On April 28, 2005, a Piper PA-20 (registration N7053K) was involved in an aviation accident near Thomaston, GA. Investigators recorded the probable cause as: The unapproved repair of the tailwheel rudder arm assembly, which resulted in an overload failure during touchdown and subsequent loss of control of the airplane and on-ground collision with an object. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
The pilot reported a hard left pull after tailwheel touchdown, with no rudder response. Post-accident examination revealed a fractured tailwheel rudder arm assembly with a previous weld repair, and metallurgical analysis showed deformation but no fatigue.
Pilot Report
The pilot stated that during landing, the main wheels touched down normally. When the tailwheel contacted the runway, the airplane pulled hard to the left, and application of the rudder had no effect. The airplane continued left off the side of the runway and collided with a lighting system.
Post-Accident Examination
Examination of the airplane revealed that the tailwheel rudder arm assembly was found fractured and separated on the right side. Inboard of the fracture, evidence of a previous weld repair was observed. The weld repair was located at the thickest area of the tapered rudder arm assembly, while the fracture occurred at a smaller-diameter area.
Metallurgical Findings
Metallurgical examination of the rudder arm assembly showed that the aluminum component exhibited deformation near the fracture surfaces. No evidence of fatigue was observed in the material. The findings indicate that the fracture was not the result of cyclic loading.