At approximately 14:30 PST, a Cessna 182S was substantially damaged in a hard landing at Vista Field. The pilot and two passengers were not injured. The flight was en route IFR from Valley Center, Calif., to Pasco, Wash., and had been cleared for the ILS runway 21R approach. While on the approach, the aircraft encountered icing conditions and diverted to Vista Field. There it suffered a hard landing due to ice accumulation. The pilot had received his instrument rating less than six months earlier. DUATS weather reports accessed by the pilot showed the approach would have taken place in icing conditions.