What happened
During the rollout phase of the flight, the aircraft experienced a loss of directional control. The tail wheel began to shimmy violently, causing the aircraft to swerve sharply to the right. This uncontrolled movement resulted in a ground loop. As the aircraft rotated on its main landing gear, the left wing and the left horizontal stabilizer made contact with the ground, sustaining damage.
The investigation
A subsequent mechanical examination of the aircraft revealed the root cause of the directional instability. Investigators found that the tail wheel spring assembly was oversized. Additionally, the component was not properly secured in place. This defect compromised the stability of the nose gear during high-speed taxi operations.
Findings
The investigation identified a specific maintenance issue as the primary contributor to the accident. The improper installation and incorrect sizing of the tail wheel spring assembly led directly to the shimmy that initiated the ground loop. Notably, this was not an isolated incident; it was the fourth reported occurrence involving ground directional control problems in this specific aircraft.