N9683PPiper PA-18-150

The pilot reported that he and his father had flown to the accident location to camp and hunt. They made three passes over an open area to find a suitable landing spot. The pilot stated that the grass appeared to be knee-to-hip height, but he believed it was safe to land. He set up for landing, and on the landing rollout, about 20-30 knots, the left main landing gear wheel struck an unseen, large embedded boulder that collapsed the left main landing gear. The airplane's wing sustained substantial damage. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.

The pilot reported that she was practicing three-point touch-and-go landings in a tailwheel equipped airplane. The first three touch-and-goes were uneventful. During the landing roll of the fourth landing, the airplane began to veer to the left. The pilot applied full right rudder, however, the airplane continued to the left and exited the runway onto a dirt surface. As the pilot added full power to attempt to avoid a taxiway sign and reenter the runway surface, the airplane briefly became airborne before pitching down and pivoting to the right. Subsequently, the left main landing gear collapsed and the left wing struck the ground resulting in substantial damage. The airplane skidded nose down until coming to a rest. At the time of the accident, the wind was reported from 110 degrees at 7 knots. The pilot reported no mechanical failures or malfunctions that would have precluded normal flight.