The pilot reported that while performing a low-level pass parallel to the runway in the airplane, he allowed himself to become distracted. The airplane started drifting to the right and he found himself, "fighting the controls not realizing I cross controlled the control surfaces." The pilot felt a sink develop and applied full power with right rudder, but the right wing "unloaded." The pilot attempted to recover; however, he reported the airplane was too low and slow, an aerodynamic stall occurred, and the airplane impacted a grass field. The airplane, which was not equipped with a stall warning system nor was it required to be, sustained substantial damage to the right wing and the fuselage. The pilot reported there were no preimpact mechanical malfunctions or failures with the airframe and engine that would have precluded normal operation.