# Accident 19920728027929A: Bell UH1B, Hayfork, CA, July 28, 1992

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: July 28, 1992, 08:00 local time
- Place: Hayfork, CA
- Damage: Substantial damage
- Phase of flight: Fcd/Prec Ldg From Cruise
- Operating rules: Rotorcraft external load (Part 133)
- Operator: WYFL
- Location: 40.5005° N, 123.1899° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=40.5005&lon=-123.1899&mi=10
- Aircraft: N89NW (not matched to a registry record)
- Reported make and model: BELL UH1B
- Reported engine: LYC T53L11D
- Fatal injuries: 0
- Pilot flight hours: 13,000 total, 3,000 in this make and model, 300 in the last 90 days
- NTSB investigation: [NTSB LAX92LA319](https://openairdocs.org/ntsb/LAX92LA319) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19920728027929A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

LOUD BANG TRAILING LONG LINE. AUTOROTATED INTO TREES. MAIN ROTOR DRIVE SHAFT FAILED. OLD O RING USED IN MAINTENANCE

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB LAX92LA319](https://openairdocs.org/ntsb/LAX92LA319), Jul 28, 1992: Bell UH-1B (N89NW), Hayfork, CA, substantial damage. 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…

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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