Abstract: An attitude control system for controlling a pitch angle in relation to a horizontal pitch reference in systems wherein the components of pitch angle and horizontal pitch combine to determine a parallel path of travel with respect to a horizontal reference plane. The attitude control system consists of a slope sensor for measuring and compensating for pitch attitude changes in conjunction with a grade control system for monitoring horizontal reference. The present attitude control system is applicable to trenching machines whereby soil conditions affecting pitch angle are compensated in conjunction with horizontal pitch to control a predetermined grade or the pitch angle can be utilized alone to control slope of an excavation line.