On November 22, 1997, at 1100 central standard time (cst), a Piper PA-28RT-201T, N8315S, operated by two certified flight instructors collided with the terrain when it undershot runway 22 at the Rock County Airport, Janesville, Wisconsin. The purpose of the flight was for one flight instructor to check out the other one in this airplane. The airplane was substantially damaged. Neither pilot was injured. Visual meteorological conditions existed at the time of the accident. The flight originated from Grayslake, Illinois, at 0930 cst. The pilot-in-command (PIC) reported that following their departure from Grayslake they performed basic airwork, two ILS approaches, two touch and go's and a full stop landing from a simulated engine out. They then decided to perform one more simulated engine out landing. The PIC stated that once in the traffic pattern he demonstrated the landing gear "override" feature to the pilot in the left seat (student). He reported that on base leg the "override" was disengaged and the landing gear extended. The student placed the landing gear handle in the down position and when he looked up he noticed the altitude of the airplane was low as they were turning onto a "very short final." The PIC stated the student overcorrected as the right wing was low. At the same time the student was adding power to extend the approach the right landing gear contacted a snowbank followed by the edge of the runway. The PIC reported that the snowbank was about 18 inches from the edge of the runway. The right main landing gear collapsed and the airplane slid off the right side and contacted a runway light upon touchdown.