On August 12, 2006, about 1645 Hawaiian standard time, a Hughes 369D, N114HD, contacted the ground with its tail rotor near Lahaina, Hawaii. Windwood Aviation, Inc., operated the helicopter under the provisions of 14 CFR Part 91. The commercial pilot, the sole occupant, was not injured; the helicopter sustained substantial damage consisting of damaged tail rotor blades and a bent and twisted tail rotor system drive shaft. The local flight departed Kahului, Hawaii (OGG), about 1600 on a firefighting mission. Visual meteorological conditions prevailed, and a company visual flight rules (VFR) flight plan had been filed. The pilot stated in a written report that he landed at a grass flat near a reservoir on the eastern side of a valley, which was prone to gusty winds. He rolled the throttle to flight idle, and applied the frictions for the cyclic and collective. He exited the helicopter, and proceeded to detach the electrical connection and hook ring of a bambi bucket used for firefighting. A gust of wind tilted the helicopter rearward on its skids. The pilot returned to the controls as the tail rotor made contact with the ground. He leveled the helicopter, accelerated to flight idle, and initiated a hover to prevent further damage. He performed several pedal turns, and collective changes. The flight characteristics seemed normal, and he noticed no control hindrance. He returned to Kahului. The pilot stated that since the event occurred while he was not flying, he did not recognize its significance. He received radio instructions to proceed to another emergency. He said that in his haste and determination to stay on his mission, he did not adhere to safety protocols. The winds at Kahului Airport, 12 miles southeast of the accident site, were reported to be 060 degrees at 19 knots gusting to 25 knots.