and other comprehensive income″. A feature of the costing process of aviation enterprises is that they use not only the typical nomenclature of items recommended by ICAO, but also use costing on dry leasing terms (without a crew) when carrying out leasing operations; prime cost under wet lease conditions (with crew); cost price on ACMI terms. In this case, it is advisable to allocate the following cost items, which the airline has an impact on, to determine the cost of aviation work ‒ these are four items: 1) Aircraft; 2) Crew; 3) maintenance; 4) insurance. The purpose of the analysis of the cost of air transportation is to identify untapped reserves of its reduction and contribute to this reduction. The objectives of the analysis are: ‒ identification of trends in operating costs and production costs; ‒ assessment of the validity and intensity of the plan at the cost of production; ‒ determination of the dynamics and degree of implementation of the plan at cost; ‒ determination of the factors that influenced the dynamics of cost indicators, the magnitude and causes of deviations of actual costs from planned ones; ‒ analysis of the cost of certain types of products (carriage of goods, passengers, etc.); ‒ evaluation and determination of the optimal ratio of income and expenses. The analysis process is proposed to be carried out in five stages. At the first stage, analyze the dynamics and implementation of the cost plan for economic elements and costing items. At the second stage, establish the composition of costs and structure, analyze the changes that have occurred in the cost structure. At the third stage, it is supposed to carry out a factorial analysis of the influence of the total amount of costs and the rate of variable costs per unit volume of air transport operations using methods of deterministic factorial analysis. The fourth stage is the study of the dynamics, the implementation of the plan, the conduct of inter-farm comparisons and the determination of the influence of factors on the consumption rate. At the fifth stage, an analysis of industry-specific, specific indicators in dynamics is carried out, implementation is carried out according to plan, and the influence of factors on the change in the cost of a flight, flight hour, tonne-kilometer, passenger-kilometer, reduced tonne-kilometer is quantified. The analysis is carried out both with the help of economic and logical traditional methods (comparison, absolute and relative values, tabular, graphical), and methods of deterministic factor analysis (chain substitutions, absolute differences, etc.). Since the ways to reduce the cost are derived from the factors that affect it and they act in combination, the main directions for reducing them in practice will be to increase the degree of extensive and intensive use of aircraft and save costs in all respects. Keywords: operating costs, cost, methodology, analysis, costs, factors, production reserves, air transportation, airline.