Abstract: The insensitivity to gust for multi input and multi output aeroservoelastic systems of the aircraft is studied. For a coupled multiloop flight control system, an aeroservoelastic analytic model, including flexible structure, unsteady aerodynamics and flight control system, is set up. On the basis of singular value of return different matrix in robust technique of modern control theory, using the criteria of insensitivity to disturbance, the ability keeping insensitivity to gust for aeroservoelastic system is determined. The sample is an aircraft with a lateral coupled control system and the gust is atmosphere turbulence with Dryden model. The insensitivity to gust is calculated and validated with the response of the aircraft to the gust.

Key words: aeroelast ics, aero servoelast icity, atmo sphere turbulence, robust, sensit ivity