Neither the instrument-rated private pilot nor his five passengers were seriously injured when their Citation II, N35403, was substantially damaged on January 1. The pilot said that while the airplane was on the GPS Runway 17 approach to Ainsworth Municipal Airport, Neb., the cockpit windows became obscured by ice and he decided to land the airplane instead of making a missed approach. IMC prevailed at the time of the accident. After the airplane first hit the ground, about 440 feet north of the runway, it struck an airport access road, became airborne again and traveled about 55 feet before touching down for the second time. The aircraft then slid about 700 feet and came to rest parallel to a taxiway.