A wind tunnel model of an aircraft, representing only the rolling motion, is constructed using two small lifting surfaces mounted in the horizontal (i.e. x – y) plane symmetrically on an axi-symmetric body. The body houses a set of ball bearings, which permit the complete model to roll about x – axis freely. Further, the right lifting surface (pointing towards positive y axis) is given an initial incidence of -3o with respect of the longitudinal axis of the body and similarly, the left lifting surface (pointing towards negative y axis) is given an initial incidence of +3o with respect of the longitudinal axis of the body. The wings have 5 cm chord, 30 cm span (for each half part) and are made of Aluminium. Generate the mathematical model of the above wind tunnel model in terms of the roll moment as the disturbance and roll attitude as the output from the system.