NTSB Identification: LAX85IA040.
The docket is stored on NTSB microfiche number 27125.
Incident occurred Sunday, November 04, 1984 in SANTA ANA, CA
Aircraft: Westland Helicopters WG30, registration: N5840T
Injuries: 2 Uninjured.

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

DURING A CLIMB TO CRUISE, THE CREW EXPERIENCED CONTROL DIFFICULTIES WHEN THE FOR-&-AFT TRIM ACTUATOR BEGAN TO MOTOR FORWARD AND WOULD NOT STOP. AN EMERG DESCENT WAS MADE WITH BOTH PLTS EXERTING AFT CYCLIC PRESSURE TO PREVENT THE SPEED FROM INCREASING OVER 120 KTS. THE ACFT RETURNED SUCCESSFULLY TO THE DEPARTURE ARPT. ALL GAGES INDICATED NORMAL AND NO WARNING LIGHTS WERE OBSERVED. AN INVESTIGATION REVEALED A FATIGUE FAILURE OF THE FB 10 ELECTRICAL RELAY AND SUBSEQUENT FOULING OF THE CONTACT OPERATION BY A BROKEN FRAGMENT. THE RELAY SPRING FAILED FROM FATIGUE, INITIATED AS MICRO CRACKS WHICH RESULTED FROM COLD FORMING BENDING AND SUBSEQUENT STRAIGHTENING PROCESS DURING MANUFACTURE.

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

ELECTRICAL SYSTEM,ELECTRIC RELAY..FAILURE,TOTAL

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

INADEQUATE QUALITY CONTROL..MANUFACTURER

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