In this paper mathematical modeling of tilt-rotor aircraft is developed and its dynamic properties are studied. In order to build a mathematical model of V-22 Osprey, the equation of force and moments are formulated for each element of the vehicle such as rotor, fuselage, stabilizor, wing. By assembling these equations, the six-degrees-of-freedom equations of motion for vehicle are constructed. The validity of this model is analyzed by using computer simulation. Furthermore, controllers for pitch SAS( stability augmentation system ) and vertical velocity control in helicopter mode are developed.
