The pilot reported that, after touchdown, during the landing roll, airplane ground looped and veered right. He corrected with left aileron and rudder, but the airplane continued right, exited the runway, rolled over a snowbank, and touched down hard again on terrain.

The airplane sustained substantial damage to the left-wing rib.

The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.