Incident Details
According to the pilot's report, after landing the airplane began to pull to the left, and he was unable to immediately correct the deviation. The airplane continued moving left and struck a taxiway sign with its right wing. The impact substantially damaged the wing spar.
Pilot Actions and Subsequent Events
The pilot applied right rudder and was able to regain directional control, with the airplane tracking in the correct direction. However, immediately after hitting the sign, the right main landing gear collapsed, which led to the airplane ground-looping to the right.
Mechanical Status
The pilot reported that there were no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation. No other issues were noted.