Airplane Ground Loop After Landing with Tailwheel Lock Not Engaged

Accident Sequence

A pilot was performing a straight-in approach and landing to a runway. The airplane touched down on the runway centerline under control. After the tailwheel settled onto the runway, the pilot applied the brakes and retarded the engine power into the beta range. Shortly afterward, the airplane began to swerve to the left. The pilot attempted to maintain directional control but was unsuccessful. The airplane departed the left side of the runway. The momentum carried the airplane into the soft ground adjacent to the runway, resulting in a classic ground loop. The airplane then contacted a crop of sugar cane.

Damage

The accident sequence caused damage to the fuselage, right wing, and vertical stabilizer of the airplane.

Pilot Statement

The pilot noted that the mishap was most likely preventable because he did not ensure that the tailwheel lock was engaged before landing.