Airplane loss of control problem: Linear controllability analysis

The controllability analysis for airplane flight dynamics is very crucial in upset/loss-of-control situations. Conventional airplanes are normally equipped with so redundant control authority. That is, an airplane might experience a loss of one or more control surfaces and remain controllable. As such, the aim of this paper is to investigate common upset situations and to explore the limits of controllability using linear analysis tools with emphasis on analysis of Thrust-only Flight Control Systems (TFCSs) where all the hydraulic systems are lost. Based on those analyses, the necessity of nonlinear controllability analysis for such situations is discussed.