Aerospace Instrument-Making Annotation << Back Synthesis of Analytical Laws of Stabilization of Short-Period Longitudinal Motion UAV in the Absence of Information About Measuring the Angle of Inclination of the Trajectory and the Angular Velocity of Pitch Zubov N.E., Mechkina K.A. The article offers an approach that provides a solution to the problem of stabilization of the short-period longitudinal motion of the UAV, which is described by a linear non-stationary model of the third order in the absence of measurement of the angular velocity of the pitch and information about the angle of inclination of the trajectory of the aircraft. The analytical solution is based on the decomposition method of modal synthesis and the relationship between modal control by state and modal control by output through the set values of the poles of a closed control system\established in the work. The proposed approach is used to analyze the possibility of obtaining solutions in the event of failure of any two sensors measuring the components of the state vector of short-period longitudinal motion. It is shown that in this formulation of the study, in the absence of two dimensions of the components of the state vector, two combinations are possible: there is only the angular velocity or there is only the pitch angle. Third combination: the presence of the trajectory tilt angle is not possible, since it is determined through the value of the pitch angle. Based on the results of the study, it is found that such control can be constructed only for one combination of failures: in the absence of measurements of the angular velocity of pitch and angle of attack. Analytical expressions for the matrix of feedback coefficients of the synthesis problem are given for this variant controls that can be used for a hypothetical UAV mathematical modeling is performed and its results are presented. Keywords: short-period longitudinal motion, unmanned aerial vehicle, exit control. DOI: 10.25791/aviakosmos.2.2025.1458 Pp. 03-11.