What happened
Following a normal approach and landing, the aircraft began vibrating immediately after the tailwheel made contact with the runway surface. As the airspeed decreased below thirty knots, the pilot lost directional control of the airplane. This loss of control resulted in a ground loop, during which one wingtip was dragged along the ground.
Prior to the takeoff phase of this flight, the pilot had observed that the aircraft was difficult to turn while taxiing. In response to this handling issue, the pilot added air pressure to the tailwheel tire. No other discrepancies were noted on the tailwheel assembly at that time.
The investigation
Post-accident examination revealed that the tailwheel retention assembly was loose. When the assembly was tightened during the inspection, it operated normally. The investigation found no other mechanical issues related to the tailwheel system.
Findings
The primary contributing factor was the loose tailwheel retention assembly, which compromised directional control during the landing rollout at low speeds.