NTSB Identification: LAX82FA247
14 CFR Part 91: General Aviation
Accident occurred Friday, July 02, 1982 in JENNER, CA
Probable Cause Approval Date: 07/02/1983
Aircraft: HUGHES 369B, registration: N1108T
Injuries: 2 Uninjured.

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.

HELICOPTER WAS ON ROUTINE POLICE PATROL WHEN ENGINE FAILED AND IT AUTOROTATED TO A ROUGH LANDING ON A ROCKY BEACH. THE 1ST STAGE OF THE GAS PRODUCER SECTION OF THE TURBINE WAS FOUND FROZEN. THE TURBINE WHEEL BLADES WERE RUBBING & SEIZED TO THE 1ST STAGE TURBINE SHROUD OF THE 2ND STAGE NOZZLE ASS'Y. PIECES OF THE TURBINE BLADE'S TRAILING EDGE TIPS WERE MISSING & THERE WAS A METAL BUILDUP ON THE 2ND STAGE NOZZLE BLADE TRACK AREA. DURING DISASSEMBLY THE 1ST STAGE WHEEL HAD TO BE FORCED APART TO BREAK IT LOOSE OF THE 2ND STAGE NOZZLE. FRACTURES OF THE BLADE TIPS APPEARED TO BE CAUSED BY ELEVATED TEMPERATURE CREEP RESULTING FROM EITHER TRANSIENT OVERTEMPERATURE OR OVERSPEED CONDITIONS.

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

TURBOSHAFT ENGINE,GAS GENERATOR TURBINE..OVERSPEED

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

TURBOSHAFT ENGINE,GAS GENERATOR TURBINE..OVERTEMPERATURE

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

TURBOSHAFT ENGINE,GAS GENERATOR TURBINE..FAILURE,PARTIAL



Contributing Factors

TERRAIN CONDITION..NONE SUITABLE


Contributing Factors

TERRAIN CONDITION..ROUGH/UNEVEN

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