This paper provides linear plant model forming methodology based on assumption of existence some reference flight configuration, on the neighborhood of which small variations of plant kinematic parameters are taken place. Kinematic parameters of motion are produced as sum of their values in reference motion and deviations of these parameters from commanded values. Obtained plant model takes the form of linear homogenous differential equation system with coefficients, which are known function of time and the state vector of formed model is vector of deviations of kinematic motion parameters from its commanded values.