On June 24, 2001, about 1000 Alaska daylight time, a wheel-equipped Arctic Aircraft S-1B2 airplane, N61AT, sustained substantial damage while landing at an off airport site, about 30 miles north of Petersburg, Alaska. The certificated private pilot, and the one passenger aboard, were not injured. The airplane was being operated as a visual flight rules (VFR) personal flight under Title 14, CFR Part 91, when the accident occurred. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated about 0930, from the Petersburg Airport, Petersburg. During a telephone conversation with the National Transportation Safety Board investigator-in-charge on June 25, the pilot reported that during the landing roll on a sand-covered beach, the main landing gear wheels contacted an area of soft sand, and the airplane nosed down. The airplane sustained substantial damage to the right wing lift strut. The pilot reported there were no preaccident mechanical problems with the airplane.