While landing for the second time on the local flight, the airplane immediately veered to the right. The pilot attempted to correct the airplane's ground track by the use of rudder and brakes. After attempting to correct the ground track through the use of increased engine power, the pilot chose to bring the airplane to a stop. The airplane departed the runway, collided with a drainage ditch, and came to rest inverted. Substantial crushing damage was sustained to the airplane's upper wings. An examination of the airplane's braking system by a responding Federal Aviation Administration (FAA) inspector did not reveal any anomalies. In an interview with the FAA inspector, the passenger seated in the front seat stated that he had placed his feet away from the airplane's rudder pedals and brakes and to his knowledge had not interfered with the airplane brakes.