Event Summary
During the landing roll of his second uneventful landing, the pilot reported that the right main landing gear began to shimmy. He reduced speed and proceeded toward the nearest taxiway. Before exiting the runway, the pilot intended to retract the flaps but inadvertently raised the landing gear handle. He quickly re-lowered the handle; however, the right main landing gear had already started to retract. The airplane veered to the right, exited the runway surface, and came to rest on the grass.
Damage
The airplane's right wing sustained substantial damage. No other damage was reported.
Pilot's Report
The pilot stated that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.