# NTSB Accident SEA99LA171
> **Garlick UH-1H** · 1999-09-21 · USK, WA, USA · NONE
## Event
- **NTSB number:** SEA99LA171
- **Event ID:** 20001212X19891
- **Type:** Accident
- **Date:** 1999-09-21
- **Location:** USK, WA, USA
- **Coordinates:** 48.300468, -117.359947
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 1
- **Total aboard:** 1
## Aircraft
- **Make:** Garlick
- **Model:** UH-1H
- **Registration:** N32800
- **FAR Part:** 133
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

Fatigue failure of the 90-degree gearbox attachment studs, resulting in separation of the tailrotor and 90-degree gearbox from the vertical fin.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=SEA99LA171) · AI Analytics · CC0 1.0*