On August 7, 1998, at 0900 central daylight time, a Hughes 269B helicopter, N9425F, owned and operated by the pilot, was substantially damaged during a hard landing immediately after takeoff, near Uvalde, Texas. The commercial pilot and 1 passenger were not injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the Title 14 CFR Part 91 cattle herding flight. The flight originated from a trailer in the vicinity of the accident approximately 0830. The pilot reported that he transported the helicopter to a ranch pasture via a trailer for the purpose of herding cattle. After flying about 30 minutes, he located 3 cattle that were in an ajoining pasture which was gated. He then landed the helicopter in a large mesquite flat near the gate so his passenger could get out and open the gate. After positioning the helicopter for takeoff (where he had successfully operated the helicopter from on previous occasions), he attempted a confined area takeoff over a stand of trees. He stated that he had to "lift straight up to clear the trees." Upon reaching a hover just above the tree tops, the pilot "felt power bleeding off so [he] nosed over trying to get airspeed." He could not "get any airspeed", so he turned toward a narrow clearing using "right pedal" and reduced collective to "make a run-on landing." Upon ground contact, the right skid dug into the rain soaked ground, and the helicopter rolled onto its side. The resultant structural damage was a separated tail boom assembly, and damage to all three main rotor blades. After the accident, the pilot reported to an FAA inspector that it had been raining for a day and a half days prior to the accident and that the weather was "hot and muggy" on the morning of the accident. He estimated the temperature to be about 95 degrees with "high humidity and no wind." He also stated that he did not believe he had any type of mechanical failure and that the engine seemed to be performing normally. He felt that the density altitude, gross weight, and the out of ground effect operation all contributed to the accident. According to Flight Service and the National Weather Service, hourly weather data was not available for Uvalde, Texas. However, the following information from the National Weather Service for July 7, 1998, at 0900 is provided. Hondo, Texas, located approximately 30 miles east of Uvalde reported a 1,100 foot broken ceiling, 7 miles visibility, winds from the southeast at 10 mph, temperature 81 degrees, and dew point 73 degrees. Del Rio, Texas, located approximately 60 miles west of Uvalde reported clear skies, 8 miles visibility, winds from the east southeast at 12 mph, temperature 82 degrees, and dew point 72 degrees. The published Uvalde Airport elevation is 941 feet MSL.