On October 23, 1994, at 1312 central daylight time, a Piper PA- 28-181, N90875, operated by Clark Aviation and flown by a private pilot, collided with rough terrain during a forced landing following a loss of engine power. The airplane was on an extended final approach for landing at the Bloomington-Normal Airport when the accident occurred. The airplane was substantially damaged. The pilot received minor injuries. Both passengers on board were seriously injured. Visual meteorological conditions prevailed. The flight was not operating under a flight plan. The personal flight originated from Danville, Illinois, at 1205 cdt. The pilot departed Bloomington, flew to Danville, and was returning to Bloomington when the accident occurred. The airplane was topped off with fuel prior to departing for Danville and had flown for approximately 2 hours prior to the accident. When 15 miles east of the Bloomington Airport, the pilot was instructed to fly a straight-in approach for runway 29. He reported he reduced the power to 1,500 rpm to initiate a descent 5 miles from the airport. He stated he applied carburetor heat, verified the mixture was rich and that the fuel pump was on. When reaching an altitude of 1,800 feet, the pilot reported, he advanced the throttle in an attempt to stop the descent, however, the engine did not respond accordingly. The pilot attempted to regain engine power to no avail. The pilot reported he set the airplane up for an off-airport forced landing into a plowed field. He reported that the airplane "lost lift approximately 20 feet above the ground." A post accident inspection of the airplane was conducted by an Federal Aviation Administration Airworthiness Inspector. This inspector reported, "There was nothing apparent found that would have caused a loss of engine power." (See Inspector's Statement)