19990901042539A

(.4)The pilot reported that the engine RPM began decreasing during the takeoff climb, about 200 to 300 feet AGL, while he was over a grove of trees. He extended his autorotative glide to make it past the trees, which resulted in a further decrease of main rotor RPM. The helicopter landed hard, about 20 to 30 miles per hour of forward velocity, and rolled over. Postcrash examination by a FAA inspector revealed no evidence of mechanical malfunction; however, the fluid found in the airframe fuel filter and mechanical fuel pump screen was noted to be about 90 percent water. About 30 percent of the fluid found in the ceco fuel system screen was also water. The FAA inspector reported that the fuel cap was loose in the opening and did not appear to seal properly; the shaft seal was worn in the cap and the cap locking mechanism was not adjusted properly. When the fuel cap was removed, the inspector noted that the bottom of the fuel filler opening was deformed from the fuel nozzles being inserted in the opening. The pilot reported that he had washed the helicopter the night before the accident. He further reported that during the preflight he had drained fuel from the airframe fuel (.4) cont'd filter and fuel sump and hadn't noted any water or contaminants(-23) engine gradually lost power 1/2 mile from takeoff, to avoid landing in a almond orchard, pilot attempted to land in yam field 1/4 to 1/2 mile away. Rotor RPM dropped to low to auto rotate, tail hit the ground first, rotor blades cut off the tail boom, helicopter then went end over and came to rest on its left side, crash occurred at 14560 west el capitan.