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FTW89LA031

1988-12-05 · SOUTH MARSH 113 · Minor · 1 aircraft · Status: Completed

Aircraft involved

Probable cause & findings

FAILURE AND SEPARATION OF ONE OF THE TAIL ROTOR BLADES FOR UNDETERMINED REASONS. THR RESULTING IMBALANCE AND VIBRATION CAUSED THE SEPARATION OF THE 90 DEGREE GEARBOX AND A PORTION OF THE VERTICAL PYLON WHICH NECESSITATED THE EMERGENCY AUTOROTATION TO THE WATER.

Factual narrative

AS THE HELICOPTER WAS CLIMBING THRU ABOUT 500 FT, THE PLT HEARD A LOUD NOISE, FELT A SEVERE VIBRATION & SAW DEBRIS FALLING IN FRONT OF THE ACFT. HE BEGAN AN AUTOROTATION & DEPLOYED THE EMERGENCY FLOATS BEFORE LANDING ON WATER IN THE GULF OF MEXICO. THE HELICOPTER REMAINED AFLOAT & THE OCCUPANTS DEPLOYED & ENTERED A RAFT FROM WHICH THEY WERE PICKED UP ABOUT 1 HR LATER. AN INVESTIGATION REVEALED THAT ONE OF THE TAIL ROTOR BLADES HAD SEPARATED & STRUCK A MAIN ROTOR BLADE. THE RESULTING IMBALANCE CAUSED THE GEARBOX TO SEPARATE & FALL IN THE WATER. THE 90 DEG GEARBOX, TAIL ROTOR HUB AND TAIL ROTOR BLADES WERE NOT RECOVERED FROM THE GULF OF MEXICO. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1988_FTW89LA031.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.