Accident Sequence
After departing their home base, the helicopter crew conducted traffic and news reporting for a local television and radio station for 42 minutes. While transiting to another location for an upcoming news story, the helicopter experienced a sudden loss of engine power while cruising at 800 feet above ground level. The pilot reported initiating a left 180-degree turn toward a clear area. The autorotation was terminated over tall grass, but during touchdown the helicopter rolled over and came to rest on its right side. The accident site consisted of wooded terrain with soft soil on rough and uneven ground.
Pilot Experience
The pilot, who had accumulated approximately 8,000 total flight hours, reported about 7,000 hours in the Bell 206 helicopter. In the 90 days preceding the accident, the pilot had logged 200 hours, with 50 hours in the last 30 days. The pilot stated that no anomalies or engine warnings were perceived prior to the loss of engine power.
Engine Examination
A preliminary examination of the helicopter was conducted under the supervision of the NTSB Investigator-in-Charge. Initial inspection revealed that the compressor (N1) would not rotate. The engine was subsequently removed from the airframe and shipped to the manufacturer's facilities for further evaluation and teardown examination. The engine examination disclosed that all blade airfoils for the 5th stage compressor had separated from the wheel, while the first four stages showed no signs of distress. Damage to the 6th stage compressor and compressor case assembly was considered secondary. A detailed metallurgical examination confirmed that the compressor failure resulted from the separation of one or more 5th stage compressor blades. Some blade fragments were recovered but were heavily damaged, precluding further analysis. The reason for the failure of the compressor blade(s) could not be determined due to extensive secondary damage to the components involved.