On October 3, 1993, at approximately 1400 hours mountain daylight time (MDT), a Taylorcraft BC12-D, N44492, registered to and being flown by William C. Neil, a certificated private pilot, sustained substantial damage when it collided with a power line and terrain during a forced landing following a power loss southwest of Shoshoni, Wyoming. The pilot and his wife sustained minor injuries. Visual meteorological conditions prevailed and no flight plan had been filed. The flight, which was personal in nature, was to have been operated in accordance with the requirements set forth in 14CFR91 and originated from Riverton, Wyoming. The pilot reported that "while en route from Boysen Lake to Riverton Regional Airport via the Wind River at approx(imately) 800' above ground level the aircraft lost power - carburetor ice - and I prepared to land along (the) river bank - I struck an unmarked power line - continued the descent - landed - and the aircraft flipped over onto its top" (refer to CHART I). Additionally, the pilot reported that there was no wind at the time of the accident and that the temperature was 70 degrees Fahrenheit. At 1402 hours the Fremont County Sheriff's Department Dispatch received a telephonic notification of an aircraft accident. Sergeant Ed Miller responded to the site and observed the aircraft at rest in an inverted attitude. Sergeant Miller reported that "When I approached the aircraft I noticed that there was no fuel spilled or leakage of fuel from the aircraft. I asked the pilot why there was no fuel around or leaking from the aircraft and he advised me that he "dumped" the fuel as he knew that he would have to put the aircraft down and this was why there was no fuel around or leaking from the aircraft" (refer to attached Sheriff's Report). The Taylorcraft BC12-D aircraft is equipped with two fuel tanks, a main tank (13 gallons capacity) and a wing tank (6 gallon capacity). The aircraft is not equipped with any fuel dump system.