Greeley-Weld County Airport
Aircraft Accident/Incident Report

Greeley, Colorado 80631
Tuesady, September 14, 1999 12:00 MDT

The pilot said that he was landing on runway 35 with a right quartering tailwind of 6 knots. The landing appeared normal until about 40 to 45 knots when the airplane began drifting to the left of centerline. He said that he corrected the airplane back to the centerline, and then it suddenly ground looped to the right. The pilot said that there was a 3 to 4 inch high dirt berm along the side of the runway. He said that when his left main landing gear and tail wheel impacted this berm, they folded under the airplane. He further stated that the rubber skid marks on the runway indicated that the tail wheel was oscillating, or shimmying. The maintenance person who recovered the airplane said that the self-centering tail wheel locking device was 'well lubricated,' which is what the maintenance manual calls for. He said the aerial application pilots that fly airplanes with similar tail wheel self-centering devices always instruct him not to lubricate their self-centering devices when he performs maintenance on their aircraft. They told him that it was easier to land in a crosswind when their tail wheel self-centering devices were dry.

The pilot's inadvertent ground loop during landing roll. Factors were the malfunctioning self centering locking device on the tail wheel, the right rear quartering tail wind, and the 3 to 4 inch high berm along the edge of the runway.