NTSB Identification: LAX89LA063.
The docket is stored on NTSB microfiche number 38432.
Accident occurred Monday, December 12, 1988 in HANALEI, HI
Probable Cause Approval Date: 01/04/1990
Aircraft: HUGHES 369E, registration: N7733H
Injuries: 5 Uninjured.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

DURING A LOCAL SIGHTSEEING FLIGHT, THE PILOT REPORTED THAT HE HEARD A MUFFLED BANG AND SIMULTANEOUSLY THE ENGINE OUT WARNING LIGHTS AND AUDIO ALARM ACTIVATED. THE PILOT INITIATED A FORCED LANDING ON THE BEACH WHICH RESULTED IN THE HELICOPTER NOSING OVER. AN ENGINE EXAM REVEALED THAT THE GAS GENERATOR TURBINE HAD FAILED. THE EVIDENCE INDICATED THAT THE FAILURE WAS DUE TO CONSTANT TURBINE OVERTEMPERATURES. THE EXHAUST TEMPERATURE PROBE SYSTEM WAS TESTED AND SHOWED CONSISTENT READINGS 50 TO 100 DEGREES LOWER THAN THE ACTUAL TEMP. ADDITIONALLY, THE LIGHTOFF FUEL FLOW WAS EXCESSIVE DUE TO THE IMPROPER SETTING OF THE START/ACCELERATOR SCHEDULE ADJUSTER. MAINTENANCE RECORDS DID NOT INDICATE A RECENT EXHAUST TEMP CHECK.

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

TURBOSHAFT ENGINE,GAS GENERATOR TURBINE..FAILURE,TOTAL

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

TURBOSHAFT ENGINE..OVERTEMPERATURE


Contributing Factors

TERRAIN CONDITION..SOFT


Contributing Factors

EXHAUST SYSTEM,PROBE..PREVIOUS DAMAGE


Contributing Factors

MAINTENANCE,SERVICE OF AIRCRAFT/EQUIPMENT..IMPROPER..OTHER MAINTENANCE PERSONNEL

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