# NTSB Accident LAX99FA057
> **Bell UH-1H** · 1998-12-23 · QUINCY, CA, USA · FATL
## Event
- **NTSB number:** LAX99FA057
- **Event ID:** 20001211X11576
- **Type:** Accident
- **Date:** 1998-12-23
- **Location:** QUINCY, CA, USA
- **Coordinates:** 39.960762, -121.000068
## Injuries
- **Highest injury:** FATL
- **Fatal:** 1
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 0
- **Total aboard:** 1
## Aircraft
- **Make:** Bell
- **Model:** UH-1H
- **Registration:** N4590
- **FAR Part:** 133
- **Engines:** 1
- **Damage:** DEST
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

An inaccurate exhaust gas temperature gauge, that allowed the engine to be run over-temperature unknowingly by the pilot, which resulted in the subsequent failure of the turbine sections.  Also causal was the pilot's failure to maintain rotor RPM during the autorotation.  A factor in the accident was the operator's failure to adequately perform engine health indicator tests.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=LAX99FA057) · AI Analytics · CC0 1.0*