NTSB Identification: LAX85FA286.
The docket is stored on NTSB microfiche number 29649.
Accident occurred Wednesday, June 19, 1985 in SQUAW VALLEY, CA
Aircraft: BELL 214B-1, registration: N214RM
Injuries: 2 Fatal.

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.

THE HELICOPTER WAS ENGAGED IN LOWERING A LARGE POLE TO THE GROUND WHEN THE ENG FAILED CATASTROPHICALLY DUE TO A TOTAL FIRST TURBINE ROTOR DISC FAILURE. THE PLT TURNED THE ACFT DOWN THE MOUNTAIN BUT WAS UNABLE TO GAIN ENOUGH SPEED TO AUTOROTATE. THE ACFT IMPACTED AT AN ANGLE AND BURNED. NO PARTS OF THE FIRST TURBINE ROTOR DISC WERE RECOVERED, THEREFORE, A FAILURE MODE COULD NOT BE DETERMINED. THE DISC HAD ACCUMULATED 2776 CYCLES AT THE TIME OF THE ACCIDENT. LYCOMING SERVICE BULLETIN NO. 5508-0002 REPORTS THE SERVICE LIFE LIMIT FOR THE DISC IS 2700 CYCLES. AN ENG TEARDOWN REVEALED NOTHING ELSE WRONG WITH THE ENG THAT COULD HAVE CONTRIBUTED TO ITS FAILURE OTHER THAN THE FIRST TURBINE ROTOR DISC DISINTEGRATION.

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

MAINTENANCE,REPLACEMENT..NOT IDENTIFIED..MANUFACTURER

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

MATERIAL INADEQUATE..MANUFACTURER

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

MATERIAL DEFECT..MANUFACTURER


Contributing Factors

TERRAIN CONDITION..DOWNHILL


Contributing Factors

TURBINE ASSEMBLY,TURBINE WHEEL..DISINTEGRATED


Contributing Factors

TURBOSHAFT ENGINE,GAS GENERATOR TURBINE..FAILURE,TOTAL


Contributing Factors

AUTOROTATION..ATTEMPTED..PILOT IN COMMAND


Contributing Factors

TERRAIN CONDITION..ROUGH/UNEVEN


Contributing Factors

ALTITUDE..INADEQUATE..PILOT IN COMMAND



Contributing Factors

FLARE..NOT POSSIBLE..PILOT IN COMMAND

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