NTSB Factual Report

The pilot reported that after landing the airplane pulled to the left, which he was not able to immediately recover from. The airplane continued to the left and impacted a taxiway sign with the right wing, substantially damaging the wing spar. After applying right rudder he was able to get the airplane tracking in the right direction, but the right main landing gear collapsed just after hitting the sign, which resulted in the airplane ground-looping to the right. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.

NTSB Probable Cause

The pilot's failure to maintain directional control of the airplane during the landing roll.