NTSB Identification: SEA04LA043
14 CFR Part 133: Rotorcraft Ext. Load
Accident occurred Monday, February 23, 2004 in Liberty, WA
Probable Cause Approval Date: 08/11/2011
Aircraft: Garlick UH-1H, registration: N6257P
Injuries: 1 Serious.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The pilot was conducting a long-line logging operation in a restricted category helicopter. During the second logging cycle of the day, which included fifty turns, the pilot was setting a load of logs down when he heard a loud bang from the rear of the helicopter. The aircraft began spinning to the left, and after the second turn the pilot chopped the throttle in an attempt to land between the loading deck and the loader. The helicopter landed hard and flat, resulting in the aircraft's main rotor blades striking the log deck and the loader, ripping out the helicopter's transmission. During an inspection of the aircraft wreckage it was observed that both of the tail rotor slider's lugs were fractured where they become tangent to the slider barrel. A subsequent examination of the tail rotor slider assembly revealed that the slider lugs had failed due to fatigue. The fatigue origin was determined to be rough machining marks.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The failure of the tail rotor slider lugs due to fatigue while the helicopter was maneuvering. Full narrative available
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