The pilot's failure to maintain control of the helicopter, which resulted in a loss of tail rotor effectiveness, and his failure to promptly initiate the proper recovery technique, which resulted in a descent that could not be arrested before impacting the terrain.

THE FAILURE OF THE PILOT TO EVALUATE WEIGHT, TEMPERATURE, AND POWER AVAILABLE PRIOR TO TAKEOFF AND THEN PERFORMING A LEFT PEDAL TURN AFTER TAKEOFF RESULTING IN THE HELICOPTER DESENDING EVEN THOUGH FULL POWER WAS APPLIED.