NTSB Identification: LAX82FA117
Nonscheduled 14 CFR Part 135: Air Taxi & Commuter
Accident occurred Monday, March 22, 1982 in NEAR BRIDEPORT, CA
Probable Cause Approval Date: 03/22/1983
Aircraft: AEROSPATIALE SA316B, registration: N9829C
Injuries: 4 Serious,3 Minor.

NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

AFTER TAKING OFF IN A MOUNTAINOUS AREA, THE PILOT BEGAN CLIMBING IN UP-CURRENTS ON THE SIDE OF A CANYON. WHILE FOLLOWING A RIDGE AT ABOUT 100 FT AGL (11,000 FT MSL), HE HEARD A LOUD NOISE THAT WAS FOLLOWED BY A SHUDDER AND VIBRATIONS. THE HELICOPTER BEGAN DESCENDING RAPIDLY. THE PILOT TURNED TOWARD THE RIDGE AND THE HELICOPTER IMPACTED IN A SNOWFIELD. AN EXAMINATION REVEALED THAT THE OIL FILTER COVER OF THE GEAR BOX HAD SEPARATED. A TAPERED PIN WHICH WAS USED TO SECURE THE COVER HAD SHEARED FROM OVERLOAD. A DISASSEMBLY OF THE MAIN TRANSMISSION REVEALED THAT THE LOWER PLANETARY GEAR HAD FAILED FROM OIL STARVATION. ONLY 20 MM OF OIL WAS FOUND IN THE BOTTOM OF THE TRANSMISSION CASE.

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

LUBRICATING SYSTEM..OVERLOAD

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

MAINTENANCE,INSTALLATION..IMPROPER

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

FLUID,OIL..EXHAUSTION

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

ROTOR DRIVE SYSTEM,MAIN GEARBOX/TRANSMISSION..FAILURE,TOTAL



Contributing Factors

TERRAIN CONDITION..MOUNTAINOUS/HILLY

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