The airplane was destroyed at approximately 0206 Mountain time when it impacted terrain during an instrument approach. The Commercial pilot and sole occupant of the airplane was fatally injured. Night instrument conditions prevailed for the on-demand air cargo flight. Shortly after the flight was cleared to land, the tower controller alerted the pilot he appeared to be well below the glideslope. There was no response. The aircraft wreckage was found approximately four miles south of the runway. All major components of the airplane were found at the accident site. Weather reported at the airport included wind from 010 degrees at eight knots, visibility 2.5 statute miles in rain and mist, broken clouds at 1000 feet, broken clouds at 1600 feet and an overcast ceiling at 2200 feet.