NTSB Identification: LAX90DUJ05.
The docket is stored on NTSB microfiche number 41956.
Accident occurred Saturday, November 04, 1989 in MESA, AZ
Probable Cause Approval Date: 06/30/1992
Aircraft: BELL UH-1E, registration: N138US
Injuries: 2 Uninjured.

INVESTIGATION DISCLOSED THAT THE TAIL ROTOR SEPARATED FROM THE HELICOPTER IN FLIGHT. THE TAIL ROTOR ASSEMBLY WAS SENT TO THE MANUFACTURER FOR ANALYSIS. ON TAIL ROTOR BLADE 'A' THE BOLT, NUT AND ASSOCIATED HARDWARE THAT ATTACHED THE PITCH CHANGE LINK TO THE BLADE GRIP WERE MISSING. THE BOLT BUSHING WAS WORN BEYOND THE SERVICE LIMITS THAT MANDATED REPLACEMENT. ON BLADE 'B' THE ATTACHING BOLT, NUT AND HARDWARE WERE DETERMINED TO BE THE WRONG SIZE. IN ADDITION, THE WRONG SPACER WAS ATTACHED TO THE BOLT. FOUR MORE WASHERS THAN ALLOWED WERE UNDER THE TRAILING EDGE BLADE RETAINING BOLT NUT. ACCORDING TO THE PREFLIGHT INSPECTION REQUIREMENTS, THE DISCREPANCIES ON THE BLADE 'A' BUSHING AND THE INCORRECT HARDWARE ON THE BLADE 'B' PITCH CHANGE LINK SHOULD HAVE BEEN DETECTED DURING THE DAILY INSPECTION EVENT.

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

THE INFLIGHT SEPARATION OF THE TAIL ROTOR DUE TO IMPROPER MAINTENANCE PROCEDURES AND THE INSTALLATION OF INCORRECT ATTACHMENT HARDWARE ON THE TAIL ROTOR BLADE PITCH CHANGE LINKAGES.

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