On March 9, 2001, approximately 1645 mountain standard time, an Erco 415-C Ercoupe, N1121J, owned and operated by the pilot, was substantially damaged when it collided with terrain during a forced landing at Ivins, Utah. The private pilot, the sole occupant aboard, received minor injuries. Visual meteorological conditions prevailed, and no flight plan had been filed for the personal flight being conducted under Title 14 CFR Part 91. The flight originated at Hurricane, Utah, approximately 1600. According to the pilot's accident report, he departed Hurricane, Utah, and was en route to St. George, Utah, with a "fly-over" at the town of Ivins, where he lived. After circling Ivins and turning towards St. George, there was an "intermittent loss of [engine] power." He suspected carburetor icing "since the Stromberg carburetor, standard [equipment] on the Ercoupe 415C, is prone to icing," and he immediately applied carburetor heat. The engine "continued a pattern of power off/power on/power off in cycles of 4 or 5 seconds." He left the carburetor heat on but soon realized that his rate of descent left insufficient altitude to arrive at St. George. He turned back towards Ivins but was forced to land on rough desert terrain. The nose and left main landing gears struck a dirt berm. The nose gear was bent back and both wings were extensively damaged. The pilot told an FAA inspector that when the engine lost power, the carburetor air temperature gauge indicated 10 degrees C. According to the Carburetor Icing Graph (see public docket), a temperature of 12 degrees C. and a dew point of 4 degrees C. [as reported by the St. George METAR (aviation routine weather report)] could result in "serious icing at glide power," and a temperature of 10 degrees C. (as reported by the pilot) could result in "serious icing at cruise power."