On September 9, 2003, at 1715 central daylight time, a Bell 206B-3 helicopter, N197AA, registered to and operated by American Applicators LLC, based in Natchitoches, Louisiana, was substantially damaged during a forced landing following a loss of engine power, near Kisatchie, Louisiana. The commercial pilot, sole occupant of the helicopter, was not injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the Title 14 Code of Federal Regulations Part 137 aerial application flight. The local flight was originating at the time of the accident. During an interview conducted by an FAA inspector, the 5,400-hour pilot stated that after taking off from the platform, with 560 pounds of herbicide and approximately 30 gallons of fuel, the engine lost power as he was passing 50 feet AGL. The pilot initiated a descending right turn to gain rotor speed, and the helicopter impacted the ground hard. The aircraft came to rest on its right side, approximately 1,000 feet from the departure point. After the pilot exited the cabin, he noticed a fuel leak on the right side of helicopter, and a small fire on the left exhaust stack. The fire burned briefly and did not ignite the spilled fuel. The FAA inspector, who responded to the site, reported the helicopter damage included the separation of the tail boom in two pieces, one was located at the rear of the wreckage and the tail rotor was 20 feet to the right of the helicopter. Both of the landing gear skids were shattered and the fuselage was deformed. One of the main rotor blades bent down and over while the other one broke off approximately six feet from the hub. The engine and transmission remained attached to the airframe. Examination of the engine was conducted with assistance from a representative from the engine manufacturer, and revealed no major damage. All engine accessories were found in good condition. All oil, fuel, and pneumatic lines were in good condition and tight. The engine fuel filter was removed revealing contaminates inside the filter element assembly. There was fuel in the fuel pump filter bowl, and also revealed contaminates. Control continuity from the cockpit to the fuel control unit was verified. The fuel control unit filter assembly was removed and the element was heavily contaminated. The oil filter element was removed and in good condition. The operator reported that the engine had been overhauled approximately 30 flight-hours prior to the accident. Fuel samples were taken from the fuel pump filter bowl and fuel cell. The sample obtained from the fuel cell was extracted by using the helicopter's boost pumps. Aviation Laboratories conducted a fuel additive test for PRIST. The test revealed no PRIST in the fuel; however, the lab test analysis revealed heavy water contamination in the fuel system.