Formulations of the Equations of Motion of an Elastic Aircraft for Stability and Control and Flight Control Applications

Abstract : This technical memorandum presents a derivation of the equations of motion for large and small disturbance perturbations from a reference state of motion. The small perturbation equations of motion are then generalized to include the effects of atmospheric turbulence and gusts on the controls-free elastic aircraft. The resulting equations are termed the EXACT formulation. These EXACT equations may be used to evaluate the stability and performance of integrated flight control systems of the Control Configured Vehicle (CCV) type. The equations are unique in that they describe a highly damped system using motion coordinates referenced to a body fixed, 'mean', non-inertial axis.