On January 22, 1996, about 1500 Alaska standard time, a wheel equipped Piper PA-18 airplane, N7797B, sustained substantial damage while landing on a remote, snow covered sandbar. The solo private pilot was not injured. Visual meteorological conditions prevailed for the 14 CFR Part 91 flight, which departed the Skwentna Airport about 1400, and was en route to Merrill Field, Anchorage, Alaska. The pilot wrote in his NTSB Pilot/Operator Aircraft Accident Report that the airplane nosed over onto its back during the landing roll. He noted in the Recommendation section of the report the accident could have been prevented if the airplane's landing gear had been equipped with skis instead of wheels. The pilot did not report the accident until November 26, 1996, when he mentioned the accident to an FAA inspector who was questioning him about another, more recent accident. The pilot said he felt the damage incurred during the first accident was minor, and thus the accident did not need to be reported. Further statements by the pilot, and excerpts from the airplane's log books, indicate the airplane received substantial damage to the rudder and right wing.