On August 24, 2002, at 1330 central daylight time, a Robinson R22 Beta helicopter, N102MH, sustained substantial damage when it collided with trees and terrain during landing approach after a loss of engine power. The landing was being made to a private heliport near Seneca, Illinois. The 14 CFR Part 91 business flight was operating in visual meteorological conditions without a flight plan. The pilot, who was the sole occupant, was not injured. The flight originated from the helicopter owner's private heliport, and was landing at the Boondocks Campground, Seneca, Illinois. The flight originated about 30 minutes prior to the accident. The pilot stated that he was preparing to turn from the downwind leg of the landing approach to the base leg. He stated that he applied carburetor heat and the engine stopped producing power. The pilot autorotated and landed in trees that were below the helicopter when the engine failed. A postaccident examination of the helicopter revealed that the inner wire of the carburetor heat control cable was fractured. The carburetor heat slide valve was found in an intermediate position. No other preexisting anomalies were found.