The state of the fixed wing navigation and position controller.

                nav_roll                  : Current desired roll in degrees (float)
                nav_pitch                 : Current desired pitch in degrees (float)
                nav_bearing               : Current desired heading in degrees (int16_t)
                target_bearing            : Bearing to current MISSION/target in degrees (int16_t)
                wp_dist                   : Distance to active MISSION in meters (uint16_t)
                alt_error                 : Current altitude error in meters (float)
                aspd_error                : Current airspeed error in meters/second (float)
                xtrack_error              : Current crosstrack error on x-y plane in meters (float)

def nav_controller_output_encode(self, nav_roll, nav_pitch, nav_bearing, target_bearing, wp_dist, alt_error, aspd_error, xtrack_error):
                '''
                The state of the fixed wing navigation and position controller.

                nav_roll                  : Current desired roll in degrees (float)
                nav_pitch                 : Current desired pitch in degrees (float)
                nav_bearing               : Current desired heading in degrees (int16_t)
                target_bearing            : Bearing to current MISSION/target in degrees (int16_t)
                wp_dist                   : Distance to active MISSION in meters (uint16_t)
                alt_error                 : Current altitude error in meters (float)
                aspd_error                : Current airspeed error in meters/second (float)
                xtrack_error              : Current crosstrack error on x-y plane in meters (float)

                '''
                return MAVLink_nav_controller_output_message(nav_roll, nav_pitch, nav_bearing, target_bearing, wp_dist, alt_error, aspd_error, xtrack_error)