On September 6, 1997, about 1800 hours Pacific daylight time, a Cessna 182B, N81MK, experienced a loss of power and nosed over in a plowed field during the subsequent forced landing near Madera, California. The aircraft sustained substantial damage and the pilot received minor injuries. The aircraft was being operated for paradrop support when the accident occurred. The flight originated from the Madera Municipal Airport about 1730. Visual meteorological conditions prevailed at the time and no flight plan was filed. The pilot had released his jumpers at 10,500 feet msl and was returning to the airport. After entering downwind about 1,500 feet msl, he cleared the engine, moved the mixture control to full rich, and applied carburetor heat. Being above traffic pattern altitude he elected to extend his downwind. Upon reaching his base leg he attempted to add power and noted there was no increase engine rpm. He switched tanks from both tanks to the right tank. After waiting about 10 seconds for the engine to respond, he then switched to the left tank. The engine continued windmilling, and after descending to 620 agl, he set up and executed a forced landing to a cotton field. The aircraft touched down perpendicular to the rows and the nose gear collapsed after encountering soft terrain and the aircraft nosed over. After the aircraft was righted, about 1 gallon of fuel was found in the right tank and 3 gallons found in the left. According to the recording tachometer, the aircraft had flown 1.6 hours since being last fueled with 19 gallons. The total fuel onboard after refueling is unknown. A representative of the engine manufacturer stated that engine would have consumed about 19 gallons during this period. A representative of the aircraft manufacturer stated that there are 1.5 gallons of unusable fuel in each tank. The temperature and dew point obtained from the aviation weather reporting station at Fresno, California, at the time of the accident were 93 and 56 degrees Fahrenheit, respectively. Comparison of those temperatures with a carburetor icing probability chart contained in DOT/FAA/CT-82/44, shows that carburetor icing was possible at glide and cruise power.