Annotation. Currently, in real conditions, the development engineer is faced with the problem of parametric uncertainty. Aircraft operate under conditions of uncertainty; there have always been, are and will be various external disturbances that act on the aircraft. This determines the development of an indefinite system for automatic control of the aircraft’s roll angle during fast lateral short-period movement, for system reliability and increased flight safety. Consequently, the obtained research results of the dissertation work are very important for science and can be used in the future to solve problems in the theory of aircraft control under conditions of uncertainty.

Key words: bank angle, mathematical model, uncertain system, airplane, autopilot, lateral movement, matrix analysis, closed system.