# NTSB Accident LAX98LA258
> **M. C. Thomas STEWART S-51** · 1998-08-05 · JACKSON, CA, USA · NONE
## Event
- **NTSB number:** LAX98LA258
- **Event ID:** 20001211X10894
- **Type:** Accident
- **Date:** 1998-08-05
- **Location:** JACKSON, CA, USA
- **Coordinates:** 38.349365, -120.770462
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 1
- **Total aboard:** 1
## Aircraft
- **Make:** M. C. Thomas
- **Model:** STEWART S-51
- **Registration:** N151MT
- **FAR Part:** 091
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

Failure of the propeller governor pulley drive shaft due to a modification made to the system by the owner that included welding a retaining pin to the center of the heat treated drive shaft, which compromised the shaft's design strength margin.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=LAX98LA258) · AI Analytics · CC0 1.0*