Abstract: The nonlinear decopling control theory is applied to aircraft spin automatic prevention systems and a method of decoupling control law synthesis is given to consider the spin dynamic characteristics. Using the method, a control law of spin automatic prevention is designed for a modern fighter according to its mathematic model. Through the law, the angle of attack, the angle of sideslip, and the roll speed are decoupled by the elevator,aileron and rudder. The associated digital simulations of the closed loop system provide satisfactory results.

Key words: nonlinear, decoupling, spin automatic prevention