Accident · 1992-07-28

NTSB case LAX92LA319 · BELL UH-1B · Part 133

What the record says

Event date: 1992-07-28
Event type: Accident
Highest injury level: Minor injury
Aircraft: BELL UH-1B (N89NW)
Operating rule: Part 133
Operator: NORTHWEST HELICOPTERS, LLC Operator named in NTSB report
Operated by (per NTSB report): NORTHWEST HELICOPTERS, INC.

Probable cause

THE FAILURE OF THE MAIN ROTOR DRIVE SHAFT DUE TO THE IMPROPER INSTALLATION BY COMPANY MAINTENANCE PERSONNEL OF AN 'O' RING SEAL, WHICH ALLOWED THE PACKING GREASE TO ESCAPE AND CAUSED THE OVER TEMPERATURE FAILURE OF THE DRIVE SHAFT. A FACTOR IN THE ACCIDENT WAS THE LACK OF SUITABLE TERRAIN IN WHICH TO PERFORM AN AUTOROTATION.

Source: NTSB case LAX92LA319

Flight crew

Flight-crew details for this event aren't in the NTSB database extract we hold (its coverage starts with 2008 events) — a gap in our data, not an absence of crew.

Facts as the NTSB records them — GroundCheck adds no judgement. Preliminary records may be revised as the investigation proceeds.

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