NTSB Identification: DFW07LA173.
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Accident occurred Monday, July 30, 2007 in Grand Prairie, TX
Probable Cause Approval Date: 04/30/2008
Aircraft: Bell 206B, registration: N4YJ
Injuries: 1 Serious,2 Uninjured.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
After departing their home base, the flight reported on the traffic and news for a local television and radio station for 42 minutes. While the helicopter was transiting from another location for an upcoming news story, the helicopter experienced a loss of engine power while in cruise flight at 800-feet above ground level. The pilot reported that he initiated a left 180-degree turn to a clear area. The autorotation was terminated over tall grass and during touchdown the helicopter rolled over and came to rest on its right side. The accident site was a wooded area with soft soil on rough and uneven terrain. The 8,000-hour helicopter pilot reported having accumulated approximately 7,000-hours in the Bell 206 helicopter, with 200-hours within the last 90 days and 50 hours in the last 30 days. The pilot reported that he did not perceive any anomalies or engine warnings prior to the loss of engine power. A preliminary examination of the helicopter was conducted under the supervision and control of the NTSB Investigator-in-Charge. Initial examination of the engine revealed that the compressor (N1) would not rotate. The engine was subsequently removed from the airframe and shipped to the engine manufacturer's facilities for further evaluation and teardown examination. The engine examination revealed that all of the blade airfoils for the 5th stage compressor had separated from the wheel, with no signs of distress on the first 4 stages of the compressor. Damage to the 6th stage of the compressor and compressor case assembly were considered to be secondary. A detailed metallurgical examination of the compressor revealed that the compressor failure was result of the separation of one or more of the 5th stage compressor blades. Some of the blade fragments were recovered during the engine examination; however they were heavily damaged precluding further analysis. The reason for the failure of the compressor blade(s) could not be determined due to the extensive secondary damage of the components involved.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The loss of engine power as result of the failure of one or more of the compressor blades for the 5th stage compressor for undetermined reasons. A contributing factor was the lack of suitable terrain for the pilot to execute a successful autorotation. Full narrative available
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