VESTNIK of Samara University. Aerospace and Mechanical EngineeringVESTNIK of Samara University. Aerospace and Mechanical Engineering2542-04532541-7533Samara National Research University55110.18287/2541-7533-2008-0-1(14)-121-127UnknownModelling changes of condition of aircraft hydraulic system working fluidGareyevA. M.gareyev@ssau.ruSamara State Aerospace University180320087112112730052014Copyright © 2015, VESTNIK of the Samara State Aerospace University2015<p>The paper presents a model of working fluid condition changes in an aircraft hydraulic system during the overhaul period. The model is developed on the basis of Marcov process theory and intended to define the working fluid purity using lead maintenance technologies in an effort to increase life expectancy of aircraft hydraulic system components.</p>Hydraulic systemworking fluidmodel of conditiontechnical condition controllead maintenanceworking fluid purityГидравлическая системарабочая жидкостьмодель состоянияконтроль технического состоянияупреждающее обслуживаниечистота рабочей жидкости