On August 8, 1985, a Bell UH-1B (registration N1385W) operated by Skyline Air Service, Inc. was involved in an aviation accident near Saint James, LA. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter at a 150-foot hover preparing to pick up a log experienced a sudden power loss after a loud bang, autorotated through trees, and impacted with high vertical speed. Investigation revealed progressive fatigue failure of compressor blades.
Accident
A helicopter was at a 150-foot hover, preparing to pick up a log, when it experienced a power loss. Witnesses reported hearing a loud bang and heard the pilot radio, "Get out of the way." The helicopter autorotated through 60- to 80-foot trees with very low rotor rpm and impacted with no horizontal speed and high vertical speed.
Investigation
Investigation revealed that the engine had suffered severe internal damage. Four compressor blades from the 4th stage rotor were found to have suffered progressive fatigue failure, which in turn caused the remainder of the blades on the 4th and 5th stages to separate, leading to an engine surge and loss of power. The accident occurred in a flight regime from which the pilot could not effect a recovery from the engine failure.