19990405017709A

(.19) On April 5, 1999, at approximately 1000 central daylight time, a Bell 206L1 helicopter, N255AL, was substantially damaged during a forced landing following the loss of engine power during takeoff climb near Shawnee, Oklahoma. The instrument rated commercial pilot and the 5 passengers were not injured. The helicopter was registered to and operated by air flite inc., of seminole, Oklahoma. Visual meteorological conditions prevailed for the title 14 CFR part 135 flight for which a company VFR flight plan was filed. The flight was originating at the time of the accident. According to the operator, the helicopter was climbing through 400 feet AGL, approximately one mile from the airport when the engine lost power. The pilot stated that thepower gradually decreased and he did not hear or observe any abnormalities from the engine. He turned the helicopter into the wind as he initiated an autorotation to an open field. During the flare/touchdown sequence of the autorotation, the helicopter landed hard and the main rotor blades struck and severed the tail boom of the helicopter. The helicopter came to rest upright and all occupants exited the helicopter without any assistance. An FAA inspector who traveled to the accident site confirmed that the tailboom of the helicopter was severed by the main rotor blades. The inspector stated that the pilot reported to him that the turboshaft engine was still running at ground idle speed upon completion of the autorotation, and the engine was shutdown by normal means. Visual examination of the engine and associated components did not reveal any anomalies. The winds at the time of the accident were reported from 230 degrees at 25 to 30 knots. (.4) the main rotor blades struck and severed the tailboom of the helicopter during a hard landing following a loss of engine power. The helicopter departed the airport to the southwest and climbed to 400 feet AGL. The pilot turned the helicopter downwind and leveled the aircraft. He set 'cruise power' and the engine 'spooled down.' The pilot performed an autorotation to a muddy, grassy field and landed hard. The engine was test run and it was determined that the fuel scheduling was incorrect as the turbine outlet temperature would exceed the maximum allowed. After replacement of the fuel control unit, the engine was 'found to meet new engine performance at all guarantee t EST points.' The fuel control unit was functionally tested and operated within service limits. The reason for the loss of engine power could not be determined. (-23)engine lost power, engine will be removed from aircraft and tested at dallas airmotive. Malfuntion/defect report will be submitted upon finding reason for power loss.