The helicopter made a landing during which the tail boom was severed. This was a dual instructional flight and according to the instructor, a high reconnaissance was performed before selecting their approach to the pinnacle. The pinnacle is a 3000 foot landing area unobstructed for 360 degrees around the pinnacle and is widely used by helicopter operators for pinnacle practice. The instructor stated that he normally would not do pinnacle work with a full load of fuel. Because the student was ready for a checkride, except for the pinnacle work, the IP elected to do it immediately. He selected an approach to the west because he said he saw no blowing snow. At 20 feet AGL he noted high sink rate and he added power as he took control, but the helicopter continued to settle with power. The aircraft hit hard in a level attitude and the tailboom was severed. Investigation immediately after the accident showed blowing snow which indicated a wind from the east.