On May 7, 2001, at 0935 mountain daylight time, a Hiller UH-12E, N40296, registered to MoAir, Inc. and operated by Miller Aero Service, Inc., under contract for the United States Department of Agriculture, was substantially damaged when it collided with terrain during a forced landing 17 miles west of Conchas, New Mexico. The airline transport pilot and his passenger were not injured. Visual meteorological conditions prevailed, and a company VFR flight plan had been filed for the public use flight being conducted under Title 14 CFR Part 91. The flight originated at a local ranch near Conchas, New Mexico at approximately 0925 . According to information provided by the pilot, he was conducting low level wildlife surveillance for the United States Department of Agriculture. The pilot stated that cloud bases were between 1200 and 1400 feet AGL (above ground level), visibility was restricted due to haze, and the atmosphere was humid. During refueling operations, he noticed that the carburetor had accumulated condensation from the humid air. The pilot departed after refueling at approximately 0925. He then began conducting a wildlife search at an altitude of approximately 20 to 25 feet AGL. Approximately 5 minutes into the flight, the pilot noticed that the carburetor air temperature gauge was reading in the lower one third of the yellow caution range. As he attempted to adjust the carburetor heat control lever, the engine lost power. The pilot initiated an autorotation to a clearing. He used "the collective control a little to allow us to clear the brush and make the clearing. I flared hard and I attempted to level the helicopter with forward cyclic as I pulled pitch.... I pulled full pitch, but there was not enough stored energy left in the rotor system (RPM) to properly cushion the landing." The helicopter landed hard and the extended gear legs collapsed. The pilot further stated that upon exiting the helicopter, he found that 3 feet of the tail boom had been severed by the main rotor blade.