Landing and Drift
The pilot reported landing on runway 35 with a right quartering tailwind of 6 knots. The landing appeared normal until the aircraft slowed to about 40 to 45 knots, at which point it began drifting to the left of the centerline.
Ground Loop and Impact
After correcting back to the centerline, the aircraft suddenly ground looped to the right. A dirt berm, approximately 3 to 4 inches high, ran along the side of the runway. When the left main landing gear and tail wheel impacted the berm, they folded under the airplane.
Tail Wheel Condition
The pilot noted that rubber skid marks on the runway indicated the tail wheel was oscillating, or shimmying, during the landing roll. The maintenance person who recovered the airplane stated that the self-centering tail wheel locking device was 'well lubricated,' as called for by the maintenance manual. However, aerial application pilots who operate aircraft with similar self-centering devices typically instruct maintenance personnel not to lubricate the device, claiming it makes crosswind landings easier when dry.