Amateur-built KITFOX SERIES 6 N506F accident near Parowan, Utah

Probable cause

The pilot’s inability to control the airplane during landing due to tailwheel assembly damage sustained during a previous shimmy event that occurred for reasons that could not be determined based on the available evidence.

NTSB analysis

The pilot reported that, during takeoff, he felt a shimmy in the tailwheel-equipped airplane. During the subsequent three-point landing, the airplane veered left immediately upon touchdown. The airplane departed the left side of runway and ground looped, which collapsed the right main landing gear and substantially damaged the right wing.

An NTSB structures engineer’s review of postaccident photographs of the tailwheel assembly determined that deformation and fracture features on the fitting flanges on the extruded base of the tailwheel assembly were from a twisting motion about the single bolt that secured the tailwheel assembly to the suspension assembly, consistent with that resulting from a tailwheel shimmy event.

The accident circumstances and damage evidence are consistent with a failure of the tailwheel assembly due to improper movement or rotation around the tailwheel attachment bolt during the shimmy event during takeoff, which resulted in a subsequent loss of control of the airplane during landing. However, the investigation could not determine if the shimmy event resulted from a loose attachment bolt, or if the movement around the attachment bolt resulted from the shimmy event.

Text from the NTSB. Open the NTSB docket for WPR24LA177 for the full record.