Accident Sequence
The pilot reported conducting takeoffs and landings in the airport traffic pattern. Three landings were completed without incident. During the fourth landing, after the airplane touched down, it became airborne briefly. As it settled back down, it veered to the right and departed the runway pavement.
The pilot-rated passenger stated that he was on the flight controls with the pilot "following lightly" during the accident landing. When the airplane began to roll to the right, the pilot assumed full control but was unable to avoid the runway excursion.
Damage
After the airplane left the runway, the left main landing gear collapsed before the airplane came to rest in the grass area adjacent to the runway. The airplane sustained substantial damage to the fuselage and horizontal stabilizer.
Pilot Observations
The pilot noted that a skid mark on the runway indicated that the right brake might have been inadvertently applied during the landing. He stated that there was no mechanical malfunction or failure associated with the airplane prior to the accident.