On April 8, 1995, at 1440 central standard time, a Gardner VariEze, N13WM, was substantially damaged during a forced landing near Addison, Texas. The private pilot received minor injuries. Visual meteorological conditions prevailed for the personal flight. The pilot reported to a Federal Aviation Administration (FAA) inspector the following information. He was on a 1.5 mile final approach at Addison Airport (ADS) and was requested by the tower controller to slow down for traffic sequencing. "Shortly" before reducing power he saw that the knob assembly of the throttle control lever had "dropped off." As he attempted to increase throttle to maintain altitude, he noticed it was "jammed." The airplane was at 1000 feet and descending; therefore, he made the decision to land in an open field. During the landing roll the airplane struck a berm damaging the landing gear, main gear fuselage attaching points, and the right wing. The pilot further reported that examination of the throttle quadrant revealed that the throttle control had become misaligned when the knob assembly "dropped off." When the throttle control was aligned, the throttle would move full travel fore and aft.