Aerospace Instrument-Making Annotation << Back Methods of system’s characteristics research applying to digital airplane control systems. G.A. Murashov Airplane, as object of controlling, is unsteady and change it’s characteristics in a wide range of diapasons, first of all because of its sphere of use great expansion. Analyzing of nonlinear control systems’ stability is one of the main items in digital airplane control systems’ creation. There are no common analytical methods of nonlinear system’s research nowadays, that’s why mathematical modeling is commonly used at first stages of constructing nonlinear compound systems. Thus it’s necessary to develop multi-purpose estimation methods of nonlinear control systems’ stability for consistent use at next stages of real systems’ examination, such as flight simulators and flight tests.