On February 7, 2001, at 1455 central standard time, a Cessna 310Q, N10ET, piloted by a private pilot, sustained substantial damage during landing roll when the airplane slid off runway 12 (6,700 feet by 100 feet, ice-covered/asphalt) at the Mitchell Municipal Airport, Mitchell, South Dakota. Instrument meteorological conditions prevailed at the time of the accident. The personal flight was operating under the provisions of 14 CFR Part 91 and was on an active instrument flight plan. The pilot and his three passengers reported no injuries. The flight had departed from the Joe Foss Field Airport, Sioux Falls, South Dakota, at 1406. According to the pilot's written statement, he was en route from Sioux Falls to Rapid City when he encountered icing-conditions at 6,000-feet mean sea level (msl). The pilot reported, "Trying to get on top after being cleared to 14,000 msl I decided it was better [to] land. Clearance was given for VOR 12 [instrument] approach at Mitchell S.D. [Mitchell Municipal Airport]. Due to poor forward visibility due to ice on the windshield, I landed on a very icy runway and slid into plowed snow, causing damage [to] the plane." According to records provided from the Federal Aviation Administration (FAA) records from Huron Automated Flight Service Station, the pilot had received a standard weather briefing prior to the accident flight. According to a transcript of the weather briefing, the Huron-AFSS briefer informed the pilot that there was, "moderate rime or mixed icing in clouds and in precipitation below flight level one eight zero for your entire route". At the completion of the standard weather briefing the pilot filed an instrument flight plan for a flight from Sioux Falls to Rapid City. A copy of the transcript is appended to this factual report. Postaccident investigation of the airplane revealed a placard located on the instrument panel that stated, "Warning - Not Certified For Flight Into Known Icing Conditions". A photo of the placard is appended to this factual report.