THE ACFT SETTLED DURING AN EMER LNDG AFTER THE PLT SAID THE ENGINE FAILED. INVESTIGATION REVEALED THE ACFT RECEIVED MINOR MAINTENANCE ON THE DAY OF THE ACCIDENT, CONSISTING OF CHANGING THE PITCH CHAIN LINKS ON THE MAIN ROTOR BLADES. THEPLT MADE A WRITTEN STATEMENT AFTER THE ACCIDENT IN WHICH WAS STATED, 'THE ACFT WAS RUNNING APRX 15 MIN BEFORE TAKEOFF WITH THE ANTI-ICE OPERATING. I PULLED INTO A HOVER APRX 6-7 FT AGL, SLOWLY, TO INSURE THAT THERE WAS NOTHING ATTACHED TOTHE SKIDS. I THEN MOVED SIDEWAYS FROM THE LANDING ZONE TO CLEAR THE AREA OF BLOWING SNOW FROM THE ACFT. I TURNED INTO THE WIND & STARTED TO APPLY POWER TO CLIMB OUT OVER ANOTHER FENCE AT ABOUT 10-15 AGL. AT APRX 10-15 MPH THE ENG OUT LIGHT & HORN SOUNDED & I APPLIED RT TORQUE PEDAL TO CORRECT FOR YAW. WE STARTED TO SETTLE TO THE GROUND & I APPLIED COLLECTIVE TO STOP THE DESCENT & LANDED ON THE OPPOSITE SIDE OF A DITCHING.' THE ROTOR OR RPM DECAYED & THE ACFT ROCKED NOSE TO TAIL & THE MAIN BLADES HIT THE TAIL BOOM. AFTER THE ACCIDENT THE ENG RAN NORMALLY AT ALL POWER SETTINGS.