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Atlas / NTSB / LAX90DUJ05

NTSB CAROL · Event

Event LAX90DUJ05

1989-11-04 MESA, Arizona, United States None 1 aircraft Status: Completed

Aircraft involved

Probable cause & findings

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.

Factual narrative

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. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1989_LAX90DUJ05.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.

Related research

What the literature says.

Academic papers and agency reports matching this event's aircraft type or causal vocabulary (stall, maintenance). Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.

Browse the full corpus — academia portal ↗