NTSB Identification: SEA88LA129.
The docket is stored on NTSB microfiche number 36307.
Accident occurred Wednesday, July 13, 1988 in OAKRIDGE, OR
Probable Cause Approval Date: 06/07/1989
Aircraft: AEROSPATIALE SA315B, registration: N3128G
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.

WHILE SLINGING A LOG THE PILOT ALLOWED THE LOG/SLING LINE TO CONTACT A TREE. THE MOMENTUM OF THE LOG AND HELICOPTER BOWED THE TREE OVER WHEN THE LINE CONTACTED IT. THE PILOT CHOSE TO RELEASE THE LOG FROM THE SLING LINE RATHER THAN DISENGAGE THE ENTIRE LINE AND LOG FROM THE HELICOPTER. ONCE THE LOG SEPARATED, THE LINE CAUGHT IN THE TREE WHICH RETURNED TO AN UPRIGHT ATTITUDE AND PULLED THE LINE TIGHT. THE FORCE APPLIED TO THE HELICOPTER AS THE LINE TIGHTENED, IN TURN ROTATED THE HELICOPTER ABOUT ITS LONGITUDINAL AXIS TO A POINT WHEREBY THE PILOT LOST CONTROL. SHORTLY THEREAFTER THE HELICOPTER DESCENDED INTO THE TREES AND COLLIDED WITH THE TERRAIN.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

CLEARANCE..MISJUDGED..PILOT IN COMMAND

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

EXTERNAL LOAD SLING/HARNESS..ENTANGLED

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

EXTERNAL LOAD EQUIPMENT..IMPROPER USE OF..PILOT IN COMMAND


Contributing Factors

OBJECT..TREE(S)

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