Aviation Accident Summaries

Aviation Accident Summary ANC93FA033

KETCHIKAN, AK, USA

Aircraft #1

N114CR

BELL 214B1

Analysis

THE HELICOPTER WAS HOVERING 200 FT AGL, WITH LOGS ATTACHED TO A 150-FT LONGLINE, WHEN IT WAS OBSERVED TO HAVE A LOSS OF CONTROL. THE LOGS WERE DRAGGED ALONG THE GROUND UNTIL CAUGHT IN STUMPS, PITCHING THE HELICOPTER INTO THE GROUND. THE LOWER PISTON ROD OF THE RIGHT DUAL HYDRAULIC SERVO ACTUATOR HAD FAILED IN FATIGUE; ALSO BEARING WEAR WAS INCONSISTENT WITH COMPONENTS OF COMPARABLE TIME. OPERATOR RECORDS SHOWED REGULAR OVERLOADING OF AEROLOGGING HELICOPTERS; ACFT OVERLOADED BY 2000 LBS PRIOR TO ACCIDENT. OPERATOR MAINTENANCE & FACILITY RECORDS INCOMPLETE. MAINTENANCE PERFORMED IN ALASKA WITHOUT FAA AUTHORIZATION. NO RECORDS OF OF FAA SURVEILLANCE OF OPERATOR EXTERNAL LOAD OPERATIONS IN ALASKA SINCE START OF OPERATIONS 4/91. THE EXTERNAL HOOK ELECTRICAL RELEASE MECHANISM WAS TESTED & FUNCTIONED NORMALLY.

Probable Cause and Findings

INADEQUATE MAINTENANCE OF THE HYDRAULIC SERVO ACTUATOR WHICH LED TO THE FATIGUE FAILURE AND LOSS OF FLIGHT CONTROL. IN ADDITION, THE FLIGHTCREW DID NOT, OR WAS UNABLE TO, JETTISON THE EXTERNAL LOAD. FACTORS WHICH CONTRIBUTED TO THE ACCIDENT WERE: THE PILOT OPERATING THE HELICOPTER OVER MAXIMUM GROSS WEIGHT, THE OPERATOR'S CONTINUED AEROLOGGING OPERATIONS WITH AIRCRAFT EXCEEDING MAXIMUM GROSS WEIGHT, AND INADEQUATE SURVEILLANCE OF THE OPERATOR'S MAINTENANCE AND OPERATIONS ACTIVITY BY THE FEDERAL AVIATION ADMINISTRATION.

 

Source: NTSB Aviation Accident Database

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