The aircraft had slowed to a speed of around 20 kt when, after a bump in the grass runway, it veered sharply to the right, exiting the runway and entering a cultivated field. The aircraft pitched forward and to the left, causing the propeller and left wing to impact the ground. The pilot, who was unhurt, made the aircraft safe and he and his passenger exited it normally.
The pilot considered the accident was caused by the left wheel entering a rut or rabbit hole in the runway. This caused the left landing gear spat to break loose and rotate forward over the wheel, rendering the left brake inoperative. When the pilot applied the brakes only the right brake was effective, with the result that the aircraft then veered to the right before departing the runway.