# NTSB Accident CHI99LA012
> **Hiller UH-12C** · 1998-10-24 · CLINTON, IA, USA · NONE
## Event
- **NTSB number:** CHI99LA012
- **Event ID:** 20001211X11218
- **Type:** Accident
- **Date:** 1998-10-24
- **Location:** CLINTON, IA, USA
- **Coordinates:** 41.839511, -90.229331
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 2
- **Total aboard:** 2
## Aircraft
- **Make:** Hiller
- **Model:** UH-12C
- **Registration:** N9739C
- **FAR Part:** 091
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

the failure of the 90 degree gearbox for reasons undetermined.  Factors were the failure of the gearbox, and it not being possible for the pilot to maintain control of the aircraft.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=CHI99LA012) · AI Analytics · CC0 1.0*