# NTSB Accident LAX00FA342
> **Sikorsky/Orlando S-55** · 2000-09-18 · HOOVER DAM, AZ, USA · MINR
## Event
- **NTSB number:** LAX00FA342
- **Event ID:** 20001212X21998
- **Type:** Accident
- **Date:** 2000-09-18
- **Location:** HOOVER DAM, AZ, USA
- **Coordinates:** 36.030448, -112.019241
## Injuries
- **Highest injury:** MINR
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 7
- **Uninjured:** 0
- **Total aboard:** 7
## Aircraft
- **Make:** Sikorsky/Orlando
- **Model:** S-55
- **Registration:** N17754
- **FAR Part:** 135
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

**This report was modified on 2/23/2016. Please refer to the public docket for this accident for more information.**  The failure of Papillon maintenance personnel to recognize the significance of the increasing metal in the oil analysis test results and the illumination of the chip detector warning, the combination of which indicated internal engine wear that subsequently resulted in loss of engine drive to the rotor systems during flight. Contributing to the accident was National Flight Services' failure to properly torque the bull and sun gear retaining nut, which resulted in wear and the ultimate disengagement of the bull and sun gear.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=LAX00FA342) · AI Analytics · CC0 1.0*