NTSB Probable Cause

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.